US3397488A

US3397488A - Cable tensioning apparatus for movable door controller

Info

Publication number: US3397488A
Application number: US621162A
Authority: US
Inventors: Goldstein Richard
Original assignee: Chamberlin Manufacturing Corp
Current assignee: Chamberlin Manufacturing Corp
Priority date: 1967-03-07
Filing date: 1967-03-07
Publication date: 1968-08-20
Anticipated expiration: 1985-08-20

Description

20, 1968 R. GOLDSTEIN 3,397,488

CABLE TENSIONING APPARATUS FOR MOVABLE DOOR CONTROLLER Filed March 7, 1957 FIG.\

.5 Sheets-Sheet L INVENTOR RmHARo Gowsrsm a 7 W7, 4W YS.

20, 1968 R. GOLDSTEIN 3,397,488

CABLE TENSIONING APPARATUS FOR MOVABLE DOOR CONTROLLER Filed March '7, 1967 3 Sheets-Sheet 2 H 1k H INvaN'roR RICHARD GOLDSTEJN A'r-rvs.

Aug. 20, 1968 R. GOLDSTEIN 3,397,488

CABLE TENSIONING APPARATUS FOR MOVABLE DOOR CONTROLLER Filed March 7, 1967 3 Sheets-Sheet '5 lnvzu'ron RICHARD Gowsrsm United States Patent 3,397,488 CABLE TENSIONING APPARATUS FOR MOVABLE DOQR QGNTROLLER Richard Goldstein, Deerfield, Ill, assignor, by mesne assignments, to Chamberlin Manufacturing Corporation, Elmhurst, 111., a corporation of Iowa Filed Mar. 7, 1967, Ser. No. 621,162 9 Claims. (Cl. 49-199) ABSTRACT OF THE DISCLOSURE A flexible cable of current carrying conductors extending between a stationary junction box and a movable door operator unit which moves between extreme positions on a guide rod where the door connected to the door operator unit moves between a vertical lowered position and a horizontal raised position is maintained in a taut flexible position by anchoring the flexible cable to the end of a horizontal pivoted arm pivotally supported about a vertical axis and spring urged into an extreme position where the end of the arm points away from the path of travel of the door operator unit, the end of the arm being capable of swinging over a wide are against the return force of the spring and toward the path of travel of the door operator unit so as to follow the movement thereof.

The present invention relates to cable tensioning apparatus for movable door controllers, particularly door operators used to raise and lower garage doors.

Door operator units for controlling the raising and lowering of garage doors of two types. In one type, a drive motor and control circuitry therefor are mounted in a stationary housing, the drive motor controlling the movement of a horizontally disposed chain or the like mounted near the ceiling of the garage which chain is coupled through a member carried by the chain and a connecting arm to the garage door. This form of door operator is particularly desirable for heavy sectional type doors.

The other type of garage door operator unit which is more usefully adapted to light weight sectional or solid trackless doors has a drive motor and control circuitry mounted in a housing which bodily moves between extreme forward and rear positions along a track or guide rod supported by brackets from the ceiling of the garage. The drive motor drives a wheel which frictionally engages the track or guide rod. This type of door operator unit is easily installed with different garage door installations having widely different paths of travel than the first type of garage controller. However, the second type of garage door operator unit requires a flexible cable of conductors extending between the movable housing and a junction box. In such case, it is imperative that the cable be kept in a relatively taut condition over the range of movement of the door operator unit housing, so the cable cannot be caught on the garage door. Various forms of cable tensioning devices heretofore developed are unsatisfactory for keeping the cable taut for a number of reasons. The conventional take-up reels sometimes used for retractable cables are too expensive and unwieldly when the cable contains four or more conductors. (Movable door operators generally require two conductors carrying current for the drive motor and at least two conductors for carrying control current for operating the control circuitry of the motor.) The use of a coiled cable is unsatisfactory because the cable tends to lose its resiliency at low temperatures and with age, an it -generally requires a clearance space between the garage door and the ceiling of the garage which is frequently not available.

The present invention overcomes the aforementioned disadvantages by providing a very simple, economical and rugged cable tensioning device which occupies a small vertical extent and is usable with door installations having a wide range of movement.

In the most preferred form of the present invention, the cable tensioning apparatus and a junction box form an integral unit. The flexible cable extending from the junction box has an inner portion which extends generally horizontally to the free end of a horizontal cable anchoring arm pivotally mounted about a vertical axis next to the junction box. A spring urges the cable anchoring arm into one extreme position as, for example, where the arm abuts against the side of the junction box. The arm is free to pivot over a substantial angle against the restraining force of the spring. The junction box is mounted on the ceiling of the enclosed space or garage involved preferably in the space above that to be occupied by the garage door in its raised position and spaced a substantial distance laterally of the guide rod or track of the door operator unit. The junction box is oriented so the free end of the cable anchoring arm with the cable unconnected to the door operator unit points away from the path of travel of the door operator unit and the distance between the point on the end of the cable anchoring arm to which the cable is attached when the arm is in its extreme position and the point on the door operator unit to which the end of the cable is connected is equal to or greater than the length of the cable between said points for all positions of the door operator unit, so the cable is kept in a relatively taut position for all positions of the door operator unit. Also, the distance between the point on the end of the cable anchoring arm to which the cable is anchored and the point where the cable is connected to the door operator unit is, for all positions of the door operator unit, no greater than the length of cable extending between these points so that the cable is not placed under any excessive tension. Moreover, it is preferred that the length of the portion of the flexible cable extending beyond the end of the cable anchoring arm be many times longer than the length of the arm. The cable anchoring arm described above is such that the cable is kept in a relatively taut condition by the spring urged arm for a wide range of door operator unit positions located a substantial distance in both directions beyond a line extending from the pivot point of the cable anchoring arm perpendicular to the path of travel of the door operator unit.

The above and other advantages and features of the invention will become apparent upon making reference to the specification to follow, the claims and the drawings wherein:

FIG. 1 shows the inside of the garage provided with a garage door operator unit and the cable tensioning apparatus of the present invention;

FIG. 2 shows a side elevational view of the apparatus shown in FIG. 2;

FIG. 3 is an end elevational view of the apparatus shown in FIG. 2;

FIG. 4 illustrates different positions of the door operating unit and cable tensioning apparatus illustrated in FIGS. 1 and 2; and

FIG. 5 is a perspective View of the combination junction box and cable tensioning apparatus forming the preferred embodiment of the invention illustrated in FIGS. 1 through 4.

FIG. 1 shows, in part, a garage door operator system installed in a garage having a garage door 1 which rides on side tracks 3, only one of Which is shown. The means for closing and opening the garage door comprise a door operator unit 5 having a carriage arm 4 which connects to the garage door at one end. The housing 7 is movably supported on a guide rod 8. The housing 7 includes a garage door drive motor (not shown) which, when energized, will cause a drive wheel .to frictionally ride along the guide rod 8 and thus cause the entire housing 7 to move along the guide rod 8. As the housing 7 moves on the guide rod 8, the carriage arm 4- attached thereto will move the garage door 1 along with it. When the housing 7 reaches one extreme position, a limit switch operating arm 9 will engage a stationary flange 10 and stop the motor, the housing 7 and garage door 1 coupled thereto. In the other extreme position of the housing 7, a limit switch operating arm (see FIG. 2) like the arm 9 will engage a flange 10' similar .to flange 10 to operate a limit switch causing de-energization of the motor.

The housing 7 includes, in addition to the motor, various other equipment such as an operator circuit (not shown in FIG. 1) which controls the operation of the garage door drive motor, and also, if desired, an electric lamp 6 extending from the housing 7. The lamp 6 preferably is automatically turned on when the garage door is in its fully open position and remains lighted several minutes after the garage door returns to its fully closed position.

The garage door drive motor may be of a type where the motor reverses in direction each time it is re-energized. In such case, the motor reverses automatically by a centrifugal switch which sets up a starting Winding thereof in opposite polarity with respect to a running winding thereof each time the motor comes to rest.

The garage door operator unit is actuated from the vicinity of the garage by manual push button switch 11 shown mounted on the wall of the garage. A pair of conductors 12 extend from the switch 11 to a junction box 17 mounted on the ceiling 18 of the garage.

The junctionbox is mounted a substantial distance on one side of the guide rod, preferably opposite the portion of the rod 8 over which the door operator unit moves when it is in the central portion of its path of travel, as illustrated in FIG. 4. A source of energizing voltage for the motor in the door operator unit housing 7 is also connected to the junction box 17 by conductors 12' in a conduit which terminates within the junction box.

A flexible cable 23 containing conductors connected to the

aforementioned conductors

12 and 12 extends from the junction box 17 to the door operator unit 5. As the door operator unit moves from the extreme left hand position shown in FIG. 1 where the garage door 1 is in its fully closed position to the extreme right hand position where the garage door 1 is in its fully open position where it extends horizontally along the upper portion of the garage, the flexible cable 23 assumes a variety of positions. For safety purposes, it is necessary that the flexible cable 23 be kept in a substantially taut position out of the path of travel of the garage door 1. As previously indicated, the present invention deals with the cable tensioning apparatus which keeps the flexible cable 23 in a taut position. The cable tensioning preferred'apparatus shown in the drawing will be described later on in the specification.

When the user desires to open the garage door, he presses the manual push button switch 11, whereupon the drive motor in the housing 7 becomes energized and effects movement of the housing 7 to the right which raises the garage door. When the door reaches the end of its path of travel, the aforementioned limit switch shuts off the motor. When the manual switch 11 is depressed again, the garage door drive motor becomes energized again and moves the housing 7 to the left which lowers the garage door. The aforementioned limit switch automatically terminates the operation of the motor when the garage door is completely closed. Depression of the push button switch 11 during movement of the garage door between its extreme position will stop the garage door drive motor. Also, a safety switch (not shown) is provided which will stop the garage door drive motor if a force is applied against the door tending to stop its movement.

If desired, a radio receiver unit 24 may be mounted in conjunction with the manual operable switch 11 on the side of the garage, which receiver unit receives radio signals from the users automobile indicating the need for a door opening or door closing operation. These radio control signals will effect the generation of signals on the conductors 12 identical to the signals developed by the depression of the manual push button switch 11.

The means for maintaining the flexible cable 23 taut for the various posit-ions of the door operator unit 5 to which it is connected includes a cable anchoring arm 25 which is preferably pivotably mounted to a bracket 27 extending from a side of the junction box 17. The arm 25 is at an elevation preferably slightly below the top surface of the junction box 17 which rests against the ceiling 18. The inner end of the arm 25 has a depending portion 29 passing through aligned apertures in a pair of flanges 31-31 of the bracket 27. A coil spring 34 is coiled around the depending portion 29 of the arm 25 and has one end 34a abutting part of the bracket 27 and another end 3412 looped around the arm 25. The spring 34 urges the arm 24 into an extreme position shown in FIG. 5 where the arm contacts a portion of the junction box. The junction box is oriented so the free end of the arm 25 points away from the direction of travel of the door operator unit 25 which is coextensive with the guide rod 8.

The inner portion of the flexible cable 23 preferably extends generally horizontally from the junction box 17 at a point near the pivot axis of the arm 25 to the end of the arm 25 where it is anchored in any suitable way as by a strap 36 which loops tightly around the flexible cable 23 and is anchored by screws 38 or the like to the end of the arm 25. The flexible cable 23 preferably enters the junction box 77 in the vicinity of the pivot axis of the arm 25 because a minimum amount of slack is then required in the portion of the cable extending between the junction box and the end of the arm 25 to enable the cable to follow the various positions of the arm 25 as it is pivoted between its extreme positions P1 to 4 (FIG. 4).

The flexible cable 23 extends a substantial distance beyond the point where it is anchored to the end of the arm 25, so that the cord tensioning arrangement of the invention can accommodate a wide range of movement of the door operator unit 5, so the combination junction box 17 and the cable anchoring arm 25 is usable with a wide variety of garage door installations. For the particular length of the cable shown in FIG. 4, the extremes of movement of the door operating unit 5 which can be accommodated is illustrated in FIG. 4.

In position P1, the arm 25 pivots toward the door o-p- As the door operator unit 5 moves to the left to close the garage door, the flexible cable 23 is first moved into a position where it is perpendicular to the guide rod 8. To accommodate this angularity thereof, the arm 25 pivots clockiwi-se into a position P2. where it is rearward of position P1. As the door operator unit 5 continues to move to the left, the arm 25 pivots counterclockwise to assume a position P3. The door operator unit 5 moves further to the left reaching an extreme left hand position where the garage door is fully closed and the arm 25 pivots counterclockwise to an extreme position P4 where it points toward the door operator unit 5 and the entrance to the garage. It should be noted that the arm 25 can pivot over degrees from an extreme clockwise position where it abuts the side of the junction box. This position of the arm is not possible with the arrangement of FIG. 4 until the cable is disconnected from the door operator unit.

It should be understood that numerous modifications may be made in the most preferred form of the invention described above without deviating from the broader aspects thereof.

I claim:

1. In combination with a door mounted for movement between a substantially vertical fully lowered position and a substantially horizontal fully raised position spaced below the ceiling of an enclosed space whose entrance is opened and closed by the door, and door operating apparatus including guide means at the top of the enclosed space and a door operator unit supported on said guide means for movement between given forward and rearward limits and including electrical means for controlling the movement of the door operator unit along said guide means and means connected between said housing and said door for positioning said door in said fully lowered position when said door operator unit is at said forward limit and for positioning said door in said fully raised position when said door operator unit is at said rearward limit, and a flexible cable including electrical conductors extending to the electrical means in said door operator unit for carrying current thereto, the improvement comprising cable tensioning means for keeping said cable relatively taut so the cable does not catch on the door as it is moved between said fully opened and closed positions, said cable tensioning means comprising a substantially horizontal cable attachment arm mounted laterally opposite the path of travel of said door operator unit for pivotal movement about a vertical axis and having a free end to which an inner portion of said flexible cable is anchored, the cable extending tautly between said free end of the arm and said door operator unit, and spring means for urging said arm into an extreme position where the free end of said arm points away from the path of travel of said door operator unit, the arm being free to pivot toward said path of travel against the force of the spring, the distance between the point on the end of said arm where the cable is anchored thereto when the arm is in said extreme position and the point on said door operator unit to which it is connected being greater than the length of the cable extending between said points for all positions of the door operator unit between said limits, where in the arm swings from said extreme position toward said path of travel and the cable is kept under tension by the return force of said spring means on said arm.

2. The combination of claim 1 wherein said cable attachment arm is mounted in the space above the path of travel of said door in said enclosed space.

3. The combination of claim 1 wherein said cable attachment arm has a length which is only a small fraction of the length of said flexible cable extending beyond the free end of said arm.

4. The combination of claim 1 wherein said cable attachment arm is positioned laterally opposite the middle region of the path of movement of said door operator unit, and the door operator unit when at its forward and rearward limits being respectively a substantial distance on opposite sides of a transverse line extending between the pivot axis of said arm and. the path of travel of the door operator unit.

5. The combination of claim 2 wherein there is further provided a junction box mounted at the top of said en closed space, conductors to be connected to the conductors of said flexible cable extending to said junction box and making connection therein to the latter conductors, the inner portion of said flexible cable extending from said junction box to the end of said cable attachment arm with a small amount of slack so it does not extend into the path of travel of said door.

6. The combination of claim 5 wherein said flexible cable extends from said junction box at a point near the pivot axis of said cable attachment arm.

7. The combination of claim 1 wherein said cable attachment arm is pivotable from said extreme position toward the path of travel of said door operator unit against the return force of said spring means over an angle at least in the neighborhood of about 180 degrees.

8. A combination cable tensioning and junction box unit for a flexible cable of conductors to extend between the junction box and a door operator unit which moves along the ceiling of an enclosed space between extreme forward and rearward positions where a door connected tothe door operator unit is respectively in a fully closed and a fully opened position, said combination cable tensioning and junction box unit comprising: a junction box to be secured to the ceiling of said enclosed space, a cable attachment arm extending horizontally from said junction box and mounted thereon for pivotable movement about a vertical axis between a first extreme position where the free end of the arm points in a first given direction and a second extreme posit-ion where the end of the arm points generally in the opposite direction from said first given direction, spring means urging said cable attachment arm into said first extreme position, and a flexible cable of conductors to make electrical connection to said door operators unit, one end of the conductors of said flexible cable extending from said junction box to a point near the free end of said cable attachment arm, the cable having a free end portion extending beyond the point where the cable is attached to the end of said arm where it can make connection to said door operator unit.

9. The combination of claim 8 wherein said cable attachment arm has a length which is only a small fraction of the length of said flexible cable extending beyond the free end of said arm.

References Cited UNITED STATES PATENTS 1,952,681 3/1934 Peelle 49-358 1,980,303 11/1934 Thompson 49--200 2,703,236 3/1955 Verdier -188 3,240,484 3/1966 Klamp 49-358 X DAVID J. WILLIAMOWSKY, Primary Examiner. DENNIS L. TAYLOR, Assistant Examiner.