US3493979A - Method and apparatus for moving objects - Google Patents

Description

Feb. 10, 1970 L. A. KOLL E' TAL 3,493,979

. METHOD AND APPARATUS FOR MOVING OBJECTS I Filed Feb. 14, 1968 4 Sheets-Sheet 2 INVENTORS 10 z 40044Xo4 ATTORNEYS Feb. l0, 970 L.A.KO..L Ea-AL 3,493 979 METHOD AND APPARATUS FOR MOVING OBJECTS Filed Feb. 14, 1968 4 Sheets-Sheet 1 w a v 3* M {I INVENTORS [flu/2E4 I? [[04 L & 5}? 3. 0270M, 7?.

ATTORNEYS Feb; 10, 1970. M, K01... ETAL 3,493,979

METHOD AND APPARATUS FOR MOVING OBJECTS 'Filed Feb. 14, 1968 4 Sheets-Sheet 3 INVENTORS 00054 12% 4.

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ATTORNEYS Feb. 10, 1970 L. A. KOLL ETAL 3,493,979

7 METHOD AND APPARATUS FOR MOVING OBJECTS Filed Feb. 14, 1968 I 4 Sheets-Sheet 4 INVENTORS Zia/754 6 X04 1.

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ATTORNEYS United States Patent 3,493,979 METHOD AND APPARATUS FOR MOVING OBJECTS Laurel A. K011 and Walter B. Crook, Jr., Ruleville, Miss., assignors to Advance Products Corporation of America, Ruleville, Miss., a corporation of Mississippi Filed Feb. 14, 1968, Ser. No. 706,755 Int. Cl. A61g 7/08, 7/10 US. Cl. 81 31 Claims ABSTRACT OF THE DISCLOSURE A variety of objects, including an invalid or a nonambulatory hospital patient, may be moved from one location to another. The transfer device includes a pair of superposed endless belts. The lower belt rotates in a predetermined direction, and the upper belt rotates in an opposite direction. The upper belt may be maintained stationary with respect to the rotating lower belt. The belts may be actuated either automatically or manually. A patient is moved by placing the device adjacent to him. The transfer device is moved toward the patient. The leading edge of the upper belt is positioned slightly forward of that of the lower belt. When the device contacts the body of the patient the leading edge of the upper belt which is rotating in an upwardly-oriented direction, gently and uniformly lifts the patient up onto the upper belt of the transfer device. The upper belt is then maintained stationary by a locking mechanism such as a brake, while the lower belt continues to rotate. The transfer device may form an integral part of a wheeled stretcher, or it may be used independently. Upon arrival the patient is off-loaded by rotating the leading edge of the upper belt in a downwardlyoriented direction. The foregoing abstract is not intended to define the scope of the invention and is only provided to permit a cursory review of the gist of the'invention.

BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION This invention pertains to a method and apparatus for moving objects to a desired location. While the method and apparatus of the present invention will be discussed with respect to transporting a non-ambulatory patient to various hospital locations, it is to be understood that the invention is equally applicable to the moving of any appropriate object, such as a box or crate, from one place to another.

Prior to this invention, the transfer of non-ambulatory patients to various locations in a hospital presented a formidable problem. Previous methods of lifting, loading and off-loading a patient have involved a waste of manpower in addition to causing further aggravation of existing injuries because the procedure was usually carried out in a hit or miss fashion.

For example, if the patient was to be lifted from his bed manually, several persons were needed to perform the task. These individuals were required to lift in unison with essentially the same amount of force in as gentle a manner as possible; if they didnt one or more parts of the body of the patient underwent excessive strain. This often resulted in aggravation of an existing injury, or caused additional injuries.

3,493,979 Patented Feb. 10, 1970 Similarly, when the patient was moved by lifting the sheet from the bed while allowing him to remain on the sheet, the same basic problems recurred, since once again several persons were required to lift the patient; they probably will not lift with the same amount of force, thus causing injury. Moreover, if one or more of the attendants lost his grip on the patient as he was being transported, there was considerable risk of serious injury ensuing, since the patient would naturally brace his body in anticipation of the impact. This, of course, is highly undesirable.

A slightly more sophisticated method of transporting the patient involved lifting him onto a stretcher and then carrying him to the desired location. It is apparent that many of the aforementioned difiiculties were also present when employing a stretcher since the patient had to be lifted onto and off of the device, thus running the risk of careless lifting and/or dropping of the patient.

Since it is obvious that any method of manually moving the patient necessarily involves considerable risk, the development of a mechanical means of moving the patient was proposed. Consequently, various winches or other lifting devices were devised in which a plurality of straps were secured under the patient along the length of his body, after which the patient was raised mechanically. However, the presence of a plurality of spaced straps created a series of intense pressure points along the surface of the patients body, quite similar to what occurs when attendants are lifting him by hand. Moreover, the patient had to be moved somewhat in order to place the straps beneath his body. Thus, the dangers inherent in this method are nearly as great as those of manual lifting and transporting.

Once it was realized that it is necessary to lift with constant, uniformly gentle pressure in order to minimize the risk of injury to the patient, the use of straps was discontinued. They were replaced by a variety of endless belt-roller arrangements. Illustrative of these devices are US. Patents 2,918,681 and 2,984,842. In these stretcher like devices a plurality of longitudinally-oriented rollers are covered by an endless belt, so that an operator may push the device under a patient, wedging him onto it without manually handling him. While these litters constitute an improvement over the prior devices, they contain several inherent disadvantages which substantially impair their ability to solve the problem of safely transporting an incapacitated patient.

The patient must still be elevated somewhat in order to wedge these devices under him, as is accentuated in the drawings of US. Patent 2,918,681. This lifting-wedging action is likely to cause pain and discomfort. Moreover, once the patient is loaded, either the entire device must be lifted and carried to a desired location, or the patient must be immediately transferred to a wheeled stretcher or the like. -In other words, these devices are merely intermediate or transitory mechanisms which are incapable of moving a patient without the assistance of additional apparatus. This inherent dependence on additional equipment is due to the fact that only a single belt and set of rollers is provided. If the operator continues to push the device after the patient is loaded, he will promptly, albeit unintentionally, be dropped back on the bed or On the floor, since the rotational movement of the endless belt will move the patient along with it, as is 3 depicted in the drawings of US. Patent 2,918,681. At best, these devices have only partially, and therefore unsatisfactorily, solved the problem.

It is apparent therefore, that prior attempts to solve the problem of safely and conveniently moving a hospital patient to a desired location have been less than successful. This is so because the patient must undergo a significant amount of discomfort and perhaps pain while being lifted onto the stretcher. Moreover, once on the litter (no matter which of the prior art devices are employed) the patient and litter must immediately be lifted onto another surface, such as a wheeled stretcher, in order to transport the patient to the ultimate destination. Thus the problem has remained unsolved.

The present invention embodies a method and apparatus which effectively solves every aspect of the patient transfer problem.

Essentially, this innovation employs a pair of endless belts, one of which is positioned above the other, rather than using only a single belt and/or a single set of rollers. Thus, the invention does not have to be wedged under the patient in order to lift him, as is the case in the prior attempts to solve the problem. On the contrary, the patient is gently and uniformly lifted up and onto the transfer device by the cooperating interaction of the superposed belts. The overall height of the superposed belts is only approximately 2 inches. When the transfer device is moved toward the recumbent patient, the lower belt rotatably advances along the surface of the bed, while the upper belt rotates in a direction opposite to that of the lower belt. Thus, as the device contacts the patient along the side of his body, the leading edge of the upper belt gently and uniformly lifts the patient up and onto the transfer device. The upper belt leading edge is located slightly forward of the leading edge of the lower belt. Since the upper belt leading edge is turning in an upwardly-oriented direction, the resulting lifting action consists of a cooperating contact movement which in no way wedges or pinches the patient. It is uniformly conveying the patient up and onto the upper surface of the transfer device, rather than initially wedging or pushing him down and away from it, as do the earlier devices.

When the patient is at rest on the transfer device, further rotational movement of the upper belt is prevented in order to ensure that the patient remains stationary during transfer, while the lower belt continues to rotate. Upon arrival at a desired location, the patient is off-loaded by rotating the leading edge of the upper belt in a downwardly-oriented direction.

Moreover, the basic concept of the invention may be effectively utilized whether the belts are automatically or manually actuated. The device may be employed either as an independent unit, or as an integral automaticallyactuated portion of a wheeled stretcher.

It is also apparent that the invention may be used to move heavy objects such as crates or boxes. The basic concept is equally applicable; the dimensions of the device could be varied if desired, and the structure could be strengthened if necessary to support extremely heavy objects.

A brief description of the various embodiments of the method and apparatus for moving objects as is follows:

Assuming that the device is to be used for moving a non-ambulatory patient, the apparatus is moved into a position parallel to the patient on the bed. According to a preferred embodiment of the invention, the transfer device forms an integral part of a wheeled stretcher unit. The overall height of the unit may be adjusted and the transfer device can be moved outwardly from the stretcher along telescoping guides or rails. The transfer apparatus or device is actuated by a pair of electric motors through appropriate control switches. The transfer device itself includes two superposed sheets of a material having a low co-eflicient of friction (such as aluminum or plastic), each of which has a rounded leading edge. Each sheet is surrounded by an endless belt which readily rotates or slides around the sheet. The endless belts are in frictional contact with each other. Each of the endless belts is looped around a roller, the rollers being positioned superadjacent to one another at the trailing edge of the sheets. Each belt is in frictional contact with a second driving roller, the driving rollers being located adjacent to the respective driven rollers. Each of the driving rollers is driven by a separate electric motor. When the driving rollers are actuated, the upper rear roller drives the upper forward roller and the lower rear drives the lower forward roller by means of frictional contact therebetween.

In operation, the stretcher is actuated by the electric motors through a drive pinion which is connected to the lower driving roller by a shaft. The pinion moves along a rack, thus extending the transfer device outwardly on telescoping guide rails. When the device contacts the patient the leading edge of the upper belt, which is positioned slightly forward of the leading edge of the lower belt, gently lifts the patient up and onto the device by reason of its upwardly-oriented direction of rotation. After the patient is safely loaded on the stretcher, the motor for the lower roller set is reversed, while the motor for the upper set is deactivated. Thus, as the transfer device is retracted or returns to the wheeled stretcher along the guide rails, the lower belt rotates while the upper belt remains stationary. A braking action occurs in the top belt because of the friction of the upper belt plus the resistance required to turn the gear reduction motor backward through the planetary reduction gearing. If desired, an electric brake could also be used to keep the upper belt stationary during retraction. Thus, the patient is comfortably resting on the non-rotating upper belt as the lower belt moves along the surface of the bed to the wheeled stretcher whereupon he is moved to a desired location. When the patient is returned to his bed the procedure is reversed.

As an alternative to relying on a frictional drive between the rollers, the lower pair of rollers could be coupled together and driven by suitable gearing; the upper roller set could be similarly arranged.

A slight modification of this embodiment could be effected by replacing each of the sheets with a plurality of spaced longitudinally-oriented rollers which would be journalled in an appropriate frame. Instead of driving the belts by frictional contact with a driving roller or the like, one of the rollers in each belt could be connected by a shaft to a driving pinion. The pinion would be driven by an electric motor located within the housing of the wheeled stretcher. The actuation of operation of this modification would be substantially identical to that which has been previously described.

As mentioned previously, the overall height of the superposed belts is only approximately 2 inches so that the transfer device may readily roll beneath and lift the patient on to the stretcher. The length of the device is approximately six feet and the width is about 24 inches. Of course, these dimensions can be varied without departing from the basic concept of the invention. If desired, a frame can be positioned transversely of the device at approximately the longitudinal midpoint thereof.

In a second embodiment of the invention the transfer device again forms an integral part of a rolling or wheeled stretcher. Instead of using electric motors however, in this embodiment the transfer device is actuated by means of a hydraulic cylinder which acts in concert with a chainsprocket system to extend and retract the device. Moreover, each of the superposed endless conveyor belts surrounds a plurality of longitudinally oriented rollers. In this adaptation of the invention, when the belts are in effective frictional contact the motion of the lower belt in one direction imparts a reverse rotational movement to the upper belt. The upper roller-belt arrangement may assume either a raised cradle transfer position, or a lowered loading/offloading position. This is accomplished by hinging or pivotally attaching each of the outer upper rollers to an adjacent inner upper roller so that the outer upper rollers can move through a limited vertical arc. Accordingly, when it is desired to load a patient, the outer upper rollers are pivoted downwardly by suitable means such as a single-acting hydraulic cylinder which forces the rollers down, overcoming an opposing spring, thereby tightening the upper belt and forcing it into frictional engagement with the lower belt. The device is caused to roll toward and under the patient, and the patient is gently lifted up and onto the upper belt. When he is at rest on the transfer device, the cylinder is deactivated and the downwardly directed force on the outer upper rollers ceases. The rollers then reassume their normal position, which forms a protective cradle or pocket of U or V- shaped, cross-section when viewed from either end of the device. Since the upper belt is slack, the rotational movement of the lower driving belt imparts no movement to the upper belt, which remains stationary during retraction of the transfer device. This embodiment alfords an added measure of protection to the patient while he is being transported from one location to another.

In each of the aforementioned embodiments of the invention, the transfer apparatus was integrated with a wheeled or rolling stretcher. In the embodiments which will be described below the transfer device would normally be placed on a separate rolling stretcher and wheeled to a desired location such as an X-ray technicians room. Moreover, the following embodiments are adapted to be actuated manually rather than mechanically or electrical- 1y.

In a first manual embodiment of the invention the transfer device consists of a pair of superposed endless conveyor belts, each of which surrounds a respective roller set. Each roller set comprises a plurality of spaced longitudinally-oriented rollers. The belts are capable of being brought into frictional contact with one another. When they are in frictional contact, the rotational movement of the lower belt imparts a reverse rotational movement to the upper belt. Thus when the latter contacts the patient it once again gently and uniformly lifts the patient up and onto the transfer device. The frictional contact force between the upper and lower belts should provide sutficient lifting force to gently ease an adult of average weight onto the upper belt.

In the aforementioned embodiment, both the upper and lower horizontal roller sets are mounted in a common main frame. Each of the rollers is journalled in the main frame by means of appropriate bearings. The trailing upper roller is connected to a pivot bar which is hinged to the main frame in such a manner that it may be pivoted about the main frame. In this particular embodiment of the invention, the superposed belts and associated roller sets are normally not in frictional driving contact with one another. However, when it is desired to load or unload a patient, the pivot bar is rotated through a rearwardly-directioned arc. This pivoting action tightens the endless belts against one another, thereby providing sufficient frictional contact to allow the patient to be gently lifted up and onto the device.

Once the patient is safely and securely on the device, the pivot bar is allowed to return to its normal (belts not in contact) positon, and the device may be rolled wherever desired without the risk of having the patient fall from the device.

In a second manual embodiment of the invention, a pair of superposed endless conveyor belts are again employed. Each of the endless belts surrounds a roller set. Each of the lower rollers is journalled in a movable frame and is linked to a corresponding upper roller which is mounted in a stationary frame. When an operator moves the transfer device toward a patient, as the lower belt rotatably advances along the surface of the bed, the lower frame pivots rearwardly with respect to the upper frame. The lower belt thus comes into frictional driving contact with the upper belt. Accordingly, when the leading edge of the upper belt contacts the patient, it gently conveys him up and onto the upper belt in the manner previously described.

During the process of moving the patient to a desired location, the upper belt is locked against further movement by a suitable brake which prevents each of the upper rollers from rotating. Upon arrival, the brake is released and the patient is off-loaded in the normal manner.

It is apparent therefore, that the basic concept of the invention resides in the provision of a pair of superposed endless belts in which the leading edge of the upper belt is turning in an upwardly-oriented direction as it approaches and contacts the patient so that it lifts him smoothly and surely up and onto the transfer device in an expeditious effective manner. There is no wedging of any kind to contend with. Accordingly, the conditon of the patient is not further aggravated by being lifted by hospital personnel, nor will his body be pinched as the belt comes into contact therewith, as would appear to be the case with prior attempts to solve the problem.

Furthermore, once the patient is safely on the device the present invention keeps him there during transport by ensuring that the upper belt remains motionless during this period.

Moreover, the fact that the transfer device can be integrated with a wheeled stretcher further enhances the utility and effectiveness of the invention, since there is no'possibility of an attendant accidentally applying too much force as he attempts to roll the patient up and onto the transfer device. Additionally, since each of the previously described embodiments can be operated by an unassisted nurse, the invention assists in the alleviation of the manpower problem which plagues most hospitals today.

In addition to the aforementioned features, other advantages of this innovation will become apparent in the more detailed description of the invention which follows; reference will be made to the accompanying drawings in which:

FIGURE 1 is an elevated perspective view of the transfer device in the extended position, with the device shown as an integral part of a wheeled stretcher;

FIGURE 2 is a cross-sectional view of the drive for the transfer device of FIGURE 1 taken along line 2-2 in the direction of the arrows;

FIGURE 3 is an elevated perspective view of the transfer device of FIGURE 1, in which the device is in the retracted position and the drive motors are located in a separate housing integral with the transfer device atop the wheeled stretcher;

FIGURE 4 is a cross sectional view of the transfer device of FIGURE 3 through lines 44 viewed in the direction of the arrows;

FIGURE 5 is a partially broken end view of a modification of the preferred embodiment of FIGURES 14 depicting a dual action hydraulic system for a modification 0f the transfer device;

FIGURE 6 is a detailed view of the transfer device of FIGURE 5 including the single-acting cylinders for pivoting the cradle belt-roller arrangement, and a spring biasing system returning the cradle to its transport posi tion;

FIGURE 7 is a partially broken top plan view of a manual modification of the transfer device which includes the pivot bar, upper belt, upper rollers, support plate, lower rollers, lower belt, and common frame;

FIGURE 8 is an end view of the transfer device of FIGURE 7;

FIGURE 9 is a partially broken end view of a second manual modification of the transfer device in the transport positon which depicts one of the brake mechanisms locked against an upper roller; and

FIGURE 10 is a broken view of the device of FIG- URE 9 showing the loading-unloading position of the transfer device in which the lower belt is pivoted rearwardly with respect to the upper belt and the brake mechanism is disengaged from the upper roller.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGURES 1 and 2 of the drawings, a preferred embodiment of the invention is depicted. A wheeled stretcher is combined or integrated with a patient transfer device which is generally indicated 22. The wheeled stretcher 20 is conventional in design and serves as a mobile platform for the invention. The patient transfer device 22 comprises a pair of rectangular endless conveyor belts 24 and 26 positioned one above the other. The endless belts themselves may consist of a rubber or canvas material which possesses suflicient gripping or adherence characteristics to convey an adult patient up and onto the transfer device without slipping or sliding occurring. The overall dimensions of the belts may be approximately 6 feet in length and 2 feet in width and may be varied if desired. The overall height of the superposed belts should not be greater than approximately 2 inches when in operation. Each of the endless belts covers or surrounds a plurality of spaced parallel, longitudinally oriented metal rollers which are generally designated 28 in the drawings. These rollers are of conventional structure and are journalled in a common U-shaped metal frame 30 by means of appropriate bearings.

If desired, the rollers could be replaced by a pair of superposed metal or plastic sheets which are shown in FIGURES 3 and 4 of the drawings. This variation will be discussed more fully hereinafter.

The transfer device 22 may be extended and retracted laterally from the wheeled stretcher 20. The transfer device will travel outwardly along a pair of conventional guide rails, one of which is located at each end of the transfer device (not shown in the drawings). Lower endless conveyor belt 26 is adapted to rotate by connecting the rear roller in the lower roller set to a pinion gear 34. This is achieved by the provision of a shaft 44. Pinion 34 in turn moves along a rack 32 which is mounted at one end of wheeled stretcher 20. A chain member 36 is linked to the pinion 34 and is also connected to a driving motor 52 which is positioned within the wheeled stretcher itself. Spacing of the chain is assured by spacer pinions 38 and associated bracing members 40. The motor 52 drives lower belt 26 through a shaft on which pinion 42 is mounted. Pinion 42 powers chain 36 thus moving pinion 34 back and forth along rack 32.

Upper belt 24 is driven by a system which is identical to that which drives lower belt 26, except that the pro vision of a rack is eliminated, and a conventional slip clutch (not shown in the drawings) is included in the drive system. Thus a motor 52, pinion 42, chain 36, spacer pinions 38 and braces 40, and pinion gear or sprocket 34 are likewise mounted at the opposite end of the stretcher '20, and pinion 34 drives the rear roller of the upper roller set in order to rotate upper belt 24. However, upper belt 24 is rotated in a direction which is opposite to that of lower belt 26. Although the driving of the lower belt 26 will be specifically described below, it is understood that this discussion is equally applicable to upper belt 24 except where indicated to the contrary.

In FIGURE 2 of the drawings a detailed view of the upper portion of the driving mechanism is disclosed. As mentioned previously, two independent driving systems are employed. Each of the belts are driven through a conventional gear reduction system. It is apparent in FIGURE 2 that the lower belt 26 is being driven by the chain and rack-pinion arrangement. Shaft 44 ex- 8 tends through longitudinal slot 46, thus enabling lower belt 26 to be extended and retracted on the guide rails.

While the invention is discussed in detail with respect to moving a non-ambulatory hospital patient, it is to be understood that the applicability of the basic concept of the invention is broader in scope. Many different objects such as boxes or crates can be safely and efiiciently moved to a desired location by the employment of the basic concept of this invention.

Assuming a non-ambulatory recumbent patient is to be removed to a desired location from a hospital bed 48, stretcher 20 is moved to a position adjacent the bed. The stretcher 20 and transfer device 22 may be vertically adjusted by a conventional mechanical crank 54. The height of the stretcher could also be adjusted by the provision of double-acting hydraulic cylinders, or if desired, by the employment of any conventional means which is normally used to raise and lower a wheeled stretcher. Each side of wheeled stretcher 20 would be provided with a cover or housing member 50 which would shield the drive mechanism from view.

The transfer device is actuated by energizing an electric switch on control box 18 which starts the motors 52. The motors impart a rotational movement through appropriate reduction gearing to the pinion 42. Pinion 42 causes chain 36 to rotate around spacer pinions 38, thus causing pinion 34 to move outwardly in the direction of the arrow along rack 32. FIGURE 1 shows the transfer device 22 in a fully extended position. Since the other end of the wheeled stretcher contains a virtually identical drive system, a simultaneous driving action occurs, except that upper belt 24 is driven, rather than lower belt 26, and the rack is eliminated as described above.

As soon as pinion 34 begins to move it imparts movement to the lower roller set 28' via shaft 44, which causes lower endless belt 26 to rotate in a clockwise direction. In other words, the leading edge of the lower belt 26 will be moving in a downwardly-oriented direction toward the bed sheet, as the transfer device moves toward the patient. Simultaneously, upper belt 24 is caused to rotate in a direction opposite to that of the lower belt; that is, the leading edge 56 of the upper belt will be turning in an upwardly-oriented direction. Belts 24 and 26 are in frictional contact with one another and thus tend to impart additional rotational movement to one another as transfer device 22 advances toward the patient. The leading edge 56 of the upper belt 24 is always positioned slightly forward of the corresponding leading edge of lower belt 26. This is clearly shown in FIGURE 4 of the drawings. Moreover, the upper leading edge is constructed so that it is directed downwardly toward the surface on which the patient is reclining; that is, it droops slightly. These effects are achieved by mounting the forward roller of the upper roller set slightly forwardly of the corresponding forward lower roller, and slightly below the horizontal plane of the rest of the upper rollers.

As the transfer device is extended outwardly, the telescoping guide rails move along with it. The guide rails provide support for the transfer device, as well as ensuring that it extends in a uniform manner. As the transfer device 22 approaches the patient, the leading edge 56 of the upper belt contacts the patient along the length of one side of his body as he reclines on bed 48. Recalling that the overall height of the transfer device 22 is not greater than approximately 2", the upwardly oriented rotation of the upper belt gently and uniformly lifts or conveys the patient up and onto the upper belt 24. The lower belt 26 has, of course, been rotatably traveling along the bed sheet in frictional contact therewith and is also assisting in imparting reverse rotation to upper belt 24 due to the frictional contact between the belts.

When the patient is completely at rest on upper belt 24, electric motor 52 which drives the lower belt is reversed by repositioning the motor switches on control box 18. Accordingly, lower belt 26 now rotates in a counterclockwise direction and the transfer device 22 begins its retraction cycle. However, the electric drive motor for the upper belt is de-energized at this point by the appropriate repositioning of its control switches. Thus upper belt 24 with the patient resting thereon remains stationary because of the friction of belt 24, plus the resistance required to turn the gear reduction motor backward through the planetary reduction gearing.

After the transfer device 22 has been fully retracted, the patient is moved to a desired location simply by wheeling the stretcher 20 in the normal manner. When it is desired to off-load the patient, the procedure is exactly the reverse of that which has been described in detail above. Thus, when the transfer device 22 is being extended, the leading edge 56 of the upper belt is rotating in a downwardly-oriented direction, and the patient is gently and uniformly off-loaded at the desired location.

Referring now to FIGURES 3 and 4 of the drawings, a transfer device 22 is disclosed in which the basic concept employed is identical to that of FIGURES 1 and 2. However, in this embodiment the electric motors are housed in an integral housing member 58 which extends and retracts together with the endless belts. Also, sheet members 60 and 62 are utilized instead of a plurality of spaced longitudinally-oriented rollers. It is apparent that the sheets and rollers are readily interchangeable with each other since they both perform the same basic function. They act as support means or members for the upper and lower belts respectively, enabling the belts to readily rotate around them. The sheet members possess surfaces which have a low co-efiicient of friction and are relatively slippery so that the upper and lower belts may readily slide over them.

Referring now to FIGURE 4 of the drawings, the switches on control box 64 are used to energize a pair of electric motors 66 and 68. Motors 66 and 68 drive rollers 70 and 72 respectively, through appropriate gear-reduction mechanisms which are not shown in the drawings. Rollers 70 and 71 are in frictional driving contact with upper belt 24 and lower belt 26 respectively. Upper belt 24 extends or is looped around a roller 74, and lower belt 26 extends around a similar roller 76. A shaft 78 extends outwardly from roller 72 to pinion gear 80, which in turn moves back and forth on rack 82.

The operation of the transfer device is virtually identical to that which has been described in detail above with respect to FIGURES 1 and 2. Thus, when the motors are energized they drive rollers 70 and 72, which in turn drive the upper and lower belts by frictional contact therewith. The belts are rotated in the direction shown by the arrows in FIGURES 3 and 4. Upper belt 24 rotates in a counterclockwise direction, while the lower belt rotates in a reverse direction to that of upper belt 24. Thus the leading edge 56 of upper belt 24 is turning or rotating in an upwardly-oriented direction as transfer device 22 moves toward the patient. As in the roller embodiment of FIGURES 1 and 2, leading edge 56 is positioned slightly forwardly of the corresponding leading edge of lower belt 26, and is directed or inclined downwardly toward the surface on which the patient is reclining. This is accomplished by forming upper sheet 62 with a downwardly inclined, overhanging leading edge which may be termed a droop snout. As before, this construction is provided in order to facilitate the lifting and loading of the patient, as well as ensuring that the downwardly-oriented rotation of the leading edge of lower belt 26 does not contact the patient.

Simultaneously, the rotation of roller 72 imparts a rotary movement to pinion 80 through shaft 78. Pinion 80 moves outwardly along rack 82, thus causing the entire transfer device 22 to extend outwardly along a pair of guide rails in the manner which has been described previously.

When the patient has been gently and uniformly lifted up and onto the upper belt 24, the motor 68 is reversed, thereby causing roller 72 to frictionally drive lower belt 26 in a counter-clockwise direction. However, motor 66 is simultaneously deenergized, thus causing upper belt 24 to remain stationary. As explained previously, a braking action occurs in upper belt 24 because of the friction of belt 24 plus the resistance required to turn the gear reduction motor backward through the planetary reduction gearing. In the alternative, an electric brake of conventional design could be employed to maintain the upper belt stationary during retraction of transfer device 22.

After the transfer device has returned to its fully retracted position on stretcher 20, the patient is transported to a desired location. In order to off-load the patient, a procedure is employed which is exactly the reverse of that described above.

Turning now to FIGURES 5 and 6 of the drawings, another embodiment of the basic concept of the invention is disclosed. As before, the transfer device forms an integral part of conventional Wheeled stretcher 20, and is capable of vertical adjustment in the manner which has been previously described.

In this embodiment of the invention, the extension and retraction of the transfer device is accomplished by a hydraulic system. A double-acting hydraulic cylinder 86 is secured to the wheeled stretcher 20 by a brace of bracket 88. The rod end of the cylinder is secured to frame 100. Lower forward roller 108 (see FIGURE 6) is connected to forward sprocket 92 by a suitable stub shaft (not shown). Similarly, rear lower roller is connected to rear sprocket 94 by a second stub shaft. Both of these stub shafts pass through openings in frame 100. A chain 96 is looped around the sprockets and is fixed to the Wheeled stretcher 20 by a bolt or the like at 98.

FIGURE 6 of the drawings is a detailed view of the transfer device employed in this embodiment of the invention. The transfer device, which is generally indicated at 102 in the drawings, consists of a pair of belts positioned one above the other. The lower or drive belt 104 comprises an endless conveyor belt which is wrapped around a plurality of spaced longitudinally-oriented rollers 106, 108 and 110. As mentioned previously, stub shafts connect the forward lower rollers 108 and 110 to sprockets 92 and 94 respectively. Accordingly, as the sprockets 92 and 94 rotate, they impart rotational movement to the lower roller set, which in turn causes lower belt 104 to rotate as it rolls along the surface such as a patients bed. The lower or driving belt 104 is tightly fitted around the lower roller set in order to maintain a taut configuration.

On the other hand, the upper belt or cradle belt 112 is normally in a slack configuration. When it is in this slack configuration it resembles a cradle or pocket since it is U-shaped or crescent-shaped when viewed from either end of the transfer device. When upper belt 112 is in the slack position, the lower driving belt 104 cannot impart any rotational movement to the upper belt due to the lack of effective frictional contact between them. Upper belt 112 is wrapped around a group of at least 4 spaced, longitudinally-oriented rollers 114, 116, 118 and 120. The outer rollers 114 and 120 are pivotally attached to the inner rollers by means of links 122 and 124 respectively, and thus are capable of movement through a limited vertical arc.

When it is desired to transport a patient who is reclining on the retracted transfer device 102, the cradle belt 112 is in the position shown in FIGURE 6. When it is desired to load or off-load a patient, upper belt 112 as sumes the position which is partially shown by the broken or phantom lines in FIGURE 6. This is accomplished by means of a pair of single-acting hydraulic cylinders 126. When hydraulic fluid is introduced through hose 130, piston 132 overcomes spring 134 and causes the outer rollers to pivot downwardly, thus tightening the belt 112.

Accordingly, in this position the rotational movement of the lower drive belt 104 imparts a reverse rotational movement to the upper belt 112 by virtue of their frictional contact.

In operation, the stretcher 20 is wheeled to a position adjacent the bed and hydraulic actuating fluid is introduced through hose 136. This extends cylinder rod 138, moving frame 100 outwardly and causing sprockets 92 and 94 to rotate, which in turn drives the lower belt 104 through rollers 108 and 110.

Simultaneously, hydraulic cylinders 126 are actuated, pivoting rollers 114 and 120 downwardly, causing upper belt 112 to assume the lifting-loading position partially shown by the broken lines in FIGURE 6. Thus, as transfer device 102 approaches the patient, the leading edge 140 of upper belt 112 is turning in an upwardly-oriented direction. Consequently, as leading edge 140 contacts the patient it gently and uniformly lifts him up and onto the upper belt 112.

Once the patient is on the belt, hydraulic cylinders 126 are deactuated and springs 134 cause the upper belt to reassume the cradle position by returning rollers 114 and 120 to their normal position. Next, fluid is removed from the piston end of hydraulic cylinder 86 and hydraulic fluid is introduced through hose 142 to the rod end of cylinder 86. This causes the cylinder rod 138 to retract, which in turn reverses the rotation of sprockets 92 and 94 causing drive belt 104 to turn in a counterclockwise direction as it returns to wheeled stretcher 20. However, cradle belt 112 remains stationary due to lack of frictional driving contact with the lower belt 104. The shape or configuration of the cradle belt assures an added measure of safety to the patient in preventing his falling from the trans-fer device While being moved to a desired location.

Referring to FIGURES 7 and 8 of the drawings, a manual embodiment of the basic concept of the invention is disclosed. In each of the previous embodiments of the invention, the transfer device was integrated with a wheeled or rolling stretcher. In the embodiments which will be described hereinafter, the transfer device comprises a separate element, which after loading the patient thereon, would normally be placed on a separate rolling stretcher and Wheeled to a desired location such as an X-ray technicians room. Moreover, the following embodiments are adapted to be actuated manually rather than by powered means.

FIGURE 7 is a top plan view of a transfer device 150. Transfer device 150 includes a common frame 152, in which are journalled a plurality of rollers 154, 156, 158, 160, 162 and 164. Rollers 154 and 164 form the upper rollers of the transfer device, and an upper endless conveyor belt 166 is Wrapped around the upper rollers. Simi larly, a lower endless belt 168 is positioned around the lower roller set. The endless belts used in all of the embodiments of the invention may be comprised of the same material, i.e. rubber, canvas or the like. A rectangular metal plate 170 is secured to the frame and is substan tially coextensive with the upper and lower belts. Albeit not an essential part of the invention, plate 170 provides additional support for an object which is to be placed on the transfer device 150. A pivot bar 172 is secured to the common frame 152, as well as to the rear upper roller 164. As is seen from FIGURE 7 of the drawings, the pivot bar extends from one side of the belts to the other, and is oriented in the same direction as rollers 154-164. The pivot bar can be manually moved in the direction of the arrow in FIGURE 8.

Upper belt 166 is normally in a slack position which is similar to that of upper belt 112 in FIGURES and 6. Therefore, when the lower belt 168 is actuated by rolling it along a surface such as a patients bed, it cannot impart a reverse rotational movement to upper belt 166 due to a lack of frictional driving contact between the belts. When it is desired to load an object such as a patient on the transfer device 150, pivot bar 172 is rotated in a 12 clockwise direction, i.e., in the direction of the arrow in FIGURE 8. This movement causes the upper belt 166 to tighten, thus achieving an effective frictional contact with lower belt 168. Accordingly, when the device is manually actuated the rotatational movement of lower belt 168 along a surface imparts a reverse rotational movement to the upper belt. Actually, once the device is in motion, each belt imparts a reverse rotational movement to the other due to their frictional interaction. Consequently, the leading edge 174 of the upper belt 166 rotates in an upwardly-oriented direction. As the device contacts a recumbent patient it gently and uniformly conveys him up and onto the'device in the same manner as has been described in detail in the previous embodiments.

Once the patient is at rest on the upper belt 166, the pivot bar is allowed to return to its normal position, causing the upper belt 166 to become slack once again. Thus, even though the lower belt 168 continues to rotate, it does not impart frictional reverse rotational movement to the upper belt 166. The patient therefore remains safely at rest while the transfer device is moved to a desired location. When it is desired to off-load the patient, the pivot bar 172 is again rotated rearwardly, the belts are once again in taut frictional contact and the patient is smoothly and efiiciently off-loaded from the device.

A second manual modification of the basic concept of the invention is disclosed in FIGURES 9 and 10 of the drawings. The transfer device is generally indicated at in the drawings. FIGURES 9 and 10 depict a side view of a plurality of spaced, longitudinally-oriented rollers. The rollers are mounted in separate upper and lower frames designated 184 and 186 respectively. A pair of endless conveyor belts are wrapped around the upper and lower roller sets. As before, upper belt 188 is superposed or positioned above lower belt 190. Each of the adjacent upper and lower rollers are linked to one another by a series of links indicated at 192 in the drawings.

FIGURE 9 shows the position of the upper and lower belts when a patient is being transported on the transfer device 180. It will be noted that the belts are not in frictional contact with one another because of the presence of brake 194. Brake 194 is mounted on lower frame 186 by means of suitable bolts and comprises an angle member 200 with a rubber nub or ball 196 which is in frictional contact with the upper roller in any given linked roller pair. A brake member 194 is provided for each linked roller pair. The brake is locked in this position by a suitable cam (not shown) when a patient is being transported on the transfer device.

When it is desired to load (or off-load) a patient, the transfer device 180 assumes the position shown in FIG- URE 10 of the drawings. The brakes 194 are unlocked, and when the transfer device 180 is manually actuated by a suitable push-pull bar (not shown in the drawings) the lower belt begins to rotatably move along a surface such as a patients bed. As it does so, the lower frame 184 on which it is mounted pivots rearwa'rdly with respect to the stationary upper frame 186. Accordingly, the upper and lower belts are brought into frictional driving contact with one another so that the lower belt imparts a reverse rotational movement to the upper belt 188 and vice-versa.

Thus, when the upwardly-rotating leading edge 198 of upper belt 188 contacts the patient it gently and uniformly lifts him up and onto the device in the same manner as described previously. In order to off-load .the patient, the reverse procedure is utilized.

It is apparent from the foregoing detailed description that the basic concept of the invention resides in the provision of a pair of superposed endless conveyor belts in which the leading edge of the upper belt is turning ly and surely up and onto the transfer device in an expedi- 13 tious, effective manner. There is no wedging of any kind to contend with. Accordingly, the condition of the patient is not further aggravated by being lifted by hospital personnel, nor will his body be pinched as the upper belt comes into contact therewith, as would appear to be the case with prior attempts to solve the problem.

Furthermore, once the patient is safely on the device the present invention keeps him there during transport by ensuring that the upper belt remains motionless during this period. Moreover, the fact that the transfer device can be integrated with a wheeled stretcher further enhances the utility and effectiveness of the invention, since there is no possibility of an attendant accidentally applying too much force as he attempts to roll the patient up and onto the transfer device. Additionally, since each of the previously described embodiments can be operated by an unassisted nurse, the invention assists in the alleviation of the manpower problem which plagues most hospitals today.

Although the Method and Apparatus for Moving Objects has been described with reference to a particular embodiment, it will become apparent to those skilled in the art that variations can be made in the transfer device. All such variations as would be obvious to those skilled in this art are intended to be included within the scope of this invention.

What is claimed is:

1. A method of moving an object onto a frame means having a horizontal upper surface through a transfer device carried by said frame means comprising the steps of:

positioning the frame means and transfer device adjacent a surface, said transfer device having a lower endless belt with a support means enclosed therein and a superposed upper endless belt with a support means enclosed therein whereby due to the superposed belts and support means the weight of the object is transferred through the belts and the support means of said transfer device to the area of said surfaces directly beneath the object during operation of said transfer device, and means for rotating said belts relative to their respective support means, rotating said lower endless belt relative to the support means of said lower endless belt to effect movement of said transfer device along said surface,

preventing rotational movement of said upper endless belt relative to the support means of said upper endless belt during a portion of the movement of said transfer device to maintain an object on said upper belt,

rotating said upper belt relative to said upper support means in a direction opposite the direction of rotation of said lower belt relative to said lower support means to effect an upward movement of a leading edge of said upper belt when loading an object onto said upper belt and a downward movement of the leading edge of said upper belt when unloading an object from said upper belt.

2. The method of claim 1 in which said leading edge of said upper belt is positioned forwardly of a corresponding leading edge of said lower belt in order to ensure that said lower belt does not contact the object which is to be conveyed up and onto said upper belt.

3. The method of claim 2 in which said leading edge of said upper belt is inclined downwardly toward the surface on which said object is located, in order to facilitate the lifting of said object onto said upper belt.

4. The method of claim 1 in which the overall height of said upper and lower belts is not greater than 2 inches along the leading edge of said upper belt.

5. The method of claim 1 in which the length and width of said upper belt is suflicient to allow an adult to safely and comfortably rest thereon.

6. The method of claim 5 in which the length of said upper belt is substantially 6 feet and the width is substantially two feet.

7. The method of claim 1 in which said belts are composed of a material which possesses sufficient gripping or adherence characteristics to ensure that said object will not slip or slide as it is lifted up and onto the said upper belt.

8. The method of claim 1 in which said transfer device is moved by power means.

9. The method of claim 8 in which said power means comprise at least two electric motors including a first motor adapted to drive said lower belt and a second motor adapted to drive said upper belt.

10. The method of claim 8 in which said transfer device is moved by fluid-power means, and said upper belt is adapted to be positioned in driven frictional contact with said lower belt in order to load or off-load said object.

11. The method of claim 8 in which each of said belts has a support means in contact therewith, including a lower support means which is in contact with the inner surface of said lower endless belt and an upper support means which is in contact with the inner surface of said upper endless belt, such that said belts may readily rotate around their respective support means. I

12. The method of claim 11 in which each of said support means comprises a sheet of material having a rounded leading edge, said material having a surface co-eflicient of friction which is sufficiently low to enable each of the respective belts to readily slide thereover.

13. In combination with a frame means having a horizontal upper surface, a transfer device for moving an object comprising:

a lower endless belt and an upper endless belt positioned above said lower belt, each of said belts having a support means in contact therewith, including a lower support means which is enclosed within and in contact with the inner surface of said lower endless belt and an upper support means which is enclosed within and in contact with the inner surface of said upper endless belt, such that said belts can rotate relative to their respective support means, 7

said upper and lower support means being superposed to prevent said upper belt from interfering with the movement of said transfer device along a surface on which the object rests and whereby due to the superposed belts and support means the weight of the object is transferred through the belts and the support means of said transfer device to the area of said surfaces directly beneath the object during operation of said transfer device and said upper and lower support means being carried by said frame means,

means for rotating said lower belt relative to said lower support means to effect movement of said transfer device along the surface on which an object to be moved is located,

means for rotating said upper belt relative to said upper support means, said rotation of said upper belt relative to said upper support means being in a direction opposite that of said relative rotation of said lower belt with respect to the lower support means whereby a leading edge of said upper belt moves in an upwardly-oriented direction when loading an object and a downwardly-oriented direction when unloading an object, and

means for preventing further rotational movement of said upper belt relative to said upper support means once the object is loaded onto said upper belt in order to ensure that the object remains stationary thereon while being moved to a desired location by said lower belt when said lower belt continues to rotate relative to said lower support to effect movement of said transfer device.

14. In the transfer device of claim 13:

a leading edge of said upper support means is positioned forwardly of a corresponding leading edge of said lower support means such that said lower belt does not contact the object as the object is lifted up and onto said upper belt by virtue of the upwardly-oriented movement of the leading edge of said upper belt or as the object is lowered from said upper belt by virtue of the downwardly oriented movement of the leading edge of said upper belt.

15. In the transfer device of claim 13:

said leading edge of said upper support means being rounded and inclined downwardly toward the surface on which said object is positioned in order to facilitate the loading and unloading of the object relative to said upper belt.

16. The transfer device of claim 14 in which said leading edge of said upper support means is rounded and is inclined downwardly toward the surface on which said object is located in order to facilitate the lifting of the object onto said upper belt and the unloading of the object from said upper belt.

17. The transfer device of claim 13 wherein the overall height of said superposed support means is not greater than 2 inches.

18. The transfer device of claim 13 in which the length and width of said upper belt is such that an adult patient may be accommodated thereon.

19. The transfer device of claim 18 wherein the length of said upper belt is substantially 6 feet and the width is substantially 2 feet.

20. The transfer device of claim 16 including:

power means for imparting rotational movement to said upper and said lower belts.

21. The transfer device of claim 20 in which said power means comprise at least two electric motors, including a first motor which is adapted to drive said lower belt and a second motor which is adapted to drive said upper belt.

22. The transfer device of claim 21 in which each of said support means comprises a sheet of material of substantially identical dimensions as those of their respective upper and lower belts, said sheet material having a coeflicient of friction which is sufliciently low to enable each of the belts to readily slide over their respective support means.

23. The transfer device of claim 22 in which said material is metal.

24. The transfer device of claim 22 in which said material is plastic.

25. The transfer device of claim 21 in which each of said support means is comprised of a plurality of spaced, longitudinally-oriented metal rollers.

26. The transfer device of claim 20 in which:

said transfer device is actuated by fluid-power means,

said fluid power means including a cylinder, said cylinder having a piston rod in operative association therewith,

said piston rod being connected at the rod end thereof to said frame means such that when fluid is introduced into said cylinder, said piston rod moves said frame means,

each of said support means comprising a plurality of spaced, longitudinally-oriented rollers, said upper support means comprising at least four rollers, including two outer rollers and two inner rollers, wherein each of said outer rollers is pivotally connected to an adjacent inner roller,

said upper belt being adapted to be positioned in driven frictional contact with said lower belt in order to load or off-load said object.

27. The transfer device of claim 26 in which said upper belt possesses a substantially U-shaped or cradle configuration while said object is being moved to said desired location.

28. The transfer device of claim 27 wherein said transfer device is hydraulically actuated.

29. The transfer device of claim 13 in which:

each of said support means is comprised of a plurality of spaced, longitudinally-oriented metal rollers, such that a lower roller set and an upper roller set positioned above said lower roller set are formed,

pivot bar means mounted on said frame means, said pivot bar means being connected to a rear roller of said upper roller set,

said upper belt being adapted to be positioned in driven frictional contact with said lower belt when said pivot bar is actuated, in order to load or off-load said object.

30. The transfer device of claim 13 in which:

each of said support means is comprised of a plurality of spaced, longitudinally-oriented metal rollers such that each lower roller is positioned below a corresponding upper roller,

each of said corresponding upper and lower rollers being coupled by a link means,

each of said lower rollers being adapted to move rearwardly of the corresponding upper roller, such that said lower belt is adapted to be positioned in driving frictional contact with said upper belt in order to load or offload said object, and

said means for preventing further rotational movement of said upper belt includes a plurality of brake means, each of said brake means being positioned adjacent to one of said upper rollers, said brake means being adapted to contact said upper roller in order to prevent rotation of said roller while said object is being moved to a desired location.

31. In combination with a wheeled stretcher, a transfer device for moving an incapacitated patient to a desired location, said combination being vertically adjustable and said transfer device comprising:

at least two endless conveyor belts, including a lower endless belt and an upper endless belt positioned above said lower belt,

each of said belts having a support means in contact therewith, including a lower support means which is in contact with the inner surface of said lower endless belt and an upper support means which is in contact with the inner surface of said upper endless belt, such that said belts may readily rotate around their respective support means,

each of said support means being connected to a frame means, in order to afford added strength to said transfer device, and said upper and lower support means being superposed, the overall height of said superposed support means being not greater than 2 inches,

said lower endless belt being capable of rotational movement along a surface on which an object to be moved is located, and said upper belt being able to rotate in a direction opposite to that of said lower belt,

said upper belt having a leading edge which is adapted to rotate in an upwardly-oriented direction as said transfer device contacts the patient, in order that said patient may be conveyed up and onto said upper belt as said lower belt moves along said surface,

a leading edge of said upper support means being p0si tioned forwardly of a corresponding leading edge of said lower support means such that said lower belt does not contact said patient as the patient is lifted up and onto said upper belt by virtue of the upwardly-oriented rotational movement of the leading edge of said upper belt,

said leading edge of said upper support means being rounded and inclined downwardly toward the surface on which said patient is reclining, in order to facilitate the lifting of the patient onto said upper belt,

remains stationary thereon while being moved to a I desired location by said lower belt, which continues to rotatably move along said surface.

References Cited UNITED STATES PATENTS 7/1939 Mottox 214-38.40 4/1949 Gibler. 3/ 195 3 Gilleland.

18 Jones 581 Decker 2l4-38.40

Richards 582 Manney 21483.36 Schilitz 21483.36 X Reed et a1. 214-516 X Underwood 583 X Morgan 581 10 CASMIR A. NUNBERG, Primary Examiner US. Cl. X.R.

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