US2347770A - Counterbalanced overhead door - Google Patents

Description

May 2 1944 A. s. D'Au-rRr-:MoN'r 27,347,770

COUNTERBALANCED OVERHEAD DOOR Filed F'eb. 25, '1942 2 sheets-sheet' 1 INVENTOR 4. 5.9 WUT/PEMONT.

BY Why@ ATTORNEY Patented May 2, 1944 UNITED STATES PATENT GFFICE COUNTERBALANCED OVERHEAD DOOR Adelbert S. DAutremont, Kernville, Calif.

Application February 23, 1942, Serial No. 431,970

(ci. 2cv- 16) I 11 Claims.

The invention relates to the mounting and control of a door to be swung between an upright closed position and a generallyhorizontal overhead open position with respect to a door opening, doors so positionable being commonly referred to as overhead doors.

An object of the invention is to provide an overhead door with a counterbalance means which minimizes the effort required to open and close the door while providing a gravita] resistance against a displacement of the door from either its closed or open position as the primary means for retaining the door in either position.

Another object is to provide a counterbalance means of the character described which is carried entirely on the door structure in unitary association therewith.

A further object is to provide a combined door mounting and counterbalancing structure which is adjustably applicable as an attachment to door structures of different weights and sizes without requiring alterations of either structure.

An added object is to provide a particularly simple and effective door counterbalance means of the character described which solely utilizes a counterweight as the control means.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth or be apparent in the following description of typical embodiments thereof, and in the accompanying drawings, in which,

Figure 1 is a fragmentary plan and partly sectional view showing the mounting and counterweight device of my invention applied to a. door which is disposed in closing relation to a door opening of a building.

Figure 2 is a sectional elevation taken at 2-2 in Figure 1.

Figure 3 is a fragmentary view taken at 3--3 in Figure 2.

Figure 4 is an enlarged fragmentary section taken at |-4 in Figure 2.

Figure 5 is a longitudinal upper side view of a stop arm of the device.

Figure 6 is an elevation taken as Figure 2, but showing the door in fully raised position.

Figures 7 and 8 and 9 are fragmentary elevan tions showing the door unit in progressively lowered positions thereof with respect to its position'in Figure 6, with Figure 9 disclosing a modied structure for the stop arm and a cooperative counterweight support.

As particularly illustrated, the device of my invention is applied to a door Ii which is mounted in operative relation to a doorway opening I2 provided in a wall I3 for controlling access to a space I4 having a floor I5 and a side wall I6. The structure of the present door I I includes a suitable panel I1 mounted for its swinging through the'opening and upwardly to a substantially horizontal open position for the door, and the disposal of its upper end portion behind and against an upper door frame member I8 when the door is in closed position behind the opening. In the present instance, a second door opening l2 to the space I4 is provided beside the opening I2 for its closure by another door. 'I'he space I I may be used as an automobile garage, or i'or other purposes, and the wall I3 may be either an outside or inside wall of a building; for descriptive convenience, however, the space I4 will be considered as being at the inner side of said wall.

A swingingA support of the present door Il is provided by means of brackets I9 xed to the door structure at its back and adjacent the side door edges and having hinged connections with iixed support elements to providefor the swinging of the door between limiting closed and open positions thereof about a flxed horizontal axis spaced from the inner door side and parallel to the door. As shown, mutually aligned pivot pins 2l mounted on support members 22 and 23 engage in bearings 24 provided by the brackets I9. In the present instance, the outer face of the door is arranged to engage the under face of the frame member I8 as a stop when the door is fully opened to the horizontal overhead position shown in Figure 6, and the same door face is arranged to engage the rear face of the member I8 as a stop when the door is in its fully closed position shown in Figures 1 to 3. For providing the foregoing pivotal relations, the pivotal axis for the door is provided at the same distance from the level of the under face of the door frame member I8 as is the distance of the axis from the frameengaging (outer) face of the door; as shown, said distance is approximately one-fourth of the height of the doorway opening.

In the present structure, the brackets I9 are triangular and comprise cotermlnus and angularlyy related members 25 and 26 arranged for the xing of their free ends to the door in upright lines, and having the bearings 24 provided in the parts 25 adjacent the bracket points. As is brought out in Figure 4, the present pivot pins 2i extend integrally from base-plates 21 xed to the supports 22 and 23. and the bearing portions of the bracket members 25 are secured right element disposed as a studding in the wall I5, while the support member 23 comprises a free post which is disposed opposite the center of the front wall portion between the openings I2 and I2', and extends upwardly from the floor I5.

' This arrangement, while providingl the widest possible free space behind the doorways, as is desirable, requires support bracket structures which dispose thel support bearings laterally of the doors for engaging the ilxedly mounted pivot pins without preventing the extension of approximately the lower half voi the door beyond the doorway when thedoor is fully open (Fig. 6), and the brackets I9 are so lformed and mounted as to meet these conditions.

Referring more particularly to the structure of a present bracket '|3,it. will be noted that the upper members 25 thereof are straight and are arranged to extend substantially perpendicularly from the door, while the sloping lower elements 28 are formedvwith lateral offsets such that the required extension of the opened door is' 'permitted while the pivot bearings 24 of the member 25 are disposed to receive the fixed support pins 2I at points laterally beyond the door panel I1. To provide the foregoing relation, a crossmember 3| of appropriatelength is provided at the back of the door to mount the base ends of the bracket members 25 at such points with respect to the door that'the fixed pins 2l may mount the door in its appointed place. As shown, a cross-member 321s mounted at the back of the panel and has the base ends of the bracket members 23 fixed thereto. The cross-member 3i neee!` extend beyond the door panel at either side edge only as necessary for the engagement of the bearing of the mounted bracket with the corresponding flxed pin, and no extension of the cross-memrn ber 3| would be needed if the pin is disposed directly behind the panel, the present bracket structure with the lateral oiTset in its lower portion 26 still, however, being usable. It will be understood that the installed cross-members 3i and 32 comprise parts of the door structure, even if they are added merely to provide attachment points for the brackets.

With the unitary doorand-bracket structure so far described, it will be evident that the center of gravity thereof will be disposed forwardly of its pivot axis for the limiting closed and open and all intermediate positions thereof, whereby the door will be constantly urged to retain a closed position and therefore must be positively held if it is to remain in an open position against the influence oi.' gravity. In accordance with my present invention, said unit is arranged to be counter-weighted in such a manner and by such means that it is gravitally urged to retain either limiting position, while the eii'ort required to shift the door between its open and closed positions is minimized. The aforesaid counterweight means essentially comprises a novel mounting of one or more counterbalance weights, or countermounts it, is rigidly related to the door.

weights, 33 on the door for their automatic functioning to accomplish the described purposes.

As shown, and for mechanical balance, duplicate installations of counterweights 33 may be provided adjacent the different side edges of the doors whereby each counterweight, may, in effect, function in the control of the gravity relations for the adjacent half of the door. For descriptive convenience, the arrangement may, however, be described and claimed in terms of one counterweight, as if e. counterweight is provided at but one side of the doorway or as if the two shown are parts of a single one. Essentially, each counterweight 33 is supported at the lower end of a support means swingably depending from a top point of the door at its back, and a, means is provided for such coaction with the swinging support that the effective line of action of the weight 33 is so confined to a. fixed zone behind the pivot axis of the door as to constantly urge an opening movement of the door against the contrary urge of the weight of the door assembly per se. As particularly illustrated in Figures 1 to 8, the latter meanscomprises a pair of mutuallyY spaced stop members 35 and 36 mounted on the door and disposed in the path of possible swinging of a flexible support element 34 under the action of gravity as the door is swung between its limiting positions, it being noted that the line of action of the countersfeight is the perpendicular line of the support element below a stop which bends it or the line of the element while it is straight.

Although the stop members 35 and 36 may be mounted directly on the back of the door in their appropriate positions, the brackets I9 of the present door mounting may conveniently mount them, with a resultant saving of material and the avoidance of additional attachment points on the door. As illustrated, an arm 31 mounting the stops 35 and 33 `is xed to a bracket member 26 as a rearward land upward continuation or extension thereof, said stops being preferably adjustable along the arm which, with the bracket I9 which In its present form, each arm 31 comprises similar bars or plates 38 having their forward ends rigidly fixed against opposite sides of the bracket member 25 and secured in mutually parallel relation by means of a spacer block 39 fixed between their 85 between them in said space which is arranged to rearward ends. 'I'he stops 35 and 36 comprise cylindrical elements adjustably xed in the elongated space 4I between the bars 3B and freely receiving the flexible weight suppOrt element 34 function -as a guideway for the element thereat.

In the present structure, the bars 38 of the arm 31 are provided with mutually opposed transverseslits 42 along their lengths for receiving the ends of bolts 43 which extend axially through the stop members 35 and 36 and for tightening to secure the stops in adjustably set positibns on the arm. The pivot connection for securing the upper end of the support element 34 to the door near its top is provided by a member 44 xed to the end of a cross-member 45 of the door mounted adjacent the door top, and, in the present instance, extending laterally beyond the door panel as does the cross-member 3i; in this manner, the element 34 may move in the plane of swinging of the arm 31 during an opening or closing movement of the door, the counterweight also being disposed in said plane. Noting that the distance from the connection 44 to the fixedly secured stops 35 and 36 are constant, whereby vide for the free suspension of the counterweigh't below an engaged stop as in Figures 2 and 9 and 6, or directly from the top connection 44 as in Figures '1 and 8. Except for the showing of Figure 9, the support element 34 is assumed to comprise a flexible rope providing an eye 41 at which the counterweight 33 is connected. In Figure 9, an alternative structure is shown having the arm 31' thereof corresponding to the described arm 31 and so extended from the bracket that the` ends of its guide-way 4l are ai? equal distances from the axis of pivoting at the connection 44 at which the upper end of a rigid rod 34' is hingedly mounted. The lower end of the support member 34 provides a weight-mounting eye 43 which is at or below the contact point of the rod with the stopsu35 and 36 adjustably mounted on the arm 31 Kas on the arm 31; the arrangement is such that when, as shown, the eye 48 is relatively close to the stops`35 or 36 engaged by the member 34', the control action of the counterweight 33 will correspond to that provided by the support'34. As particularly illustrated, each counterwelght 33 comprises a cylindrical bucket-like container 52 having a supporting bail 53 swingably engaging through the eye 41 of the element 34 or through the eye 43 of the element 34 to provide a flexible connection thereat; the bail 53 and rod 34 are understood to provide the operative equivalent of the flexible connection provided by the flexible member 34 per se.

Since the counterweight mass required may vary for different door structuresy the lower portion of the container 52 may contain a permanent filling 54 of heavy material such as concrete or a heavy metal, while the top portion o1' the container cavity receives additional free weight elements 55 as required; in this manner, the mass of the counterweight is arranged to be adjusted for each particular installation ot the present counterbalance assembly. It will be noted that the present counterweight suspension and control device, which provides for the disposal of the counterweight in the plane oi' movement of the bracket member 25 and the stop-carrying arm 31 or 31', is also such that the extreme vertical movement of the counterweight as the door is swung between its limiting closed and open positions is relatively small, being much less than the height of the door; in this manner, the installation may be made in an existing space behind the door and occupies a portion of the space which is of least value,

Noting, by reference to Figures 2 and 9 and 8, that it is the action of the stop 35 against a counterweight suspension element which prevents the line of action of the mounted counterweight moments are equal only when the door is in an intermediate position of unstable equilibrium at which the center of gravity of the unitary doorand-counterweight assembly is in said plane and above said axis. Having the mass of the counterweight and the position of the stop 35 appropriately adjusted, the counterbalancing action thus provided is arranged to so minimize the effective action of gravity to urge a swinging of the unit that a relatively small resistance is offered to a movement of the door toward said intermediate position of unstable equilibrium from either of its limiting positions; in this manner, the present door, being completely counterbalanced only when in an intermediate position thereof, may be manually swung to said position by the exertion of relatively small and adjustably predetermined efforts. To facilitate such manual swinging of the door from the limiting positions thereof which it is gravitally urged to maintain, handles 56 may be provided on the inner and outer sides of the door adjacent its bottom edge.

When the door is in its fully closed. position shown in Figure 2, each stop 35 engages the weight suspension element 34 at a point 'above the level of the fixed pivotal axis while the center of gravity of the unitary door-and-bracket per se is below said level and in or adjacent a plane including the top point of the vertical portion of the weight SliDpOrt element and said axis; the exact location of said center of gravity is, of course, variable in accordance with different door-and-bracket structures and determines the best counterweight mass and the best position for the stop 35 on the arm 31 (or 31') for providing the degree of counterbalance desired. As the door is swung toward its open position, the stop 35 moves downwardly while the said center of gravity moves upwardly, both in arcuate paths about the pivotal axis for the door; in this manner, the counterbalance relation existing when the door is in closed position is substantially maintained as long as theelement 34 engages the stop 35. When the door reaches the position shown in Figure 9, wherein the stop 35 is operative in a horizontal plane through the pivot axis, the line of action of the counterweight 33 is furthest from said axis, and said center of gravity is at least approximately at its furthest horizontal distance from said axis.

As the door is swung from closed position to and through the position shown for it in Figure 9, the resulting rearward movement of the connection point for the weight support element 34 finally disposes the point in the position shown in Figure 8 wherein the element is straight and vertical to directly and fully support the weight from said point. 'I'he continued opening movement of the door permits the movement of the element 34 outwardly in the guide space 4| for its ultimate contact with the outer stop 3,6, as is shown in Figure 7, it being noted that the horizontal distance of the line of action of the counterweight from the pivot axis automatically increases as the door is raised between the positions of Figures 8 and 7 therefor. During this vportion of the door-raising movement, the unit passes' through its position of unstable equilibrium whereby the moment of the counterweght thereafter prevails over the moment of the door mass to urge a further opening of the door with a progressively increasing effectiveness.

The outer stop 36 is preferably so positioned on its supporting arm that the possible rearward movement of the counterweight is limited thereby to decrease the door-closing force which would otherwise be required when the door is in its fully open position shown in Figure 6. In Figure 7 the door is shown in the position thereof at which the weight-supporting element 3d irst engages the adjustably positioned stop Se as the door is being opened, it being understood that the stop 36, by reason of its arcuate forward movement serves to draw the weight 33 forwardly as the door opening operation is completed and thereby reduces the effectiveness of the door-opening urge resulting from the then dominating action of the counterweight; the latter is predetermined and adjustably varied byappropriately adjusting the stop 36 along the door-carried arm which mounts it. When the opened door is to be closed, the control effects of the described counterweight device are, of course, reversed in direction and their order.

From the foregoing description taken in connection with the accompanying drawings, the advantages of the construction and method of operation will be readily understood by those skilled in the art to which the invention appertains. While I have described the features and the principles of operation of structures which I now consider to be preferred embodiments of my invention, I desire to have it understood that the showing is primarily illustrative, and that such changes may be made, when desired, as fall within the scope ofthe following claims.

I claim:

l. In a device for counterbalancing a door which is mounted for its swinging between a limiting upright closed position at a doorway opening and a limiting overhead horizontal open position about a fixed horizontal axis which is transversely spaced from a door side and parallel to the door, a counterweight, a suspension member supporting said counterweight from a top point of the door for its swinging movement with respect to the door as the door is moved about said axis, and means carried bythe door in xed relation thereto and directly cooperative with said suspension member to so limit the swinging movement of the counterweight with respect to the door that the line of action of the counterweight is maintained at the opposite side of said axis from the opening while the door-andcounterweight assembly is arranged for its swinging about said axis through a position of unstable equilibrium with respect to said axis at a door position between said limiting positions ci the door.

2. In a device for counterbalancing a door which is mounted for its swinging between a lim,- iting upright closed position and a limiting overhead horizontal open position about a xed horlzontal axis which is transversely spaced from a door side and parallel to the door, a counterweight, a suspension member swingably supporting said counterweight from a top point or the door for its swinging with respect to the door and disposed opposite the same side of the door as is said axis, an arm extending from the door in flxed relation thereto, and a stop means on the: arm operative against said suspension member to maintain the line of action of the counter- Weight at the opposite side of said axis from the door for all permitted door positions.

3. In a device for counterbalancing a door which is mounted for its swinging between a limiting upright closed position and a limiting overhead horizontal open position about a xed horizontal axis which is transversely spaced from a door side and parallel to the door, a counterweight, a flexible suspension member swingably supporting said counterweight from a top point of the door` and disposed opposite the same side of the door as is said axis, an arm extending from the door in fixed relation thereto, and a stop member carried by the arm for its adjusted spacing with respect to said axis and operative against said suspension member at the door side thereof and at a point further from the said door side than is said axis for the bending of the suspension member about it to limit the movement of the line of action of the counterweight toward the door as the door is closed.

4. In a device for counterbalancing a door which is mounted for its swinging between a limiting upright closed position and a limiting overhead horizontal open position about a fixed horizontal axis which is transversely spaced from a door side and parallel to the door, a counterweight, a flexible suspension member swingably supporting said counterweight from a top point of the door and disposed opposite the same side of the door as is said axis, an arm extending from the door in xed relation thereto, and a stop member carried by the arm for its adjusted spacing with respect to said axis and operative against said suspension member at the opposite side thereof from the door to limit the movement of the line of action of the counterweight from the door as the door is opened.

5. In a device for counterbalancing a door which is mounted for its swinging between a limiting upright closed position and a limiting overhead horizontal open position about a fixed horizontal axis which is transversely spaced from a door side and parallel to the door, a counterweight, a suspension member swingably supporting said counterweight from a top point of the door for its swinging with respect to the door and disposed opposite the same side of the door as is said axis, an arm extending from the door in fixed relation thereto, and stop members on said arm cooperative with said suspension member to so limit the swinging of the counterweight with respect to the door as to confine its line of action to a limited zone at the opposite side of said axis from the door.

6. A structure in accordance with claim 5 hav-- ing the stop members independently adjustable with respect to the door for varying their effectiveness with respect to the suspension member.

7. A structure in accordance with claim 5 having the suspension member bendable adjacent a stop member operatively engaging it, whereby the portion of the member below the stop member deiines the line of action of the counterweight.

8. A structure in accordance with claim 5 having the stop members disposed at substantially equal distances from the axis of swinging of the suspension member and having the latter member comprise an inflexible element having a hinged connection with the counterweight at a point below the point of contact of the diierent stops with the member.

9. In a means for mounting and counterbalancing a door for its swinging on ilxed bearing elements between `a limiting upright closed position and a limiting overhead horizontal open position, brackets on the door providing bearing elements cooperative with said fixed bearing elements to ei'ect the support of the door for its swinging between the aforesaid limiting positions therefor and about a xed horizontal axis which is transversely spaced from a door side and parallel to the door, a counterweight, a suspension member swngably supporting said counterweight from a top point of the door, an arm extending rigidly from a said bracket, and a stop member carried by said arm for such cooperation with the' suspension member as to stop the swinging of the member with respect to the door before the door reaches a said limiting position thereof.

10. In a means for. mounting and counterbalancing a door for its swinging between a limiting upright closed position with respect to a doorway opening which is opposite a space extending laterally of the opening and a limitingpverhead open position with respect to the opening in which position a lower portion of the door is arranged to extend through the opening from said space, mutually aligned pivot bearing part'silxed at the sides of the space and defining a horizontalfpivotal axis which is parallel to the plane of the opening, brackets providing bearing parts for simultaneously and cooperatively engaging the fixed bearing parts, means xing the brackets to the door for the simultaneous operativel engagement of their bearing parts with the fixed bearing parts to provide for the swinging ofy the door and brackets about said axis, a counterweight, a suspension member for swingably supporting said counterweight, means for pivotally attaching said suspension member to an upper door point in the plane of swinging of a said door-carried bearing part which is disposed laterally of the doorway opening, an arm extending from the door in iixed relation thereto, and a stop member xediy positioned on said arm and operative against an intermediate point of the 'suspension member in the latter plane to stop the swinging with respect to lthe door of the portion of the member between its attachment point and the latter point before the door reaches a said limiting position thereof toward which it is moved. I f

11. A structure in accordance with claim 10 having the stop-supporting arm carried directly vby the bracket, and having the suspension member comprise a laterally flexible element whereby the' portion of the member below said stop mem- `ber deilnes the line of action of the counterweight andthe counterweight and the suspension member and the point of attachment of the suspension vmember all lie in said plane includling the bearing part of the bracket. y

i v ADEIIBERT D'AUTREMONT.

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