US 3495342 A
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Description (OCR text may contain errors)
Feb. 17, 1970 A. GOLDSTEIN 3,495,342
HAND DRYER WITH FRONT OPENING AND IMPROVED TIMER Filed Feb. 2 1968 a Sheets-Sheet 1 FIG.1.
I INVENTOR M m we Gawsrw ATTORNEY Feb. 17,1970 AGQLDSTEN 3,495,342
HAND DRYER WITH FRONT OPENliNG AND IMPROVED-TIMER FIG-.2.
Filed Feb. 28. 1968 INV EN TOR Mew-ave (r0 bsrm 3mm M ATTORNEY s sheets-sheet 2 Feb. 17, 1970 I A. s ows-ram 3,
HAND DRYER WITH FRONT OPENING AND IMPROVED TIMER Filed Feb. 28, 1968 3 Sheets-Sheet} FIG.4.
- i 12 r\ I J] INVENTOR men-Ne "Mam v 'WLM (AM ATTORNEY United States Patent O US. Cl. 34-44 4 Claims ABSTRACT OF THE DISCLOSURE An electromagnetic switch intended for use with a hand drying appliance as described in Patent No. 3,305,- 938 and with a hot-air dryer and a towel container. The switch controls the dryer and is operated by withdrawing a towel from the container. An actuating contact set of the switch is actuated by movement of a trip arm which carries one contact of the set. The trip arm is biased to a position in which the contacts of the set are open. The other contact of the set is carried by an intermediate arm biased towards the contact on the trip arm.
BACKGROUND OF THE INVENTION This invention relates to delayed opening electromagnetic switches.
It is an object of the invention to provide a simple and inexpensive device electric switch which will be held open or closed for a predetermined time interval after each time it has been operated. The invention is primarily intended for the control of an electrical heater and blower in a hand drying device as described in the specification of the specification of my Patent No. 3,305,938. However, the invention is not restricted to such use as it could be used with advantage for many other purposes such as the control of traffic lights at pedestrian-operated pedestrian crossings.
SUMMARY OF THE INVENTION In the aforesaid specification, there is described an electromagnetic switch comprising an electric solenoid having an armature which is displaceable from an inoperative position when the solenoid is energised, but which is biased to return to the inoperative position when the solenoid is de-energised, a pair of suction cups one of which is carried by the armature, the cups being so arranged that their faces are closed together when the armature is displaced on energisation of the solenoid thereby to hold the armature in the displaced position; an operating plunger which is carried by the armature and a controlled contact set which is held open or closed as desired by the operating plunger when the armature is in its inoperative position, but which is movable to the closed or open position when the armature is displaced, air being permitted to enter between the cups after they have been closed whereby the cups will open after a predetermined time to permit the armature to return to its inoperative position. The present invention provides a modification in which an actuating contact set is actuated by movement of a trip arm which carries one contact of the set and is biased to a position in which the contacts of the actuating contact set are open, the other contact of the actuating set being carried by an intermediate arm biased towards the contact on the trip arm.
With this arrangement, an improved and more positive operation of the switch is obtained.
3,495,342 Patented Feb. 17, 1970 "ice BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a sectional diagram illustrating an end of a hand drying device which is a preferred embodiment of the invention, and
FIGURE 2 is a scrap view,
FIGURE 3 is a view of a drying apparatus including the switch of the invention, and
FIGURE 4 is a circuit diagram.
DESCRIPTION OF THE PREFERRED EMBODIMENT In the illustrated embodiment of the invention an apparatus for drying the hands is provided with a delayed setting switch comprising an electric solenoid 1 mounted in a suitable bracket 2 on a magazine 3 removably mounted in a cabinet 4 of the drying apparatus. The timer solenoid 1 has an armature 5 which will be upwardly displaced when the solenoid is energised by operation of a main actuating contact set 6. The armature is biased by a weight 7 so that it will occupy a lower, inoperative position of rest, when the solenoid 1 is not energised.
The armature 5 has an upper extension which carries, the lower one (7) of a pair of suction cups. The upper one (8) of these cups is supported by a screw 9 in the bracket 2 in an adjustable fixed positon. The faces of the two cups 7a, 8 are presented to each other and the cups are so positioned that when the armature 5 is raised, by energising the solenoid, the faces of the cups are closed together. This will cause the cups to be held together so that the armature 5 is held in its raised position. An air inlet 10 is provided in the upper cup 8 so that air can enter between the cups when closed whereby the suction between the cups will be broken after a predetermined time dependent on the amount of air between the cups and this will depend on the setting of the adjustable upper cup. as the solenoid is then de-energised the armature will return to the inoperative position. The suction cups can be made of a combination of rubber together with a non-sticky substance such as polyethylene or P.T.F.E.
The armature carries at its lower end a weight 7 which acts as an operating plunger which projects beneath the solenoid 1. This weight 7 is engagable with a pivotally mounted arm 11 of a contact set 12 to be controlled. The arm 11 is made of electrical insulating material. When the armature 5 is at its normal or inoperative position, the weight 7 is engaged with the arm 11 to press it down and hold the contacts 12 in the open condition as shown in the drawing. When the contact set 6 is closed, the solenoid 1 is energised to raise the armature 5 and the weight 7 thereby to enable the contacts 12 to close. The same movement also closes the cups 7, 8 together. After the predetermined time interval the cups will open owing to the fact that air can enter through the air inlet 10 thereby to enable the armature 3 and the Weight 7 to fall so as to open the controlled contacts 12.
If the contact set 6 is re-closed before the cups have opened, the device will be re-set so that the time interval desired will commence at the time of re-setting.
The actuating contact set 6 is actuated by movement of a pivotally mounted trip arm 13 of insulating material. The trip arm 13 is connected through a slip clutch 14 with an operating roller 15 extending through the casing 3. A stack of paper towels T inside the magazine 3 rests on the roller 15 in such a way that the roller is rotated when the lowermost towel in the stack is withdrawn for the purpose of drying the hands. This will pivot the trip arm 13 connected to the roller 15. The arm 13 has a conactildofflthecqntact set 6,.and the. .distancebetweenthe.
contact and the roller of the arm is relatively long so that a small turning movement of the roller 15 will produce a relatively large movement of the contact 16. The arm'13 carries a weight 7 which' biases the arm toward a stop 18. A freely pivoted intermediate arm 19 has a contact 20 (which is the outer contact of the contact set 6) and a Weight 21 when the roller 15is rotated on withdrawal of a paper towel, the contacts 16 and 20 will close together and will remain in contact for a period of about two seconds depending on the length of the arm 13. Thus, the solenoid 1 will be energised to set in operation for a limited period, a blower motor 22 and'an electric heater 23. An electric pre-heater 24 remains permanently in operation. 1 t v If the towels T should become jammed between the roller 15 and the stack of towels, the contacts 16, 20 will, nevertheless, gradually be opened owing to the vibration setup by the vibration of the blower driven by the motor It is sometimes desirable to be able to operate the blower motor 22 and heater23-without withdrawing a towel; for example, if the supply of towels should be temporarily exhausted. The trip arm 13 can, therefore, be operated to close the contacts 16, 20 by operation of a push button 25 operable through an opening 26 at the front of the cabinet 4. This push button 25 controls a spring loaded plunger 27 to rock a bell-crank arm 28 and depress a foot 29 of the arm 13.
The magazine 3 contains all the operative parts of the apparatus and can be removed as a unit from the top of the cabinet 4 for servicing. The cabinet 4 has a front door 30 to permit replacement stacks of towels to be inserted as required.
What I claim is:
1. An electromagnetic switch comprising an actuating contact set; a trip arm movable to close the contacts of the actuating contact set, the trip arm carrying one contact of the actuating contact set and being biased to a position in which the contacts are open; an intermediate 4 arm carrying the other contact of the actuating contact of the actuating contact set and being biased towards the contact on the trip arm; an electric solenoid having an armature .which. is ,displaceable from .an inoperative posi: tion when the contacts of the contact set are closed, but which is biased to return to the inoperative position when the solenoid is de-energized; a pair of suction cups one of which is carried by the armature, the cups being so arranged that their faces arezclosed'together when the armature is displaced thereby 'tohold'the armature in its displaced position; an operating plunger which is carried by the armature; and a controlledcontact set-which is-h'eld open by the operating plunge'r'when the armature is in its inoperative position, but which is movable to the closed position whenthe armature is displaced, means to permit airinto the space between the cups after. they have been closed whereby the cups will open after a predetermined time to permit the core to return to its inoperative position. e 1
2. A switch as claimed in claim 1 wherein the trip arm-is connected wi'than operating roller through a slip I, clutch so that rotation of the roller'will move the trip b arm'to actuate the'actuating contact set.
-3. A switch as claimed in claim 2 wherein a bell crank I arm is arranged between the-trip and a push button device whereby the trip arm can be moved to close the actuating contact set by operation of the push button.
4. An electric hand drying appliance including a towel container and provided with a device as claimed in claim 2, the operating roller being rotatable by withdrawal of a towel from the container.
References Cited UNITED STATES PATENTS FOREIGN PATENTS 6/1959 Great Britain.
FREDERICK L. MATTESON, JR., Primary Examiner H. B, RAMEY, Assistant Examiner U.S. c1. X.R. 3453; 200-34; 219--364; 335-61