Abstract:
A garage door drive assembly for moving a linkage arm connected to a garage door, the assembly being adapted for shipping in a partially assembled condition in at least a box for on-site installation, the assembly has a longitudinally-extending rail with laterally extending flanges. The assembly also has a carriage shaped to fit about the flanges. A drive mechanism is movably mounted to the rail. An anchor is coupled to the drive mechanism. The assembly also has a coupler with a selectively releasable connection to the anchor, a connector pivotably connectable to the linkage arm, and a detachable connection enabling the coupler to be fixedly secured to and carried by the carriage. The rail and the carriage may be shipped to the installation site in a box having a smaller cross-sectional profile than would be required to accommodate the carriage and coupling in their connected state.

Description:
BACKGROUND OF THE INVENTION 
     The present invention is directed to electronic garage door openers and, more particularly, to a drive assembly for an electric garage door opener rail. 
     In the garage door industry, T-rails are shipped in long corrugated cardboard boxes that are approximately 90 to 130 inches long. During shipping, the boxes are frequently damaged and crushed due to excess empty space in the box, which causes handling problems. The shipping survivability of the drive assemblies and boxes can be improved by adding polymer inserts to fill the empty spaces in the box. This is disadvantageous because of the expense of the polymer inserts, the space required for storing bulky packaging components, and the need for disposal of large quantities of non-biodegradeable packaging components. Additionally, drive assemblies are often damaged during shipping, requiring an installer to install a new drive assembly. 
     Another approach to improve shipping survivability is to design a box that fits tightly with the T-rail to reduce the empty spaces that are vulnerable to crushing. In order to reduce the empty space, because the drive assembly is the largest profile component in the assembly, the drive assembly is removed from the T-rail assembly. Removal of the drive assembly from the T-rail during shipping eliminates drive assembly damage from shipping. However, the disadvantage of this approach is that the installer has to reassemble the drive assembly onto the T-rail at the point of installation. Often, in order to reassemble the drive assembly onto the T-rail, the installer has to disassemble other components, such as the drive mechanism and a pulley. This can be a time consuming, confusing and frustrating procedure. Installers are often paid on a piece-meal basis per installation, so lost time can be costly for the installer. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a garage door drive assembly for moving a linkage arm connected to a garage door to raise and lower the garage door. The assembly is adapted for shipping in a partially assembled condition in at least one box for on-site installation. The assembly, according to an exemplary embodiment of the present invention, includes a longitudinally-extending rail having laterally extending flanges extending therefrom. The assembly also includes a carriage shaped to fit about the flanges thereby supporting the carriage for sliding motion along the rail. A drive mechanism is movably mounted to the rail for longitudinal motion along the rail. An anchor is coupled to the drive mechanism for movement with the drive mechanism. The assembly also includes a coupler. 
     The coupler has a selectively releasable connection to the anchor, a connector pivotably connectable to the linkage arm, and a detachable connection enabling the coupler to be fixedly secured to and carried by the carriage. The rail and the carriage may be shipped to the installation site in a box having a smaller cross-sectional profile than would be required to accommodate the carriage and the coupler in their connected state. 
     In an embodiment, the anchor has a first half and a second half. The second half is coupled to the first half using at least one fastener passing through the drive mechanism. The first half and the second half of the anchor form a locking notch. The coupler has a locking tab moveably engageable into the locking notch. Additionally, a spring and a lever are coupled to the locking tab. The lever engages and disengages the locking tab from the locking notch. In an additional embodiment, the lever has a detent at one end, the detent engaging with the coupler to prevent the locking tab from engaging in the locking notch. 
     In an embodiment, the carriage has a retainer, and the coupler has both a mounting base and a plurality of retention brackets. The anchor is prevented from disengaging from the locking tab by the retainer, the mounting base, and the retention brackets. 
     The connector pivotably connectable to the linkage arm has a bracket with a fastener opening. In an exemplary embodiment, the bracket has two bracket arms, each of which has a fastener opening. The linkage arm has an orifice to facilitate attachment to the bracket. The linkage arm is inserted between the two bracket arms and a fastener is passed through the fastener openings and the orifice. 
     In an exemplary embodiment, the detachable connection of the coupler to the carriage includes a biased clip connected to the coupler, the biased clip having a hook; and a clip opening in the carriage. The clip opening is positioned so that the hook is inserted into the clip opening upon proper engagement between the carriage and the coupler. Additionally, the detachable connection includes a plurality of coupler insertion openings extending laterally across the carriage and a plurality of inserts extending laterally across the coupler. The inserts are insertable into the plurality of insertion openings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a perspective view of an interior of a garage showing a garage door and an electronic garage door opening system; 
     FIG. 2 is a perspective view of a carriage coupled to a T-rail with the coupler oriented for insertion into the carriage according to an exemplary embodiment of the present invention; 
     FIG. 3 is a side view of a carriage according to an exemplary embodiment of the present invention; 
     FIG. 4 is a cross-sectional view of a carriage according to an exemplary embodiment of the present invention taken along line A—A of FIG. 3; 
     FIG. 5 is a perspective view of a coupler according to an exemplary embodiment of the present invention; 
     FIG. 6 is a cross-sectional view of a coupler according to an exemplary embodiment of the present invention taken along line B—B of FIG. 5; 
     FIG. 7 is a perspective view of a coupler mounted to the carriage which is in turn mounted to the T-rail according to an exemplary embodiment of the present invention; and 
     FIG. 8 is a side view of a chain anchor according to an exemplary embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     As shown in FIG. 1, a garage door opener system  10  has a garage door opener  12  coupled to a garage door  14 . An exemplary garage door  14  is sectional and is mounted for travel on a pair of rails  16 ,  18 . The garage door opener has a drive unit  20  coupled to a drive mechanism. In an exemplary embodiment, the drive mechanism is a chain  22 . The chain  22  extends along a T-rail  24  mounted from the drive unit  20  and extending longitudinally to a point above the garage door. The T-rail has laterally extending flanges. A drive assembly  25  is releasably coupled to the chain  22 . The chain  22  is driven by the drive unit, and the drive assembly  25  is driven along the T-rail  24  by the chain  22 . A linkage arm  26  is coupled to the drive assembly  25  and to the garage door  14 . As the drive assembly  25  is driven along the T-rail  24 , the arm  26  causes the garage door  14  to be raised or lowered. A switch  27  activates the drive unit  20 . A safety beam emitter  28  and a safety beam receiver  29  are electrically coupled to the drive unit  20  and may stop the drive unit  20  to prevent the garage door  14  from closing on an obstruction. 
     As shown in FIG. 2, a drive assembly according to an exemplary embodiment of the present invention consists of two pieces, a carriage  30  and a coupler  32 . The carriage  30  and the coupler  32  are releasably coupled together. The carriage  30  rides on the T-rail  24 . 
     The carriage  30  has a length extending along the longitudinal axis of the T-rail and a width extending along a lateral axis of the T-rail. As shown in FIGS. 3 and 4, the carriage has a horizontal web  34 . The horizontal web  34  terminates in two C-shaped brackets  36 ,  38  extending along the length of the horizontal web  34 . The horizontal web  34  and the C-shaped brackets  36 ,  38  fit around a wide part of the T-rail  24  and hold the carriage  30  onto the T-rail  24 . A chain anchor retainer  40  extends vertically from the C-shaped bracket  38  on the side of the T-rail where the coupler  32  is attached. The chain anchor retainer  40  extends along the length of the carriage. 
     The horizontal web  34  has a thickness. As shown in FIGS. 2 and 4, portions of the horizontal web  34  are cut away to create two coupler insertion openings  42 ,  44  extending across the width of the horizontal web  34 . In an embodiment, the coupler insertion openings  42 ,  44  are elbow shaped with a horizontal portion  46  adjacent to the horizontal web  34 . A vertical portion  48  is in communication with, and extends downward from, the horizontal portion  46 . In an exemplary embodiment, the horizontal portion  46  is contiguous with the horizontal web  34 . 
     Additionally, an elastic clip  50  with a downward bias is formed into the bottom of the horizontal web. The clip has horizontal portion extending across the width of the carriage. The clip terminates in a downward facing hook  52 . The carriage may be made of many different materials, such as injection molded polymer, stamp formed steel, die-cast steel, die-cast aluminum, and die-cast zinc. 
     The carriage is placed on the T-rail by inserting the carriage over one end of the T-rail so that the C-shaped brackets are placed over the wide part of T-rail. There is no need to remove the carriage from the T-rail for shipping or for garage door installation. 
     As shown in FIGS. 2 and 5 to  7 , the coupler  32  has a length extending along the longitudinal axis of the T-rail, a width extending along a lateral axis of the T-rail, and a vertical axis perpendicular to both the length and the width. The coupler  32  has three different portions. To describe the coupler it is helpful to describe an exemplary embodiment along the vertical axis from the bottom up. However, it will be readily understood by one skilled in the art, that the vertical order and orientation of the described features may be rearranged. 
     A first portion of the coupler  32  engages with the garage door linkage arm  26 . To engage with the linkage arm  26 , a bottom surface of the coupler is formed with a vertically oriented bracket  54 . The bracket  54  has two bracket arms  56 ,  58 . The arms  56 ,  58  contains fastener openings  60 ,  62 . A portion of the linkage arm  26  has a hole with a diameter corresponding to the diameter of the fastener openings  60 ,  62 . The linkage arm is inserted between the two bracket arms  56 ,  58  and the hole in the linkage arm is aligned with the two fastener openings  60 ,  62 . A fastener is inserted through both fastener openings  60 ,  62  and through the hole in the linkage arm to attach the linkage arm to the coupler. In an embodiment, the fastener is a carriage bolt with a retaining pin. 
     A second portion of the coupler engages with the carriage. In an exemplary embodiment, the portion that engages with the carriage is formed above the portion that engages with the garage door arm  26 . Two elbow shaped inserts  64 ,  66 , corresponding to the coupler insertion openings  42 ,  44  of the carriage, are formed across the width of the coupler with a horizontal web between. Two ribs  68 ,  70  extend across the width of the horizontal web. Between the two ribs  68 ,  70  is a raised portion  72  over which passes the clip  50  of the carriage. 
     A clip opening  74  is formed in the raised portion  72 . The clip opening is positioned so that when the coupler is completely inserted into the carriage, the downward facing hook  52  of the clip is sprung into the clip opening  74 . To disengage the coupler  32  from the carriage  30 , a user inserts a tool into the clip opening from a bottom of the coupler and pushes the hook back up over the too of the clip opening  74 . 
     A third portion of the coupler engages with a chain anchor  76 . In an exemplary embodiment, the portion that engages with the chain anchor  76  is formed above the portion that engages with the carriage. 
     As shown in FIG. 8, the chain anchor  76  is placed on the chain to connect the chain to the coupler. In an exemplary embodiment, the chain anchor  76  has two identical halves  77 , although in an alternative embodiment, the chain anchor may be formed as a single piece. A locking notch  78  is formed in the bottom surface of the chain anchor halves. The locking notch  78  allows the anchor to engage a locking tab of the coupler as discussed below. The bottom surface of each anchor half is angled downward from each longitudinal end to an edge of the locking notch  78 . Therefore, the bottom surface of the assembled anchor  76  forms a V-shape along a longitudinal axis with the locking notch  78  at the point of the “V”. 
     Each chain anchor half has two fastener holes  79 ,  80 . One chain anchor half is placed on each side of the chain, and the anchor halves are then aligned. A fastener is placed in each fastener hole  79 ,  80  of one chain anchor half. The fasteners extend through gaps in the links of the chain and out through the fastener holes of the other chain anchor half. The fasteners hold the chain anchor to the chain. Because the fasteners extend through gaps in the links of the chain, the fasteners prevent the chain anchor from moving up or down the length of the chain. In an embodiment, the fasteners are nuts and bolts. In an alternative embodiment, the fasteners are rivets. The chain anchor halves  77  may be made of many different materials, such as injection molded polymer, stamp formed steel, die-cast steel, die-cast aluminum, or die cast-zinc. 
     Referring again to the coupler, as shown in FIGS. 2 and 5 to  7 , A chain anchor mounting base  82  is formed above the second portion of the coupler on the side of the coupler away from the T-rail  24 . The chain anchor mounting base  82  has a hole  83  (See FIG. 5) through which is mounted a spring loaded locking tab  84  that engages with the locking notch  78  of the chain anchor  76 . A lever  86  coupled to the locking tab  84  is positioned on the underside of the mounting base  82 . 
     In an embodiment, the lever has a bracket formed of two arms. Each arm has a hole. Likewise, the locking tab  84  has a hole for passage of a fastener. A fastener is placed through the holes in the arms of the lever bracket and through the locking tab hole to secure the locking tab to the lever  86 . When a free end of the lever  86  is pulled downward, the opposite end contacts a portion of the coupler  32  and acts as a fulcrum. Further downward movement of the free end of the lever pulls the locking tab  84  downward. A rounded detent  88  is formed on one end of the lever  86 . When the lever  86  is pulled downward to retract the locking tab  84 , the detent prevents the lever from moving upward, and the locking tab  84  from re-engaging with the locking notch  78  of the chain anchor  76 . 
     Two right angled chain anchor retention brackets  90 ,  92  are formed above the chain anchor mounting base  82 . The brackets  90 ,  92  have a vertical portion  94  and a horizontal portion  96  extending from the vertical portion toward the T-rail  24 . As shown in FIG. 7, once the coupler  32  is engaged with the carriage  30 , the retention brackets  90 ,  92  and mounting base  82  of the coupler, and the retainer  40  of the carriage, form a cage surrounding the chain anchor  76 . The cage prevents lateral and vertical movement of the anchor relative to the coupler  32 . 
     The coupler may be made of many different materials, such as injection molded polymer, stamp formed steel, die-cast steel, die-cast aluminum, or die cast zinc. Additionally, the carriage and the coupler may be made of two dissimilar materials to improve bearing surfaces. For example, the carriage may be made of low friction material for ease of sliding along the T-rail, while the coupler may be made of a higher strength material for engagement with the chain and the linkage arm. 
     In order to assemble the drive assembly of the present system, the installer removes the T-rail  24  from a shipping box with the carriage  30  already mounted to the T-rail  24 . The installer aligns and inserts the elbow shaped inserts  64 ,  66  of the coupler into the insertion openings  42 ,  44  of the carriage until the hook  52  of the clip  50  snaps into the clip opening  74 . Once the coupler  30  is snapped into the carriage, the installer moves the now assembled drive assembly  25  along the T-rail  24  until the drive assembly  25  is adjacent to the linkage arm  26  of the garage door. 
     The installer connects the coupler  30  to the linkage arm  26  by inserting an end of the linkage arm  26  between the two bracket arms  56 ,  58  and passing a fastener through holes in the two bracket arms  56 ,  58  and the linkage arm  26 . Once connected to the linkage arm  26 , the drive assembly  25  is prevented from moving along the T-rail by the weight of the garage door. The drive unit is activated and the chain and the anchor travel along the T-rail until the anchor reaches the drive assembly. 
     As the drive unit continues to drive the chain and anchor, the anchor enters the cage created by the mounting base  82  and retention brackets  90 ,  92  of the coupler  32  and the retainer  40  of the carriage. The V-shaped bottom surface of the anchor depresses the locking tab  84  as the anchor  76  moves into the cage. The anchor continues to enter the cage and depress the locking tab until the locking notch  78  is positioned over the locking tab  84 , at which time, the locking tab  84  snaps into the locking notch  78 . 
     In additional embodiments, the carriage and coupler are used with a belt, screw, or shaft as the drive mechanism instead of a chain. For example, an anchor may be placed on a belt or a screw to facilitate connection to the coupler. Additionally, the present invention may be used with longitudinally extending support structures other than T-rails with the carriage shape being modified to correspond to the shape of the support structure. 
     The two piece drive assembly allows the shipping box to fit tightly around the T-rail, without requiring time consuming reassembly by an installer. This is because the carriage remains on the T-rail during shipping. The carriage conforms closely to the shape of the T-rail, and adds very little cross-sectional profile to the assembly. 
     Additionally, a two-piece drive assembly according to an exemplary embodiment of the present invention is easier to repair than existing systems. If the coupler is damaged, the coupler may simply be snapped off of the carriage and replaced without removing the entire drive assembly from the T-rail. 
     Although references have been made in the foregoing description to an exemplary embodiment, persons of ordinary skill in the art of designing garage door openers will recognize that insubstantial modifications, alterations, and substitutions can be made to the exemplary embodiment described without departing from the invention as claimed in the accompanying claims.