US2393052A - Bifold canopy door - Google Patents

Description

R. S. MEHARD Jan.` 15, 1946.

BI-FOLD cANoPY DooR 'Filed March 13, 1945 5 Sheets-Sheet 1 Il f III 'Ill' Jan. l5, 1946. R. s. MEHARD FOLD CANOPY DOOR 3 Sheets-Sheet 2 -Filed March 13', 1945 klan. l5, 1946. R. s. MEHARD BI -FOLD CANOPY DOOR Filed March 15,l 1945 5 Sheets-Sheet 3 Patented Jan. l5, 1946 BIFOLD CANOPY DOOR Robert S. Mehard, Youngstown, Ohio, assigner to Truscon Steel Company, Youngstown, Ohio, a corporation of Michigan Application March 13, 1945, Serial No. 582,547

1 (Cl. i60-185) Claims.

This invention relates to doors, and has particular reference to improvements in so-called bi-fold" doors of the type comprising an upper leaf which is pivoted at or near its upper end to a building structure, at or near the topof a doorway therein, for upward and outward swinging movement from a vertically disposed, closed position to a substantially horizontally disposed, open position in which it extends, canopy-like, from the building structure at the top of the doorway, and a lower leaf which is pivotally connected at or near its top to the upper leaf near the bottom thereof for inward and upward swinging movement relative to `the upper leaf from a vertically disposed, closed position to an open position in which it underlies the upper leaf when the latter is open.

While the doors of the general type mentioned are known, their designs heretofore have been Such that they are quite heavy and require considerable expensive fabrication. Accordingly, one special and important object of the present invention is to provide a door of the type mentioned which, comparatively speaking, is of light weight, much simplified design, and which may be produced with little fabrication and, therefore, economically, in most part from standard structural elements such as I-beams, channel members and the like.

Another special and important object of the present invention is to provide a door of the type mentioned embodying a simple leaf-movementcontrol-mechanism which is effective to hold the leaves securely in both their open and their closed positions and which also is elfective to cause the lower portion of the lower leaf to move directly vertically during initial opening and final closing movement of said leaf, thereby to adapt said leaf for free and easy engagement with and disengagement from simple keeper means at the bottom of the doorway and to insure that snow or the like which may become packed against the lower part of the lower leaf will not interfere with opening and closing of the door.

Another special and important object of the invention is to provide a leaf-movement-controlmechanism which is conducive to distribution of stresses throughout the door and to free and easy operation of the latter.

Another special and important object of the invention is to provide spring means to assist in initiating opening movement of the door and to cushion opening and closing movements thereof, thus to eliminate undesirable shocks to which the door might otherwise be subjected.

With the foregoing and other objects in View, which will become more fully apparent as the nature of the invention is better understood, the same consists in a door of the type mentioned embodying the novel features of construction, combination, and arrangement 0f parts as will be hereinafter more fully described, illustrated in the accompanying drawings and dened in the appended claims.

In the accompanying drawings, wherein like characters of reference denote corresponding parts in the different views:

Figure l is a vertical section through a door constructed in accordance with one practical embodiment of the invention and showing, in full lines, the leaves in their vertically disposed, closed positions and, in dotted lines, different positions assumed by said leaves during opening and closing of the door.

Figure 2 is an enlarged, fragmentary section, similar to Figure l showing in detail the pivoted, slidable connection between the door leaves.

Figure 3 is a rear elevation of the structure shown inFigure 2.

Figure 4 is an enlarged vertical section similar to Figure 2.

Figure 5 is a cross section on the line 5 5 of Figure 4; and

Figure 6 is a view similar to Figure 2 showing the leaves in partly opened positions.

Referring to the drawings in detail, A designates a part of a building structure such, for example, as an aircraft hangar, having a doorway a, and B designates, generally, a door constructed, mounted and operable in accordance with the invention to control closing and opening of said doorway a.

The door B is composed of an upper leaf b and a lower leaf b', and, in accordance with the invention, the upper leaf b is pivoted, at or near its top, to the building structure A, at or near the top of the doorway a therein, as indicated at I0, for swinging movements between a vertically disposed, closed position, as shown by full lines in Figure 1, and a substantially horizontally disposed, open position in which it extends, canopylike, from the building A, as shown by dotted lines in Figure 1. On the other hand, the lower leaf b is suitably connected, at or near its top, to the upper leaf b, near the bottom of the latter, both for limited vertical moveme'lntsl relative thereto and for swinging movements relative thereto between a vertically disposed, closed position and a substantially horizontally disposed open position in which it underlies said upper leaf b when the latter is in its open position. In this latter connection, depending upon the width of the door,

there may be any desired number of vertically slidable, pivoted connections between the leaves at any desired locations spaced apart along the width of the door.

Further in accordance with the invention, the leaves b and b' are connected together and to the building structure A'by arm and link assemblies to brace the leaves and to assist in controlling their opening and closing movements, and, as in the case of the connections between the leaves, there may be, depending upon the width of the door, any desired number of these arm and link assemblies spaced apart as desired along the width of the door. In any event, the connections between the leaves are duplicates of one another 4and a description of one therefore will suice for all. Likewise, the arm and link assemblies are duplicates of one another and a description of one of these will sufce for all.

While the leaves b and b' may be of any suitable constructions they include vertically disposed, alined I-beams I I and I2, respectively, and in accordance with the specic embodiment of the invention illustrated in the drawings, any given vertically slidable, pivotal connection between said leaves includes a pair of spaced apart channel members I3, I3 suitably fastened rigidly at their lower ends to the upper end of an I-beam I2 of the lower leaf and rising therefrom behind the lower portion of the related I-beam II of the upper leaf.

Extending through the upper end portions of the channel members I3, I3 is a shaft I4 upon which is mounted, between said channel members, a roller I5 which engages the rear face of the related I-beam II of the upper leaf b, while mounted upon the end portions of said shaft I4 are angle members I6, I6 having anges I1 which overlie the front face of the rear flange of said I-beam Il. These angle members IB thus are prevented from moving rearwardly relative to the I-beam I I, but are vertically slidable with respect thereto, and since the channel members I3, I3 are pivotally connected with said angle members by the shaft I4, it follows that the lower leaf b' is connected adjacent to its top to the lower portion of the upper leaf for vertical sliding and pivotal movements relative thereto.

Fixed to the lower portion of the I-beam I I and extending rearwardly therefrom, one to either side of the channel members I3, I3, is a pair of plates I8, I8 which carry, at their inner sides upwardly and rearwardly inclined cams I9, I9, respectively, while mounted upon the channel members I3, I3, at the outer sides thereof, are rollers 20,20 for cooperation with said cams, respectively, during initial opening and final closing movements of the door.

Any given arm and link assembly comprises, according to the specific embodiment of the invention illustrated in the drawings, an arm 2l pivoted at its upper end to the building structure A a suitable distance inwardly from the doorway a at about the level of the top thereof, as indicated at 22, and a pair of links 23 and 24, each pivoted at one end to the lower end of the arm 2l, as indicated at 25, and pivotally connected at their opposite ends to the upper and the lower leaves b and b', respectively, as indicated at 26 and 21, respectively. As shown, each link 23 and 24 comprises two arms, but either or both of said links may comprise only a. single arm if desired. In any event, when the door is closed the lower end of the arm 2| is spaced rearwardly from the door and is disposed at about the level of the bottom of the upper leaf, while the links 23 and 24 extend upwardly and forwardly and downwardly and forwardly, respectively, from the lower end of said arm 2| to the leaves b and b', re-

- spectively, to which they are connected at points spaced suitably above the bottom of the upper leaf and suitably below the top of the lower leaf| respectively. Moreover, when the door is closed, the arm 2l is inclined upwardly and rearwardly. Accordingly, each arm and link assembly constitutes a truss `,effectively holding the upper leaf against swinging inwardly, at its bottom and the lower leaf against swinging inwardly at its top when the door is closed.

When the door is closed the rollers 20, 20 are disposed in front of and against the cams I9, I9 at the bottoms thereof, and the top of the lower leaf b is spaced downwardly a suitable distance below the bottom of the upper leaf b, the space between said leaves then being closed by an apron 28 depending from the lower end of the upper leaf into overlapping relationship to the top of the lower leaf. Thus, when the door is closed, the lower leaf is capable of being raised a, limited distance relative to the upper leaf. In this connection, suitable door operating means is provided and may comprise one or more cables 29 connected to the bottom of the lower leaf, as indicated at 30, and extending over one or more sheaves 3l to a suitable power or manually operated drum (not shown) located wherever desired, the sheave or sheaves 3I being mounted upon th'e building structure A a suitable distance above the doorway a and preferably spaced a suitable distance inwardly therefrom. l.

The inclination and height of the cams I9 is such, in relation to the length of the arm 2l and 40 the lengths Of the links 23 and 24, that as the lower leaf b is lifted from its lowermost or closed position, its lower end portion is constrained to move vertically a predetermined distance before it may shift either inwardly or outwardly. In other words, during initial raising of the lower leaf, the link 24 swings upwardly and outwardly about its pivotal connection with the lower end of the arm 2| and thereby causes the top of the lower leaf to swing outwardly, which in turn causes the lower end of the upper leaf b to swing outwardly due to the slidable, pivotal connection between the leaves. At the same time, this Outward swinging movement of the top of the lower leaf and the bottom of the upper leaf is controlled by the engagement of the rollers 20 with the cams I9 and by the arm 2| and the links 23 and 24 so that for a given amount of initial upward, opening movement of the lower leaf b',

its lower end is constrained to move vertically without shifting laterally. The amount of this initial vertical movement of the bottom of th'e lower leaf may be predetermined by a proper selection of the lengths of the arm 2| and the links 23 and 24 and by a corresponding proper inclination of the cams I9. In any event, it preferably is sucient to permit the bottom of the lower leaf to rise above or clear any normal or expected height of snow or the like before the bottom of said leaf partakes of any inward or outward movement. It is, moreover, sucient to permit complete disengagement of the lower leaf from any locking means with which it may be engaged at its bottom when the door is closed. The provision of suitable locking means for the bottom of the lower leaf thus is simplified and said locking means may simply consist, for example, of a rail 32 fastened to the floor of the building at the bottom of the doorway a and receivable in a channel member 33 carried by the lower leaf b at the bottom thereof.

As the lower leaf b' is raised, the roller I5 rolls upwardly over the rear face of the I-beam I I and the rollers roll upwardly over the front faces of the cams I9 until they reach the tops of said cams, whereupon further control of swinging movement of the leaves by said cams ceases and devolves solely upon th'e arm 2| and the links 23 and 24. In this connection, it will be apparent that as raising of the lower leaf progresses, the roller 20 will ride over the tops of the cams I9 and leave the same; that the upper leaf will be swung upwardly and outwardly; and that the lower leaf will be swung upwardly and inwardly into underlying relationship to said upper leaf until the leaves reach their fully open positions in which they extend substantially horizontally, canopy-like, from the building structure A above the doorway a.

During opening of the door the lower leaf b' will tend to continue to move upwardly relative to the upper leaf even after the cam rollers 2U have been moved over and have become disengaged from th'e cams I9, and this tendency will continue as long as the angle between the leaves is obtuse. When, however, the angle between the leaves begins to become acute, the tendency of the lower leaf will be to shift toward the bot- 4tom of the upper leaf. In this connection, it is.

of course, desirable to limit shifting movements of the lower leaf relative to the upper leaf, and while any suitable means may be provided for this purpose, one suitable and practical means may comprise suitable upper and lower stops 36 and 35, respectively, fastened to the I-beam II to be engaged by the roller I5.

Although not essential, suitable spring means preferably is provided to resist downward movement of the lower leaf relative to the upper leaf, thus to avoid shocks due to the roller I5 contacting the stop 34 during opening of the door and due to the bottom of the lower leaf engaging its keeper means at the bottom of the doorway during final closing movement of said lower leaf. In this connection and according to the specific construction illustrated in the drawings, a pair of helical tension springs 36, 36 are connected at their lower ends to the angle members I6, I6 respectively, and at their upper ends to the ends, respectively, of an arm 31 which is suitably suspended medially and pivotally from the upper leaf b. Accordingly, said springs tend to yieldably resist and to cushion downward movements of the lower leaf relative to the upper leaf both during opening of the door, as the leaves begin to assume an acute angular relationship to each other and during closing of the door as the lower leaf partakes of the final portion of its downward or closing movement. Moreover, since said springs are in tension when the door is closed, they obviously assist in initiating upward or opening movement of the lower leaf b.

The arm 31 maybe suspended by a rod 38 from a bracket 39 by which the link 23 is connected to the upper leaf b, and said rod may be vertically adjustable relative to said upper leaf by a nut 40, whereby the effective strength of the springs 36 may be varied.

When the cable or cables 2S is or are released, the door gravitates to closed position and the leaves simply partake of the reverse of their opening movements, the rollers 20 beginning to cooperate with the cams I9 during the final portion of closing movement of the door to insure that the final portion of the closing movement of the bottom of the lower leaf shall be directly downwardly.

Preferably each I-beam I2 is provided at its inner side and adjacent to its bottom with a suitable bumper 6I to engage the under side of the related arm 2l when the door is fully opened, thus to limit upward movement of the leaf and thereby prevent the door from becoming locked in its fully open position.

From the foregoing description considered in connection with the accompanying drawings, it is believed that the construction and operation of the present door will be apparent. It is likewise believed to be clear wherein the present construction accomplishes the objects hereinbefore stated. Itis desired to point out, however, that while only a single specific construction has been illustrated and described, the invention is readily capable of embodiment in specifically different constructions within its spirit and scope as defined in the appended claims.

I claim:

l. A door comprising an upper leaf pivoted at its top for upward and outward swinging movement from a vertically disposed closed position to a substantially horizontally disposed open position, a lower leaf having a vertically slidable and pivotal connection adjacent to its top with the lower portion of said upper leaf, means connected to the lower leaf for raising the same, means to cause the upper leaf to swing outwardly and upwardly and the lower leaf to swing inwardly and upwardly with respect thereto in response to raising of the lower leaf, and means cooperating with said last-named means to cause the bottom of the lower leaf to move directly upwardly for a predetermined distance during initial opening movement of the door.

2. A door comprising an upper leaf pivoted at its top for upward and outward swinging movement from a vertically disposed closed position to a substantially horizontally disposed open position, a lower leaf having a vertically slidable and pivotal connection adjacent to its top with the lower portion of said upper leaf, means connected to the lower leaf for raising the same, means to cause the upper leaf to swing outwardly and upwardly and the lower leaf to swing inwardly and upwardly with respect thereto in response to raising of the lower leaf, and a cam and a cam follower, one on one of said leaves and the other on the other of said leaves, cooperating with each other and with said last-named means to cause the bottom of the lower leaf to move directly upwardly for a predetermined distance during initial opening movement of the door.

3. A door comprising an upper leaf pivoted at its top for upward and outward swinging movement from a vertically disposed closed position to a substantially horizontally disposed open position, a lower leaf having a vertically slidable and pivotal connection adjacent to its top with the lower portion of said upper leaf, means connected to the lower leaf for raising the same, means to cause the upper leaf to swing outwardly and upwardly and the lower leaf to swing inwardly and upwardly with respect thereto in response to raising of the lower leaf, said last-named means comprising an arm having a fixed pivotal mounting at one end and a pair of links each pivotally connected at one end to the other end of said arm and respectively pivotally connected to said leaves, and means cooperating with said arm and said links to cause the bottom of the lower leaf to move -directly upwardly for a predetermined distance during initial opening movement of the door.

4. A door comprising an upper leaf pivotedat its top for upward and outward swinging movement from a vertically disposed closed position to a. substantially horizontally disposed open position, a lower leaf having a vertically slidable and pivotal connection adjacent to its top with the lower portion of said upper leaf, means connected to the lower leaf for raising the same, means to cause the upper leaf to swing outwardly and upwardly and the lower leaf to swing inwardly and upwardly with respect thereto in response to raising of the lower leaf, said last-named means comprising an arm having a fixed pivotal mounting at one end and a pair of links each pivotally connected at one end to the other end of said arm and respectively pivotally connected to said leaves, and a cam and a cam follower one on one of said leaves and the other on the other of said leaves cooperating with each other and with said last-named means to cause the bottom of the lower leaf to move directly upwardly for a predetermined distance during initial opening movement of the door. A

5. A door comprising an upper leaf pivoted at its top for swinging movement between a vertically disposed closed position and a, substantially horizontally disposed open position, a lower leaf having a vertically slidable and pivotal connection adjacent to its top with the lower portion of said upper leaf and swingable about its said connectio'n between a vertically disposed closed position and a. substantially horizontally disposed open position in which it underlies said upper leaf, when the latter is open, means for raising and for controlling lowering of said lower leaf, means to cause the upper leaf to swing outwardly and upwardly and the lower leaf to swing inwardly and upwardly relative thereto in response to raising of said lower leaf and vice versa. in response to lowering of said lower leaf, means cooperating with said last-named means to cause the bottom of the lower leaf to move directly vertically for a predetermined distance during initial opening and final closing movements of the door, and spring means to resist and cushion downward movements of the lower leaf relative to the upper leaf.

6. A door comprising an upper leaf pivoted at itstop for swinging movement between a vertically disposed closed position and a substantially horizontally disposed open position, a lower leaf having a vertically slidable and pivotal connection adjacent to its top with the lower portion of said upper leaf land swingable about its said connection Abetween a vertically disposed closed position and a substantially horizontally disposed open position in which it underlies said upper leaf, when the latter is open, means for raising and for controlling lowering of said lower leaf, means to cause the upper leaf to swing outwardly and upwardly and the lower leaf to swing inwardly and upwardly relative thereto in response to raising of said lower leaf and vice versa in response to lowering of said lower leaf, means cooperating with said last-named means to cause the .bottom of the 1ower leaf to move directly vertically for a predetermined distance during initial opening and nal closing movements of the door, and stop means limiting upward and downward movements of said lower leaf relative to said upper leaf.

'1. A door comprising an upper leaf pivoted at its top for swinging movement between a, vertically disposed closed position and a substantially horizontally disposed open position, a lower leaf having a vertically slidable and pivotal connection adjacent to its top with the lower portion of said upper leaf and swingable about its said connection between a vertically disposed closed position and a substantially horizontally disposed open position in which it underlies said upper leaf, means for raising and for controlling lowering of said lower leaf, when the latter is open, means to cause the upper leaf to swing outwardly and upwardly and the lower leaf to swing inwardly and upwardly relative thereto in response to raising of said lower leaf and vice versa in response to lowering of said lower leaf, means cooperating with said last-named means to cause the bottom of the lower leaf to move directly vertically for a predetermined distance during initi-al opening and final closing movements of the door, stop means to limit upward and downward movements of said lower leaf relative to said upper leaf, and spring means to resist and cushion downward movements of the lower leaf relative to the upper leaf.

8. A door comprising an upper leaf pivoted at its top for swinging movement between a vertically disposed closed position and a substantially horizontally disposed open position, a lower leaf having a. vertically slidable and pivotal connection adjacent to its top with the lower portion of said upper leaf and swingable about its said connection between a vertically disposed closed position and a substantially horizontally disposed open position in which it underlies said upper leaf, when the latter is open, means for raising and for Controlling lowering of said lower leaf, means to cause the upper leaf to swing outwardly and upwardly and the lower leaf to swing inwardly and upwardly relative thereto in response to raising of said lower leaf and vice versa in response to lowering of said lower leaf, and means cooperating with said last-named 4means to cause the bottom of the lower leaf to move directly vertically for a predetermined distance during initial opening and nal closing movements of the door, said last-named means comprising an upwardly and rearwardly inclined cam on the upper leaf below the slidable and pivotal connection between said leaves, and a. cam follower on the lower leaf in front of and engaging said cam.

9. A door comprising an upper leaf pivoted at its top for swinging movement between a vertlcally disposed closed position and a substantially horizontally disposed open position, a, lower leaf having a vertically slidable and pivota1 connection adjacent to its top with the lower portion of said upper leaf and swingable about its said connection between a vertically disposed closed position and a substantially horizontally disposed open position in which it underlies said upper leaf, when the latter is open, means for raising and for controlling lowering of said lower leaf, means to cause the upper leaf to swing outwardly and upwardly and the lower leaf to swing inwardly and upwardly relative thereto in response to raising of said lower leaf and vice versa in response to lowering of said lower leaf, said last-named means comprising an arm having a fixed pivotal mounting at its upper end behind the door and near the level of the top thereof and a pair of links each pivotally connected at one end to the lower end of said arm and respectively pivotally connected to said leaves above and below their pivotal slidable connection with each other, an upwardly and rearwardly inclined cam on the upper leaf below the pivotal slidable connection between said leaves, and a cam follower on the lower leaf in front of and cooperating with said cam during initial opening and nal closing movements of said lower leaf to constrain the bottom of said lower leaf to move directly vertically.

10. A door comprising an upper leaf pivoted at its top for swinging movement between a vertically disposed closed position and a substantially horizontally disposed open position, said leaf including an I-beam extending vertically thereof and disposed at the rear thereof, a lower leaf connected near its upper end to said I-beam for vertical sliding movement relative to upper leaf and also for swinging movement relative thereto between a vertically disposed closed position and a substantially horizontally disposed open position in underlying relationship to said upper leaf when the latter is open, spring means resisting downward movement of said lower leaf relative to said upper leaf, stop means to limit vertical sliding movement of said lower leaf relative to said upper leaf, means to raise said lower leaf, an arm having at one end a fixed pivotal mounting at a. point spaced rearwardly from the door and near the level of the top of the door, a link connecting the other end of said arm with the upper leaf, a second link connecting the said other end of said arm with the lower leaf, and cam and cam follower means on said leaves, respectively, cooperating with each other and with said arm and links to cause the bottom of the door to move directly vertically during initial opening and final closing movements of the door, said cam and cam follower means comprising an upwardly and rearwardly inclined cam on the upper leaf and a follower on the lower leaf.

ROBERT S. MEHARD.

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