US3887890A

US3887890A - Switch mechanism ensuring the automatic closing of a motor-operated garage door

Info

Publication number: US3887890A
Application number: US449269A
Authority: US
Inventors: Florian Lafontaine
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-03-08
Filing date: 1974-03-08
Publication date: 1975-06-03
Anticipated expiration: 1992-06-03

Abstract

The mechanism comprises two switches: a first thermostatic switch consisting of three successive adjacently spaced bimetallic blades; and a second switch having its contacts opened or closed by a first of said three blades. Movement of this first blade is caused by the passage of a motor-operating current through a heating element mounted on the first blade. The second switch is connected to the latching relay coil in the garage door motor circuit and its actuation, after the garage door has travelled to a fully opened position, ensures the automatic return of the garage door to a closed position. This mechanism enables the garage door to always close after it has been opened and also to give indication of its imminent closure.

Description

United States Patent 1 1 Lafontaine 1 June 3,1975

[ SWITCH MECHANISM ENSURING THE AUTOMATIC CLOSING OF A MOTOR-OPERATED GARAGE DOOR [76] inventor: Florian Laiontaine, 10747 Hotel de Ville, Montreal Nord, Quebec, Canada [22] Filed: Mar. 8, 1974 211 Appl. No.: 449,269

Primary Examiner]. D. Miller Assistant Examiner-Fred E. Bell [57] ABSTRACT The mechanism comprises two switches: a first thermostatic switch consisting of three successive adjacently spaced bi-metallic blades; and a second switch having its contacts opened or closed by a first of said three blades. Movement of this first blade is caused by the passage of a motor-operating current through a heating element mounted on the first blade. The second switch is connected to the latching relay coil in the garage door motor circuit and its actuation, after the garage door has travelled to a fully opened position, ensures the automatic return of the garage door to a closed position. This mechanism enables the garage door to always close after it has been opened and also to give indication of its imminent closure.

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0 F LATCHWG RELAY 1 SWITCH MECHANISM ENSURING THE AUTOMATIC CLOSING OF A MOTOR-OPERATED GARAGE DOOR FIELD OF THE INVENTION The present invention relates to a switch mechanism for ensuring the automatic closing of a motor-operating garage door after the door has travelled to a fully opened position.

BACKGROUND OF THE INVENTION The popularity of operating a garage door with a radio remote control increases everyday. However, the possibilities of having doors opened by people other than those permitted increase also proportionally. This is explained by the fact that remote controls are subject to rigid federal laws which limit the amount of frequencies available for this purpose. Hence, it is relatively easy for persons not permitted to have access to a particular garage to find the given frequency for the operation of the garage door. Serious inconveniencies can result in having a door remaining opened in a very cold wheather for example, where severe and costly damages can occur to the building or articles inside the garage.

STATEMENT OF THE INVENTION It is therefore an object of this invention to provide a mechanism which will ensure the automatic closing of a garage door once it has reached a fully opened position.

I The mechanism consists in the combination of two interacting switches; the first switch consists of three successive adjacently spaced bi-metallic blades, one of which is provided thereon with an electric heating element for operating the blade. Such thermostatic switch may be found disclosed in U.S. Pat. No. 3,533,039 is-, sued Oct. 6, 1972 to DB. Mundt. The second switch is disposed adjacent the heater carrying blade of the thermostatic switch and is provided with contacts which are opened or closed depending on whether a motoroperating current passes through the heating element. The contacts of the second switch are connected to a latching relay coil in the motor circuit; when these contacts are closed after the door has travelled to a fully opened position, the garage door motor is energized to return the garage door to a fully closed position.

DESCRIPTION OF THE DRAWINGS Other objects, purposes and characteristic features of the present invention will be in part obvious from the accompanying drawings, and in part pointed out as the description of the invention progresses. In describing the invention in detail reference will be made to the accompanying drawings, in which like reference characters designate corresponding parts throughout the several views, and in which:

FIG. 1 is a front elevational view of a switch mechanism made in accordance with the present invention;

FIG. 2 is an end view of the switch mechanism shown in FIG. 1; and

FIG. 3 is a circuit diagram for carrying out the operation of the switch mechanism shown in FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. I there is shown a switch mechanism 10 which consists principally of a thermostatic switch 12 and of a second switchld. These

switches

12 and 14 are mounted on an iron angle support 16 which includes two

contiguous walls

18 and 20.

The thermostatic switch 12 includes three successive adjacently spaced

blades

22,24 and 26, each having one end fixedly mounted in a block 28 of rigid insulating material, such as 'porcelaine, which is fixedly mounted to the wall 18 by means of a bracket 19. A heating element 30 covers a substantial part of the blade 22. The particular construction and material preferably used for the thermostatic switch 12 are taught in the above-mentioned U.S. patent to Mundt and will not be repeated in the present disclosure. Blade 22 is connected to the line voltage, while blade 24 is connected to a lamp 25 and blade 26 is connected to the garage door motor 27.

Blade 22 is flat and bi-metallic and tends to curve toward the bi-metallic blade 24 as the temperature raises in the heating element 30.

Each end of the blades includes contacts, such as 32, 34, 36 and 38, so that suitable contact may be effected between

blades

22, 24 and blades 24 and 26. The opposite ends of the blades are secured in block 28, and this allows a certain movement for the free ends of the blades.

Although not shown in FIG. I, but schematically represented in FIG. 3, the heating element 30 is ground to blade 22; a metallic connection 40 is provided between the heating element 30 and the third blade 26.

Switch 14 includes a metallic blade 42 which is adapted to move into contact with contact 44 when actuated by the blade 22 of the thermostatic switch 12. Switch 14 includes two

connections

48 and 50 for connection with the coil of a latching relay used for the operation of the garage door motor.

Referring to FIG. 2, switch 14 is fixedly secured to wall 20 by means of

fasteners

52 and 54; fastener 54 is suitably received in a slot 56 so as to allow adjustment of the position of the switch l4"and its blade 42 relative to the thermostatic switch 12 or its blade 22.

Although not illustrated in the drawings, the garage door mechanism includes a series of limit switches which operate to de-energize the motor circuit when the garage door has reached a fully opened position or a fully closed position; also provided are mechanisms which will stop or reverse the ,door movement when an obstacle is encountered during operation. Such mechanisms may be found described in U.S. Pat. No. 3,633,313 issued Jan. 11, 1972 to Lucien Lafontaine.

An ON-OFF switch 58 may be inserted in the circuit between switch 14 and the latching relay coil should the automatic closing feature be temporarily not wished.

OPERATION OF PREFERRED EMBODIMENT When the garage door is in a fully closed position, blade 22 is in the rest position shown in FIG. 1 and contacts blade 42. In this position, however, the motor is not energized since a limit switch, which was actuated when the door reached its closed position, caused the opening of the motor circuit assuming now that the door is opened as resulting from a remote radio signal or directly through button actuation, a motor operating current passes through the heating element 30 causing blade 22 to bend toward the intermediate blade 24. As blade 22 raises, connection between blade 42 and contact 44 is opened. The contact of blade 22 with blade 24 causes the illimination of the lamp 25 to indicate that the door is being opened. Depending upon temperature condition, the time taken to blade 22 to contact blade 24 may vary by adjusting the relative po sition of the

blades

22 and 24. Contact may be accomplished before or after door operation has been accomplished. When contact is established between 22 and 24, the lamp current does not pass through the heating element. There is provided an automatic door control switch which stops the motor when the door has reached a fully opened position. Should the blade 22 continue to respond to a raising temperature from the heating element, there will be contact between

blades

24 and 25 thereby short-circuiting the heating element 30 and this is irrespective whether the motor is operating or not.

The important feature of the present invention is that, once the door is completely opened, the return of blade 22 to its normal rest position, either through the motor stopping or the short-circuiting of the heating element, results in closing blade 42 on contact 44. This, together with the actuation of the upper limit switch, will cause the energization of the latching relay coil and the operation of the motor in a reverse direction to close the door. Once the door will have reached a fully closed position, an automatic door control switch will open the motor circuit.

It can be seen that, when the light 25 is turned off as a result of blade 22 separating from blade 24, this is an indication to theiobserver that the door is about to close in a given lapse 'of time. This time lapse may be varied by adjusting switch 14 on sidewall 20.

Although the'invention has been described above in relation to one specific form, it will be evident to the man skilled in the art that it may be refined and modified in various ways. It is therefore wished to have it understood that the present invention is not limited in interpretation except by the terms of the following claims' What] claim is:

1. A switch mechanism for ensuring the automatic closing of a motor-operating garage door after said door has reached a fully opened position, comprising, in combination:

a. a thermostatic switch for providing delayed switch action including:

i. a first bi-metallic blade having an electric heating element mounted longitudinally thereon; said heating element operating on said blade when energized by a motor-operating current;

ii. a second blade adjacently spaced from said first blade for turning on an electric lamp when contacted by said first blade when temperature raises in said heating element;

iii. a third blade adjacently spaced from said second blade for short-circuiting said heating element when energized for an excessively long period of time;

b. a second switch having contacts normally closed by said first blade of said thermostatic switch when the garage door is in a fully closed position; said second switch being connected to a latching relay coil adapted to operate the garage door motor; said contacts opening when said motor-operating current passes through said heating element and said first blade moves to contact said second blade; said contacts being subsequently closed by said first blade when, after the garage door has reached a fully opened position, said first blade returns to itis initial contact closing position.

2. A switch mechanism as defined in claim 1, wherein said thermostatic switch and said second switch are mounted on a support having contiguous walls; one of said walls supporting said second switch and having thereon means for adjustably securing said second switch relative to said first blade of said thermostatic switch.

3. A switch mechanism as defined in claim 2, wherein the contacts of said second switch include a movable blade in normal contacting engagement with said first blade of said thermostatic switch.

4. A switich mechanism as defined in claim 2, wherein said one of said walls being provided with a slot therein for the adjustment of said second switch relative to said first blade.

Claims

1. A switch mechanism for ensuring the automatic closing of a motor-operating garage door after said door has reached a fully opened position, comprising, in combination: a. a thermostatic switch for providing delayed switch action including: i. a first bi-metallic blade having an electric heating element mounted longitudinally thereon; said heating element operating on said blade when energized by a motor-operating current; ii. a second blade adjacently spaced from said first blade for turning on an electric lamp when contacted by said first blade when temperature raises in said heating element; iii. a third blade adjacently spaced from said second blade for short-circuiting said heating element when energized for an excessively long period of time; b. a second switch having contacts normally closed by said first blade of said thermostatic switch when the garage door is in a fully closed position; said second switch being connected to a latching relay coil adapted to operate the garage door motor; said contacts opening when said motor-operating current passes through said heating element and said first blade moves to contact said second blade; said contacts being subsequently closed by said first blade when, after the garage door has reached a fully opened position, said first blade returns to itis initial contact closing position.