US3166306A

US3166306A - Garage door operator

Info

Publication number: US3166306A
Application number: US295947A
Authority: US
Inventors: Henry C Peltier
Original assignee: ASTROTEC Inc
Current assignee: ASTROTEC Inc
Priority date: 1963-07-18
Filing date: 1963-07-18
Publication date: 1965-01-19
Anticipated expiration: 1982-01-19

Description

Jan. 19, 1965 H. c. PELTIER 3,

GARAGE DOOR OPERATOR Filed July 18, 1963 3 Sheets-Sheet 1 INVENTOR.

//Me/ (t Par/ 7e Jan. 19, 1965 H. c. PELTIER GARAGE DOOR OPERATOR 3 Sheets-Sheet 2 Filed July 18, 1963 N 1 e-a INVENTOR. 6231 4? P5177457? Jan. 19, 1965 H. c. PELTIER 3,

GARAGE DOOR OPERATOR Filed July 18, 1963 3 Sheets-Sheet 5 INVENTOR.

United States Patent 3,166,306 GARAGE DOGR OPERATOR Henry C. Poitier, Hackensack, N31, assiguor to Astrotec, Ina, Garfield, N.J., a corporation of New Jersey Filed July 18, 1963, Ser. No. 295,947 17 (Iiaims. (ill. 268-59) This invention relates to a garage door operator and, more particularly, to a motorized garage door operator which selectively opens and closes a garage door upon receipt of a signal from a local station or a remote control unit.

It is a primary object of my invention to provide a garage door operator which carries out its normal function of raising and lowering a garage door in a new and improved manner and which is particularly suited to be added to an already existing sectionalized garage door that is mounted for movement from a closed vertical position to an open overhead horizontal position and which is hereinafter referred to as an overhead garage door. My invention is well adapted to be added to a previously installed overhead garage door which was theretofore only manually operable and which can by the addition of my unit be automated so that upon the sending of a signal the home owner will without further effort open or close his garage door.

It is a further object of my invention to provide a garage door operator of the character described which may be quickly and easily installed in a garage with a minimum expenditure of elfort and funds and which may be installed by a relatively unskilled worker following a simple set of directions. My garage door operator is characterized by its simplicity of installation. No large beam members or other complex or cumbersome parts need be added to an already existing overhead garage door. Rather, by the simple addition of a drive assembly and guide cables, my garage door operator may be made a permanent part of a garage in a matter of hours with the use of only simple handymans tools.

It is a further object of my invention to provide a garage door operator of the character described which is particularly adapted for installation in garages wherein there is a minimum of space between the garage door in its open condition and the ceiling of the garage, only a few inches of clearance being needed for the installation of my operator. Other garage door operators of which I am aware require considerable head room for their installation and operation. That is to say, beams and sprockets chains and other apparatus are commonly necessary and must be installed and located in the space between the garage door in its open position and the ceiling of the garage. This limitation has made it extremely difiicult and often impossible to install a garage door operator in a garage which has not been especially constructed to allow sufficient clearance space for a garage door operator. Further, it should be noted that low ceiling garages are quite popular today and thus there exists a great number of such garages wherein a minimum, i.e. less than half a foot, of space exists between the open garage door and the garage ceiling.

It is yet another object of my invention to provide a garage door operator of the character described which is rugged and foolproof in use and yet is economical in manufacture and assembly.

I further desire that my garage door operator be so constructed so that should for some unusual reason, as a motor failure, the operator become jammed, I may by release means quickly disengage my garage door operator so that the garage door can be manually opened or 3,166,305 Patented Jan. 19, 1965 closed and appropriate repair and maintenance services may be performed.

These and various other objects and advantages of my invention will become apparent to the reader in the following description.

My invention accordingly consists in the features of construction, combinations of elements and arrangements of parts which will be exemplified in the device hereinafter described and of which the scope of application will be indicated in the appended claims.

In the accompanying drawings in which is shown one of the various possible embodiments of my invention,

FIG. 1 is a perspective view of the interior of a garage with my garage door operator properly installed;

FIG. 2 is a front elevational view of the drive assembly of my garage door operator, the drive assembly takingthe illustrated posture when the garage door is in its closed position;

FIG. 3 is a side view of the drive assembly in the position shown in FIG. 2;

FIG. 4 is a side view of the drive assembly in the posture which it takes when the garage door is approaching its open terminal position;

FIG. 5 is an enlarged fragmentary side cross-sectional view of the drive unit taken substantially along the line 5-5 of FIG. 2 but illustrating the drive assembly in its horizontal terminal position;

FIGS. 6 and 7 are fragmentary side cross-sectional views of the drive assembly illustrating the follower means approaching a horizontal terminal position, and in a vertical terminal position, respectively;

FIGS. 8 and 9 are fragmentary perspective views, respectively, of the end portion of .a guide track, and an impact buffer within the track;

FIG. 10 is a perspective view'of the guide bracket for the main cable;

FIG. 11 is a perspective view of the cross-cable yoke; and

FIGS. 12 and 13 are, respectively, plan and side views of the quick-release extendible coupling.

Referring now in detail to the drawings, the reference numeral 10 denotes an overhead garage door of a conventional type. The door 10 moves from one terminal position (shown in FIG. 1) in which it is substantially vertical and in which it closes the entrance to the garage to another terminal position in which it is overhead and horizontal and in which latter position the entrance to the garage is open. Dual track means 12 guide and support the garage door 10 in its movement between its closed terminal position and its open terminal position. Each of said dual track means 12 comprises an inwardly opening track 14 (see FIGS. 8 and 9) which is C-shaped in cross-section. Flanged rollers 16 are rotatably joined to the vertical side edges of the door 10 at the junction between the sections of the garage door and at the top and bottom of the door. Said rollers are captively held within the C-shaped section of the tracks 14. As the garage door 10 moves between its terminal positions the rollers 16 roll along and within their afiiliated tracks 14 and the sections of the door'10 swing so as to allow the garage door to shift as desired between an open and closed position. The sectionalized garage door 10, the track means 12 and the rollers 16 are entirely conventional and are well known to those skilled in the art. The garage door operator to be described may be installed concurrently with the erection of the garage or may be added to any conventional preexisting garage having an overhead door.

The garage door 10, mounted for movement between its open and closed positions, is automated by a garage door operator generally designated by the reference numeral, 18. Said garage door operator includes a drive assembly which is attached to the garage door Ill at the top edge thereof and is centered between the side edges of the garage door. The drive assembly 20 includes an electrical motor 22 which is energized by appropriate and well known circuit means including a supply cable 23. The electric circuit means is preferably of the type which is energized by an outside source of electrical energy, e.g. electrical power lines, and in response to a radio signal or key or push button signal given by the homeowner. The electric motor 22 as well as the other components of the drive assembly 26 are mounted on the door 10 by a support plate 24 which is a heavy metallic flatmember having spaced apertures 26through which screws 28 pass and attach the plate to the garage door 10. The top of the support plate 24 has integral with it a flange 30 which extends at a right angle to'the plate 24 and which overlies the top edge of the garage door 10.

The drive assembly 2% by virtue of the position of the support plate 24 is located directly on the garage door 10 at the top central portion thereof. The motor 22 is carried by a casing 32 which is joined to the support plate 24, as by welding. The casing 32 rotatably mounts a shaft 34 of a traction drive wheel 36. Both ends of the shaft 34 project from different sides of the casing 32 and the shaft 34 is mounted in a horizontal position and parallel to the curved plane in which the garage door 10 moves. The motor 22 by an appropriate gear reduction mechanism within the casing 32 drives the shaft 34 and thus the traction drive wheel 36 which is fast thereon. The circumference of the traction wheel 36 includes two circumferential flanges 33 which define therebetween a semicircular peripheral groove 40. The surface of the groove 40 is preferably composed of a friction inducing material such as semi-hard rubber.

The drive assembly 20 further includes plural idler wheels, respectively a first idler wheel 42 and a second idler wheel 44. The idler wheels 32 44 are fast on different freely rotatable shafts, respectively 48, 46, the shafts being carried by U-shaped back-to-back brackets, respectively, 50, 52 the bottom brackets 52 being joined as by Welding to the casing 32. The shafts of the

idler Wheels

42, 44 and the shaft 34 of the traction drive wheel 36 are parallel to one another. As seen in FIG. 3, when the door 10 is in its closed terminal position, the axis of rotation of the idler-wheel 42 is located above the axis of rotation of the traction drive wheel 36 and the axis of rotation of the second idler wheel 44 islocated above and forwardly of the axis of rotation of the traction wheel 36 and also forwardly of the axis of rotation of the idler wheel 42. The

idler wheels

42, 44 have grooves on their outer peripheries of the same contour and dimension as those of the traction wheel 36; however the idler wheels are of somewhat smaller diameter than the traction drive wheel.

A strong elongated flexible element, e.g. a main cable 54 of a Wound wire type, is horizontally disposed, is located above the garage door ll) in both its closed and open positions and runs from the front to the rear of the garage. The main cable 54 is fixed at both of its ends and is located centrally between the tracks 14. A

portion of said cable 54 (dependent on the location of the garage door) 'is engaged by the wheels of the drive assembly 20. More specifically, the cable 54 passes clockwise (going from rear to front) around the first idler 42 (as seen in FIG. 3) and engages a portion of its periphery which faces the second idler wheel 44. The cable then passes counterclockwise around the traction drive wheel 36 and then clockwise around the other idler wheel 44. The cable 54 is thereby entrained about and frictionally gripped by the wheels and the idler wheels are so placed that more than one-half of the circumference of the traction drive wheel 36 is in contact with the cable.

Follower means 56 is carried by the drive assembly 2t and is guided by the cable 54 throughout the movement of the garage door 10 between its closed and its open terminal positions. To this end the follower means 56 is mounted for rotation relative to the garage door 10 about an axis which is horizontal and parallel to the axes of rotation of the traction and idler wheels. Said follower means 56 comprises an elongated stifl hollow rod 58 which is rectangular in cross-section and open at both ends. The rod 58 includes two parallel horizontally aligned coextensive slots 60 of uniform width located in opposed vertical walls of the rod in the forward portion thereof adjacent the drive assembly 20. One end of the shaft 48 of. the upper idler wheel 42 external to the bracket 5t passes through both of these slots 60. The follower means 56 by virtue of the aforesaid shaft 48 and slots 60 in the rod 58 is mounted for rotation about the axis of the shaft 48 relative to the garage door it). The rearward end of the rod 58 carriers an eye bolt 62 having an elongated shaft 64 which passes diagonally through the rod 58 and which is joined thereto as by nuts 66 disposed on the shaft 64 against opposite corners of the rod. 58 through which the bolt passes. The cable 54 is threaded through the eye 68 of the bolt 62.

The follower means 56 is mounted for movement relative to the drive assembly alonga second axis, this axis being the axis of symmetry of the rod 58 which is parallel to the reach of the cable 54. The slots 6t) are slightly larger than the diameter of the shaft 43 so that the rod may shift axially forwardly or rearwardly with respect to the shaft 48 as well as rotate about this shaft.

Biasing means urges the rod 58 rearwardly with respect to the shaft 48. For this purpose an elongated helical compression spring 7% is captively held within the hollow rod 58, the spring being abutted on one end bythe shaft 64 of the eye bolt 62 and on the other end by the shaft 48. The coil spring 70 is under compression so as to urge the rod 53 rearwardly, i.e. away from the shaft 43. That is to say, the end of the rod 58 distant from the eye bolt 62 is biased toward the shaft 48.

Switch means responsive to the follower means 56 as garage door It approaches either of its terminal positions deenergizes the drive assembly when the switch means is actuated upon the arrival of the door at either of such positions. Said switch means comprises a momentary snap switch 72 such as a Micro switch or a Mu switch attached to the outside of the bracket 52. The body of the snap switch 72 carries an actuating button '74 which is spring biased outwardly and a pivotally mounted actuating lever 76. The actuating lever 76 is so positioned that it overlies the actuating button 74 and so that rotation of the lever 76 toward the switch body depresses the button 74 so as to actuate the snap switch 72 and thereby deenergize the motor 22 which has been moving the garage door. In a position of repose the lever 76 permits the button 74 to be spring biased to unactuated position. Upon depression of the lever 76, the button 74 is correspondingly depressed into the housing of the snap switch to cut 0E power to the motor. Theend of the lever 76 distant from the pivotal end rotatably mounts a small roller 78, this being provided so that a body (the end of the rod 58) contacting the lever 76 if caused to strike the roller 78, will slide thereon.

7 Stop means are fast to the cable $4 at arearward portion thereof. Said means constitutes an apertured disc 8!} encircling the cable 54 and frictionally joined thereto as by a radially inwardly protruding set screw 82. The

diameter of the disc 80 is larger than that of the aperture of the eye 68 of the eye bolt 62 so that the disc 8% cannot pass through the eye.

The shaft 48 and the switch 72 are so mutuaily located that both rotativemovement and axial movement of the rod 58 will cause depression of the actuating lever 76. As shown in FIGS. 5 and 6, when the rod 58 strikes the disc 8t and is caused thereby to translate axially and forwardly relative to the door and drive assembly, the end of the rod 58 adjacent the drive assembly 20 travels forwardly in a straight line intersecting the lever 76. During such straight line forward travel the rod strikes the lever near its pivoted end and forces the lever to depress the button 74. Rotative movement of the rod 58 about the shaft 48 as the door approaches its closed position causes one side of the rod to swing against the actuating lever roller 78 (see FIGS. 3 and 7) again forcing the lever 76 to depress the button 74 and shut off the motor. A screw 81 extends from the bracket 58 and acts as a stop to limit the rod 58 in its rotative actuating movement.

When the rod 58 by axial or rotative motion strikes the lever 76, the follower means has assumed an operative location. This happens when the garage door has reached either of its terminal positions. The switch means is responsive to the follower means in both of these locations to deenergize the drive assembly. The spring 78 urges the follower means 56 away from the lever 76 and to an inoperative location.

As has been previously mentioned, the cable 54 is fixed at both of its ends. For the front end, a guide bracket 84 is attached to a portion of the garage door frame centrally and immediately above the garage door entrance between the tracks 14. The bracket 84 includes a flat heavy rigid plate 85 which is joined, as by screws 86, to the frame of the garage door. The bracket 84 further includes an arm 88 pivoted at one end on the plate 85, as by a rivet 98 which passes through the lever and the plate 85. The arm is mounted for limited rotation in a plane parallel to the plane in which the plate 85 lies. from the plate 85 and has its legs joined, as by welding, to the top and bottom edges of the plate. The bail 92 spans a central portion of the arm 88 near and parallel to the plate 85 so as to relieve pressure on this rivet 90 when the garage door operator is in motion. The legs of the bail limit upward and downward rotational movement of the arm. The other end of the arm 88 is angularly oifset and apertured. The cable 54 passes through the'aperture in the arm 88, making a right angled bend and then being joined to one end of a strong elongated helical tension spring 94. The other end of the spring 94 is attached, as by a screw 96, to the frame of the garage door 10. The spring 94 maintains the cable 54 in tension.

An elongated flexible element, a cross-cable 98 carries the other end of the main cable 54. Thecross-cable 98 runs from one side of the garage to the other and is disposed between the ends of the tracks 14. The crosscable 98 is horizontal and approximately perpendicular to the main cable. A central portion of the cross-cable 98 supports the rear end of the main cable 54 (see FIG. 1). A hollow self-centering tubular yoke 100 is disposed about the central portion of the cross-table 98 and is of sufiicient internal diameter so as to be able to slide, i.e. ride along the cross-cable. One side of an S-shaped hook 102 is joined to the yoke 100 as by welding. The other side of the hook 182 is joined to the rear end of the cable 54 and passes through a loop in the cable formed by a conventional anchor clamp 104. When the main cable is under tension the yoke will slide along the crosscable until it reaches approximately a central location thereon.

Impact buffers 186 are carried within the C-shaped channel formed in each of the tracks 14 at a rearward portion thereof (see FIG. 9). Both buffers are identical and only one will be described. The impact buffer 186 is held by a multi-apertured length of. rigid angle-iron 188, the angle-iron fitting within the channel-shaped opening of the track 14. The apertures 118 in the angle-iron are disposed in a row parallel to the length of the track 14 and are provided so that the impact buffer 106 can be positioned at any spot at the rear end of the track 14 as by a bolt 105 which passes through an aperture in the A U-shaped bail 92 has its central portion spaced track 14 and an aligned aperture 110 in the angle-iron 108. (See FIG. 8.) Each bulfer 106 comprises a vertical carrier plate 112 secured to the front end of its afliliated angle-iron and having a central through bore 114 about which is disposed a collar 116 that is integral with the plate 112. An elongated shaft 118 passes through the bore 114, the collar 116 effectively prohibiting sidewise roofing movement of the shaft. The shaft 118 has a head 120 on its rearward end. The front end of the shaft 118 is enlarged as by a hard rubber cap 122 which is disposed over and frictionally grips said end of the shaft. A helical compression spring 124 is wound about the shaft 118 and is disposed between the plate 112 and the cap 122. The spring 124 resists rearward movement of the shaft 118.

An apertured ceiling hanger 126 is joined to the end of track 14 by the bolt 105 and serves to suspend the track means 12.

Each end of the cross-cable 98 is held under tension by an elongated eye bolt 128 which also protrudes through an aperture 110 in the angle-iron 108. (See FIG. 8.) A loop formed in the end of the cross-cable 98 by use of a conventional anchor clamp 130 passes through the eye 132 of the eye bolt 128. The eye bolt has an elongated shank 134 which extends through an angle-iron aperture 110 and has a tapped end distant from its eye 132. A nut 136 is screwed onto this end, and a helical compression spring 138, disposed about the shank 134 between the angle-iron 108 and the nut 136, urges the eye bolt 128 outwardly through the angle iron and thus tensions the cross-cable 98 and, in turn, the main cable 54.

Quick release extendible coupling means is provided to permit fast manual loosening of the cross-cable 98 so that the main cable 54 may be relaxed to an extent sufficient to free the main cable from the drive assembly 20. This may be necessary when for some unusual reason the garage door operator becomes jammed as by failure of the motor 22. Said quick release means comprises a quick release coupling 140 which interrupts the cross-cable 98 adjacent one end thereof. The coupling 140 carries a hook 142 on one side which passes through a loop formed in the cross-cable 98 by an anchor clamp 144. The hook 142 has one longer leg rotatably joined to the cross-bar of a yoke 146, the yoke legs 148 extending away from and generally parallel to the longer leg of the hook 142. An elongated downwardly sloping handle 150 which has a bifurcated end 152 is rotatably mounted at the beginning of its bifurcated portion between the tips of the yoke legs 148 by pins 154 passing through aligned apertures in the adjacent yoke legs and the bifurcated end 152. Another hook 158 has one end extending through a loop in the cross-cable 98 formed by an anchor clamp 160. The other end of the hook 158 is an eye 162 through which passes a pin 164 mounted between the ends of the bifurcated portion 152. When in a contracted position, and when there is tension on both sides of the coupling 140 at the

hooks

142, 158, the pin 164 is pulled downwardly to the left (as viewed in FIG. 13) and below the pins 154 by force along the long reach of the hook 158. The pin 164 moves downwardly until the handle 150 rotating clockwise abuts the hook 158 thus locking the coupling in contracted position. When it is desired to expand the coupling 140 and thus slacken the cross-cable 98, the handle 150 is pulled downwardly in the direction indicated by the arrow A. The handle will rotate on the pins 154, the bifurcated end 152 thereby rotating with the handle in a counterclockwise direction across dead-center and then to a position on the other side of the pins 154. The distance between the

hooks

142, 158 will thereby be greatly enlarged, thus slackening in the cross-cable 98.

When the garage door 10 is closed, the position of the drive assembly 20 relative to the garage door is as shown in FIG. 3. The follower means 56 is substantially horizontal (as it always is) and is perpendicular to the garage door 18, being held in this position by the eye bolt 62 which is supported by the drive cable 54. Uponacontrol signal given by the homeowner, the drive assembly 2% is energized causing the electric motor 22 to drive the trac tion drive wheel 36 in a counterclockwise direction as seen in FIG. 3. The drive assembly 21) will thereby exert first an upward and then rearward force on the garage door 10 so that the door will move along the tracks 14.

As the garage door 10 moves from its closed terminal position toward its open position, it swings from the vertical to the horizontal. The follower means 56, being rotatably mounted about the shaft 48 and sliding along the main cable 54, remains in a substantially constant attitude relative to the main oable.

FIGS; 4 and 6 illustrate the position of the follower means 56 as it approaches its horizontal terminal (open) position. The door 10 in moving between its terminal positions has rotated 90 with respect to the constant attitude follower means.

FIG. shows the position of the follower means 55 at its horizontal terminal position. The eye bolt 62 has struck the disc 80 fixed on the cable 54 andthereby the rod 58 has been forced axially forwardly (relative to the rearwardly moving door) against the force of the coil spring 70 so that its forward end struck the actuating lever 76. This in turn forced the lever to depress the actuating button 74 and caused the snap switch 72 to deenergize the drive assembly 20. The position of the actuating lever immediately prior to its operative engagement by the rod 58 is illustrated in dot-and-dash lines in FIG. 5.

The impact buffers 106 are located in the tracks 14 in a position such that the top edge of the garage door reaches the buffers shortly before the eye bolt 62 strikes the disc 80. The top edge of the garage door 16 strikes the fronts of the caps 122 moving the shafts 118 rearwardly so that the coil springs 1.24 are compressed. The impact buffers 106 restrain and inhibit movement of the garage door beyond a predetermined location and prevent the disc 80 from absorbing the heavy momentum of the moving garage door.

When-the homeowner wishes to close his garage door he gives a control signal that actuates the electric motor 22 in a reverse direction. The motor then rotates the traction drive wheel 36 in a clockwise direction as shown in FIG. 4 and the drive assembly 20 begins to move the garage door back forwardly along the cable 54 and down to its vertical closed position. Immediately afterleaving its horizontal terminal position the coil spring 70 moves the rod 58 rearwardly and away from the actuating lever 76 until the ends of the slots 60 abut the shaft 48. This position is shown in FIG. 6. The drive assembly 26 continues to move the garage door It? along the tracks 14 and back to its vertical terminal position, and, as the garage door swings and this position is approached, the follower means 56 rotates relative to the garage door It) about the shaft 48. A 90 rotation takes place and as the garagedoor approaches its closed terminal position the rod 58 swings against the roller 7% mounted on the actuating lever '76. This abutment again causes depression of the actuating button 74 so that the drive assembly 2t? isdeenergized.

a The bracket-84 allows limited rotation of the arm 83 andhence limited upward and downward movement of the main cable 54 so as to adjust for the rise and drop in the drive assembly 29 as it moves around the bend It will now be evident toa reader of the instant dis closure that the several objects of my.invention have been attained. My garage door may be quickly and easily installed by simple attachment of the support plate 24 to the top edge of the garagedoor wand the proper location and installation of the main cable 54 and the cross-cable 98. No heavy, cumbersome or complex parts need be installed and the installation previously de scribed may be accomplished through the use of handymans tools. The pie-existing track structure of the garage door'is retained so that no additional heavy supporting members are called for.

As shown in FIG. 3 the height of my garage door op erator is only a few inches higher than the garage door when the garage door is in its closed position. When the garage door is in'a horizontal position, as shown in FIG. 4-, the garage door operator extends barely more than a cables width over the garage door. Attention also is called to the location of the idler wheel 44 which is such that the reach of the cable extending therefrom forwardly is clear of the top surface of the garage door.

It thus will be seen that I have provided a device which achieves the several objects of my invention and which is well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent,

1. A motorized garage door operator for selectively opening and closing a sectionalized overhead garage door supported and guided by dual track means for shifting the garage door between a closed vertical terminal position and an overhead open horizontal terminal position, said garage door operator comprising a horizontal central front-to-rear flexible elongated element fixed at its ends and located above the garage door, a drive assemly mounted on the door adjacent the top edge thereof, said drive assembly including traction means operatively engaging the elongated element for reversible movement therealong, follower means mounted for rotational movement about an axis relative to the garage door, said follower means being guided by the elongated element and thereby swinging to an operative location when the garage door approaches its closed vertical terminal position, said follower means being further mounted for movement along a different axis and moving along said axis to an operative location when the garage door approaches its open horizontal terminal position, means for energizing the drive assembly, and switch means carried by the garage door and mechanically responsive to the follower means to deenergize the drive assembly only when the follower means assumes either of its operative locations.

2. A motorized garage door operator as set forth in claim 1 wherein the axes with respect to which the follower means is mounted are transverse to one another.

3. A motorized garage door operator as set forth in claim 1 wherein the rotational axis of the follower means is horizontal and parallel to the plane of the garage door and the second-named follower means axis is parallel to the elongated element.

4. A motorized garage door operator for selectively opening and closing a sectionalized overhead garage door supported and guided by dual track means for shifting the garage door between a closed vertical terminal position and an overhead open horizontal terminal position, said garage door operator comprising a horizontal central front-to-rear flexible elongated element fixed at its ends and located above the garage door, a drive assembly mounted on the door adjacent the top edge thereof, said drive assembly including traction means operatively V engaging the elongated element for reversible movement therealong, follower means mounted for rotational movement relative to the garage door about a horizontal axis parallel to theplane of the garage door and swinging to an operative location when the garage door approaches its closed vertical terminal position, said follower means slidably riding along the elongated element and maintaining a substantially constant attitude along a second axis parallel to the elongated element as the garage door moves between its terminal positions, said follower means being further mounted for reciprocal movement along the second axis, stop means joined to the cable at a rear portion thereof and abuttingand thereby moving said follower means along its second axis to an operative location when the garage door approaches its open terminal position, means for energizing the drive assembly, and switch means carried by the garage door andmechanically responsive to the follower means to deenergize the drive assembly only when the follower means assumes either of its operative locations.

5. A motorized garage door operator as set forth in claim 4 wherein biasing means urges the follower means along the second axis and to an inoperative location.

6. A motorized garage door operator as set forth in claim 4 wherein the follower means swings through an arc of 90 between its operative locations.

7. A motorized garage door operator as set forth in claim 4 wherein the elongated element is fixed at its rear end by an elongated side-to-side horizontal flexible crosselement, said first named element being ridable along a central portion of the cross-element.

8. A motorized garage door operator as set forth in claim 7 wherein biasing means joins each of the ends of the cross-element to a different track means, said biasing means holding said cross-element in tension.

9. A motorized garage door operator as set forth in claim 7 wherein a quick-release mechanism selectively slackens the elongated elements whereby to selectively release the garage door operator.

10. A motorized garage door operator as set forth in claim 4 wherein the drive assembly is joined directly to the top edge of the garage door and wherein said drive assembly includes a motor, a traction wheel driven by the motor and plural idler wheels, all of said wheels being.

mounted for rotation about parallel axes and frictionally entraining the elongated element and being located so that when the garage door is in its, closed vertical position the axes of the idler wheels are above and rearward of the axis of the traction wheel.

11. A motorized garage door operator as set forth in claim 10 wherein the rotational axis of the follower means is coincident with the axis of rotation of one of the idler wheels.

12. A motorized garage door operator as set forth in claim 4 wherein the elongated element is fixed on its front end by a bracket arranged to constrain the front end of the cable for limited vertical movement.

13. A motorized garage door operator as set forth in claim 4 wherein a spring-loaded impact buffer is carried by each of the track means and abuts the top edge of the door so as to slow and restrain movement of the garage door shortly before the door reaches its horizontal open terminal position.

14. A motorized garage door operator for selectively opening and closing a sectionalized overhead garage door supported and guided by dual track means for shifting the garage door between a closed vertical terminal position and an overhead open horizontal terminal position, said garage door operator comprising a horizontal central front-to-"ear flexible elongated element located above the garage door and supported at its forward end, a drive as sembly mounted on the door adjacent the top edge thereof, said drive assembly including traction means operatively engaging the elongated element for reversible movement therealong, an elongated side-to-side horizontal flexible cross-element having a central portion carrying the rear end of the first named element, and means tensioning the said first named element.

15. A motorized garage door operator as set forth in claim 14 wherein biasing means urges the ends of the cross-element apart so as to hold said cross-element in tension.

16. A motorized garage door operator as set forth in claim 14 wherein a member is joined to the rear end of the first named element and slidably rides along the crosselement.

17. A motorized garage door operator as set forth in claim 14 wherein a member is joined to the rear end of the first named element and slidably rides along the crosselement and a bracket supports and constrains the front end of the element for limited vertical movement.

References Cited in the file of this patent UNITED STATES PATENTS 2,703,236 Verdier d. Mar. 1, 1955

Claims

1. A MOTORIZED GARAGE DOOR OPERATOR FOR SELECTIVELY OPENING AND CLOSING A SECTIONALIZED OVERHEAD GARAGE DOOR SUPPORTED AND GUIDED BY DUAL TRACK MEANS FOR SHIFTING THE GARAGE DOOR BETWEEN A CLOSED VERTICAL TERMINAL POSITION AND AN OVERHEAD OPEN HORIZONTAL TERMINAL POSITION, SAID GARAGE DOOR OPERATOR COMPRISING A HORIZONTAL CENTRAL FRONT-TO-REAR FLEXIBLE ELONGATED ELEMENT FIXED AT ITS ENDS AND LOCATED ABOVE THE GARAGE DOOR, A DRIVE ASSEMBLY MOUNTED ON THE DOOR ADJACENT THE TOP EDGE THEREOF, SAID DRIVE ASSEMBLY INCLUDING TRACTION MEANS OPERATIVELY ENGAGING THE ELONGATED ELEMENT FOR REVERSIBLE MOVEMENT THEREALONG, FOLLOWER MEANS MOUNTED FOR ROTATIONAL MOVEMENT ABOUT AN AXIS RELATIVE TO THE GARAGE DOOR, SAID FOLLOWER MEANS BEING GUIDED BY THE ELONGATED ELEMENT AND THEREBY SWINGING TO AN OPERATIVE LOCATION WHEN THE GARAGE DOOR APPROACHES ITS CLOSED VERTICAL TERMINAL POSITION, SAID FOLLOWER MEANS BEING FURHTER MOUNTED FOR MOVEMENT ALONG A DIFFERENT AXIS AND MOVING ALONG SAID AXIS TO AN OPERATIVE LOCATION WHEN THE GARAGE DOOR APPROACHES ITS OPEN HORIZONTAL TERMINAL POSITION, MEANS FOR ENERGIZING THE DRIVE ASSEMBLY, AND SWITCH MEANS CARRIED BY THE GARAGE DOOR AND MECHANICALLY RESPONSIVE TO THE FOLLOWER MEANS TO DEENERGIZE THE DRIVE ASSEMBLY ONLY WHEN THE FOLLOWER MEANS ASSUMES EITHER OF ITS OPERATIVE LOCATIONS.