This invention pertains to access windows and similar equipment more particularly to access windows for drive-through and walk-up fast food service installations. These access windows are typically provided in a building, such as a fast-food service establishment, a convenience drive-up food store, a service station attendant's booth, a free-standing kiosk, or the like.
The present invention especially relates to access windows typically installed on the side of a building adjacent a driveway or sidewalk to facilitate business transactions between an employee and customer. Such windows are conventionally located in a manner permitting an employee to view the customer approaching his window and to personally transact business with the customer.
In a typical commercial environment a drive-up access window must easily permit the employee to transact business with a customer and yet provide the necessary isolation between the outside environment and the inside environment to satisfy health end safety requirements.
Prior art windows are described in U.S. Pat. No. 4,411,102; U.S. Pat. No. 4,442,630; U.S. Pat. No. 4,733,498; and U.S. Pat. No. 4,641,460. The windows may be actuated solely by manual force or by electrical motors triggered by an employee or by the presence of an employee.
Mechanically operated prior art devices require a substantial amount of physical exertion to operate as many windows in busy fast-food establishments may be operated in excess of 900 times per day. In an effort to reduce the physical strain and exertion associated with such operation many fast-food establishment employees resort to mechanically blocking a window in the open position which violates many local and state health codes. In some cases motor operators have been installed in such windows, however, switches and the like used to trigger the windows also have proven problematic inasmuch as the employees typically must open the windows without the use of their hands. Where automatic sensing means have been used, the auto-sensing means for the motor-operated windows has also proved problematic as the windows open unintentionally due to employee traffic in the proximity of the window or in some cases close inadvertently whenever the employee fails to maintain a physical pose in a manner that breaks an infrared beam or the like.
The present invention meets the above-mentioned disadvantages by providing a reliable sensor and triggering device for a motor-assisted fast-food service window. The present invention uses an upwardly focused light emitting diode (LED) emitter/receiver sensor in a new and novel fashion that substantially reduces the number of times that a fast-food service window is unintentionally opened while at the same time providing for reliable sensing of an employee in the fast-food window area just prior to providing a customer with food, drinks, change or other items required wherever business is transacted. The invention is further characterized by the application of an infrared emitter/receiver sensor in a manner not requiring a fixed reflective surface to serve in a manner to return the infrared beam from the emitter to the receiver.
The preferred embodiment of the apparatus comprises a plurality of upwardly focused infrared emitter/receivers mounted on the internal side of a fast-food service window at an angle slightly off of the horizontal plane in a manner emitting an infrared beam at an angle slightly askew of the vertical axis. The sensors are used to detect an employee in the immediate proximity of a fast-food service window as the employee bends over the horizontal service shelf as the employee begins to reach towards a customer, that is, as the employee extends an arm over the sensor. The sensors, although focused towards the interior of a building, do not detect employees or traffic in the immediate vicinity of the fast-food service window thereby virtually eliminating the unintentional opening of the window. In the preferred embodiment, the sensor circuit is equipped with a time delay of approximately 0.2 seconds (2/10 seconds) time delay in sensing an object as an additional aid in eliminating false openings and closings of the access window. The uniquely oriented sensors are connected to an electric motor operator which opens the window as an employee prepares to deliver merchandise or other items to a customer. As the employee retreats from the fast-food service window area, the sensors then detect the absence of the employee thereby causing the motor operator to close the fast-food service window.
In the preferred embodiment, the electrically operated service window also is equipped with a switch to facilitate the use of the window by a wheel-chair bound employee or handicapped employee who may not bend over the horizontal service shelf in the traditional manner. In this fashion a wheel-chair bound employee can open the window by operating the switch and thereafter close the window by again operating the switch in the other direction. When the switch is oriented such as to close the window, the window is also returned to the automatic operation phase in a manner that will permit it to again property detect the proximity of an employee reaching across the horizontal service area as such employee reaches towards a customer on the outside of the window, that is, to detect an extended arm of the employee before the torso of the employee is detected.
The various features and principles of the invention will become obvious to those skilled in the art upon review of the detailed description in conjunction with the appended drawings and claims.
Corresponding reference numbers indicate corresponding parts throughout the several views of the drawings.
Referring now to the drawings, and with specific reference to
Referring now to
Another important aspect of the present invention is illustrated in
An electrical circuit for a window motor operator including motor, electronic control and accompanying circuit board, and linkages to open and close the sliding window panel would be apparent to one skilled in the art. Typically, an electric motor is linked to the sliding window pane 16 by means of a belt drive from the output of a motor shaft. In the preferred embodiment the motor is such that it is energized and operates to open the sliding window pane whenever an employee is detected within the sensing field of the sensors 29 and the motor is thereafter reversed thereby causing the window pane 16 to close when an employee is no longer detected within the sensing field of proximity detector 29. Appropriate limit switches serve to limit the opening and closing distance of the window pane 16. In addition to typical limit switches, a clutch is typically employed together with a motor and belt drive to permit manual intervention to cause the window to open in the event of power failure or to prevent the window from continuing to open or close whenever it is partially or completely obstructed by a person, a person's limb, or an object.
By upwardly focusing the proximity sensors, the present invention addresses and comprehends the posture of a fast-food service employee providing service to a customer while at the same time minimizing the inadvertent opening of the fast-food service window by passing employees who are not attempting to service a customer. The present invention further addresses and comprehends the propensity of a fast-food service employee who typically presses against the horizontal service area, by providing mounting rings 40 which minimize the potential of completely blocking the light reflected from the LED emitter 50 back to the receiver/detector 52.
In view of the above, it will be seen that the other objects of this invention are achieved and other advantageous results obtained.
As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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