US1942074A - Time switch - Google Patents

Description

2, 1934- R. TowNsENb 1,942,074

TIME SWITCH Filed Oct. 15, @929 Inventor: Georoe R Townsend,

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His Attorney.

Patented Jan. 2, 1934 PATENT OFFICE 1 UNITED STATES v SWITCH George B. Townsend, Schenectady, N; Y., as-

signor to General Electric ration of New York Company, a corpo- Application October 15, 1929. .Serial No. 399,835 4 Claims. (01. zoo-3s) Another object of my invention is the provision of a switch which may be continuously driven by means of a synchronous motor. Another object of my invention is to provide a switch in which adjustments may be made so that circuits may be opened and closed at any predetermined time.

A further object-of my invention is to provide a switch by which a snap action of acontactor thereof takes place in opening and closing the circuit.

It is a further object of my invention toproduce a device as set forth above which is simple in construction'and positive in operation. Other objects will appear hereinafter.

Although my invention is susceptible of use for other purposes, in the present case it is used to change the control of a heat supply appara "tus, namely an oil'burner, from one thermostat to another. The, .thermostats are set for different temperatures, one for controlling the oil burner apparatus during the night and another for controlling the oil burner apparatus during the day. v

In the preferred embodiment of my invention a synchronous motor which is continuously oper ated from an A. C. jower line is used to drive the time switch mechanism. This. motor drives a shaft upon which are rotatably mounted adjustable cams. These cams cooperate with U- shaped pivoted members which carry contacts thereon toopen and close circuits particularly to transfer the control of the circuit from one thermostat to another.

My invention will be better understood from the following description when considered in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

The drawing represents a schematic diagram of my invention. g

A synchronous motor 10 is connected to the A. C. line L1 and L2 and continuously actuated thereby. A shaft 11 is driven through a series of gears from the synchronous motor 10.. The gear 10' is rotatably mounted on the shaft 11 and frictionally drives theIshaft-ll through aslip drive connection. The "purpose of such a drive is to permit adjustment of the disc 12 which is rigidly mounted on the shaft 11. Such adjustment would be desirable for example, when the device is first installed or when a voltage failure for a period of time leaves the disc atan incorrect setting. On the disc 12 appear numerals indicat-- ing the time of the day and night. -Rotatably' mounted upon the shaft are cams 13 and 14 provided with arms 15 and 16. Spring urged pivoted members 17 and 18 connect the arms with the disc 12. The cams therefore, are made to rotate by means of the disc 12. These members are rotated in a counter-clockwise direction. The 85 U-shaped members-wand 20 are concentrically mounted upon a common pivot. They are provided with parts 21 and 22 which coact with the cams 13 and -14 to produce an action which is to be described later.

Rigidly attached to the U-shaped member 19 is an insulating arm 23 which carries the contacts 24 and 25. Rigidly attached to the member 20 is the insulating arm 26 which carries a second arm 2'7 which has contact elements upon both [5 sides of the arm at its end. As shown upon the drawing these last contacts move between the contacts 24 and 25 carried by the arm 23. Conductor 32 connects to the arm 2'7 which carries contacts and one side of the circuit to be controlled by the thermostats. Conductor '33 is connected to the thermostat 31 .and the contact 24 carried upon the arm 23. The thermostat 30 is connected to the contact 25 on the arms of 23 by means of the conductor 34. It will thus be seen that if the contact 24 is closed by means of the contact carried on 27 that the thermostat 31 which is the. night thermostat. controlsthe circuit. As shown upon the drawing the contact "25 is closed thus placing the thermostat 30 in 9 .more heat is necessary.

In operation the synchronous motor 10 eontinuously drives the shaft 11 and the indicating disc 12 to which the cams 13 and 14 areradiustably mounted. The shaft andhcams mountedthereon are rotatedin a counter-clockwise direction. The contact at 25 is closed and when in'this position the part 21- of theU-shape'd member "19 is slightly spaced from the cam 13. In this position the thermostat 30 is in the control circuit. As the cam 14 rotates in a counter clockwise direction, part 22 or the U-shaped member 20 will 110. I

ride off the cam surface which will permit the U-shaped member 20 to be rotated in a clockwise direction with a snap action to close the upper contact 24 carried on the arm 23 and open the contact 25. This will permit the part 21 of the U-shaped member 19 to come into contact'with the cam surface 13. Contact 24 then acts as a stop for the pivoted member 20. In this posi-- tion thermostat 31 is in the control circuit. When the part at 21 of the U-shaped member 19 reaches the limit of the surface of the cam 13, this member will be permitted to be rotated in a clockwise direction with a snap action which will cause the lower contact 25 to close upon the lower contact carried upon the arm 27, thus again placing thermostat 30 in the control circuit. A stop 22' is provided to limit the clockwise rotation of the U-shaped member 20. This stop permits the member 20 to close upon the contact 24 while element 2l is in contact with the surface of cam 13, but prevents further rotation when 21 rides oif the cam 13 and closes the lower contact 25. Further rotation of the cams will again bring the cam surface 14 into contact with the part at 22 of the U-shaped member 20. Since the arm 27 is in contact with 25, both members will be caused to move in a downward direction thus keeping the contactor 25 closed. Upon continued rotation the cycle will be repeated, 'that is, the contact carried on the arm 27 will be permitted to move in a clockwise direction, thus again closing the upper contact 24. The lower contact 25 upon the arm 23 will thus again be permitted to rotate in a clockwise direction, thus closing the bottom contact. Later both contacts will be rotated in a counter-clockwise direction. Thus, either the thermostat 31 or 30 will be placed in the controlling circuit.

"By releasing the spring pressed members 17 or 18 the cams 13 or 14 may be adjusted so that they actuate the U-shaped members 20 or 19 at difi'erent times. This is accomplished by rotating the cams 13 or 14 upon the shaft 11 and then reengaging the elements 17 or 18 with the disc 12 at the proper indication.

The numerals on the darkened portion of the indicating disk indicate the hours of the night and adjusting the element 17 to any of these numerals changes the position of the cam 14 so that the pivoted member 20 coacting therewith will be permitted to close the contact 24 at the designated time to place the thermostat 31 in the control circuit. A like adjustment of the member 18 will determine the operation of the pivotedmember 19 to close the contact 25 at the hour of the day desired to place the thermostat 30 in the control circuit.

The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the invention is susceptible of being modified to meet the diflferent conditions encountered in its use and I therefore aim to cover by the appended claims all modifications in the true spirit and the scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A time switch comprising a shaft, means for driving said shaft, an indicating disc rigidly mounted on said shaft provided with a plurality of teeth upon its circumference, a plurality of cams rotatably mounted on said shaft and provided with arms engaging the teeth on said disc, said tooth engaging arms being adjustable with respect to'said teeth to permit diiferent settings of saidcams to predetermin'e the operation of said switch, and pivoted U-shaped members, spring urged and concentrically mounted engaging with said cams and provided with contacts, said members being actuated by said cams to ;open and close said contacts.

3. A circuit controlling device comprising apair of cooperating movable switch members, two pairs of cooperating contacts, one of each pair of contacts being mounted on one of the switch members and the other of each pair of contacts being mounted-on the other of the members, means for biasing one of the switch members to engage the first pair of contacts and to disengage the second pair of contacts, means for biasing the other switch member to disengage the first pair of contacts and engage the second .pair of contacts, a pair of cams associated with second contact, a second cam for holding the said first contact upon the release of said second contact to efi'ect the disengagement of said contacts, and a stop for holding said second contact upon the release of said first contact to effect thereengagement of said contacts.

GEORGE R. TOWNSEND.

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