US2841724A - Mounting for garage door unit - Google Patents

Description

July 1, 1958 s. 5. BROWN MOUNTING FOR GARAGE DOOR UNIT 2 Sheets-Sheet 1 Filed April 27, 1954 INVENTOR JTEFFEN 6"- BROWN ATTORNEYIS y 1-958 s. s. BROWN 2,841,724

MOUNTING FOR GARAGE DOOR UNIT Filed April 2'7, 1954 2 Sheets-Sheet 2 \STEFFEN 6. BROWN ATTORNEYS E IN VENTOR nite States MOUNTING FGR GARAGE DODR UNIT Application April 27, 1954, Serial No. 425,853

4 Claims. (tll. 310-36) This invention relates to an electric motor-control device, more particularly to an automatic operator especially adapted for roll-up garage doors, and comprising a reversible electric motor, a gear drive, a clutch assembly, and a-switch control boxall of which are built into an integral and compact unit.

Inthe past, many types of motor-control units have been devised in order to operate garage doors and other mechanical devices which are generally controlled between certain prescribed limits of travel. Such mechanical devices are commonly found in the machine tool field.

A motor-control unit which is employed to operate a garage door must be small, compact, easily controlled and dependable. if the entire control device can be made as one unit, then this is very much preferred as the entire unit may be easily installed in any desired position. Motor-control units have been proposed in the past which have been particularly adapted to operating garage doors. However, in most cases the control means, the gear driving means, and a clutch assembly, if used, have been separated when assembled into a motor-control device. This, of course, results in a structure which is not compact, and is usually not in a complete unit.

Also, while it is desirable in most applications of a motor-control device to a garage door to utilize a clutch, the use of a clutch has certain disadvantages. The principal disadvantage is that a garage door which is connected to an electric motor by means of a clutch may be operated when the motor is de-energized by merely slipping vthe clutch. Since it is preferable to retain a clutch assembly in such a motor-control unit in order that damage to .the electric motor may be eliminated when the door reaches the limits of its travel, a few steps have been proposed in the past to secure a garage door against operation when the motor is de-energized.

In this invention there is disclosed a positioning device for a vertically-slidable garage door in which the control means, the gear-driving means, and a clutch assembly are allcornbined within one casing which in turn is secured to a reversible electric motor. in addition, a solenoid-actuated pin is provided which serves to lock the clutch assembly and the gear means at all times when the motor is tie-energized. This invention also discloses an improvement in the driving connection between the countershaft and the motor control device, and the counterbalance shaft of a conventional, vertically-slidable garage door. in the driving connection disclosed as this invention, the countershaft is inserted into the counterbalance shaft and secured against rotation therein.

It is .pointed out that this invention is described in connection with a vertically-slidable garage door. However, the control device disclosed in this invention is susceptible togeneral application in many different fields. However, the extremely compact arrangement of the components of this motor-control .device lends this device to anefiicient operation as an operator for a garage door.

vIt is, ;therefore, a principal object .of this invention to provide an improved motor-control device.

atent O 2,841,724 Patented July 1, 1958 It is another object of this invention to provide a compact and unitary motor-control device especially suited to operate a vertically-slidable garage door.

It is a further object of this invention to disclose a motor-control device which essentially comprises a reversible electric motor, a gear drive, a clutch assembly, and a switch control box, all of which are built into a single, independent unit.

It is an additional object of this invention to provide a novel connection between a motor control unit and a vertically-slidable garage door by inserting the units countershaft into a hollow counterbalance shaft which operates the garage door, and securing the countershaft within the counterbalance shaft.

It is still another object of this invention to provide a motor-control device in which the clutch assembly is included within the gear box.

It is still a further object of this invention to provide a motor-c0ntrol device with a gear motor having a clutch assembly and a limit switch control box mounted on one end of a countershaft, and the other end of the countershaft used for driving purposes.

It is yet another object of this invention to provide a motor-control device having means to lock the clutch assembly when the motor is not energized.

Other objects and advantages of this invention will become apparent when reference is made to the following description when taken in conjunction with the accompanying drawings, wherein:

Figure l is an overall perspective view showing a motor-control device constructed in accordance with this invention, mounted to operate a vertically-slidable garage door;

Figure 2 is a front elevational view showing the arrangement between the gear box housing and the reversible electric motor;

Figure 3 is a sectional view taken along the lines 33 of Figure 2, and showing in detail the limit switch construction, the gear construction, and the clutch assembly;

Figure 4 is a sectional view taken along the lines 4 'i of Figure 3; and

Figure 5 is a wiring diagram showing the connection between the limit switches and the reversible electric motor.

Returning now to the drawings, more particularly to Figure 1, wherein like reference numbers indicate the same parts th oughout the various views, it) indicates the front wall of a garage having an opening 11 (not shown) therethrough which is closed by a verticaliy-slidable garage door 12. The garage door 12 comprises a plurality of sections 13 connected to each other by means of hinges 14. Mounted on the vertical edges of the garage door 12 is a plurality of spaced rollers 15, which are received within trackways 16. Thus, it can be seen that the garage door 12 slides within the trackways 16 between its open and closed positions.

To actuate the door 12 in its sliding movements between the open and closed positions, flexible elements 17 are connected to the top and bottom of each of the vertical sides of the garage door. Flexible elements 17 pass over or about rotary members 18 which are fixed on opposite ends of a counter-balance shaft 19, which in turn is rotatably supported in spaced brackets 20, 21, and 22, which are located at the ends and approximate center of the counter-balance shaft. A bracket 20A having suitable bearing means supports the end of the counterbalance shaft which receives an end of a counter-shaft as will be described later. The spaced brackets 20, 21 and 22 sufficiently support the counter-balance shaft so that bracket 20A may be omitted if desired.

Counter balance springs 23 and 24 are mounted upon the counter-balance shaft 19 in such a manner that the counter-balance springs become loaded when the door is lowered, and unwind when the door is elevated, thereby reducing the amount of work in moving the door to a minimum.

It is to be understood that the operating structure which has thus far been described is capable of many Variations in form. Consequently, the drawings illustrate only an example of this particular portion of the construction.

In order to operate the garage door 12, a motor-control device 25, which is constructed in accordance with this invention, is mounted upon the front wall 10 adjacent the bracket 20. The motor control device 25 comprises a reversible electric motor 26 and a gear box housing 27,

, which is integrally attached to the reversible electric motor 26. A supporting bracket 28, having one end 29 suitably fastened to the front wall 10, is used to support the motor-control device 25 in position. A conduit box 30 is suitably fastened to the reversible electric motor 26.

Proceeding now to Figure 3, the structure of the interior of the gear box housing is shown in considerable detail. It can be seen that the reversible electric motor 26 has an output shaft 31 which extends along one side of the gear box housing 27. That portion of the output shaft 31 which is within the gear box housing 27 has a helical thread 32 thereon. A shaft housing 33 encloses that portion of the output'shaft which has the helical thread 32 thereon.

It can be seen in Figure 3 that the gear box housing 27 comprises a switch control box 34 and a gear box 35. A removable cover plate 34A provides access to the interior of the switch control box 34. A wall 36 separates the switch control box 34 from the gear box 35. There is an opening 37 in the center of the wall 36, and a suitable bearing 38 is disposed within the opening 37. A countershaft 39 is supported at approximately its center section in the bearing 38. An end 40 of the countershaft 39 extends into the switch control box 34, and the other end, 41, of the countershaft extends outside of the gear box housing 27. It is noted that the countershaft 39 is transverse of the output shaft 31, and spaced therefrom.

The driving means between the electric motor 26 and the countershaft 39 comprises a gear 42 which is rotatably fitted upon the countershaft 39 and is in driving engagement with the helical thread 32 on the output shaft 31. In order to drivingly connect the gear 42 with the countershaft 39, a clutch assembly is used. This clutch assembly is of the friction clutch type, and comprises a first clutch element 43, which is secured to the countershaft 39 by means of a pin 44. This first clutch element 43 is disposed adjacent the gear 42. Also disposed on the countershaft 39 adjacent the opposite side of the gear 42 is a friction disc 45 which is pressed into contact with the adjacent face of the gear 42 by means of a ring 46 and a compression spring 47. One end of the compression spring 47 bears against a shoulder 48, which is on a clutch-adjusting member 49. The larger diameter portion 49A of the clutch-adjusting member 49 is threadedly received within an opening located within the end wall of the gear box housing 27. The clutch-adjusting member 49 has an axial bore 498 therethrough to accommodate the countershaft 39. There is a bearing portion 51 located within the axial bore 49B, and said bearing portion rotatably supports the countershaft 39. The clutch-adjusting member 49 has a plurality of recesses 52 on its outer face. A suitable tool may be used to engage these recesses, and by movement of the clutch-adjusting member along the threads of the opening 50 the tension of the compression spring 47 may be easily varied.

Thus it can be seen that with the clutch assembly just described the gear 42 is in driving connection with the countershaft 39 at all times.

According to this invention, the end 40 of the countershaft 39 which is received within the switch control box 34 has external threads 53 thereon. Threadedly engaging the external threads 53 is a cam member 54 which is held against rotation by a rod 55 extending between and rigid with the opposite end walls of the switch control box 34. The rod 55 is received within a diametrical slot 56 in the cam member 54. The rod 55 is parallel with the countershaft 39, so that the cam member 54 will move along the shaft when the shaft is rotated, but the cam member 54 itself will not be rotated.

Additional rods 57, 58, and 59 are rigidly mounted between the opposite end walls of the switch control box 34 in parallel relationship with the rod 55 and the countershaft 39. Limit switches 60 and 61 are mounted upon the rods 57 and 59 by means of members 62 and 63 which are secured to the sides of the limit switches 60 and 61 respectively. Each of the members 62. and 63 has bent-out apertured tabs which slidably engage the rods 57 and 59, and at least one of said tabs has a projection receiving set screws 64 and 65 by means of which the limit switches can be clamped in the switch control box in any desired adjusted position thereof. Members 66 and 67 are also secured to the opposite sides of the limit switches 60 and 61, and each of the members 66 and 67 has at least one bent-out portion which is apertured so as to slidably engage the rod 58. The limit switch 60 has an actuating member 68 on one side of the cam member 54, and the limit switch 61 has an actuating member 69 on the opposite side of the cam member 54. The limit switches are adapted for being connected in the motor circuit in a manner presently to be described, so that energization of the motor through either one of the limit switches will cause the motor to run in such a direction that cam member 54 will be moved toward the actuating element of the limit switch.

Means are also provided in the switch control box 34 for preventing the rotation of the countershaft 39 when the electric motor 26 is de-energized. This means essentially comprises a pin 70 which is reciprocably mounted in an aperture 71 located in the wall 36 which serves to divide the switch control box 34 from the gear box 35.

w A retaining ring 72 is secured to the wall 36 on the gear box side thereof, and serves to retain the bearing in position, and also to guide the pin 70. There is a plurality of arcuate notches 73 in a flanged portion of the first clutch element 43. These arcuate notches 73 are for receiving the free end of the pin 70. It can be seen that when the extreme end of the pin 70 is inserted into one of the arcuate notches 73, the first clutch element 43 and consequently the countershaft 39 will be restrained against further rotation. Consequently, should any attempt be made to rotate the countershaft when the electric motor is de-energized, it will be impossible to do so.

The pin 70 is secured to an armature 74 which is free to move within a solenoid coil 75. A spring 76 serves to bias the armature 74 and the pin 70 into engagement with one of the arcuate slots 73. The solenoid coil is so connected into the electric motor circuit that whenever the motor is energized, the coil will be energized, and consequently the armature will be attracted into the coil. This will cause the pin 70 to be withdrawn from the arcuate slot into which it was biased by means of the spring 76.

The countershaft 39 is connected to the counterbalance shaft 19 by inserting the countershaft into the hollow counterbalance shaft, and by means of a pin 77 securing the countershaft to the counterbalance shaft. This driving connection eliminates the need for any sprockets, chains, or other structure.

Proceeding now to Figure 5, the reversible electric motor 26 is illustrated diagrammatically as to its electrical components. 'The reversible electric motor 26 comprises a rotor 78 and field windings 7,9 and 80. Field windings 79 and 80 are angularly placed in the frame of the motor, and are'preferably identical. 'One end of each of the field windings is connected with power line L-2, and between the other ends of the field windings there is arranged a phase-shifting reactance 81, which is in series with a rotor-operated centrifugal switch 82. The switch 82 may be by-passed by resistance 83, if desired, but this element is by no means essential. The end of the 'fieldwinding 80 that is opposite power line L-2 is connected through the normally-closed limit switch as with one terminal 84 of a selector switch 85. Similarly, the end of the field winding 80 opposite power line L-2 is also connected through the normally-closed limit switch 61 with another terminal 86 of the selector switch 85. The selector switch 85 has a blade terminal 87 which is serially connected to one end of the solenoid coil 75. The other end of the solenoid coil 75 is then connected to the line L-l.

Thus it can be seen from the above description that the reversible electric motor 26 will run in either one direction or the other depending on which way the selector switch 85 is thrown. If desired, the electric motor may be of the instantaneously reversible type.

In operation, assuming the garage door 12 to be closed, the selector switch 85 will be actuated to energize the reversible electric motor 26 to run in a direction to elevate the garage door. This will cause rotation of the countershaft 39 in a direction to move the cam member 54 toward the one of the limit switches 60, 61 which is at that time in the motor circuit. Upon the cam member 54 reaching and engaging the actuating element for the said limit switch, the motor will become de-energized, and thereafter again only be energized to run in the opposite direction by throwing the selector switch 85 to its other position.

In normal operation, the cam member 54 will engage the actuating element of the limit switches at or slightly beyond the limit of travel of the garage door 12. If adjusted to slightly beyond the travel of the garage door 12, the friction clutch connecting the motor with the door will slip somewhat each time the door reaches one of its limit positions, and this will prevent the door from being damaged.

It is pointed out that an additional advantage of this invention is that should the door become jammed for any reason whatsoever in an intermediate position, the friction clutch will slip, and permit continued rotation of the electric motor 26 for a short time until the cam member 54 engages that one of the limit switches which is then in control of the energizing circuit. This not only prevents damage to the door, but also prevents such abuse of the motor as would occur if it were merely to stall but remain energized. It will be evident that under these circumstances the position of the cam relative to the limit switches will not be in correspondence with what is actually required. However, the next time that the motor is energized, and assuming that the door r turns toward the position from which it started, the friction clutch will permit continued rotation of the motor after the door reaches its end position, and this will bring about realignment of cam member 54 with the position of the door. Accordingly, once the mechanism disclosed as this invention has been installed and adjusted, no further adjustment thereof is ever required. Mishaps such as accidental or temporary jamming of the door are automatically compensated for.

It can also be seen that since the solenoid coil 75 is in series with the motor circuit, the coil will be energized whenever the motor is energized. Consequently, as soon as the motor is energized, the solenoid coil will serve to attract the armature 74, and this in turn will withdraw the pin 76 from one of the arcuate notches in the first clutch element 43. This means that whenever the door is closed and the motor is not energized, it

will be impossible to open the door by forcing the clutch assembly to slip to permit rotation of the countershaft 39.

From the preceding description, it can be seen that this invention discloses a compact motor-control device which is particularly suited for operating vertically slidable garage doors. This motor device, however, is capable of many other applications, and the application of this invention to operate a garage door should be construed as being exemplary only.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions, and accordingly it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What is claimed as this invention is:

l. in a motor-control device, a reversible electric motor having a casing, a gear box housing secured to one end of said casing, a countershaft journaled in said gear box housing, one end of said countershaft being adapted for driving purposes, gear means interconnecting said electric motor and said countershaft, said gear means loosely engaging said countershaft whereby said motor is rotatable when said countershaft is stationary, a clutch assembly drivingly engaging said gear means and said countershaft, means engageable with said clutch assembly to lock said countershaft against rotation in response to de-energization of said motor, limit switch means associated with the other end of said countershaft to control movement of said electric motor, and said clutch assembly, said gear means, and said switch means being located in said gear box housing.

2. In combination, a reversible electric motor, a countershaft driven thereby, a gear box housing rotatably supporting said countershaft, external threads on one end of said countershaft, a cam member threadedly mounted on said threaded end for movement thereon, means to prevent rotation of said cam member when moving, a limit switch positioned within said gear box housing and actuated by said cam member, and circuit means between said limit switch and said electric motor to control the limit of movement of said electric motor, said circuit means including means operable by the de-energization of the electric motor to lock said countershaft against rotation.

3. In combination, a reversible electric motor, a countershaft driven thereby, gear means for drivingly connecting said electric motor and said countershaft, a clutch assembly to drivingly connect said gear means and said countershaft, and means engageable with said clutch assembly to lock said countershaft against rotation when said motor is de-energized.

4. A motor control device comprising a casing, a reversible electric motor attached to said casing and having an output shaft extending therefrom, a worm on said output shaft, a countershaft extending transversely of said output shaft and spaced therefrom, a worm gear rotatably mounted on said countershaft and in mesh with said worm, a first clutch disc fixed to said countershaft on one side of said worm gear, :a second clutch disc rotatably mounted on said countershaft and engageable with the other side of said worm gear, circumferentially spaced notches in the periphery of said second clutch disc, means urging said second clutch disc into engagement with said worm gear to drivingly connect said worm gear and said first clutch disc, and means engageable with a single one of said notches when said motor is de-energized to prevent rotation of said countershaft.

References Cited in the file of this patent UNITED STATES PATENTS (Other references on following page) UNITED STATES PATENTS Blodgett, Nov. 16, 1937 Fitz Nov. 24, 1942 Zoller Nov. 30, 1943 Merrill June 20, 1944 Vallen June 12, 1945 Wehuer Aug. 10, 1948 McVicker et a1. July 10, 1951 8 Schlytern July 31, 1951 Cooley Nov. 20, 1951 Richards Mar. 11, 1952 Hall Sept. 30, 1952 Nardone Dec. 2, 1952 Moler Dec. 1, 1953 Wilcox Apr. 20, 1954 Watson et a1. May 25, 1954 Yates Nov. 9, 1954

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