US2045100A

US2045100A - Overhead door

Info

Publication number: US2045100A
Application number: US630547A
Authority: US
Inventors: David M Robinson
Original assignee: Stanley Works
Current assignee: Stanley Works
Priority date: 1932-08-26
Filing date: 1932-08-26
Publication date: 1936-06-23
Anticipated expiration: 1953-06-23

Description

June 23 1936. I

D. M. ROBINSON OVERHEAD DOOR Fi\led Aug. 26-, 1932 4 Sheets- Sheet l gwwhac JUNE 23, D M ROBINSQN I OVERHEAD DOOR Filed Aug. 26, 1952 4 Sheets-Sheet 2 l )gwmwtoz 0mm Mfiobmaan June 23, T1936. D ROBINSQN 2,@45,110

OVERHEAD DOOR Filed Aug. 26, 1932 {Sheets-Sheet 5 June D M ROBINSON I OVERHEAD DOOR Fild-Aug. 26, 1932 4 Sheets-Sheet .4

rear of the door in taken substantially on line Patented June 23, 1936 UNITED STATES 2,045,100 OVERHEAD DOOR David M'. Robinson, to The Stanley corporation of New Britain, Com, assignor Works, New Britain, Conm, a Connecticut Application August 26. 1932, Serial No. 030,547

11 Claims.

This invention relates to doors, and specifically refers to doors of the type adapted to be moved from a closed vertical position in the doorway to an open overhead positio As an instance of a use to which doors constructed in accordance with the present invention may be applied, reference may be had to garages, but it is understood-that my improvements are not limited to that specific application, the improved structure being also applicable to pier sheds, factories, etc.

The object of the invention is to provide an improved door arrangement which is very rugged and durable in construction; which may be easily and quickly installed without requiring the services of a skilled mechanic or carpenter; which is readily adaptable or adjustable to the conditions presented in any specific instance of installation; which may be easily manipulated (that is, raised and lowered) with a minimum expenditure of energy, due consideration being had to the size and weight of the door; which, when the door is in closed position, presents a tight closure along, each side edge of the door; which requires but little head room to accommodate the door in open position; and which is characterized by its simplicity in manufacture, set-up, and operation.

Other objects will. be in part obvious and, in part, pointed out more in detail hereinafter.

The invention accordingly consists in the features 'of construction, combination of elements andarrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

In the accompanying drawings, wherein is illustrated one of the many embodiments which the present invention may take:

Figure 1 is an elevational view of the inside or closed position, with parts broken away;

Fig. 2 is a side elevation of my improved arrangement, the door frame not being illustrated;

Fig. 3 is an inside elevational view showing the manner in which the upper end of the door is supported by one of the tracks, this view being 33 of Fig. 2;

Fig. 4 is a longitudinal sectional view showing a latch for securing the door in overhead horizontal position;

Fig. 5 is a side elevationalview showing one of the bearing brackets and the arm and spring associated therewith;

Fig. 6 is a rear view of what is shown in Fig. 5,

portions being shown in cross section along the line 6-8 of Fig. 5;

Fig. 7 is a view similar to Fig. 2 but showing the door partly raised by full lines, almost completely raised by dot and dash lines; andfcom- 5 pletely raised by da'sh lines;

Fig. 8 is a detail top plan view showing the connection between the rear end of one of the tracks and the cross brace for holding the tracks in spaced relation; 1 Fig. 9 is a detail view showing one of the hangers for the tracks;

Fig. 10 is a face view spring clips; and

Fig. 11 is a detail view and brace applied tothe taken substantially on line I l| I of Fig. 1.

In Figs. 1 and 7 is shown as much of agarage or other structure as is necessary to illustrate one embodiment of the invention, the structure having a doorway of suitable size provided with a frame which comprises two side posts P and a lintel L. The door, designated generally by the letter D, comprises a single unit or one piece which may be formed of two parts or. sections I0 25 and II positioned edge to edge and secured together, as by means of cross strips l2 which may be in the form of angle irons. In the present instance, these cross strips or angle irons are secured to the inner face of the door adjacent the 30 upper and bottom edges thereof. In order. to prevent the doors from warping due to atmospheric conditions, or sagging due to its own weight, suitable reinforcing struts or braces may be provided. In the present instance, one strut is associated with each angle bar I! and comprises (see Figs. 1 and 11) a pair oi' tie rods i3 suitably secured at their extreme ends to the respective end portions 01' the angle bar and connected at their adjacent ends by a turnbuckle 40 H. The extreme and of each tie rod is bent over and provided with a head I! which is adapted to of one of the extension showing an angle arm 15 door, this view being take into a key slot in the angle bar. At the central portion of the strut is a tie rod support it comprising a generally U-shaped bracket secured to the central portion of the angle bar and having a pair of apertured rearwardly extending arms through which the tie rods extend. It may be stated here that it is of advantage to provide the door in twoparts l0 and II, asby adding two standard doors may be employed instead of making a special door the full width of the doorway.

Adjacent the upper end of the each side thereof are rearwardly doorway and to extending horizontally disposed tracks of any suitable cross section for supporting the rollers of a carriage or trolleyl the tracks preferably being of the cross sectional shape shown in Figs. 1 and 3. The forward ends of these tracks are suitably secured to and brackets 18 which, in turn, are secured to the inside of the door frame. The tracks, adjacent their rear ends, are supported by straps i9 adjustably secured in place to an overhead beam of the garage structure. In the present illustrative disclosure, to provide for the vertical adjustment of the tracks, each strap l9, as shown in Fig. 9, is provided with a plurality of apertures 2| through which the securing bolt 22 is adapted to selectively extend. In order to prevent lateral movement of the rear ends of the tracks and to hold those ends in rigid, spaced relation, a cross brace 23 in the form' of an angle iron is provided, and the ends of this cross brace are respectively secured to the rear portions of the tracks by gusset plates 24, as shown in Fig. 8. Means are provided for adjustably securing these plates both to the tracks and the bar 23 in order to accommodate the structure to doorways of different widths, and to doors of different heights. In the present instance, each gusset plate is provided, along its side edge, with spaced holes 25 through which bolts 26 are adapted to selectively extend. These bolts also extend through holes in the top flange of the track. Along the rear edge of the plate are equally spaced elongated slots 21 through which the bolts 28 extend, those bolts being employed for securing the brace to the gusset plates.

The upper edge of the door is pivotally sup-- ported by suitable carriers or trolleys respectively traveling along the side tracks H. In the present instance, each of these carriers includes a depending truck body 35 in the form of a stamped metal plate, and having a pair of studs 36 constituting bearings for antifriction rollers 31 which engage in the trackway, as shown most clearly in Fig. 3. Pivoted to the truck body, as at 38, is a truck bracket 39 secured to the rear face of the door adjacent one edge thereof and at a slight distance below the top of the door. This bracket extends laterally and rearwardly beyond the side edge of the door when the latter is in closed position. In order to facilitate assembly of the parts; insure the proper relation therebetween; and to strengthen the structure, each truck bracket 39 is secured to a door plate 40, which is provided with means for properly locating the truck bracket with respect to the upper and side edges of the door. In the present instance, this plate is in the form of a wide metal plate or strip secured to the rear face of the door, as by means of screws or bolts 4i and with its outer edge overlapping the door frame. The plate has two or more punched-out tongues 42 bent forwardly at right angles to the plane of the plate and adapted to engage the side edge of the door in order that the plate is properly positioned laterally with respect to the door. These tongues also aid in preventing the door plate from swinging in its own plane. The top of the plate has a turned over flange 43 adapted to engage the top edge of the door so that the plate, together with the truck bracket carried thereby, will be in proper relation to the upper end of the door. By preference, the truck bracket is riveted or otherwise permanently secured to the plate 40 at the factory so that all that it is necessary for the person installing the arrangement to do in order to get the correct relation between the door and the tracks, is to position the door plates on the opposite corners of the doors,

as just described.

The door is so supported that, when it is moved from vertical closed position to an overhead horizontal position, the upper end of the door moves rearwardly of the tracks and the lower end swings forwardly and upwardly and then rearwardly. To effect this movement, the door is supported, adjacent its lower end, by a pair of swinging arms 50, one at each side edge of the door and each pivoted to the lower end of the door and to a suitable bearing bracket or the like. The constructions at opposite sides of the door are similar and, therefore, a description of one will apply to both. Referring to Figs. 1, 5, 6 and 7, the arm 50 is illustrated as .being in the form of an angle bar which may be slightly bent adjacent its normally upper end. The upper end of this arm is fixed to the projecting end of a bearing shaft 5i supported by antifriction bearings 52 mounted in a hearing or jamb bracket 53. In the present instance, the upper end of the swinging arm is reinforced by a plate 54, and this plate and a web of the angle iron have a non-circular opening 55 (see Fig 5) which receives a correspondingly shaped portion of the shaft 51, so that when the arm is swung, the shaft will turn in its bearings. The extreme end of the shaft may be riveted or headed, as at 56. The bearing bracket 53 is in the form of an elongated channel-shaped member, in the rearwardly extending webs of which are supported the ball bearing units 52. The base of the bearing bracket is riveted or otherwise se cured to a jamb plate 51 which is secured to the side posts of the doorway, as by means of screws 58, in such manner that one edge of the plate extends into the door opening and constitutes a jamb against which the frontface of the door is adapted to engage when the door is in closed position. On the lower end of the arm 50 is secured a fulcrum piece or bracket 60 which may be in the form of a U-shaped plate riveted or otherwise secured to the lower end of the arm, as shown in Figs. 5 and 6. This fulcrum piece straddles a bracket 6i secured to the door adjacent its bottom edge and at its side edge. The fulcrum piece is pivoted to the door bracket 6| by means of a pintle 62.

For the purpose of counterbalancing the door in order that it may be raised with as little effort as possible, and in order to prevent the door from quickly dropping to closed position when it is released from overhead position, two tension springs are provided, each spring being interposed between a bearing bracket and the door. In the present illustrative disclosure, each spring 65 is in the form of a uniformly coiled heavy wire. The upper end of the spring is anchored to the bearing bracket at a point above the pivot for the swinging arm, and the lower end of the spring is anchored at a point adjacent the pivot 62 between the arm and the door. More specifically, there is mounted, as shown in Fig. 6, in the webs of the bearing bracket and above the bearing shaft 5|, a stud 66, one end of which projects into the space behind the door opening. The upper end of this spring is connected to this end of the stud, as by means of a clip 61 which may be in the form of a generally U-shaped member having outtumed curved fingers 68 in which the uppermost convolution of the spring is adapted to engage. In order to prevent wear and friction between the clip and its stud, the roller bearing arrangement shown in Fig. 6 is provided. This includes roller bearings 69, and end cups which the clip is turned. The

rear faces of the door plates the post to which the jamb plate is As previously pointed out, the door plate is proparts in place, the cenwhich may be in the form of two plates securedv together and having aligned opposed grooves forming an opening through which a bolt 14 extends. The head 15 of this bolt bears against the lower edge of the anchor. Threaded on the bolt 14 is a clip I6 which comprises, as shown most clearly in Fig. 10, a generally disk-shaped memher with a notch 11 atone side and with prongs 18 struck up from its a tween opposed prongs is substantially equal to the external diameter of the spring. The clip also includes a nut 19 on which is provided the thread which cooperates with the thread on the bolt. The clip is adapted to be screwed into the lower end of the spring. The prongs of the clip hold the lower end of the spring in centered position with respect to the bolt. It will be seen that, with this arrangement, the anchor 13 is pivoted relative to the fulcrum piece so that wear and friction between these parts is reduced. The effective length of the spring may be changed by turning the clip 16 with respect to the spring and thus bringing into operation more convolutions of the spring or less convoluticns of the spring, as the case may be, depending on the direction in effective length of the spring may be varied by longitudinally adjusting the bolt with respect to the anchor, and this may be eifected by turning the bolt 14.

The tension of the springs per inch will depend largely upon the weight of the door employed in the particular installation, a heavier spring being used with a heavy door than is the case with a light door. In order that the parts may be readily adapted for use in connection with the doors of various weights and heights, a further adjustment is provided for the tension springs. This adjustment takes the form of a plurality of vertically spaced apart holes in the bearing bracket 63, and which holes are adapted to selectively I receive the spring stud 66.

There is provided substantially in the plane of the rear face of the door, when closed, and at each side of the door opening, a fulcrum or cam against which the door is adapted to engage as it is being brought to closed position. In the present illustrated disclosure, these cams are provided by curved or round lips 85 on the upper forward corners of the bearing brackets 53. The 40 are adapted to engage these cams, as shown most clearly in Fig. 7. The lower end of this plate is notched, as at 88, and the upper outer corner of the jamb plate 5! is correspondingly notched, as at 81. The upper end of the jamb plate is accommodated by. the notch 86, and the lower end of the door plate is accommodated 'by the notch. 81. This jamb plate has punched-out tongues 88 which are adapted to engage the outer edge of to be secured.

vided with tongues 42 and a top flange 43 which insure proper positioning of the door plate on the door. To properly locate the bearing on the respective posts, it is merely necessary to position periphery. The distance beoutwardly, say

' In order to facilitate the initial opening movement of the tension of the Y the jamb plates so that the upper ends thereof engage the lower ends of the door plates and the tongues 88 engage the opposed faces of the posts and then secure the Jamb plates, as by means of screws 89. The jamb plates are relatively long but, in some instances, will not reach the floor, particularly when the door is of greater than the minimum height. v In order to complete the lamb surfaces, supplemental jamb plates 80 are provided. Preferably, there is a number of these supplemental jamb plates of different sizes so that, by selecting the proper size jamb plates,

the space between the lower edge of the main jamb plate and the floor will be closed.

When the door is in the closed position shown in Fig. 2, the springs 65 are not of material assistance in the operation of swinging the lower end of the door initially outwardly when it is desired to raise the door, and, in case the door is heavy, considerable effort may be necessary on the part of the operator to initially open the door, that is, throw the lower end of the door the first eight or ten inches, and, after which time, the springs 65 are fully effective to carry the door up to its full open position.

door and thus relieve the operator of excessive effort in that direction, I provide means acting through an arm 58 (or both of them) and tending to swing that arm outwardly when the door is in closed position. Referring particularly to Figs. 5 and 6; there is pivoted to the bearing shaft 5!, a lever arm 80 generally of U-shape construction in cross section and preferably formed from rolled stock stamped and bent to shape. The lower rear corner of this arm is provided with a forwardly turned lip 8| adapted to cooperate with a stud 82 projecting radially from the bearing shaft 5|. The free-end of the lever arm cooperates with a coiled spring 83 which abuts against a rest 83 secured to the front wall of the bearing bracket. For the purpose of adjusting the effectiveness of this spring, a screw 84 is provided. This screw is carried in a threaded opening adjacent the upper end of the lever arm 80 and bears against a cap or washer 84' mounted in the rear end of the spring 83. With this arrangement, as the door is brought to its closed position, the stud 82 being moved clockwise, referring to Fig. 5, engages the lip 8| and thereby throws the upper free end of the lever arm forwardly, thereby placing the spring 83 under compression. Thus, during the final closing movement of the door, the spring acts as a buffer and assists in preventing the door from banging against' the jamb. The spring 83, now being compressed, has a tendency to throw the lower end of the door outwardly, but the com pression of the spring is not suflicient of itself to accomplish this operation. When it is desired to open the door, the operator need exert only such outward pressure on the lower edge thereof as is necessary to supplement the force of the spring 83.

The cross brace 23 which connects the is provided with a number of bumpers, two being shown in the present instance. Each of these bumpers may include a bolt 9| slidably mounted in an opening in the vertical web of the angle bar 28. On the forward protruding end of this bolt 7 is a coiled spring 92 located between clips or end disks 83. These end disks have suitable prongs 88 on their peripheries which serve to prevent lav ral movement of the spring. Between the rearmost disk 93 and the angle bar and between the adjustable nut 95 and the angle bar are suitable washers 96. By selecting the proper number of washers, the bolt may be adjusted longitudinally. By turning up the nut 95, the compression of the spring 92 may be adjusted to meet conditions. It will be understood that, in the event the door is thrown into raised position with such force as to bring the door against the forward ends of the bolts 9|, these bumpers will take up the strains and stresses to a large extent, and thus avoid damage to the parts which might result if the door were brought up against a rigid stop.

In order to latch the door in the full open position shown by dash lines in Fig. 7, a suitable locking or latching device may be provided. In the present instance, this latching device includes a latching member I00 pivoted, as at IM, to the outer face of the door adjacent its free or lower end. The latch is normally urged outwardly from the face of the door by a spring I02. 0n the under side of the lin'tel of the door frame is a strike plate or keeper )3 behind which the free end of the latch is adapted to engage when the door is in full raised position, as shown most clearly in Fig. 4. In order to disengage the latching member from the strike or keeper when it is desired to lower the door, the latching member is connected to a link IM which extends rearwardly through an opening in the door. Secured to the rear face of the door is a bracket 35 in which is journalled a U-shaped lever we, the lower arm of which has an elongated opening I01 through which the inner end of the link ill l extends. The inner end of this link is provided with a nut I88 adapted to engage against the lower arm of the lever. The other or upper arm of the lever I06 has connected to it a rod Hi9 which, in the present instance, has one end slidably passing through an opening in a stud H0 carried by an operating lever or handle I l i. This operating lever is for the purpose of lowering the door from the inside of the garage. It is pivoted, as at I I2, to one of the swinging arms 50 adjacent the pivot of that arm. It has, at its pivoted end, a lug H3 adapted to engage the arm when the lever is moved to the operative position shown in Fig. 'I. In order that this lever will normally lie in the out-ofway position when not in use, a spring H3 is provided. This spring normally urges the lever to the position shown in Fig. 2 where the lever is closely adjacent to the arm.

From the foregoing description, taken in connection with the accompanying drawings, it will be seen that, in accordance with the present invention, there is provided a very simple and durable structure which may be quickly and easily installed by unskilled persons. When it is desired to make an installation, two doors of standard size may be obtained and secured edge to edge so as to form a single unit by means of the angle pieces [2 which are braced by the struts l3. After the unit has been cut to size, the door is positioned within the opening with the desired clearance about the door, then the door plates 40 are positioned on the corners of the doors with their flanges engaging the top edge of the door and their tongues 42 engaging the side edge of the door. Then the tracks are secured in place. In doing this, the trolleys are engaged in the tracks and the tracks pushed up so that the runways engage the trolleys. The rear ends of the track are secured by the gusset plates to the cross brace so as to hold the tracks rigid; then the lamb plates 51 are brought to position with their upper ends pressed against the lower ends of the door plates and with their tongues 8| engaging against the side edges of the door frame. The jamb plates having been secured to the posts, the lower or free ends of the arms are swung towards the door, and the door brackets 61 are secured wherever they may engage the door. The door is now swung to raised 'position, and the springs are installed. The doors are now lowered, and the springs are adjusted either by turning the bolts It or the clips 16, or both, depending on the character of adjustment desired until these springs will lift the door to full open position after the door has been opened to the extent of ten or twelve inches at the bottom. It will be observed that the installation may be efi'iected without the person setting up the same making any measurements, except for the sizeof the door. The door trucks have means for determining their position with respect to the door; the tracks are positioned with respect to the previously secured trucks; and the jamb plates, together with their hearing brackets, are positioned with respect to the previously positioned door plates.

To open the door, the lower end thereof is pushed outwardly as, for example, by pressing the foot against the door adjacent its lower edge and, after the lower end of the door has been moved out about ten or twelve inches, the springs will automatically complete the opening movement of the door. During initial opening movement of the door, the spring 83 is of assistance as previously described. After the door has been brought to full open position, the latch automatically cooperates with the strike plate so that the door is held against coming down. When it is desired to lower the door, the operator will pull downwardly and inwardly on the outer end of the operating lever and, due to the connection between this lever and the latching member, the latter is disengaged from the strike plate. On continued swinging movement of the operat ing lever, the lug thereof will engage the swinging arm, and then the arm and lever will swing as a unit. The free end of the door will swing downwardly, of course, and the upper end will roll forwardly on the tracks. After the door is brought to substantially the position shown in Fig. '7, the door plates engage and slide along the fulcrum or cams 85 of the bearing brackets, insuring pivotal movement, so to speak, of the door about the line of those cams so that, on continued closing movement of the door, the upper edge of the door is positively moved outwardly and the lower edge of the door is positively moved inwardly to final position. When the door is in final position, the overhanging portions of the door plates thereof engage the posts, and the door, at its side edges, engages the jamb plates.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

tracks adjacent the upper end of the doorway and disposed on opp site sides thereof, a carrier movable along each track, means for pivotally connecting the door adjacent its upper end to said carriers, a pair of swinging arms disposed behind the door adjacent opposite sides thereof, each arm being fixedly pivoted at its upper end and being pivotally connected to the door adjacent the lower end of the latter, counterbalancing springs for assisting in raising the door, and fixed fulcrum members fixed to the door frame and projecting into the door opening and against which the rear face of the .door is adapted to engage as the door is brought into closed position.

2. In an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from a vertical closed position to an overhead horizontal position, a pair of rearwardly extending horizontally disposed straight tracks. adjacent the upper end of the doorway and to opposite sides thereof, a carrier movable along each track, means for pivotally connecting the door adjacent its upper end to said carriers, a pair of s g arms disposed behind the door and adjacent opposite side edges thereof, fixed pivots for said arms, means for pivotally connecting the arms to the door adjacent the lower end of the latter, a pair of tension springs, each fixed at its upper end at a point above the pivot for the respective arm, said springs being operatively connected to the door adjacent the pivots between the door and the arms, and fixed cam elements located substantially in the plane of the rear face of the door when the latter isclosed and disposed above and forwardly of the fixed pivots for said arms, the rear face of said door being adapted to engage and slide along said cam elements as the door is brought-to closed position. 7

3. In an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from i a vertical closed position to an overhead horizontal position, a pair of rearwardly extending tracks adjacent the upper end of the doorway and to opposite sides thereof, a carrier movable along each track and having a roller and a truck body, a truck plate secured to each upper corner of the door and pivotally connected to a respective truck body, means for determining the location of each truck plate with respect to the upper edge and a side edge of said door, a pair of bearing brackets secured to the inside of the door frame to opposite sides of the door open-. ing, means connected to said bearing brackets for determining the proper position thereof with respect to the previously positioned truck plates, a swinging arm pivoted to each bracket, each arm being pivotally connected to the door adjacent the lower end thereof, and a pair of tension springs, each anchored at one end to a respective bearing bracket and at the other end to the door adjacent the pivots between the arms and the door.

4. In an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from door plates, a bearing bracket fixed to each jamb a vertical closed position to an overhead hori zontal position, a pair of rearwardly extending tracks adjacent the upper end of the doorway and to opposite sides thereof, a carrier movable along each track'and having a depending truck body, a

truck plate pivotally connected to each truck body, a pair of door plates to which'the truck plates are respectively and permanently secured, means on each door plate for locating the same with respect to the upper edge and a side edge of the door, a -pair of jamb plates secured to the door frame to opposite sides of the door opening, said jamb plates having their upper edges in substantially abutting relation to the lower edges of the plate, a swinging arm pivoted to each bearing bracket, each arm being pivotally connected to the door adjacent the lower end thereof, and a pair of tension springs each anchored at one end to the respective bearing bracket ata point above the pivot of said arms, the other ends of said springs being operatively connected to the door adjacent the pivots between the arms and the cor.

5. In an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from a vertical closed position to. an overhead horizontal position, a pair of rearwardly extending horizontally disposed straight tracks adjacent the 3o 1 upper end of the doorway and to opposite sides thereof, a carrier movable along each track and having a depending truck body, a pair of door plates fixed to the inner face of the door at opposite upper corners thereof, each door plate having'a flange at its upper end adapted to rest upon the top of the door and tongues adapted to engage a side edge of the door, truck plates respectively fixed to said door plates and respectively pivoted to said truck bodies, jamb plates secured to the inner face of the door frame to opposite sides of the door opening and with their opposed edges extending into the door opening, said jamb plates having their upper edges in substantially abutting relation to the lower ends of the door plates and said jamb plates having tongues adapted to engage opposed faces of the door frame, bearing brackets secured to the respective jamb plates, a swinging arm pivoted to each bracket, each arm being pivotally connected to the door adjacent the lower end thereof, and a pair of tension springs each anchored at one end to a. respective bearing bracket, the other ends of said springs being operatively connected to the door adjacent the pivots between the armsand the door.

6. In an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from a vertical closed position to an overhead horizontal position, a pair of rearwardly extending generally horizontally disposed tracks adjacent the upper end of the doorway and to opposite sides thereof, a carrier movable in each track, said door adjacent its upper end being pivoted to said carriers, a swinging arm adjacent each side edge of said door, each arm being pivotally connected to the door adjacent the lower end thereof, said arms being pivoted on a line behind said door and between the upper and lower edges thereof, a pair of tension springs each anchored at one end above the pivot of said arms andoat the other end to the door adjacent the pivot between the arms and the door, resilient means including a compression spring and a manually operable lever for assisting in initially opening the door, and adjustable means on said lever engageable with the spring whereby it may be compressed to regulate the initial opening pressure exerted thereby.

7. In an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from a vertical closed position to an overhead horizontal position, a pair of rearwardly extending generally horizontally disposed tracks adjacent the upper end of the doorway and to opposite sides thereof, a carrier movable in each track, said door adjacent its upper end being pivoted to said carriers, a swinging arm adjacent each side edge of said door, each arm being pivotally connected to the door adjacent the lower end thereof, said arms being pivoted on a line behind said door and between the upper and lower edges thereof, a pair of tension springs each anchored at one end above the pivot of said arms and at the other end to the door adjacent the pivot between the arms and the door, and spring means for assisting in initially opening the door, said spring means including a compression spring and a lever and operatively associated with one of said first mentioned arms whereby said compression spring is placed under compression as the door is brought to final closed position.

8. In an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from a vertical closed position to an overhead horizontal position, a pair of rearwardly extending horizontally disposed tracks adjacent the upper end of the doorway and to opposite sides thereof, a carrier movable along each track, said door adjacent its upper end being pivoted to said carriers, bearing shafts journalled rearwardly of the door opening and to opposite sides thereof, a swinging arm carried by each shaft, each arm being pivotally connected to the door adjacent the lower end thereof, a pair of tension springs each anchored at one end at a point above said shafts, the other ends of said springs being secured to the door adjacent the pivot between the arms and the door, a lever arm journalled on one of said'shafts, a projection on said shaft adapted to engage said lever arm and swing the same as the door is brought to final position, and a compression spring cooperating with said arm and adapted to be compressed thereby as the door is brought to final position.

9. In .an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from a vertical closed position to an overhead horizontal position, a pair of rearwardly extending horizontally disposed straight tracks adjacent the upper end of the doorway and to opposite sides thereof, a carrier movable along each track, said door adjacent its upper end being pivomd to said carriers, bearing brackets secured to the inside of the door frame and to opposite sides thereof, a bearing shaft journalled in each bracket, a swinging arm fixed to each shaft, each arm being pivotally connected to the door adjacent the lower end thereof, a pair of tension springs each anchored at one end to a respective bearing bracket, the other ends of said springs being secured to the door adjacent the pivot between the door and the frame, a lever arm pivoted on one of said shafts, a projection on said shaft adapted to engage said lever arm as the door is brought to final position, and a compression spring between the free ends of said lever arm and said bracket.

10. In an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from a vertical closed position to an overhead horizontal position, a pair of rearwardly extending tracks adjacent the upper end of the doorway and to opposite sides thereof, a carrier movable along each track, means for pivotally connecting the door adjacent its upper end to said carriers, a pair of swinging arms disposed behind the door and adjacent opposite side edges thereof, fixed pivots for the upper ends of said arms, means for pivotally connecting the lower ends of said arms to said door adjacent the lower edge of the latter, tension springs each fixed at one end and operatively connected to the door at its other end, a lever pivoted to the inner face of one of said arms and having an abutment adapted to engage said am when the lever is swung downwardly and inwardly to lower the door, and a spring normally urging said lever to a position where it is closely adjacent to said arm.

11. In an overhead door construction, a door frame having a door opening, a one-piece door adapted to close said opening and movable from a vertical closed position to an overhead horizontal position, a pair of rearwardly extending tracks adjacent the upper end of the doorway and to opposite sides thereof, a carrier movable along each track, means for pivotally connecting the door adjacent its upper end to said carriers, a pair of swinging arms disposed behind the door and adjacent opposite side edges thereof, fixed pivots for the upper ends of said arms, means for pivotally connecting the lower ends of said arms to said door adjacent the lower end of the latter, tension springs each fixed at one end and operatively connected to the door at its other end, a lever operatively connected to one of said arms for lowering the door, means for latching said door in raised position, and an operative connection between said latching means and lever whereby the latch is moved to inoperative position when the lever is operated to lower the door.

DAVID M. ROBINSON.