The present invention relates to the field of overhead sectional doors and their complementary hardware (collectively referred to herein as ‘sectional door assemblies’).
Overhead sectional door assemblies are in common use in both residential and industrial building structures. A typical conventional sectional door assembly (a) is shown in
The sectional door assembly (a) comprises a door (m) having several vertically stacked door panels (b) connected together along their abutting edges by metal hinges (not shown). Each door panel (b) supports a pair of roller hinges (d) at its upper corners. Each roller hinge (d) has a roller (e) which engages and runs along one of a pair of C-shaped tracks (f) secured to the jamb (g) at the sides of the door opening.
Each track (t) has a lowermost, upwardly extending section (i), an uppermost, inwardly extending, generally horizontal section (j) and a curved corner section (k) joining the upwardly extending and horizontal sections (i), (j). The curved corner section (k) usually has a single radius, typically falling in the range 12-15 inches, and bends through about 90°.
A torsion spring lifting assembly (l) is commonly provided to lift the sectional door (m). This lifting assembly (l) usually comprises a horizontal shaft (n) rotatably mounted to the header or jamb (g) above the door opening (h). The shaft (n) carries a cable drum (o) at each of its ends. A torsion spring is connected to and coiled around the central portion of the shaft (n). A lift cable is connected between each drum (o) and the underlying bottom corner of the sectional door (m). If the tensioned torsion spring is released, it rotates the shaft (n) and drums (o) and winds in the cables, thereby lifting the door (m) along the tracks (l).
A door operator (not shown), usually comprising a jack shaft driven by an electric motor, is commonly provided to push the door (m) toward the upright closed position from the horizontal open position.
Together, the door operator and torsion spring lifting assembly require a significant amount of space or “headroom” above the door. Typically, in a residential garage case, about 10-12 inches of headroom is needed. If the headroom is reduced an inch or two, this will bring the cable drums (o) closer to the top of the sectional door (m). There is then a risk that the upper end of the top panel (b) will contact the cable drums (o) as the panel travels through the curved corner track sections (k).
Builders have long pressed manufacturers of sectional door assemblies for reduction in headroom requirements.
It has been conventional to incline the upwardly extending sections of the tracks away from the door jamb, from the bottom to the top. This is done primarily to break the door (m) away from the weather stripping (t) so that the door will not wear the stripping as the door moves up and down. It has also allowed the headroom to be reduced to about 10-12 inches.
The use of inclined tracks, however, carries with it the penalty of having to use “wedge-type hardware”. By this is meant that the track mounting brackets, which connect the tracks (f) to the door jamb (g), and the panel roller hinges (d) necessarily are “stepped” or vary in size. It will be appreciated that, while the sectional door (m) is to roll along inclined tracks, it still needs to be vertical when closed, to press against the weather stripping (t) mounted on the vertically oriented door jamb and thereby provide an effective seal against wind. To accomplish this, wedge-type hardware needs to be used. Wedge-type hardware is expensive.
With this background in mind, it therefore is one object of the present invention to modify a sectional door assembly so that it can work in a reduced headroom, for example in the order of 8 to 10 inches.
It is a preferred object to provide an assembly that does not need inclined tracks and wedge-type hardware.
A pair of guide assemblies are provided (one for each side of the sectional door). The guide assemblies are adapted to control the positioning of the upper end of the top panel of an overhead sectional door, as it moves back and forth between closed and open positions, so as to keep the panel from contacting the lifting assembly, particularly the cable drums, when the headroom is reduced, for example to 8-10 inches.
In one embodiment, each guide assembly combines the following elements:
In a preferred or optional feature, the curvilinear guide means is a track section having three curved portions in sequence, namely: a convex first portion that connects with the upper end of the upwardly extending track section and guides each upwardly rolling roller inwardly as the door opens, to thereby position the adjoining panel obliquely; a concave central or second portion that generally mirrors the curvature of the adjacent cable drum and is operative to guide the upper end of the top panel away from and past the cable drum while maintaining it out of contact therewith; and a convex third portion that guides the top panel toward horizontal (all when the sectional door is opening).
The pivoting support bracket preferably is generally triangular in shape having a cam follower positioned at its upper apex, a pivot connection located at its rearward apex and a roller at its forward apex.
By way of explanation:
a-1d are simplified side views showing the upper panels of a sectional door advancing along a track from a closed upright position (
a is a perspective exploded view of the pivoting support bracket of
a is an enlarged side view showing the pivoting support bracket and top panel in the fully closed position of
a is a partial expanded side view of the pivoting support bracket and upper end of the sectional door top panel as shown in
Having reference to
Each track 8 comprises a lowermost, substantially vertical track section 15, an overhead, substantially horizontal track section 16 and a corner curvilinear track section 17. The curvilinear track section 17 connects track sections 15, 16. Each track 8 has a C-shaped configuration and defines a channel 18 through which the rollers 7 move.
As shown in
A pair of corner brackets 20 are provided, each mounted to one of the upper corners of the door jamb 10. Each corner bracket 20 extends perpendicularly out from the door jamb 10.
A corner bracket 20 is shown by itself in
The elongated curvilinear track section 17 is supported or carried by and extends across the corner bracket 20 at its lower end. The track section 17 comprises a convex first portion 26, a concave second portion 27 and a convex third portion 28.
The curvilinear track section 17 has one end 29 that is substantially vertically oriented and the other end 30 substantially horizontally oriented, for connection with the vertical and horizontal track sections 15, 16.
A pair of parallel side walls 31, 32 define the channel 18 formed by the curvilinear track section 17.
The corner bracket 20 also supports an elongated cam track 34 extending thereacross, contiguous to the curvilinear track section 17. The cam track 34 is formed by the upper side wall 31 of the curvilinear track section 17 and an extension 33 thereof, together with a top side wall 35. The cam track 34 provides a cam channel 36 defined by upper and lower cam surfaces 37, 38. The cam surfaces 37, 38 each function separately during different modes of door movement to guide and control the cam follower 49 and thereby control the pivoting of the support bracket 45. More particularly the cam follower 49 engages the lower cam surface 38 in the course of opening travel and the upper cam surface 37 in the course of closing travel (as shown by
The top side wall 35 of the cam track 34 has angularly arranged, first and second portions 39, 40, each of generally straight line configuration, which provide the upper cam surface 37. The lower cam surface 38 has first, second and third portions 41, 42, 43. The second portion 42 of the lower cam surface 38 is concave in configuration; the first portion 41 is generally straight and the third portion 43 is convex.
The shaping of the track section 17 and cam track 34 illustrated in the Figures correspond closely with a prototype built and tested by applicants. Those skilled in the art of computer modelling will be able to work out the specific shaping and dimensions appropriate for their circumstances.
Having reference to
From the foregoing it will be seen that a pair of guide assemblies 13 are provided, one at each upper corner of the door opening 11. Each guide assembly 13 comprises the combination of a corner bracket 20, carrying a curvilinear track section 17 and a cam track 34, and a support bracket 45, pivotally connected to an upper corner 6 of the top panel 12, which engages the cam track 45 by means of the cam follower 49 and which further engages the curvilinear track section 17 by means of the top panel roller 7.
The operation will be described with reference to only one guide assembly 13. However it will be appreciated that the two guide assemblies work in unison, the same way, in conjunction with the sectional door 1. In the door-closed position shown in
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Applicants contemplate that various changes may be made in the embodiment described by substituting mechanical equivalents for the components described. The scope of the invention is defined by the claims now following.