US2104399A

US2104399A - Circuit controlling device

Info

Publication number: US2104399A
Application number: US754749A
Authority: US
Inventors: Clarence W Kuhn
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1934-11-26
Filing date: 1934-11-26
Publication date: 1938-01-04
Anticipated expiration: 1955-01-04

Description

Jan. 4, 1938. c. w. KUHN CIRCUIT CONTROLLING DEVICE Filed NOV. 26, 1934 la IHHIHIH; 15

5 ,e4 lxj 1,6 11 11 16 I' O o 36 o O o o Patented Jan. 4, 193s 2,104,399 CIRCUIT Con'rnoLLiNG DEVICE Clarence W. Kuhn, Milwaukee, Wis., assigner to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application November 26, 1934, SerialV No. 754,749

7 Claims.

This invention relates to circuit controlling devices, and while not limited thereto is particularly applicable to starting relays for split phase motors.

A relay embodying certain features of the present invention is disclosed in my copending application Serial No. 514,363, filed February 9, 1931, which became Patent No. 1,988,848 on January 22, 1935 and the present application is lo a continuation of the aforesaid application as to all common subject matter.

As is well known, split phase motors are provided with a running winding and a starting winding and it is the usual practice to effect control of the latter winding by means of a relay which is responsive to current conditions in the running winding. Small split phase motors are commonly employed in electric refrigerators of the household type and in such installations difculty has heretofore been encountered in providing a starting relay which is of the required sensitiveness and which operates without objectionable noise.

It is an object of the present invention to provide a low cost starting relay which is exceedingly sensitive and quiet in operation and which is particularly adapted for use in connection with electric refrigerators of the household type.

Another object is to provide a relay of the aforesaid character having improved adjusting means associated therewith.

Various other objects and advantages of the invention will hereinafter appear.

'I'he accompanying drawing illustrates certain embodiments of the invention which will now be described, it being understood that the embodiments illustrated are susceptible of modification without departing from the spirit and scope of the appended claims.

In the drawing,

Figure 1 is a front elevational view of a starting relay embodying the invention;

Fig. 2 is a sectional view taken on line 2--2 of Fig. 1;

Fig. 3 is a plan view of the relay shown in Fig. 1;

Fig. 4 is a plan View of the relay shown in Fig. 1 illustrating a modified contact and terminal arrangement therefor;

Fig. 5 is a sectional view on line 5-5 of Fig. 4;

Figs. 6 and 7 are diagrammatic views illustrating the circuit connections for the relays shown in Figs. 3 and 4;

Fig. 8 is a vertical sectional view of a modified form of relay embodying the invention, and

CTI

(Cl. 20G-111) Fig. 9 is a view in the operated position of a part of the modified form of Fig. 8.

The relay illustrated in Figs. 1 and 2 is provided with an elongated spring contact I0 arranged upon the upper face of an insulating 5 plate II and having one end thereof secured to said plate, between the insulated washers I2 and I3, by a bolt i4. Plate II is xed to a supporting bracket I5 by screws I6 and said plate carries a solenoid winding I I having a plunger 10 I8 associated therewith which is operatively connected to the free end of spring contact I0.

Winding I'I is Wound upon an insulating spool I9 having a center opening therein for receiving plunger I8, and said spoolis secured to a magl5 netic washer 20 which is fixed to the under side of insulating plate II by screws 2| shown in Fig, 3. insulating spool I9 is secured to washer 20 by a plug 22 which is threaded into said washer and is provided with an enlarged head 20 23 for engaging a shoulder formed on the upper end of said spool within the `opening therein. The lower end of plunger I8 is weighted by a projecting nange 24` and said plunger has an insulating pin 25 mounted upon the upper end 25 thereof which is guided within an opening in plug 22 and extends upwardly through an opening in insulating plate II. The free end of spring contact I0 is provided with an opening for receiving pin 25 and the upper end of said 30 pin has an insulating washer 26 mounted thereon for engaging the upper face of said spring contact.

Spring Contact I0 is normally held in the position shown in Fig. 2 by the weighted plunger 35 I8 and said contact is biasedto move upwardly upon upward movement of said plunger into its attracted position. To minimize noise upon movement of plunger I 8 into its attracted position the same has cushioning means associated 40 therewith comprising a plurality of relatively thin fabric washers 28 and a soft rubber washer 29 which are mounted upon the upper face of flange 24. The fabric washers 28 are preferably located between washer 29 and

flange

24 and 45 upon attraction of plunger I8 washer 29 abuts the lower face of spool I9 to prevent sealing of the upper end of said plunger with the face of plug 22. Obviously the washers 28 and 29 act as a cushion to minimize noise upon movement 50 of plunger I8 into its attracted position. Also it should be noted that the number of fabric washers 28 may be varied to adjust the air gap between the upper end of plunger I8 and plug 20 and thereby provide for dropping out of the 55 plunger at a selected current value in the solenoid winding i1.

The relay is also provided with means for adjusting the value of current in solenoid winding il which is required to effect movement of plunger i8 into its attracted position. For this purpose washer 26 is loosely mounted upon pin 25 and a plurality of relatively thin shim washers 30 are arranged between the upper face of washer I6 and a Cotter pin 3i secured to the upper end of said pin. As is apparent, by varying the number of shim washers 3U the normal air gap between plunger i8 and plug 22 may be varied to adjust the current value at which said plunger responds.

The above described relay may be used in starting systems or various types, as for example those shown in Figs. 6 and '7. For a starting system of the type shown in Fig. 6 the relay has a resistance element 33 secured to the bracket il by a bolt 34 and insulating plate il is provided with 'the Contact terminal arrangement shown in Fig. 3. For the starting system shown in Fig. 7 the resistance element 33 is omitted and insulatr ing plate il of the relay is provided with the contact and terminal arrangement shown in Fig. 4.

In the embodiment shown in Fig. 3 insulating plate il has a stationary contact 35 xed to the upper face thereof to be engaged by spring contact IO upon upward movement thereof from the normal position shown in Fig. l and said plate also has a plurality of

terminal plates

36, 3l and 38 mounted upon the upper face thereof. Terminal plate 36 is electrically connected to the inner end of spring contact i0. Resistance element 33 is connected between

terminal plates

36 and 31 and the solenoid winding il of the relay is connected between stationary contact 35 and terminal plate 38.

The relay shown in Fig. 3 is connected as shown in Fig. 6 to control starting of a single phase alternating current motor M having a running winding R and a starting winding S. The supply circuit for the motor is indicated by lines Ll, L2 and a switch 39 is shown for establishing power connections for the motor, it being understood that such switch may be of any desired type, as for example a temperature controlled switch of an electric refrigerator. Upon closure of switch 39 circuit is established from line L2 to stationary contact 35 of the starting relay, and thence through the solenoid winding Il of said relay and the running winding R of the motor to line L1. The inrush of current through the running winding R causes immediate response of the relay and the starting Winding S is then energized by a circuit extending from line L2 to stationary contact 35, through spring contact i to terminal 36, through resistance element 33 to terminal 31, and thence through the starting winding S to line L1. As the speed of the motor increases the current in the solenoid winding I1 decreases in value and when the motor is brought up to its running speed plunger I8 drops out to return spring contact l0 to open position. The circuit for the starting winding S is thus interrupted and the running winding remains energized for continued operation of the motor.

In the embodiment illustrated in Fig. 4 the insulating plate l i has terminal plates 40 and 4| mounted upon the upper face thereof. The terminal plate I0 is electrically connected to the inner end of spring contact i0 and the operating winding il of the relay is connected between the terminal plates 40 and Il. Also a stationary contact 3l is provided for engagement by spring contact Il upon response of the relay and an additional stationary contact 42 is provided to be engaged by said spring contact when the relay is in normal position.

'I'he relay shown in Fig. 4 isconnected as shown in Fig. 7 to eii'ect starting of motor M through the medium of an autotransrormer winding 43 and a condenser u, said transformer winding being connected in series with the starting winding S of the motor and said condenser being connected in-shunt with said autotransformer winding. The left'hand terminals of starting winding S and running winding R of the motor are permanently connected to line Ll and upon closure of switch 33 circuit is established from line L to terminal plate 4l through winding I1 of the starting relay to the right hand terminal of the running winding R. The inrush of current through the running winding R causes immediate response of the relay and spring contact Il then engages stationary contact 3l to connect terminal T1 of the autotransi'ormer winding 43 to line L. 'I'he motor is then adapted to accelerate and when the same is brought up to running speed the current in winding l1 of the relay is reduced to a value which permits return of the relay to normal position. Terminal 'I'l of the autotransformer winding is then disconnected from line I..2 and the terminal 'I'2 of said winding is connected through stationary contact l! and spring contact i3 to line I..z for running.

Referring now to Figs. 8 and 9, the same illustrate a modification of the relay shown in Fig. l1. The relay shown in Fig. 8 is provided with an insulating plate 45 having a movable contact l( mounted upon the upper face thereof. The rear end of contact II is fulcrumed upon a proiection 4T on the upper face of plate 4l and is provided with an opening for receiving a screw Il fixed to said plate. The iront end oi'- contact 4l is biased to move upwardly from the position shown in Fig. 8 into the position shown in Fig. 9 by a spring 49 which is held under compression between the upper face of said contact and a nut Bil on the upper end of screw Il.

Contact I6 is provided with an operating solenoid which is similar to that employed in the relay hereinbefore described. However, the plunger Il is provided with a soft felt washer instead of a rubber washer 2l and the insulating spool Il for winding i1 is directly secured to the under side of plate Il" by the plug 22 which is screwed within a threaded opening in said plate. A metal pin l2 is iixed to the upper end of plunger Il and said pin is guided within the opening in plug 22 by an insulating washer 53 mounted upon said plug. Pin l2 extends upwardly through an opening in contact 4|, said opening having a shouldered insulating washer 54 mounted therein for guiding said pin and for preventing engagement thereof withsaid contact. The upper end of pin II has an. insulating washer 55 mounted thereon which is held in place by a nut 5I and said pin has a coil spring I1 associated therewith which is arranged between said nut and the insulating washer u on contact 43.

As shown in Fig. 8. plunger il normally acts bygravity to hold the insulating washer Il thereon in engagement with the washer I4 on' movable contact 4l against the action of vspring I1 and to also hold the contact in the position shown in this figure against the action of spring 43. Upon movement of plunger Il into its attracted position the pin i2 moves upwardly with respect to contact I6 to permit expansion of spring 51 and to also permit contact 46 to move upwardlyinto the position shown in Fig. 9 under the action of spring 49. In connection with the foregoing it should be noted that the felt washer 5l acts as a cushion to minimize noise incident to movement `of the plunger into its attracted position. Also it should be noted that upon dropping out of the plunger spring 5l is compressed and the same thus acts as a cushion to minimize noise incident to return of said plunger and contact 4B to normal position.

What yI claim as new and desire to secure by Letters Patent is:

1. In a. starting relay for alternating current motors, in combination, an insulating support comprising a horizontally arranged body portion having an associated vertically arranged spool on the under side thereof, cooperating stationary and movable contacts mounted upon the upper side of said body portion, said movable contact being movable between given extreme positions, a'winding carried by said spool, a plunger for said winding movable vertically within an opening in said spool, said plunger having an enlarged weight projection on the lower end thereof and being suspended from said movable contact to normally hold the latter in one extreme position, means for moving said movable contact into its other extreme position prior to full movement of said plunger into a given attracted position, said plunger being movable with respect to said contact to permit full movement thereof into its attracted position and a plurality of removable shims associated with said plunger and arranged between the weight projection on the lower end thereof and the lower end of said spool, said shims providing for adjustment of the attracted position of said plunger.

2. In a starting relay for alternating current motors, in combination, an insulating support comprising a horizontally arranged body portion having an associated vertically arranged spool on the under side thereof, cooperating stationary and movable contacts mounted upon the upper side of said body portion, said movable contact' being movable between given extreme positions, a winding mounted upon said spool, a plunger for said winding movable vertically within an opening in said spool, said plunger having an enlarged Weight projection on the lower end thereof and being suspended from said movable contact to normally hold the latter in one extreme position, means for moving said contact into its other extreme position prior to full movement of said plunger into a given attracted position, said plunger being movable with respect to said contact to permit full' movement thereof into its attracted position and a yielding member and a plurality of relatively thin removable shims associated with said plunger and arranged between the weight projection on the lower end thereof and the lower end of said spool, said yielding member serving as acushioning stop for said plunger upon attraction thereof and said shims providing for adjustment of the attracted position of said plunger.

3. In an electromagnetic relay, in combination, a movable contact, an operating solenoid therefor, having a fixed winding and a movable plunger, said plunger being suspended from said contact and acting by gravity to hold said contact in a given extreme position, said plunger being also normally positioned with respect to said winding to render the normal magnetic pull thereon of'relatively low value, spring means for moving said contact into an opposite extreme position and also tending to move said plunger out of normal position to thereby reduce the current value required to move said plunger out of such position, said contact being movable under the action of said spring means into its last mentioned extreme position prior to full movement of said plunger into its attracted position, a lost motion operating connection between said plunger find said contact permitting full movement of said plunger into its attracted position upon arrest of said contact in its last mentioned extreme position and cushioning means associated with said plunger for arresting the same in its attracted position.

4. In an electromagnetic relay, in combination, a. movable contact, an operating solenoid therefor, having a fixed winding and a movable plunger, said plunger being suspended from said contact and acting by gravity to hold said contact in a given extreme position, said plunger being also normally positioned with respect to said winding to render the normal magnetic pull thereon of relatively low value, spring means for moving said contact into an opposite extreme position and also tending to move said plunger out of normal position to thereby reduce the current value required to move. said plunger out of such position, said contact being movable under the action of said spring means into its last mentioned extreme position prior to full movement of said plunger into its attracted position, a 10st motion operating connection between said plunger and said contact permitting full movement of said plunger into its attracted position upon arrest of said contact in its last mentioned extreme position and adjusting means associated with said plunger for varying the normal and attracted positions thereof. l

5. In an electromagnetic relay, in combination, a movable contact, a fixed insulating spool having a solenoid winding mounted thereon, a vertically arranged solid cylindrical plunger movable within an opening in said spool and having an enlarged weight projection on the lower end thereof, said plunger being suspended from said contact and acting by gravity to hold said contact in a given extreme position, said plunger being also normally positioned with respect to said winding to render the normal magnetic pull thereon of relatively low value, spring means for moving said contact into an opposite extreme position and also tending to move said plunger out of normal position to thereby reduce the current value required to move said plunger out of such position, said contact being movable under the action of said spring means into its last mentioned extreme position prior to full movement of said plunger into its attracted position and a lost motion operating connection between said plunger and said contact permitting full movement of said plunger into its attracted position upon arrest of said contact in its last mentioned extreme position.

6. In an electromagnetic relay, in combination, a switch including a movable contact, a fixed insulating spool having a solenoid winding mounted thereon, a vertically arranged plunger movable within an opening in said spool and having a weight projection on the lower end thereof, said plunger being suspended from said contact and acting by gravity to hold said contact in a given extreme position, said plunger being also normally positioned with respect to said winding to render the normal magnetic pull thereon of relatively low value, spring means for moving said contact into an opposite extreme position and also tending to move said plunger out oi normal position to thereby reduce the current value required to move said plunger out of such position, said contact being movable underthe action of said spring means into its last mentioned extreme position prior to full movement of said plunger into its attracted position, a lost motion operating connection between said plunger and said contact permitting full movement of said plunger into its attracted position upon arrest of said contact in its last mentioned extreme position, and a cushioning member located between the lower end of said spool and the weight projection on said plunger for arresting said plunger in its attracted position.

7. In an electromagnetic relay, in combination, a horizontal insulating base, a switch mounted on the upper side of said base and including a movable Contact, an insulating spool fixed to the under side of said base and having a solenoid winding mounted thereon, a vertically arranged plunger movable within an opening in said spool and having an enlarged weight projection on the lower end thereof, said plunger being suspended from said contact and acting by gravity to hold said contact in a given extreme position, said plunger being also normally positioned with respect to said winding to render the normal magnetic pull thereon oi' relatively low value, spring means associated with said contact for moving the same into an opposite extreme position and also tending to move said plunger out of normal position to thereby reduce the current value required to move said plunger out of such position, said movable contact being movable under the action of said spring means into its last mentioned extreme position prior to i'ull movement of said plunger into its attracted position, a. lost motion operating connection between said plunger and said contact permitting full movement of said plunger into its attracted position upon arrest of said contact in its last mentioned extreme position, and a cushioning member located between the lower end of said spool and the weight projection on said plunger for arresting said plunger in its attracted position.

CLARENCE W. KUHN.