Patent Application
20140290878
This invention relates generally to overhead doors, and in particular, to an overhead door with stacking panels.
Overhead doors are utilized to provide security and access control in institutional, industrial and commercial buildings. They fall into two general design categories: coiling doors and segmented panel doors. Each have their advantages and disadvantages making one better suited for a given design application.
Often times a segmented panel door is better suited for a particular application but cannot be used due to the increased space requirement needed to house the panels once the door is opened. Various attempts have been made to reduce the profile of the opened door, such as stacking the panels as taught in U.S. Pat. No. 4,460,030 to Tsunemura et al. and in U.S. Pat. No. 5,685,355 to Cook et al.
The stacking design of those two patents, as do all other known panel stacking designs, maintain a connection point between the panels such as a hinge, or otherwise link the opened panels, for example, with chains, to support the weight of the panels during opening.
Having to maintain a connection point between the panels presents many disadvantages such as placing limitations on the ease of repair of damaged panels and requiring higher energy consuming operators to open the door. Accordingly, there is still a continuing need for improved stacking panel overhead door designs. The present invention fulfills this need and further provides related advantages.
The following disclosure describes a stacking panel overhead door design wherein the panels are independent of one another.
One advantage of unconnected stacking panels is the spring torque to door weight ratio is easy to control. The weight of the door decreases as the door is lifted and a panel disengages completely from its adjacent panel as it reaches the stacked position. This allows for a linear spring torque to door weight relationship requiring a smaller motor compared to existing designs to provide the lifting torque necessary to operate the door, thereby providing concomitant energy savings. Chart A represents the spring torque to door weight ratio.
A second advantage of independent stacking panels is the ease of replacement or repair of a damaged panel.
Other features and advantages of the present design will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
The accompanying drawings are included to provide a further understanding of the present invention. These drawings are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the present invention, and together with the description, serve to explain the principles of the present invention.
Chart A represents an ideal spring torque curve.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate by way of example the principles of the invention.
As required, detailed embodiments of the present invention are disclosed; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. The figures are not necessary to scale and some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed are not to be interpreted as limiting but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. Where possible, like reference numerals have been used to refer to like parts in the several alternative embodiments of the present invention described herein.
Turning now to
As shown in
Turning to
All panels 4, including the bottom panel 48 are interchangeable to allow for easy removal of a damaged panel and replacement. The bottom panel 48 (
When the drive mechanism 64 is a cable, the cable arrangement provides the cable 64 an effective operative cable geometry that will allow the cable 64 to operatively wrap on a cable drum 66. As shown in
Turning to
To insure proper panel engagement/disengagement during door closing and opening and to prevent water from traveling from the outside environment to the inside environment, angles α and β are about 10 degrees to about 25 degrees, preferably about 15 degrees to about 20 degrees and optimally about 18 degrees.
While the following elements may be attached directly to a panel 4, for the advantages described above, in a preferred embodiment they are fabricated as part of the end cap 46. As shown in
Activation engagement member 34 aids in engaging/disengaging the lip 20 and trough 22 of adjacent panels by riding on the panel guide 38 around the panel bottom edge radius 40 to nest the panels in the fully engaged (door closed) position. Bearing 34 remains in contact with panel guide 38 in the stacked position, the fully closed position, and throughout the panel engagement/disengagement operation.
The second positioning assembly 28 comprises an engagement member, for example, a bearing 36, extending inward from the panel inner surface 12 to operatively engage the second track 8.
Although optional panel stiffeners may be added to the panel 4, the present design does not require any stiffeners to be operatively effective, providing additional benefit over known sectional door designs which require stiffeners to achieve equivalent wind load ratings. In a preferred embodiment the insulating material 14 comprises an expandable foam injected between the outer 10 and inner 12 panel surface. While bearings have been used as exemplars for the engagement members, any low friction member, for example, PTFE pads are also contemplated.
Turning now to
The optimal sizing of the radii γ and δ allows for the advantageous reduced force required to operate the door 2. Larger radii would require increased initial force to hold the panels, thereby causing the spring torque to door torque to become out of balance near the closed position as those panels are no longer traveling within the radii. Larger radii would also increase the height of the stacked panels 4 above the door opening creating the need for additional overhead space. In the preferred embodiment, the radii γ and δ are about three inches to about five inches, and optimally, about four inches. Along with providing the optimal spring torque to door torque ratio, the optimal radii allow the footprint of the panel stack 58 to fit within the current requirements for a typical rolling steel door construction, thereby allowing easy retrofit.
In operation of a preferred embodiment, to close the overhead door 2 a motor 60 turns a shaft 62 in a direction to unwind a cable 64 from a cable drum 66 attached to the shaft 62. The bottom panel 48 gravity closes as the cable 64 unwinds. The bottom panel 48 maintains the panel immediately superior to it in the panel stack 58 until the point of transition to the engaged position. As the lip 20 and trough 22 of adjacent panels 4 become engaged, the process begins again as the newly engaged panel maintains its immediately superior panel in the panel stack 58 until the point of transition to the engaged position. The process repeats until all of the panels necessary to close the opening are in place.
To open the door 2, the opposite occurs. As the motor 60 turns the shaft 62 winding the cable 64 onto the cable drum 66 the bottom panel 48 is raised thereby raising all the panels above it. As a panel 4 travels through the radii γ and δ, the activation bearings 34 located at each panel end disengage the lip 20 and trough 22 of adjacent panels as the activation bearings 34 ride on the panel guide 38 around the panel bottom edge radius 40. As each succeeding panel is disengaged it pushes the preceding panel into and forms the panel stack 58.
In this manner, the weight of the door 2 decreases as each panel 4 disengages and joins the panel stack 58. This allows for easier control of the spring torque to door weight ratio. This linear relationship (indicated by Chart A) requires a much smaller motor to provide the lifting torque necessary to operate the door when compared to known technology where the panels cannot separate from one another.
Because the panels 4 are independent from and unconnected to one another, repair or replacement is easily and quickly accomplished. Returning to
Although the present design has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present design is capable of other variations and modifications within its scope. For example, although a cable lifting mechanism has been described, any motion that provides for raising and lowering the bottom panel is contemplated. These examples and embodiments are intended as typical of rather than in any way limiting on the scope of the present design as presented in the appended claims.
