US2803454A - Belt-driven door operator with slackcontrolled safety switch - Google Patents

Description

HHHHU L. G. TATRO SAFETY SWITCH ATTORNEY Aug. 20, 1957 BELT-DRIVEN DOOR OPERATOR WITH SLACK-CONTROLLED Filed June 13, 1956 m/w/ A 2 mm w m m w 3 3 KW m .QQMQW A. m mm Q, w. in Wm WM w NM N v EM. \QN RN\ ww RM 0 Wm H WM 3 L. G. TATRO 2,803,454 BELT-DRIVEN DOOR OPERATOR WITH SLACK-CONTROLLED SAFETY SWITCH Aug. 20, 1957 V s Sheets-Sheet 2 Filed June 15, 1956 IN VEN TOR. 1 192; a 72720 L. G. TATRO 2,803,454 BELT-DRIVEN DOOR OPERATOR WITH SLACK-CONTROLLED SAFETY SWITCH Aug. 20, 1957 3 Sheets-Sheet 3 Filed June 13, 1956 INVENTOR. 734720 ATTUENEY United States Patent r 2,803,454 Patented A g- 1957 BELT-DRIVEN DOOR ()PERATOR WITH SLACK- CONTROLLED SAFETY SWITCH Lysle G. ,Tatro, Reseda, Califi, assignor to Pres-To-Line Corp. of America, Los Angeles, Calif a corporation ,of California Application June 13, 1956, Serial No. 591,034

12 Claims. (Cl. 268-59) is to provide a door-operating mechanism that automatically stops its closing or descending movement upon encountering any object in the path of such movement.

Another object of the invention is to provide a dooroperating mechanism that may be remotely controlled,

and which applies the full power of its prime mover for moving a door to open or raised position, which applies said power in a manner tending to provide a slippage or clutch type of drive for moving a door to lowered or closed position, and which, during the latter movement and upon encountering an obstruction, becomes fully disconnected to stop descent of the door.

A further object of the invention is to provide a mechanism of the character referred to in which the prime mover is stopped upon arresting of closing movement of the door.

The invention also has for its object to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts,

' which will more fully appear in the course of the following description. However, the drawings merely show and the following description merely describes, preferred embodiments of the present invention, which are given by way of illustration or example only.

In the drawings, like reference characters designate similar parts in the several views.

Fig. 1 is a top plan view of a door-operating mechanism according to the present invention.

Fig. 2 is a side elevational view thereof in operative position.

Fig. 3 is an enlarged longitudinal sectional view as taken on line 33 of Fig. 1.

Fig. 4 is a cross-sectional view as taken on line 44 of Fig. 3.

Fig. 5 is a plan sectional view as taken on line 5-5 of Fig. 2 with the mechanism in the position assumed when the door is lowered.

Figs. 6 and 7 are cross-sectional views as taken on the respective lines 66 and 77 of Fig. 5.

Fig. 8 is an enlarged longitudinal sectional view as taken on line 88 of Fig. 1.

Fig. 9 is a view similar to Fig. 2, showing a modification of the invention.

Fig. 10 is an enlarged and fragmentary plan view of the left-hand end of Fig. 9.

Fig, 11 is a partial side elevational and partial longistitute part of this invention.

tudinal sectional view of the portion of the mechanism shown in Fig. 10.

The present mechanism is shown as installed in operative position on a ceiling 10 in transverse relationship to the width of a door opening 11 in a wall '12. Said opening 11 is shown as provided with an overhead door 13, the guides and other hardware which guide the movement of said-door between closed and open position'being omitted since the same are generally well-known and do not con- This above merely discloses a typical environment in which the present mechanism may be installed.

The door-operating mechanism that is illustrated comprises, generally, a prime mover 15, an operating unit 16 connected to and embodying a control for said prime mover, an elongated frame 17 extending from the unit '16 and constituting a combined guideway and slideway, a carriage 18 guided in the frame and connected 'to the door 13, a drive means 19 connected to the prime mover and to the carriage to move the latter longitudinally along the frame, limit means '20 to control the limit of movement of the carriage according to the limit of movement of the door 13 between open and closed positions, a tension-mounted slide means 21 controlling the operation of the drive means 19, and means 22 operable by said drive means, as controlled by the slide means 21, to stop the prime mover when there is an obstruction in the path of door 13, when descending.

The prime mover 15 preferably comprises a reversing motor which may be set into operation in various ways, by a manual switch, by radio-controlled means, by a photo cell circuit, etc. The particular mode of operation is not here important and may be varied as desired. In this instance, the prime mover is provided with a worm 23 on the output shaft 24 thereof.

The operating unit 16 may comprise an enclosure in which worm 23 resides and, also, may house such electrical components that may be required for operating the reversing motor according to the mode or type of control or operation. As shown, said unit 16 houses a shaft 25 that is in operative engagement with the prime mover through a worm wheel 26 that is in mesh with worm 23. Thus, the speed of the shaft 25 is relatively slower than the speed of the motor and is self-locked against rotation except by the motor.

The frame 17 is shown in the form of the invention illustrated in Figs. 1 to 8 as comprising a pair of elongated angles 27 in transversely spaced relation so that their corner edges 28 are opposite and parallel and their Walls 29 define slideways. Said angles 27 are connected by transverse straps 30 that are longitudinally spaced to render the frame rigid. At the end directed toward the unit 16, the frame angles are formed to have spaced ears 31 through which shaft 25 extends and in which the same has bearing. Since the motor 15 is provided with a pad 32 for fastening to a ceiling 1-3 and the opposite end of the frame may carry members, such as the angles 53 for fastening either to the ceiling or to wall 12, the opposite ends of the frame are rigidly secured in operative position.

The carriage 18 comprises a pair of vertically spaced plates 34 and 35 that are connected at their corners by studs 36 on which are mounted wheels 37 disposed between said plates. Said wheels have traction in the mentioned corner edges of the angles 27, the plates 34 and 35, thereby, residing in the space between the angles. Said carriage is provided with a depending and rigid arm 38 that extends from a cam member 39 which is secured to the lower plate 35. The latter member is shown as a rectangular block of which one edge 40 constitutes the cam part, the same terminating at rounded corners 41, as shown in Fig. 5.

and a resilient mount 50 for said slide.

drive shaft 25 and is shown as comprising a grooved pulley 44 affixed to said shaft and disposed between the ears 31, an endless belt 45 trained over said pulley and over a similar idler pulley 46 carried by the slide means 21 later described in detail. The belt 45 is preferably made of rubber or like material and has frictional engagement in the grooves of the pulleys over which trained to provide a substantially non-slipping drive connection between pulley 44 and the belt.

The limit means 20 of Figs. 1 to 8 is shown as two longitudinally spaced normally-closed switches 47 and 48 that are attached to one of the angles 27 and are so placed and spaced from each other as to be actuated by the cam face 40 at the ends of the movement of the door to open and closed position. Said switches are connected in the electric circuit of the prime mover 15 so that the latter will operate in one direction or the other depending on which switch is held open by the carriage while the other maintains its closed position. In any case, switch 47, when opened by face 40, stops the prime mover after moving the door to open position. Then, after the current to the motor 15 is instituted, as explained before and the door starts down to closed position, opening of switch 48 stops said motor. Door opening is instituted in the same way except switch 47 is closed and the motor direction is reversed.

The slide means 21 is best seen in Figs. and 7 and comprises a slide 49, guided in the slideway formed by frame members 27, and mounting the idler pulley 46, Said mount is shown as a cross bar 51 on the slide 49, a set of elastic members in the form of springs 52 connected at one end to said bar 51 and at the other end to a plate 53, a connecting link, shown as a turnbuckle 54, connected at one end to said plate 53, and a fixed bridge member 55 connected to the other end of said turnbuckle.

Said bridge 55 is preferably placed near the end of frame 17 with the slide 21 directed toward the end of the frame to which the prime mover is connected. Thus, the belt 45 is subject to the tension imposed thereon by the springs 52 and according to the adjusted length of the turnbuckle 54. 7

The means 22 is shown as a switch 56, mounted by a bracket plate 57, on one frame member 27, and provided with an actuator 58 in contact with belt 45 rearward of the bight 59 that said belt forms over pulley 44. Said switch 56 is normally closed to maintain the circuit to the prime mover and when open, breaks said circuit.

In the modification shown in Figs. 9 and 10, the frame 17a, rather than being formed of strap-connected angle members, is integrally formed to provide carriageand slide-guiding means of comparable cross-sectional form to that of the earlier-described form of the invention.

The drive means 19 of the modification has an endless belt 45a that, in part, comprises a rubber or like material section 70 that is trained over and has driving connection with the pulley 44 and, in part, a cable section 71 that is trained over pulley 46 of the slide means 21. The arrangement is such that section 70 does not achieve engagement with pulley 46 and section 71 does not achieve engagement with pulley 44. However, the endless belt 45a has the same functional properties as belt 45 and of rubber belt.

The limit means of the alternative or modified form of the invention omits the switches 47 and 48 and makes use of the switch 56 to stop the motor at each end of movement of the door 13. By providing the belt section with projections or cams 72 and 73-one adjacent one end of said section and the other adjacent the other end the switch actuator 58 is moved by said projections to trip switch 56. It will be clear that when the door 13 reaches full open position, projection 73 acts to stop the drive, as above, and when the door reaches full closed position, projection 72 stops the drive. The opening of switch 56 to stop the drive when there is an obstruction in the path of descent of the door is carried out as stated in the second paragraph below. Thus, the use of projections 72 and 73 enables use of but one control switch ,with the resultant economy that follows elimination of ,the limit switches and the wiring necessary therefor.

The normal operation of the present door operator is deemed to be. clear from the foregoing. Any overrun of the door-closing drive is arrested by the door achieving its fully-closed position against the pavement in the door opening. Overrun of the door-opening drive is arrested 'by a stop block 60 on the belt 45 and achieving engage- .ment with cross strap 61 of the frame 17.

It will be noted that block 39 is grooved at 62 for the belt 45 and the part of said belt that is in the groove is fastened by bolts 63 to effect a firm and non-slipping connection between said belt and the carriage 18. Since the gears 23 and 26 are self-locking, there is no possibility of the door to descend except when under power of the prime mover.

If during the closing movement of the door, the same encounters an obstruction, the movement of link 42 will be arrested since the same is connected to the door. Thus, as belt 45 seeks to continue its drive movement and said link stops movement of the arm 38, the latter will tilt and cause the springs 52 to stretch, producing slack in the belt 45. This stretching of the spring and formation of the slack results from the positive drive between pulley 44 and the belt pulling on the top run 64 of the belt while movement of the carriage 18 is arrested. Since the top run 64 is held taut by said positive drive and the center-to-center distance of the pulleys 44 and 46 foreshortens according to the stretch of springs 52, the slack in the belt forms in the lower run 65. Inasmuch as said slack is first formed where the run 65 starts at pulley 44, the switch actuator 58 is depressed thereby to cause opening of switch 56 immediately that the normal descending movement is arrested.

While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention, the construction is, of course, subject to modification without departing from the spirit and scope of the invention. It is, therefore, not desired to restrict the invention to the particular form of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A door-operating mechanism comprising an elongated frame, an endless belt mounted in said frame, a reversing drive for said belt, a resilient belt tensioner, a connection between the belt and a door to move the door between open and closed positions according to the direction of the reversing drive, means responsive to an obstruction in the path of closing movement of the door to stretch the belt tensioner to introduce slack in the belt, and means engaged with said slack to stop the doorclosing drive.

2. A door-operating mechanism comprising an elongated frame, an endless belt mounted in said .frame,'a reversing drive for said belt, a resilient belt tensioner, a connection between the belt and a door to move the door between open and closed positions according to the direction of the reversing drive, limit switches carried by the frame in longitudinally spaced relation to stop said drive at opposite end points of its movement, means responsive to an obstruction in the path of closing movement of the door to stretch the belt tensioner to introduce slack in the belt, and means engaged with said slack to stop the door-closing drive.

3. A door-operating mechanism comprising an elongated frame, an endless belt mounted in said frame, a reversing drive for said belt, a resilient belt tensioner, a connection between the belt and a door to move the door between open and closed positions according to the direction of the reversing drive, said connection including a carriage afiixed to the belt and guided in the frame, and a link interconnecting said carriage and the door, means responsive to an obstruction in the path of closing move ment of the door to stretch the belt tensioner to introduce slack in the belt, and means engaged with said slack to stop the door-closing drive.

4. A door-operating mechanism comprising an elongated frame, an endless belt mounted in said frame, a reversing drive for said belt, a resilient belt tensioner, a connection between the belt and a door to move the door between open and closed positions according to the direction of the reversing drive, the drive including a reversing electric motor as a prime mover, a controller for said motor in feeling engagement with the belt to respond to a slackening of the belt and to open the circuit to the motor, and means actuated by an obstruction in the path of closing movement of the door to cause said slackening of the belt.

5. A door-operating mechanism according to claim 4 in which the last-mentioned means comprises a springtensioned slide guided for longitudinal movement in the frame, the same being tensioned in a direction to tauten the belt.

6. In a door-operating mechanism, an endless belt trained over two longitudinally spaced pulleys, a reversing drive connected to one of said pulleys, a resilient belt tautener mounting the other pulley, a carriage connected to said belt and adapted to be connected to a door to open and close the same according to the direction of movement of the reversing drive, means responsive to an obstruction in the path of closing movement of the door to stretch said belt tautener while the belt is being driven in a directon to close the door to introduce slack in the belt, and means operable by said slack to control the mentioned drive to arrest closing movement of the belt and door.

7. In a door-operating mechanism according to claim 6, the pulley connected to the drive being grooved, and the belt having frictional engagement in the groove of the pulley to constitute a non-slipping connection during drive in the door-opening direction and to constitute a slipping connection upon introduction of slack in the belt.

8. In a door-operating mechanism according to claim 6, the mentioned reversing drive being self-locking, the pulley connected to the drive being grooved, and the belt having frictional engagement in the groove of the pulley to constitute a non-slipping connection during drive in the dooropening direction and to constitute a slipping connection upon introduction of slack in the belt.

9. a door-operating mechanism, an endless belt trained over two longitudinaliy spaced pulleys, a reversing drive connected to one of said pulleys, a resilient belt tautener mounting the other pulley, a carriage connected to said beit and adapted to be connected to a door to open and close the same according to the direction of movement of the reversing drive, limit means controlled by said carriage at opposite ends of its movement to stop the drive, means responsive to an obstruction in the path of closing movement of the door to stretch said belt tautener while the belt is being driven in a direction to close the door to introduce slack in the belt, and means operable by said slack to control the mentioned drive to arrest closing movement of the belt and door.

10. A door-operating mechanism comprising an elongated frame, an endless beit mounted in said frame and provided with longitudinally spaced switch actuating elements, a reversing drive for said belt, a resilient belt tensioner, a connection between the belt and a door to move the door between open and closed positions according to the direction of the reversing drive, a switch controlling said drive and carried by the frame and provided with an actuator in feeling engagement with the endless belt, said actuator being moved by said actuating elements to switch-opening position to stop said drive, and means responsive to an obstruction in the path of closing movement of the door to stretch the belt tensioner to introduce slack in the belt where said switch actuator engages the belt, the latter means including the drive-controlling switch.

ll. A door-operating mechanism according to claim 4 and in which longitudinally spaced portions of the belt are provided with controiler-operating projections to stop the prime mover when the door has reached either its open or its closed position.

12. In a door-operating mechanism, an endless belt trained over two longitudinally spaced pulleys, a reversing drive connected to one of said pulleys, a resilient belt tautener mounting the other pulley, a carriage connected to said belt and adapted to be connected to a door to open and close the same according to the direction of movement of the reversing drive, limit means controlled by said endless belt at opposite ends of its movement to stop the drive, means responsive to an obstruction in the path of closing movement of the door to stretch said belt tautener while the belt is being driven in a direction to close the door to introduce slack in the belt, and means operable by said slack to control the mentioned drive to arrest closing movement of the belt and door.

References Cited in the file of this patent UNITED STATES PATENTS 2,334,981 Ackley Nov. 23, 1943 2,335,336 Zoller Nov. 30, 1943 2,401,082 Konter May 28, 1946 2,544,239 Schirmer Mar. 6, 1951

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