Patent Application
20050126720
The present invention relates to an articulated or rolling door and a drive system for opening and closing the door.
Articulated doors are formed from a plurality of panels hingedly connected to one another. These types of doors are becoming more and more popular for many different uses. They are for example used to cover large openings to garages and warehouse spacing etc. They are further used as rear truck doors on large truck trailers.
In the past, articulated doors were typically made from wood or lightweight steel materials. More recently there have been developments with respect to plastic panels which have become particularly suitable for use in rolling door applications.
A conventional rolling door is provided with cables to opposite sides of the door. These cables are used to raise and lower the door. In many garage type setups an automatic control in the form of a bar secured to the roof of the garage and extending to the upper end of the door is used to provide automatic opening and closing of the door. These garage door controllers are further able to hold or lock the garage door in its closed position.
It is not known in the trucking industry to use the conventional automatic door opener for a truck trailer door. This is because of the overhead space limitations of the trailer. A conventional roll up truck trailer door is therefore manually operated and necessitates a door lock for securing the door in its closed position.
The present invention provides a door system based on a chain drive for opening and closing an articulated door. The system of the present invention is one which has numerous different applications including truck trailer applications. In these particular applications the truck trailer door can be opened and closed using a power drive without having space limitation concerns.
In particular, a door assembly of the present invention comprises an articulated door formed from a plurality of preferably plastic panels hingedly connected to one another. Each of the panels has an end fitting. The end fitting of the panels are pivotally linked with one another to form a chain to the side of the articulated door.
The assembly further includes a rotatable toothed gear which engages the chain formed by the end fittings for opening and closing the articulated. The toothed gear may be a power driven gear.
The above as well as other advantages and features of the present invention will be described in greater detail according to the preferred embodiments of the present invention in which;
A pair of these panels secured to one another are shown in
The panels are all identical in construction with one another. Each panel includes a curved tail 11 at one end of the panel and a correspondingly shaped slot 13 at the other end of the panel. The tail of one panel fits into the slot of an adjacent panel to form a hinged joint between panels.
End fitting 15 comprises a link part 17 provided with internal lugs 19 and spaces between the lugs. A roller 21 is rotatably trapped to one end of the link as shown in
Provided on the outside surface of link 17 is a cover plate 23 with a plug part 25 projecting from plate 23.
Like panel 5 end fitting 15 preferably has a resin base construction. The end fitting may be injection molded from a relatively hard durable plastic material such as nylon or the like. The panel on the other hand is preferably made in an extrusion or even a pultrusion process. Foam material 9 may be introduced to the interior of panel 5 as the panel is being formed. The pultrusion process lends itself particularly well to formation of the panel while simultaneously injecting the foam into the interior of the panel.
End fitting 15 is mounted to panel 5 by pushing plug part 25 of the end fitting into the open end 7 of the panel. The plug portion will then embed itself into the foam material to secure the fitting with the panel end. Adhesives may also be used to assist in securing the panel and the fittings to one another.
As an alternative method of securing the fitting with the panel, the plug part 25 of the fitting can be pushed into the open end of the panel before foaming. The injected foam will then fill the hollow interior of plug part 25. The foam hardens within the plug part to secure the end fitting with the panel.
In
A drive system generally indicated at 35 operates in conjunction with the chain formed by the end fittings to raise and lower door 3. This drive system comprises a rotary gear 39 having teeth 40. Teeth 40 and more particularly the gaps between teeth 40 engage the lugs 19 of the chain links 17.
Rotary gear 39 is attached to a second rotary gear 41 having teeth 42. The teeth 42 of gear 41 engage with correspondingly shaped teeth of a transfer gear 43. Transfer gear 43 is rotated by a power driven gear 45.
The chain formed by the panel end fittings is guided in its up and down travel by means of a track 31 mounted to the interior of the truck.
As earlier noted the door assembly of the present invention will typically include a power drive system as described immediately above to both sides of the door for a balanced opening and closing of the door.
A further benefit provided by the power drive system is that when the main drive gear 45 is not in operation it is locked against rotation. This in turn locks up the rest of the assembly which eliminates the need for any type of an external lock on the door. As can be seen with respect in
Although various preferred embodiments of the present invention have been described in detail, it will be appreciated by those skilled in the art that variations may be made without departing from the spirit of the invention or the scope of the appended claims.
