US1675683A - Switch - Google Patents

Description

Jilly 3 19281 H.- A. WOQFTER SWITCH Filed Ma 24, 1926 2 Sheets-Sheet H. A. WOOFTER SWITCH Filed May 24, 1926 2 sheets-sneer Zeriek Ali/aft? Patented July 3, 1928.

1,675,683 PATENT OFFltZE.

HERBERT A. \VOOFTER, F KENTON, OHIO, ASSIGNOR TO SWIFT ELECTRIC WELDER COMPA Y, or DETROIT, MICHIGAN, a CORPORATION or MICHIGAN.

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Application filed May 24,

This invention relates to switches and more particularly to improved construction of regulator switch.

Theinvontion finds particular utility in connection with those types of switches which, either because of their use in high tensioned circuits, or for other reasons, are provided with a plurality of contact elements, the surfaces of each of which are of a relatively large area. 1n the conventional forms of" regulator switches it is customary to arrange these contacts in arow in spaced relation whereby they may be selectively or successively engaged by a movable contact element or arm. In the character of switches aforementioned where contacts of relatively large area are provided it is furthermore custoijnary to form the movable contact element or arm with a contact surface of substantially the same area as that of each contact. However, in constructing the'switches of this character heretofore manufactured, it was necessary to space the contacts from one another a. distance greater than the width of the movable contact element or arm so that during the successive engagement of this arm with the contacts, a complete disengagement between the contact arm and one contact would be accom- 0- plished before the movable arm engaged the next succeeding contact to thereby eliminate the possibility of bridging the stationary contacts and causinga short circuit.

Consequently in regulating switches employing a plurality of contacts, the necessary wide spacing of the contacts either increased the totalsizeof the switch beyond reasonable limits, or placed a limitation upon the number of contacts which might be provided. lVhile the difliculties above mentioned were experienced more appreciablyin connection with switches requiring, for the purposes of eficiency, relatively large contact surfaces, nevertheless the same conditions present themselves in smaller and more compact switches of the regulator type involving a series of spaced contacts and movable contact elements associated, therewith.

It is therefore one of the primary objects of this invention to pro 'ide a switch wherein the aforementioned problems and difficulties are solved and overcome by providing means for causing a relative transient separation of the contact arm and contacts inn substantially relative perpendicular direc- 1926. SeriaLNo. 111,402.

tion during the movement of the contact arm fromv one contact to another. By such a construction it is possible to arrange the contacts spaced apart a distai'ice less than the width of the movable contactarm without liability of a bridging of the contacts and consequential short circuiting during the operation of the switch;

Many other objects, advantages and novel details'of construction are involved in the present invention, all of which will be made more apparent as this description proceeds, especially when considered in I connection w t h a compan ng i ian ii-h r in,

Figure 1 is a front elevational view, with certain parts broken away, of a switch constructed in accordance with this inventon.

Figure 2 is a central vertical sectional view through the switch.

Figure, 3 a fragmentary detail sectional view taken substantially on the plane indi cated by the line 3+3 of Figure 1,

Figure 4 is a fragmentary detail sectional view taken substantially on the plane indicated by the line 4 of Figure 1 Figure?) is a fragmentary view taken substantially on the plane indicated by line 5-5 of Figure 2. i

Referring now particularly to the drawings wherein like reference characters indicate like parts, it will be noted that the ref erence, character 10 indicates a switchboard or baseconst-ructed as customary of insulating material to the front face of which. a plurality ofspacer sleeves 11 are. secured for mounting a front panel 12 in spaced relation to the board 10. Bolts or the like 13 pass.

through front panel 12, the sleeves or bushing lland through the board 10 uniting and holding these parts in the relation illustrated in Figure 2 of the drawings. The cover 14 is arranged peripherally of the switch for enclosing and protecting the operative parts thereof and extends, in the embodiment herein illustrated, around three sides thereof. the ends of this cover being anchored at 15 to two of the bushings 11.

Mounted upon the board 10 a plurality of contact plate studs 16, each of which is provided with a threaded rearwardly pro,

.jecting extension 17 for engagement with terminals 18 of the electricaldeads (not shown). connecting the switch to the transformer or other device to, be. controlled. These terminals may be, conveniently secured in place by means of nuts 19. Each contact plate stud 16 has a forwardly directed stud-like extension 20 which passes through the board 10 and has a threadedengagement with the contact plate 21. Inthe em- V relation illustrated. "While obviously only element with an extension 25.

brace the end of the contact arm.

one of the. contact plate studs 16 need'be associated with each of the contact plates, nevertheless in'the' present embodiment of the invention double conduits or leads are connected to each of the contact plates because of the amount of current passed through the switch;

Each of the contact elements 21 is provided with a contact surface 23 on the forward face thereof and with the contact surface 24 at the rear provided by forming the contact 7 The contacts 21 are here shown as arranged in a circular row and as will appear more fully hereinafter, the space between the contacts 21 is considerably less than the width of the movable contact or regulator arm yet to be described. I V

The reference character 26 indicates the point for the movable contact or regulator arm 27. This arm has apart thereof a contact lead strip 28which is secured to the arm 27 at one end thereof by means of screws 29. The center post 26 is formed with-a plate-like head 30 formed with laterally extending side flanges 31 whichem- The center post is further provided with a spring bearing on the one hand against the board 10 and on the other against a nut or- 'nuts 38 which are adjustable to vary the ten sion of the spring and consequently the pres sure of the'head 30 of the center post against the contactarm interposed between the end of the contact arm 27 and the switch board 10 is a jumper 34 which functions as an electrical lead orconnection between the contact strip and terminals 35 connected by suitable leads (not shown) to the source of current. The end of the contact arm 27 is held tightly against the adjacent end of the of aregulat-or wheel 36 secured to a hub 37 which is connected to the end of the cen-,

ter post 26 by means of a screw bolt 38. For

' rotatably locking the hub 37 to the arm 27 I provide dowel pins 39 which enter recesses in the hub 37. An indicator finger 40 is secured to the hub and cooperates with indicia medium of a shaft 48. lever 42 is adapted to engage contact surfaces 24 aforedescribed. The inner end of the lever 42 is provided with a surface 44 adapted to' on the panel 12 which indicia is arranged to externally indicate the position of the several contacts 21. V

The contact lever 27 is provided with-apair of spaced ears 41for pivotally supporting an inner contact lever 42 through the The outer end of this engage thecam surfaces of a ring cam secured-to the board 10. This lever is urged into contacting position and the end 44 in engagement with the cam 45 by means of'a resilient connection with the contact arm 27 which includes a headed bolt 46- passed loosely through the lever 42and the lever 27 and alsothrough a lever spring 47 and provided with a compression spring 48 which bears on the one hand against a washer 49 interposed'between it and the spring 46 andon the other hand against a washer 50'held in place at the end of the bolt by means of a cotter pin. Thus this resilient device just described not only urges the contact lever 42 into contacting position but also urges the lever 27 into contacting relation with the contacts 21 so that each contact is in effect gripped between a pair of contact levers 2742.

During the movement of the contact lever from one contact 21 to the next succeeding one, means is pro'vided for lifting the end of the lever out of the plane of thecontacts or otherwise "secured to the board 10 1 by means of securing-elements54. The rollers shafts 52 and project perpendicularly from the board 10 into the path of and for engagement by the contactarm 27. *Consequently during the transient movement of this arm from one contact to another the contact arm will be forced substantially perpendicularly out of its plane of contact or'in other words, out of the plane of the plurality of contact plates 21. As the contact arm rides over the roller 51 and comes into alignment with the next succeeding" contact plate it will ride off the roller.51 and snap into engagement with the next contact. This movement of the contact arm is permitted because'of its inherently resilient nature owing to its'con: struction. r V Q During the transient movement of the contact arm and the perpendicular movement aforedescribed of the portion engaging the contact surfaces 23 of the contacts, a similar movement is imparted to the contact arm 42 forming apartuof thecontact 51 will obviously be free to rotate upon the lever. During the movement of the contact arm-from one contact'to the next succeed-' ing one, the surface 44 of the arm 42 engages cam surface on the cam ring 45 and is accordingly rocked-aoout its shaft 43 in a direction which moves its upper end thereof substantially perpendicularly with respect to the'cont act surface 24. The shape and extent of the cam surface is such that the end of this lever is held thus out of the plane of i-tsvcontact until the contact lever 27 has cleared the previous contact and is adjacent the next succeeding one whereupon the arm 42'is permitted to again niove into engagement with the contact surface 2d of the next contact. Hence during the transient movement of the contact arm 27 from one contact to the next the contacting ends of the elements 27-42 are moved apart or in substantially opposed directions to clear the contacts and do not again come into contacting relation until they are in substantial alignment or superposed relation with the next succeeding contact. Thus liability of bridging a pair of contacts 21 is eliminated notwithstanding the fact that the contact arm is wider than the distance between the contacts 21.

As mentioned, the lead from the source of current is connected to the terminals 35 and is conducted through the jumper 34: to the contact arm 27,. The current passe-s through this arm to the selected contact 21 thence through the windings of the transformer connected to the selected contact and then back through leads (not shown) to the source of current. For convenience the return lead may be connected to terminals 51 mounted upon the board 10, the current passing through studs 52 and out through terminal connections 53 to which the return lines to the source of current are connected. Such a connection is unnecessary but in practice is convenient asthe leads to and fromthe source of current are usually protected by conduits which extend to a point adjacent the swicth board and the structure herein described providesmeans for conveniently connecting both the incoming and return lines.

A switch constructed as above described has been found to give remarkably good results in practice but it is evident from the above considerations that the specific design hereinbefore described is only typical of the various forms in which the invention may be embodied and accordingly reservation is made to make such changes as may come within the purview of the accompanying claims.

hat I claim as my invention is:

1. In a regulator switch, a contact arm and a pair of contacts spaced apart a distance less than the width of said contact arm and means including a plurality of rollers engageable with said arm for moving engageablo therewith and cam means inde-v pendent of said contacts operable upon a movement of said arm-foroppositely moving the said members'out of their planes of contact.

In a regulator switch, a pair of contacts, a movable contact arm ha ing spaced members engageable with said contacts and means engaging said arm and one of said iembers during their transient movement between contacts for simultaneously moving said members out of their planes of contact.

4. In a regulator switch, a pair of contacts. a resilient contact arm having portions adapted for successive clamping engagement with said contacts and means between said contacts for releasing said clamping portions during transient movement of said arm between contacts.

5. In a switch, a pair of contacts, each provided with opposed contact surfaces, a contact arm havin parts concurrently engageable with said opposed surfaces and means for moving said arm parts out of their plane of cont-act upon the transient movement of said arm.

6. In a switch, a pair of contacts each provided with opposed contact surfaces, a contact arm having parts engageable with said opposed surfaces and means for separating said arm parts during the movement of said arm between contacts.

7. In a regulator switch, a plurality of contacts, each including a plate having opposed contact surfaces, a movable contact arm including parts resiliently urged into engagement with said opposed contact surfaces and means functioning during the transient movement of said arm between contacts for moving said contact arm parts out of their plane of contact.

8. In a switch, a pair of contacts, a contact arm having a portion engageable with said contacts, a member pivoted on said contact arm also engageable with said contacts and means for moving the contact engaging portion of the contact arm and the said member perpendicularly out of their planes of contact during transient movement of the contact arm.

9. In a switch, a pair of contacts, each provided with opposed surfaces, a contact arm having parts engageable with said opposed surfaces, means engageable with said contact arm for moving one of said parts perpendicularly out of its plane of contact and separate means engageable with one of the other of thesaid parts for moving the same perpendicularly out of contact. w 7 i 7 10. In a switch, a pair of contacts, 'a switch arm having a'portion successively engageable'with the upper faces of said contacts, and a member pivoted to the said switch'arm respectively engageable with the under faces of'the said contacts.

11. In a switch a pair of'contacts, a

its plane of v switch arm, a contact engaging member pivoted to said switch arm and a headed member extending through said switch arm and said pivoted member for urging the SWltClT 12. In a switch, a plurality of contacts,

and means successively engageable with saidcontacts, said means including a switch arm, a

a member pivoted to said switch arm, a

and the said spring, and'resilient means.

sleeved on the said headed member and engaging the said spring, for urging the free 7 end of the contact arm and the pivoted eon-;

. VVHERBERTHA. WOOFTER.

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