The invention relates generally to electric door systems and operators for the same and more particularly to a sliding door system and an operator for moving doors. In one preferred embodiment, the sliding door system includes an operator that requires an individual to assist in the initial movement of a door of a commercial cooler/freezer.
Conventionally, heavily insulated doors, such as for walk-in cooler/freezer, have often used swinging doors that need to be manually opened and closed. However, manual operation of freezer or cooler doors can be quite inconvenient and burdensome, especially when the doors are heavily insulated and weighty and are opened frequently. In addition, swinging doors can also be hazardous to individuals in close proximity to the doors. Specifically, individuals opening the doors as they enter or exit the freezer or cooler unit can strike others in close proximity with the door and cause serious physical harm to the person.
Sliding doors for walk-in freezer or cooler units are well known in the industry. Manually operated doors have the advantage of being relatively inexpensive, but frequently are difficult and inconvenient to open and shut. As a consequence, it is not uncommon for workers to leave the door in the open position for extended periods of time, particularly when the worker intends to make repeated trips into and out of the cooler/freezer. Leaving the door open, of course, results in substantial energy loss, and economic waste. It also is known to use sliding doors that are motor-driven. Unfortunately, due to the weight of the doors and the especially the energy required to initially move the doors from their sealing position, relatively large electrical motors are required to open the doors. What has been needed in the industry, but has not been available, is an inexpensive door system that is easily and inexpensively installed, that opens easily and closes when it is desired to close the door.
Many of the designs that have been proposed have proven unreliable and costly, due to their highly complex designs. In addition, such prior designs have also been found to be difficult to install and difficult to service and maintain by maintenance personnel.
As such, there remains a need for an system for an electric door that includes an operator which can be installed with existing low power electrical service and which overcomes the unreliability, costs and difficulties noted above and provides a simple, straightforward and inexpensive system for sliding doors.
In one embodiment of the invention, a system for moving a door between open and closed positions to selectively allow access to an enclosed space. The system comprising a door, the door being slidably movable between a first closed position and a second open position, the door being operative to close an opening to an enclosed space, an actuator operative to initiate movement of the door from its first closed position toward its second open position, and a control unit, the control unit including a motor, the control unit being responsive to initial movement of the door and being operative to actuate the motor, the motor being selectively operative to slidingly move the door toward the open position in response to the initial door movement after the door has initially moved from its closed position.
In yet another embodiment of the invention, an operator for moving a door between open and closed positions to selectively allow access to an enclosed space. The operator comprises an actuator operative to initiate door movement from its first closed position toward its second open position and a control unit, the control unit including a motor, the control unit being responsive to initial door movement and being operative to actuate the motor, the motor being selectively operative to slidingly move the door toward the open position in response to the initial door movement after the door has initially moved from its closed position.
While the invention concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which like reference numbers identify the same elements in which:
Reference will now be made in detail to certain exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings.
Referring now to the drawings,
In the exemplarily embodiments illustrated in
In the exemplary embodiments illustrated in
Referring now to the embodiments illustrated in
In the exemplary embodiments illustrated in
The door 30 of a cooler/freezer normally is kept in its closed position in order to avoid excessive loss of energy. In use, an individual wishing to gain access to the interior space of the cooler/freezer initially grasps and rotates the handle 40. This manual movement of the handle 40 applies a force against the pry plate 45. This force results in an initial movement of the door 30 that move the rollers out of the detents in the track 50, unsealing the door 30 and moving it upwardly and outwardly toward the open position. After this initial opening displacement, the control unit 70 senses the displacement of the door 30 through use of the encoder 70B and activates the motor 70A. Once activated, the motor 70A completes movement of the door 30 to the open position without any further force needed by the individual and thereafter holds the door 30 in the open position. Closing of the door 30 can be initiated after an number of selected events. For example, the control 70 could be programmed to close the door 30 after a predetermined amount of time. Alternatively, or in addition, the system could be programmed to reverse direction of the motor 70A and close the door 30 upon the displacement of the door 30 toward the closed position. In either event, the motor 70A would cease complete displacement of the door 30 at its closed and sealed position.
Advantageously, the electric door system and operators illustrated in the exemplary embodiments of
The foregoing description of the preferred embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims in their fair and broad interpretation in any way.
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/223,102, filed Jul. 6, 2009.
Number | Date | Country | |
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61223102 | Jul 2009 | US |