US 3602452 A
Description (OCR text may contain errors)
United States Patent References Cited UNITED STATES PATENTS 2,879,011 3/1959 Nelson 242/1562 3,351,302 11/1967 Lang 242/1562 Primary Examiner'-George F. Mautz Assistant Examiner-Gregory A. Waltersi 'Anomey- Dressler', Goldsmith, Clement &'Gordon ABSTRACT: A dispenser for coiled strapping material having a reel assembly rotatably mounted on a depending arm assembly, which is pivoted to a supporting frame structure. An unwound length of strap is trained about a guide on the arm assembly which causes the arm to pivot as tension is applied to the strap. The frame structure includes two spaced-apart frictional brake pads which react in varying degrees onthe rim of the reel assembly and control the'rat'e of rotation of the reel assembly as the reel is moved in relation to the frame in response to the pivot action of the arm assembly.
STRAP DISPENSER This invention relates generally to means for dispensing strap material for use in conjunction with tools that operate to tension and secure straps about bundles, cartons, or the like. More particularly, this invention concerns a strap-dispensing apparatus in which the strap material may be easily withdrawn from a rotating coilthereof, manually, or automatically, and the dispensing apparatus provides frictional braking means to prevent overtravel, or backlash, thereby eliminating the possibility of snarling and entanglement of the unwound strap material.
In the past, it has been a common practice to support a rotatable reel of coiled strapping material and to turn the reel manually, or by power means, in order to feed the strap into tensioning and securing tools. One example of this type of structure is found in U.S. Pat. No. 3,061,235, granted to H. C. Lingle, on Oct. 30, I962, and assigned to the assignee of the present invention. Prior dispensers have been adequate for the purposes for which they were designed, but certain operational deficiencies have been encountered due to the development of more proficient strapping tools. Increased capacity and efficiency of improved strapping tools have required higher feeding rates of strap material and to eliminate the need for frequent replenishing of the supply of coiled material, dispensers have been required to handle larger coils of strap material. Because of the increased size of coils of strapping materials handled by the dispenser, there has been an increase in weight of the coils, which has affected the ability to start and stop and control the rotation of the reel assembly.
There has been a need for a dispenser mechanism which will respond in accordance with the demand for strap material and which can stop and start easily, as well as effectively control the acceleration and deceleration of the rotating coil and reel assembly in proportion to the demand for and the supply of the material. If a rotating coil and reel assembly overtravels due to rotational inertia and does not stop when the demand for strap material is satisfied, an uncontrollable condition will result with a slack, or untensioned length of strap material being unwound from the coil, which will in turn become snarled and entangled. This condition usually results in snarls and permanent kinks in the strap material which will upset the operation of the strapping tool, as well as cause losses of material and operating time devoted to untangling and straightening out of the snarled strap.
Accordingly, the present invention has solved the foregoing problems by providing a dispensing apparatus which will start, stop and control the rate of rotation of the dispensing reel and the feeding of the strap material therefrom in accordance with the demands from the strapping tool operator. A pivoted, depending arm assembly supports the reel of strap material and guides the unwound strap as it is drawn therefrom. By such an arrangement, the arm assembly reacts to the pull on the strap and responds in a direct relation to the demand for the strap, as well as the weight of the strap supply and thereby controls the rate of rotation of the reel. Another advantage is found in a simple braking arrangement in which frictional force applied to the reel is in proportion to the tension in the strap, thereby coordinating the acceleration and deceleration forces within the strap and reducing the shocks to which the strap might be subjected.
The dispenser assembly is a relatively simple mechanism which requires no springs, chains, or levers to apply the brake force to the reel. This arrangement has the obvious advantage of lower manufacturing costs, as well as eliminating maintenance requirements for periodic adjustment. The arm assembly supports the reel assembly by a simple arrangement which allows easy removal of the reel therefrom to minimize the time required to replenish the supply. Reel assemblies are interchangeable and thus the replenishing of the supply merely amounts to the substitution of an-additional reel assembly with a full coil of material.
Other advantages and features will become apparent from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a side elevational view of the strap-dispensing apparatus with certain portions broken away;
FIG. 2 is a rear elevational view of the strap-dispensing apparatus shown in Figure l; 7
FIG. 3 is a top plan view of the strap-dispensing apparatus shown in Figures 1 and 2; and
FIGS. 4, 5 and 6 are schematic side views of the strapdispensing apparatus showing the operating parts in various working positions during the acceleration, deceleration, and braking phases of operation.
The apparatus of the present invention provides a positive means of controlling the rotation of a coil of strapping material after a length of strap has been withdrawn from the coil, thus eliminating any undesirable overtravel of coil-strapping material and preventing a condition in which loose and uncontrolled lengths of strapping material could become snarled and entangled.
The present invention includes a frame structure which supports a pivoted arm assembly that holds a rotatably mounted reel of coil material. The invention operates in response to a tug, or a pull, on the strap material by the strapping tool operator. This pull will tension the'strap and react on the arm assembly, which will pivot and lift the reel of a strap material from a rest position in which the rim of the reel is in contact with a first and second frictional brake means secured to the supporting frame. When this occurs, the reel is allowed to rotate freely on its pivot axis and strap material can unwind in response to the operator demand. The weight of the arm and the reel of strap material resists the pull of the operator, which results in strap tension. The strap tension will increase as force is applied by the operator until the reel is accelerated to a point that its speed is equal to the rate of demand. As the reel rotates, the combined forces of demand, weight, and tension will allow the arm assembly to pivot until a balanced condition is reached. In this condition, the rim of the reel is in engagement with at least one of the two frictional brakes and will continue in this relationship until the demand has been satisfied. At that time, the tension is relaxed and the arm is allowed to return to a rest position. When the arm returns to its rest position, both braking means are in contact with the rim of the reel and thereby stop all unwinding action.
Referring particularly to Figures 1, 2, and 3, the dispenser apparatus comprises generally a coil of strap material 10 supported by and contained within a reel assembly 12 which is rotatably mounted on a shaft assembly 14 and supported on a depending arm and strap guide assembly 16. The arm and strap guide assembly 16 is pivotally secured to the support frame assembly 18 and swings in relation thereto as strap 20 is withdrawn from the coil 10.
The reel assembly 12 includes a pair of spaced-apart disks 22 and 24 having peripheral rim surfaces 26 and 28. An annular support 30 extending from disks 22 and 24 supports the coil of material 10 concentrically in relation to the shaft assembly 14.
The shaft assembly 14 is supported on the arm assembly 16 and provides rotational axis for the reel assembly 12, and is utilized to lock the reel assembly 12 by means of a conventional wingnut 32 engaged with suitable threads (not shown) on the periphery of shaft 14. Included in this securing arrangement are hubs 34.
The supporting frame assembly 16 comprises a pair of side frame members 36 and 38, only one of which is shown in detail in FIG. 1. Each of the side frame members 36 and 38 includes a horizontal base portion 40, and upstanding leg portions 42 and 44. The side frame members 36 and 38 are joined by transverse braces 46, 48, 50 and 52, which are suitably welded, or otherwise secured, to form a rigid frame assembly. Brace members 50 and 52 also serve to support blocks or pads of frictional material secured thereto which serve as a first braking means 54 and a second braking means 56, as will be hereinafter explained. Brace member 50 additionally serves to support a block of resilient material 58 which serves as a bumper for the arm assembly 16 when it returns to a rest position.
An idler roller 60 is rotatably mounted on a shaft 62 which is secured in suitable aligned apertures in a pair of spacedapart brackets 64 that are fixed to the upstanding leg portions 42 of the side frame members 36 and 38. The idler roller 60 can be adjusted in one of two positions by placing the shafts 62 in an alternate pair of spaced apart aligned apertures 66 in the brackets 64. This adjustment arrangement is provided to allow for repositioning of the idler roller 60, depending on the direction in which the strap 20 is withdrawn from the coil.
A pair of laterally extending, inwardly directed stop members 68 are fixed to horizontal braces 70, which are secured at the respective ends to the upstanding leg portions 42 and 44 of the side frame members 36 and 38. Located at the upper ends of the upstanding leg portions 44 of each of the side frame members 36 and 38 are a pair of aligned bearing members 72 which are secured to the side frame members 36 and 38 and which receive a pair of stub shafts 74 that pivotally support the arm assembly 16 in relation to the frame assembly 18. The arm assembly 16 comprises a pair of spaced-apart, depending side members 80, only one of which is seen in detail in FIG. I. The identical side members 80 are joined by a transverse member 82. The entire arm assembly 16 may be manufactured in various ways, such as welded fabrication, or casting, forging, or the like. An idler roller 84 is pivotally mounted on the lower ends of the side members 80 by a transverse shaft 86, which is received and secured in suitable spaced-apart aligned apertures. A flat spring member which serves as a strap snubber 88 is fixed to the transverse brace 82 by any suitable means, such as screws 90. The object of this strap snubber 88 is to maintain engagement of the strap 20 with the periphery of the roller 84, particularly when there is no tension or pull on the strap 20.
At the upper end of arm assembly 16, along the upper edge of the side members 80, there are a pair of spaced-apart sockets or notches 92 which receive the outer ends of the reel shaft assembly 14 and support the reel assembly 12 in its relation to the arm assembly 16, the first and second braking means 54 and 56, and the frame assembly 18.
Each notch or socket 92 is formed by a pair of upwardly extending side surfaces 94 and 96, and a bottom surface 98. In the particular embodiment shown, the bottom surface 98 also includes a parallel wear pad 100. A boss, or outward projection, extends from the side surface 96 and overlies the bottom surface 98 in each of the notches 92. The object of this projection, or boss 102 is to prevent accidental movement of the shaft assembly 14 out of the notch 92 under certain operating conditions, particularly when swinging the arm assembly 16 to an extreme position in the direction shown in Figure 4. The stop 68 serves to limit the amount of forward movement, or swinging of the arm 16 in that particular direction, while the resilient bumper 58 serves to limit the rearward swinging of the arm assembly 16 and determines the rest position. Accordingly, the arm assembly is free to swing between the rest position to the upper stop position.
In operation, the coil of strap material is loaded in the reel assembly 12 by placing it over the annular support 30 and between the disk members 22 and 24. The shaft assembly 14 is positioned in the reel assembly 12 and the nut 32 and hubs 34 secure the entire assembly as a unit. The reel assembly 12 is positioned within the frame assembly 18 between the frame side members 36 and 38. The ends of the shaft assembly 14 are aligned with the socket 92 of the side members 80 of the arm assembly 16 In this particular position, as shown in FIGS. 1 and 6 of the drawings, the outer periphery, or rims 26 and 28 of the reel disk members 22 and 24 are at rest and bear against the first brake means 54 and the second brake means 56. The ends of the shaft assembly 14 in this particular position are relatively free within the notches or sockets 92. In other words, as seen in FIG. 1, the periphery of shaft 14 is not in contact with the upper surface of wear pad 100 of the sockets or notches 92. The entire weight of the reel assembly and the coil of strap material bears against the break pads 54 and 56. Furthermore, the arm assembly 16 is in its rearmost position, or rest position, against the resilient bumper 58.
The strap material is threaded around the outer periphery of theidler roller 84 between the strap snubber and extends upwardly and outwardly of the frame assembly 18 to the strap tool mechanism (not shown). The snubber 90 pushes the strap 20 against the outer surface or periphery of roller 84 to insure that it is in position when the dispenser assembly is operated and minimizes any slack that may occur due to the absence of tension, or pull, on the strap 20. The idler roll 60 serves to assist in guiding and orienting the direction of the strap 20 between the idler roll 84 and the strapping tool (not shown). The idler roll 60 may be adjusted to an alternate position, as previously explained, depending on the location of the strapping tool operator relative to the strap dispenser.
Referring now to FIGS. 1, 4, 5, and 6, as the strapping tool operator requires strap material, strap 20 is pulled from the dispenser reel 12, which results in tension in the strap 20 and when the force is sufficient, the assembly 16 moves away from the resilient bumper 58, and the arm assembly 16 pivots around the shaft 74. As the arm assembly 16 moves away from theresilient bumper 58 and pivots around the shaft 74, the socket 92 embraces the periphery of shaft ends 14, thereby lifting the entire reel assembly 12 away from the first and second braking means 54 and 56.. This action allows the reel 12 to rotate freely on its pivot axis established by shaft 14 and the strap 20 begins to unwind.
The rate of unwinding depends upon the amount of force or pull applied to the strap 20 by the tool operator and the overall weight of the coil of strap and reel assembly. The weight of the arm assembly 16 added to the weight of the coil of strap material 10 and the reel assembly 12 resists the pull on the strap 20 and increases the strap tension. As the tension develops in the strap 20, the reel rotation is accelerated to a speed equal to the demand for strap by the tool operator. This condition is generally shown in FIG. 4. As the speed of rotation of the reel assembly begins to increase beyond the demand of the tool operator, the tension within the strap 20 will diminish. When this condition occurs, the arm assembly 16 begins to rotate rearwardly around its pivot 74 towards the bumper 58. As the arm assembly 16 pivots rearwardly around its pivot axis 74, the reel assembly will reach the condition shown in FIG. 5 with the disk rims 26 and 28 in contact with the second brake means 56. When the reel assembly 12 comes in contact with the second brake means 56, the reel will be slowed down and subjected to a frictional drag, which will increase the tension within the strap and require additional pull on the part of the operator. This condition will again accelerate the rate of revolution of the reel in relation to the demand applied to it by the operator through the pull in the strap 20 At this point, it should be noted that the pressure against the second brake pad 56 is determined by the friction and pressure of the rotating reel rims 26 and 28against the frictional surface of the pad 56. This pressure is not only determined by the tension of the strap and the weight of the coil, but additionally by the angle of the bottom surface 98 of the socket 92 in relation to the surface of the brake pad 56. As seen in FIG. 5, the bottom surface 98 of the notch 92 is nearly normal, or approximately 90 to the angle of the surface of the brake pad 56. As the arm 16 rotates towards its rest position, the angle of the bottom 98 will increase, allowing the shaft 14 to move forwardly within the socket towards the upwardly extending surface 94 of the socket. This will allow additional pressure to bear against the brake pad 56, thereby slowing down the reel additionally.
When the tension within the strap increases due to additional pull on the part of the operator, the arm will again move forwardly and relieve the pressure on the brake surface 56 in acceleration of the speed of the unwinding of the reel 12 in accordance with the demand placed on the dispenser assembly by the operator. This alternative action of acceleration and deceleration will continue as long as strap 20 is being pulled off the reel.
It will be seen that in this manner the strap will never get out of control and the reel cannot overtravel because as soon as there is a reduction in pull and a corresponding reduction in tension within the strap, the arm assembly will move rearwardly, bringing the rim surface in greater and greater contact with the second braking means, or frictional pad 56. During this alternative acceleration and deceleration action, there will be reached a balance point in which the braking resistance of the reel rims 26 and 28 against the brake pad 56 will develop just enough tension within the strap 20 to support the weight of the arm, the weight of the reel and coil material, and will be in direct proportion with the desired speed of rotation with the strap unwinding from the reel.
When the supply of strap has been satisfied and strap 20 is no longer being pulled from the dispenser apparatus by the operator, the arm 16 will be allowed to swing around its pivot point 74 to the position shown in FIG. 1 and HO. 6. In this condition, the first braking pad or brake means 54 will be in contact with the rims 26 and 28 of the reel disks 24 and 22, and the full weight of the reel will rest upon the frictional surfaces of pads 56 and 54. The reel rotation will be quickly stopped, and there will be no overtravel, or uncontrolled unwinding of the strap material. When the reel and arm assembly moves to the position shown in FIG. 6, the arm assembly will contact resilient bumper 58 to cushion the abrupt stopping of the arm assembly.
As previously mentioned, the force of the braking action depends on the weight of the arm and the weight of the reel assembly added to the weight of the coil material. While the weight of the arm and the weight of the reel assembly is constant. the weight of the coil material varies as the supply of material is depleted. ln other words, when a new and heavy coil of material is in the dispenser, a greater pull and corresponding greater tension is required to operate the entire mechanism. Correspondingly, a greater braking force is required to stop the rotation of the coil, because the entire added weight bears on the frictional surfaces. When partially used C coils, or lighter coils, of material 10 are utilized, decreasing amounts of force are required to brake and stop the rotation of the coils. By this arrangement, it will be seen that the braking force needed to stop the rotation of the entire assembly is in direct proportion to the weight of the entire assembly, and, therefore, large braking forces are not applied to lighter coils of material, thereby reducing the internal shock and tension. it will also be noted that the braking blocks or pads 54 and 56 are positioned in spaced-apart positions around the circumference of the reel to give a uniform braking force applied at different points on the rims 26 and 28. Their relative positions are also allowed for equalized wear on the braking pads.
As previously explained, this dispenser apparatus is extremely simple because it responds to operator demand and requires no chains, blocks, levers, or other types of mechanisms to apply the required brake force to control or coordinate the acceleration or deceleration of the rate of rotation as the material is drawn from the coil 10.
Thus, it will be seen from the foregoing that the present invention provides an effective, efficient, manually operated dispenser apparatus for strap material which responds to the demand for additional strap and adjusts its unwinding action to the tension in the strap to insure continuous control of the amount of material dispensed therefrom. No slack, or uncontrolled lengths of material can result because of the positive elimination of overtravel which can be caused by rotational inertia. As soon as there is no pull or tension within the strap, there is a positive braking action due to the movement of the arm to its rest position.
Furthermore, the payout, or normal direction of material being dispensed, can be altered without substantial physical effort or the repositioning of the dispenser assembly in relation to the operator and the strapping tool. The reloading of the dispenser and the positioning of the reel within the entire assembly is simplified and the utilization of interchangeable reel assemblies eliminates the complication of additional mechanisms which can add to the cost of the entire dispenser unit.
While there has been shown and described the preferred embodiment of the invention, it will be apparent that the numerous modifications and variations can be made without departing from the underlying principles of the invention. Therefore, it is desired by the following claims to include within the scope of this invention all such variations and modifications by which the results of the invention can be obtained through the use of substantially the same, or equivalent means.
What is claimed is:
1. A dispensing mechanism for strap comprising the combination of a frame, an arm pivotally mounted on the frame, a reel, a coil of strap material supported on the reel, means on the arm spaced from the arm pivot supporting the reel for free rotary movement, means on the frame disposed adjacent the reel for frictionally engaging the reel to brake its free rotational movement when strap is not being unwound from the reel, strap guide means on the arm spaced from the arm pivot and defining a reaction member about which an unwound length of strap is trained, whereby a pull on the unwound length of the strap will react on the strap guide means and cause the arm to pivot and move the reel out of engagement with the brake means to allow the reel to freely rotate and as the pullon the unwound length of strap is decreased, the arm will pivot to bring the reel into engagement with the brake means thereby stopping its free rotational movement.
2. The combination set forth in claim 1 and including a second brake means connected to the frame and disposed adjacent the reel for frictionally engaging the reel to brake its rotation, the second brake means being spaced from the first brake means, whereby as the pull on the unwound length of strap is decreased and the arm pivots toward the first brake means, the reel will contact the second brake means and slow the free rotation thereof prior to contact with the first brake means.
3. The combination set forth in claim 1 wherein the means on the arm spaced from the arm pivot for supporting the reel for rotary movement comprises a pair of spaced-apart aligned sockets, each socket defined in an upper edge of the arm assembly and including spaced-apart upwardly extending side surfaces and a bottom surface extending between the side surfaces.
4. The combination set forth in claim 3 wherein each socket includes an outward projecting boss extending from one of the side surfaces and spaced above and partially overlaying the bottom surface.
5. The combination set forth in claim 1 wherein the means on the arm spaced from the arm pivot for supporting the reel for rotary movement comprises a pair of spaced-apart aligned sockets defined in upper edge surfaces of the arm assembly and said reel assembly includes a shaft having an outwardly projecting end removably received in said sockets.
6. A dispensing mechanism for strap, and the like, comprising the combination of a frame, an arm pivotally mounted on the frame, a reel, a coil of strap material supported on the reel, means on the arm spaced from the arm pivot supporting the reel for rotary movement, first means on the frame disposed adjacent the reel for braking the rotary movement of the reel, stop means on the frame engageable with the arm for locating the arm in a rest position and for positioning the reel in engagement with the first brake means when strap is not being unwound from the reel, strap guide means on the arm defining a retraction member about which an unwound length of strap is trained, the strap guide means being spaced from the arm pivot, whereby the arm is pivoted away from the rest position and the reel is moved away from the first braking means in response to a pull on the unwound length of strap acting on the reaction member, second means on the frame disposed adjacent the reel for braking the reel when the reel is rotating at said reel into engagement with the second braking means and continuing decrease in the pull in the strap will allow the arm to return to rest position, thereby engaging the reel with the a rate faster than the strap is being pulled from the reel, said first brakmg means arm being pivoted by gravity toward a rest position to move