US1783421A - Electric switch - Google Patents

Description

masgm B. E. GETCHELL ELECTRIC SWITCH Bea 2, i930.

ofiginal Filed Sept.

22, 1927 3 Sheets-Sheet l ec. 2, 1930. B. E. GETCHELL 9 ELECTRIC SWITCH Original Filed Sept- 22, 192'. 5 Sheets-Sheet 2 ETCHEL ELECTRIC SWITCH Original Filed Sept. 22, 1927 3 Sheets-s 3 NVENTOR Y E N m A T T illlllllllili Patented Dec, 2, 1930 UNITED STATES PATENT OFFICE BENJAMIN E. GETCHELL, F PLAINVILLE, CONNECTICUT, ASSIGNOR TO THE TRUMBULL ELECTRIC MANUFACTURING COMPANY, OF IPLAINVILLE, CONNECTICUT, A COR- PORATION OF CONNECTICUT ELECTRIC swr'rcri Original application filed September 22, 1927, Serial No. 221,215. Divided and this application filed.

December 27, 1927.

This invention applies to magnetically I operated switches particularly of the class commonly known as the remote control type.

A particular object of my invention is to provide a construction in which the movable contacts of a switch are so connected with the movable member of an electro-magnet that the movement of the magnet member will simultaneously move the switch contact at an angle relative to the corresponding stationary contact so as'to engage the latter with an angular or wiping movement.

Another object is to provide a construction inwhich the movable switch contacts and the movable member of an electro magnet are so connected as to move simultaneously and so that the switch contacts may be moved at any desired angle relative to the lineal path of movement of the magnet member.

Another object is to provide a construction in which the movable contacts of a switch, or

a similar construction, are connected with the movable member of an electro-magnet 'so as to move simultaneously with the magnet member and to further provide a guiding means whereby the switch contacts will be moved in a predetermined angularpath of movement with respect to the lineal movement of the magnet member.

An important object is to provide a construction in which the movable switch contacts are connected to the movable member of an electro-magnet so as to move simultaneously with the magnet member and for a proportionate relative distance as required.

In the specific form shown herein, the armature of an electro-magnet is arranged to be moved to effect the desired result although in some cases it may be desirable to provide a movable magnet coil to cooperate with a relatively stationary armature but, in either case, it is my purpose to provide for a certain relative movement between the magnet and its cooperating armature.

In reducing my invention to actual practice, I preferably provide an electro-magnet (together with its core and pole pieces as a unit) with a form of mounting which will permit a limited free movement and a cooperating movable armature which has an Serial No. 242,560.

operable connection with movable switch contacts or other parts which are to be operated.

In the preferred form of apparatus the vertically movable armature is connected by link motion to an angularly movable cross bar which carries the movable switch element.

The foregoing describes the basic ideas of the invention, but in practice, certain refinements of detail are desirable; for instance, it is desirable that some of the shock of the fast moving armature be cushiphed or absorbed by a suitable yielding means' before the armature actually strikes against the poles of the magnet and it is also desirable that the switch contacts close with a yielding pressure. These two requirements are provided for by using spring contacts which engage the corresponding stationary contacts before the armature reaches the poles of the magnet and, for the reason that the spring contacts are connected with the armature, the closing impact of the latter is checked.

When the armature has completed its switch closing movement, it rests against the pole ieces of the magnet and will. remain in tiat position against the tension of the spring contacts which however will operate to cause a rapid separation of the armature from the magnet when the circuit is broken. These spring contacts also operate to move the magnet unit back into its normal position as it stood before being struck by the moving armature.

The accompanying drawings show one form of mechanism embodying all of the improvements of my invention.

This is a division from my former application #221,2l5 'filed September 22, 1927.

Fig. 1 is a front view of the construction but omitting the relay elements.

Fig. 2 is a side view showing one of the relays preferably intended to be used with the construction. Such a relay is shown in my former Patent No. 1,569,364, dated January 12, 1926.

Fig. 3 is a horizontal sectional view and plan.

Fig. 4 is a front view and partial section,

the insulating base being removed.

Fig. 4a is a detail side view and section of one of the movable switch elements.

Fig. 5 is a view from the right hand side, the ri ht hand side plate being omitted and parts eing shown in section.

Fig. 6 is a perspective view of one side plate and parts of the link motion.

Fig. 7 is a side view of a modification, the base being omitted.

Fig. 8 IS a fragmentary side view of another modification.

The base or body 15 may be formed of insulating material, such as molded composition. In the form shown the side plates 16 and 17 are of metal and rovided with flanges which are secured to the base by screws, such as 18 and 19. The back plate 20 may be secured to the side plates by screws such as 21. This particular form of back plate is adapted for convenient attachment to a back board or in a switch box (not shown). For conveniin the form of a cross bar.

ence this back plate 20 is provided with a keyhole slot 22 at the top by means of whichit may be conveniently hung ona screw (not shown). The lower corners of this plate 20 are provided with notches 23 and 24 which open toward one side and toward the bottom for convenience in mounting the plate under the heads of screws (not shown) in an enclosing box. Y

The line terminals 25, 26 and 27 are mounted on the front face of the base along its lower edge. The load terminals 28, 29 and 30 are mounted in the same plane along the upper edge of the base. The terminals 31, 32 and 33 adapted to be connectedto a control station or switch are mounted along the upper edge of the base at its rear. The loadmay be, for instance, a motor (not shown). v

The switch has three circuit controlling units in the particular form shown. The left hand unit has stationary contacts 35 and 36 and a movable switch member composed of contact members 37 and '38 connected together by a flexible strip 39 which may be formed of thin laminations so that the two contact members 37 and 38 are free to tilt and rock so as to assure perfect contact with the raised portions 40 and 41 of the stationary contacts. The details of this construction are shown particularly in Fig. 4a.

The back plate 42 has its ends ofiset fromthe plane of its central portion 43 and is provided with small bosses 44 adapted to rest against the back of the connecting strip 39 so as to permit relative tilting of the contact pieces 37 and 38. The movable contact parts just described and the corresponding movable contacts for the other switch units are all carried by the insulating member 45 which extends across the base of the switch cross bar has set in it a fiat stud 46, the end of which extends through a spring 49 and a cup-like washer 50. This washer has a central slot 51 to permit it to be slipped on to the end of the stud 46. In this Way the movable contact parts may be readily removed and replaced when desired by the simple operation of pressing down upon the washer and turning it with the fingers.

The upper contact 35 of the left hand switch unit is electrically and mechanically secured to the terminal 28 by a screw 54. The lower contact 36'is secured to the clip 55 for the relay 56. The lower clip 57 for the relay is electrically and mechanically connected to the lower terminal 25 by screw 58 which may be seated in a suitable insert in the base in any suitable manner. The intermediate clip 59 for the relay is similarly secured to the base.

The right hand switch unit is constructed in the same manner as the one previously described and has stationary contacts 60 and 61 and a movable contact 62. Relay clips 63, 64 and 65 for relay66 are similarly mounted to those previously described. The central switch unit also has stationary contacts 70 and 71 and a movable contact 72. This unit, however, requires no relay and hence the contact 71 is connected directly to the terminal 26 by a strip 73.

The carrier bar 45 is provided with insulating flanges 75 and 76 on opposite sides of the central switch unit to serve as barriers between the switch members of the respective units. The base 15 is provided with a transverse groove 77 to receive the cross bar 45 which also serves as abarrier between the contacts of each respective pair of the stationary contacts. The base is also grooved at 78 and 79 to receive the ends of the flanges 75 and 7 6,-respectively. The opposite ends of the switch carrier 45 are provided with projecting lugs 80 and 81 which are movably mounted in grooves 82 and 83 in the side plates 17 and 16 respectively.

A cross connecting contact 85 is mounted in the back of the cross bar 45 and adapted to connect the resilient contact members 86" and 87. The two latter contacts. are connected respectively to the control switch terminals 32 and 33 and the operation will be explained hereinafter.

At the back of the base 15 is mounted an electromagnet and armature. This magnet has a coil 90 one terminal of which is connectsupported in the side plates 16 and 17. The magnet core frame is mounted so that it may move vertically in the slots 93 a limited amount. The armature 94 may also be laminated and movable vertically with respect to the'magnet coil and core. The armature is connected to the insulating cross bar or contact carrier 45 by a link motion which is supported by the side plates 16 and 17.

Lever plates 95 and 96 of substantially bell crank form are pivoted to the side platesl7 and 16 respectively, and connected to the lugs 80 and 81 of the insulating cross bar by links 97 and 98. Extending from these levers 95 and 96 are connecting rods 99 and 100, the lower ends of which are connected to the ends of the cross bar 101 which carries the armature 94. The connecting rods and links 99 and 100 may be guided between lugs or projections 102 and 103 formed in the side plates 16 and 17. v

When the magnet is energized it lifts the armature 94 and, through the medium of the connecting links 99 and 100, tilts the lever plates 95 and 96, and thus through the pull of the links 97 and 98 draws the contact carrier 45 toward the base so as to cause the movable contacts to engage the station'ar contacts. On account of the inclination o the guide slots 82 and 83 the movable contacts slide upwardly on the stationary contacts until fully seated, thus affording a sliding orwiping contact which insures perfect electric connection. As the contact carrier 45 is drawn backward and upward toward the base, the springs 49 are compressed,

thus insuring an even pressure between the contacts and afl'ordin a yielding engagement which prevents shoc to the parts of the switch. As the cross piece 85 engages the resilient contacts 86 and 87 additiona'l resiliency is provided to bring the parts to rest without shock. In the form shown the electro-magnet is vertically movable being guided in the slots 93 which are elongated sufficiently at the upper ends so that even the inertia of the moving armature cannot a ply a direct blowlon the stationary parts of the mechanism. I

When the remote control switch (not shown) is operated to start operation, the circuit through, the coil 90 is closed so as to energize the magnet and lift the armature 94, operate the carrier 45 and close the load line circuits and connect the conductors 86 and 87 and keep the magnet circuit closed when the remote control switch is released. The magnet circuit may of course be opened through the remote control switch.

In case of overload the magnet circuit will automatically be opened through one or both of the relays. In case of failure of line voltage or abnormal drop of line voltage, the magnet will become weakened and unable to hold the armature against gravity and the force of the springs and the armature will drop away from the magnet thus opening the load and magnet switches. After the switch is once opened, it cannot normally be closed again except by the remote switch or equivalent. This feature is of great value in that it protects the operator against the unexpected starting of the motor or other device after it has once been stopped. Obviously additional spring means may be employed to assist in the natural gravity switch opening movement.

Although I prefer to have the switch carrier guided on an incline by the slots 82, 83 so as to cause the switch contacts to slide as they come to their seats, it should be understood that I may vary this angle to suit various conditions. For instance, the lugs 81 ma be guided in arms 105 pivoted at 106 and clamped at 107. By this construction the switch members may be angularly adjusted with respect to the stationary contacts.

In the form shown in Fig. 8 the slot 108 is horizontal so that the movable switch element will move at-right angles to the base and the stationary contacts carried thereby.

Although I have described the preferred form of the complete apparatus and its method of operation, it should be understood that some of the features may beemployed independently of others, for instance, the link connecting features of the armature and the contact carrier herein set forth are applicable to other types of switches, so also it should be understood that the invention is not limited to the use of the particular thermostatic relay herein set forth. It should also be un derstood that although I have described the invention as particularly applicable to control from a remote point, certain features may be employed without such limitations, for instance, in some cases the control buttons may be mounted directly upon the box which encloses the main swltch. I intend that the claims shall be interpreted broadly as they may appear except as ma be required by the state of the art or by t e terms thereof.

The details of the contact mechanism er se are claimed in my co-pending application 432,107, filed February 28, 1930.

I claim: a

1. In a switch, an insulating base, switch mechanism mounted at the front thereof and including a cross bar, side plates secured to said base and extending rearwardly therefrom, an electro-magnet mounted at the rear of the base and having acore and an armature supported between said side lates, levers pivoted to said side plates, lin rs connecting said cross bar with said levers and links connecting said levers with said armature.

2. An electric switch including stationary switch contacts, a resilient switch member mounted to move transversely thereof, re-

silient auxiliary switch contacts forming an abutment for said switch member, an electromagnet, an armature movable thereby, a link mechanism connecting said armature and said switch member for moving said switch member at an angle to the direction of movement of said armature.

3. An electric switch including a base, pairs of stationary contacts mounted on said base, a slidably movable contact carrier, contacts for bridging the respective pairs of stationary contacts mounted on said carrier, side plates secured'to said base and having slots for guiding the movement of said contact carrier in a predetermined straight line direction with respect to said stationary contacts, an electromagnet, a.movable armature for said magnet and link connections between said movable contact carrier and said armature for causing acorresponding movement of said carrier when said armature is moved.

4. An electric switch including a base, pairs of stationary contacts mounted on said base, a slidabl i movable contact carrier, contacts mounted on said carrier for bridging the respective pairs of stationary contacts, side plates secured to said base and having slots for guiding the movement of said carrier in a predetermined direction with respect to said stationary contacts and. for maintainin a substantially parallel relation between said stationary contacts and their respective movable contacts.

5. An electric switch construction including a base, pairs of spaced stationary contacts mounted on said base, a slidable contact carrier having contacts mounted thereon for bridging the respective pairs of saidstationv ary contacts and having guide lugs, plates secured to said base and having slots to receive the In on said carrier, an electromagnet, a mova le armature for said magnet and toggle links connecting said contact carrier and said armature forcausing the movement of said carrier when said armature is moved. 6. An electric mitchconstruction includmg a base, pairs of spaced stationary contacts mounted on said base, a slidable contact carrier having contacts mounted thereon for bridging the respective pairs of said stationary contacts and having guidelugs,plates secured to said base and having slots to receive the lugs on said carrier, a vertically movable operator and toggle links connecting said contact carrier and said operator for causing the movement of said carrier when said operator is moved, the angular relation of the slots in said plates and the lugs on said carrier being such that the movable contacts will constantly be maintained in parallel re-. lation with said stationary contacts out will have an endwise movement to-provide for a sliding engagement of the respective contacts.

7. A switch including a vertically disposed base, upper and lower rows of station- .ary contacts mounted on the front of the circuit, BENJAMIN E. GETCHELL.

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