US 3429072 A
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Description (OCR text may contain errors)
FebZS, 1969 Filed July 14, 1967 FIGJ FIG.5
0 2 2 4 1/; M Z a w M A b w E K M I. M 4 J r 4 y M United States Patent 2 Claims ABSTRACT OF THE DISCLOSURE The specification describes a novel coiled spring and safety cable assembly employed as part of the actuating and over-center mechanism of a door opening mechanism of a kind suitable for use in operating overhead doors, such as garage doors.
The safety cable extends from a point at the exterior of the elongated coiled spring and is threaded between adjacent coils at one end of the spring into and along the interior of the latter. At the other end it is threaded between adjacent coils to the exterior of the spring. The portion of the cable which is disposed within the spring has a length not less than that of the portion of the spring which lies between the point of entrance and emergence of the cable when the spring is stretched in maximum degree. The cable has dimension, at the point of entry into and emergence from the interior of the spring, sufiiciently great to insure that the cable Will be pinched between the adjacent coils of the spring through which it is threaded in any degree of extension of the spring including maximum extension.
This invention relates to improvements in coiled spring assemblies generally and, more particularly, it relates to coiled spring assemblies of the type that are used in garage door closing mechanism.
An object of the invention is to provide a coiled spring assembly which will be less dangerous in the event the spring is broken. While not limited thereto, the invention is advantageously employed in connection with overhead door operating mechanisms that incorporate coiled springs. Accordingly, another object of the invention is to provide an improved coil assembly for use in such door operating mechanisms and to provide improved mechanisms for that purpose, particularly for garage doors.
Several classes of garage door openers or operating mechanisms incorporate elongate coiled springs. They are employed in the overhead track mechanism often associated with horizontally sectioned garage doors. Another example is the combination hinge and over-center operating mechanism often employed with single section overhead doors. Most door mechanisms employing elongate springs operate so that the spring is stretched when the door is closed. The arrangement of the combined hinge and over-center type is such that the spring is subjected to a relatively great amount of extension when the door is closed whereby its coils contain a large quantity of potential energy when the door is closed and spring breakage is not an uncommon occurrence. If such a spring should break, the likelihood is great that its pieces will be propelled with great force giving rise to the possibility that substantial injury to persons and property may occur. It is an object of the invention to provide a simply installed, inexpensive, but highly effective arrangement for precluding propulsion of the spring parts on the occasion of such spring breakage.
These and other objects and advantages of the invention which will hereinafter appear are realized in part by the provision of a coiled spring including coils at the region of its ends connected by additional coils and adapted for extension in selected degree such that suc- 3,429,072 Patented Feb. 25, 1969 cessive coil-s are spaced apart from one another, and by provision of an elongate and flexible retaining member having lateral dimensions exceeding such spacing and having portions pinched between coils of the spring in the region of both ends of the spring. The retaining member is made to extend interiorly of such spring through the coils between the end regions and exteriorly of said spring in those regions at each end of the spring.
A single embodiment of the invention is illustrated in the accompanying drawings. It is to be understood that various modifications may be made in this embodiment and that other embodiments are possible without departin g from the spirit of the invention.
In the drawings:
FIGURE 1 is an isometric view of a garage door operating mechanism of the hinge and over-center type mounted upon a fragment of a garage door and door frame shown in the garage door closed position;
FIGURE 2 is an isometric view of a fragment of the upper end of the mechanism of FIGURE 1 illustrating how the safety member is assembled with the mechanism and the coiled spring;
FIGURE 3 is an isometric view of a portion of the lower end of the coiled spring of FIGURE 1 showing how the safety member is assembled with that end;
FIGURE 4 is an isometric view of a fragment of the lower end of the door operating mechanism showing the spring in relaxed condition and showing how the lower end of the safety member is assembled with the garage door frame;
FIGURE 5 is a view in side elevation of the door operating mechanism as it is assembled on the door and frame and as it appears in the door closed position; and
FIGURE 6 is a view in side elevation of the door operating mechanism shown in the door open position.
Referring to FIGURE 1 of the drawings there is shown a fragment of a garage door designated by the numeral 10. The numeral 12 designates a fragment of the garage wall and the numeral 14 designates a fragment of the frame which defines the garage door opening. Means are provided for swinging the door up overhead relative to the door frame .14. This means may comprise, and in the form of door operating mechanism selected for illustration in the drawings it does comprise, an elongate angle iron 15 extending parallel to the side edge of the garage door on the inside face of the door. The angle iron is secured to the door by any convenient means such, for example, as by a series of screws 16. One face of the angle is flush against the door and the other face of the angle extends rearwardly from the door on the side of the angle toward the door edge spaced slightly from the edge and from the frame 14 of the garage door opening. The rearwardly extending portion of the angle iron 15 is designated 18 in the drawings.
The mechanism employs two brackets. One, the door bracket 20, is secured to the door, and the other, the frame bracket 22, is secured to the garage frame 14. Bracket 20 is shown as a triangular plate whose base is secured, by any convenient means such as bolts 24, to side 18 of the angle iron 15 such that the plate 20 extends rearwardly of the door in parallel with side -18.
Bracket 22 is shown to comprise a generally flat plate with one end bent over at a ninety degree angle so that the result is L-shaped. The bracket 22 is secured by any convenient means, as for example by being screwed or bolted, to frame 14 of the garage by its laterally bent portion. The remainder of the bracket 22 extends rearwardly from the frame in parallel with side 18 of angle iron 15 and parallel to the bracket 20.
The angle iron 15 is located so that it is approximately equidistant from the top and the bottom of the garage door. Its placement is not critical. The bracket 20 is located just below the horizontal through the center of gravity of the door. Bracket 22 is located on the frame above bracket 20 at a distance approximately midway between the position that bracket 20 has when the door is closed and the position that it is desired to have, in view of the height which the door is to have, when the garage door is open.
The door mechanism selected for illustration further comprises a pair of arms. One is called the operating arm and is designated by the numeral 30. Advantageously, as shown, it comprises an elongate metal bar having pivotal connection at its lower end in FIGURE 1, by a pivot pin 32 to the rearwardly extending side 18 of angle iron 15 at a point above bracket 20 and above the horizontal through the center of gravity of the door. At a point near the central region of its length, the arm 30 has a pivotal connection by a pivot pin 34 to the uppermost of two pivot points near the rear edge of the bracket 22. The arm continues upwardly and its upper end is provided with a number of spaced perforations 3:6 by which to accommodate hard-ware to be described below. The other arm 38 is subjected to lesser force in operation and may be made of lighter weight metallic bar stock as shown. At is lower end the arm 38 has pivotal connection by a pivot pin 40 to a point near the apex of the triangularly shaped bracket 20. At its upper end the arm 38 has pivotal connection by a pin 42 to the lower-most of the two pivot points near the rear edge of bracket plate 22. Thus both arms have pivotal connection to bracket 22 and both of them are secured at their other ends to hardware carried by the door 10. Since that hardware lies in a plane parallel to the plane of bracket 22 but not coincident with that plane, both arms are provided with offsets, designated 46, in the case of arm 30 and designated 48 in the case of arm 38, so that the ends of the arms are parallel to the hardware to which they have pivotal connection in the region of those connections. In addition, the lower rearward portion of bracket 22 is offset laterally to avoid interference between the upper end of arm 38 with arm 30.
Thus arranged the arms form a parallelogram with the brackets 22 and 20 and the angle iron 15. The corners of the parallelogram are marked by pivot pins 32, 34, 42 and 40. This pivoted parallelogram arrangement permits rotation of the door about the bracket 22 through ninety degrees as illustrated in FIGURES and 6.
The perforations 36 at the upper end of arm 30 are adapted to accommodate hardware which holds one end of a coiled spring generally designated '50 and whose lower end is secured to a point below bracket 20 on frame 14. The spring constitutes a means by which kinetic energy may be stored and used to assist in opening the door against the force of gravity. In addition the spring cooperates with the remainder of the hardware in forming an over-center mechanism which serves to hold the door firmly in vertical position when it is closed. Referring to FIGURES 1 and 2, the upper spring mounting hardware comprises a pair of plates 52 spaced on opposite sides of the arm 30 and having pivotal connection to the arm by a povit pin 54 extending through one of the openings 36 at the upper end of arm 30. The two plates 52 are held spaced apart at a distance slightly greater than the thickness of arm 30 by a nut and bolt 56 and a spacer-washer 58. At their opposite ends the plates 52 are perforated to accommodate a bolt 60 which bridges the space between the plates 52 and forms an anchor rod for the upper end of an S-shaped spring hanger 62. As best shown in FIGURES 1 and 4 a similar spring hanger 64 is employed at the lower end of the spring assambly. Hanger 64 is connected by a short length of chain 66 to a lag screw 68 which is turned into the frame 14.
The coiled extension spring 50 extends between these two S-shaped hangers 62 and 64. At each end of the spring the end portion of the end coil is bent at approximately ninety degrees out of the plane of the coils to form a loop for easy attachment to a loop of the respectively associated S-shaped hanger. In addition the spring 50 may be described as comprising a continuous series of coils about the central axis of the spring. Some of the coils occur in the end regions of the spring adjacent the end loops which are designated 70 in the case of the upper loop and 72 in the case of the lower loop. Other coils of the spring lie between the two end regions. The end regions of the spring are specifically referred to because they are employed in retaining a safety means which comprises part of the coiled spring assembly.
The safety means advantageously comprises, as shown, an elongate flexible member sufficiently strong to hold pieces of the spring from being propelled away in the event that the spring is broken. This safety member, which in its preferred form comprises a metal cable as shown, extends through the coils of the spring. In the event the spring should break it will retain every piece of the spring which is at least one coil in size. Examination of FIGURES 5 and 6 will show that the coil is much longer when stretched in the garage door closed position than it is when the garage door is open as shown in FIGURE 6. One end of the safety cable is secured to the arm 30 and the other end of the cable is secured to the door frame 14. Thus the safety cable must be somewhat longer than the spring is shown to be in FIGURE 5. The distance between the points at which the ends of the cable are connected is substantially less when the door is opened as in FIGURE 6 than when the door is closed as in FIG- URE 5. Thus it is necessary to provide some means by which the excess length of cable, that length of cable which is equal to the difference in the separation between the cable connection points in the door open and door closed positions, will be precluded from becoming tangled in the door closing mechanism. The excess of cable is sufiiciently long to permit its becoming entangled with the bracket 22 or the plates 52 and the several bolts attached to those plates.
The invention provides a means to preclude such entanglement of the safety cable. The upper end of the cable is attached to the arm 30. Advantageously as shown the upper end of the safety cable is provided with a loop by which it is secured by a bolt 82 and nut 84 to the plates 52 just above the nut and bolt '60 to which the S-shaped spring hanger 62 is hung. The other end of the safety cable 86 is provided with a loop 88. This loop and the cable '86 is threaded through the upper end loop of spring 50. This is best shown in FIGURE 2. The end 88 and the cable 86 are then threaded between two loops in the upper end region of the spring and the cable is drawn down through the interior of the spring as best shown in FIGURE 1. Advantageously as shown, the safety cable is threaded back into the interior of the spring between the upper coil 90 and the coil below 92 at the upper end of the spring 50. At the lower end of the spring, as best shown in FIGURES l, 3 and 4, the safety cord or cable is withdrawn from the interior of the spring between two of the coils in the lower end region of the coil. Advantageously, as shown, the safety cable is withdrawn between the lower coil 94 and the next to the lowest coil 96 of the spring 50. FIGURES 2 and 3 illust-rate how an ordinary screw driver may be employed to pry apart the coils to permit passage of the safety cable between them. The screw driver 98 does not form part of the finished assembly.
As best shown in FIGURES l and 4, the lower loop 88 of the safety cable 86 is then passed through the lower loop 72 of the spring and is secured as by a lag bolt and washer combination 100 to the frame 14.
In any given installation the length of the spring, the diameter of its coils and the degree in which it is stretched defines the maximum spacing between successive coils of the spring as it is extended in maximum degree. The safety cable is selected so that its lateral dimension, in this case its diameter, exceeds that maximum spacing between successive coils. The result is that the safety cable is pinched at the upper and lower ends of the spring between those coils of the spring between which it is threaded. Advantageously, in assembling the cable with the spring only so much cable is permitted to extend outside of the spring at its ends as required to make it secure to nut and bolt 82 and 84 at its upper end and to the lag screw and washer at its lower end. The length of the safety cable is selected so that only a little slack remains and that slack is confined within the interior of spring 50. When the door is opened as shown in FIGURE 6 the cable has excessive length as previously described but that excessive length is entirely confined to the interior of the spring and it is not free to tangle with the remainder of the hardware.
As best shown in FIGURES 5 and 6, the spring provides an over-center action in that when viewed from the side as it is in those two figures, the spring lies between pivot pins 32 and 40 in the door closed position and does not lie between them in the door open position. The overcenter action is very slight and occurs in the final degrees of door closing movement. It is sufiicient to insure that the closed door will be held vertically in closed position. Because of this action this spring becomes slightly longer than the length it is shown to have in FIGURE 5 as the door is opened and the pivot pin 40 is moved passed the vertical axis of the spring. It is because of this that the length of the safety cable must be slightly greater than the separation, of the coils between which it is pinched, that those coils have in the door closed position. The coils in FIGURE 1 between the end regions of the coil have been broken away to show that the cable has such slack.
It will be understood by those skilled in the art that in practice two mechanism assemblies like those shown in the drawings are employed, one on each side of the door.
Although I have shown and described certain specific embodiments of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated 'by the prior art and by the spirit of the appended claims.
1. In a door closing mechanism, means for exerting force to maintain the door open or closed including a coiled spring which is stretched in variable degree by being elongated upon opening and closing of said door, and safety means for rest-raining movement of pieces of such spring upon the occasion of its being broken comprising a flexible elongate member extending from a point exterior to said coiled spring between adjacent coils of said coiled spring at one end thereof into the interior of said coiled spring and thereafter along its length and thence between adjacent coils of said coiled spring to the exterior thereof, the portion of said elongate member disposed within the interior of said coiled spring having a length exceeding the maximum length to which that portion of the spring extending between said end coils is to be stretched during operation, the dimensions of said elongate member at the point of entry into and at the point of emergence from the interior to the exterior of said spring being sufliciently great to insure that said elongate member is pinched by said adjacent coils of said spring in any degree of elongation of said spring not exceeding said maximum length.
2. In a door closing mechanism, means for exerting force to maintain the door open or closed including a coiled spring which is stretched in variable degree by being elongated upon opening and closing of said door, and safety means for restraining movement of pieces of such spring upon the occasion of its being broken comprising a flexible elongate member threaded through said spring and means for fixing the ends of said member independently of said spring; said means for exerting force to maintain the door open or closed comprising a hinge adapted for connecting said door to its frame including a first member adapted for connection to said door, a second member adapted for connection to said frame, and a pivot interconnecting said first and second members; said door closing mechanism further comprising an overcenter mechanism including said stretched coil spring and attachment means for connecting opposite ends of said spring onto said door and onto said frame such that said spring is movable from one side of alignment with said pivot when said door is closed upon said frame to the other side of alignment with said pivot when said door is open from said frame and such that said coiled spring experiences maximum stretching as an incident to being moved into alignment with said pivot; a first portion of said elongate member extends between adjacent coils of said spring near one end of said spring into the interior of the spring and there along and thence extends between adjacent coils of said spring at the other end thereof to the exterior of said spring, the portion of said elongate member disposed Within said spring having a length no less than the distance between said pair of adjacent coils of said spring when the spring is elongated in maximum degree and said flexible member having dimensions at the point at which it extends between said adjacent coils of said spring sutficient to urge said adjacent coils apart against the renitence of said spring in any degree of elongation of the latter to said maximum amount whereby said elongate member is pinched between the adjacent coils of said spring through which it extends.
References Cited UNITED STATES PATENTS 803,427 10/ 1905 Monroe 297-275 2,708,525 5/ 1955 Woleslagle 24817 X 1,983,856 12/1934 Johnson 209 X 2,012,336 8/1935 Blodgett 160-209 X 2,139,383 12/1938 Robinson 160191 2,926,727 3/1960 Purdy 160191 X 2,953,928 9/1960 Anderson et al. 160193 X 2,985,446 5/ 1961 Mormont et al. 49-205 REINALDO P. MACHADO, Primary Examiner.
DENIS L. KAYLOR, Assistant Examiner.
US. Cl. X.R.