US2671149A - Electric switch - Google Patents

Description

March 2, 1 54 H. HUBBELL ET AL ELECTRIC SWITCH m 3 O 5 6 R YM/ 2 2 3 mHh HY m m 1 qwww m 1 I H JI 5 A 7 I 3 l R N i M 8 AE 3H 8% 3 HH 2 2 Y B Filed April 50, 1953 Patented Mar. 2, 1954 ELECTRIC SWITCH Harvey Hubbell, Long Hill, and Henry J. Modrey,

gnors to Interlock Corpo- St'amford, Gonna ration, New York;

assi

Application April 30, 1953, Serial N0. 352,189

The present invention relates. to electric switches,-. more particularly to .m'inia't'urized switches in which. the switch components are held in. contact making engagement by spring pressure- ."Inswitches of. the. general type above referred meant-act is. usually made. and. maintained by a. leaf springv and a. rubbing or sliding engagement between thecontact elements of thes'witch. As miniature switches. the. leaf spring must necessarily be small and. hence weak, the contact quality of such switchesis already initially not very satisfactory and deteriorates rather rapidly due t'o's'pring fatigue and. wear. The use of a stronger leaf spring-v which of course would impi'ov'e. th Contact. quality'and the useful" life of the Switch,- enfiailsiaii increase in the dimensions dffthe'springl which. in turn results in an undesirable and ofte'ri'fnnpractical increase in the.

overall dimensions of the. switch.

one, of the. principal? njects of the invention is to provide a. novel. and improved switchdesign which permits rnanuracturecf miniature switch afibrdi'n'g a good" andlr'easonably constant quality and low resistance at the contacts for a. ldhg. peridd". 6f service. Such miniature switches have many useful fields" or application elements}. conventionally: used" switches' are replaced hyacoil spring and knife edge contact-un er pressure by said". coil spring.

far superior to and" longer lasting than those obtainable With a contact arrangement Of m- 17" Claims. (01. 200-155) A further object or" the invention is to provide an electric switch design permitting to open and close, permanently or temporarily, a plurality of contact connections by movement of a single replaceable contact member.

Other and further objects, features andadvantages of the invention will be pointed out hereinafter and set forth in the appended claims forming part of the application. 2

In. the accompanying drawing, several now preferred embodiments of the invention are shown byway of illustration and not by way .of limitation.

In the drawing: H

Fig. 1 is a sectional view of an electric switch according to the invention.

Fig. 2 is a fragmentary exploded view of Fig. 1.

Fig. 3 is a sectional view of a modification of the switchv according to the invention.

port member.

movable contact means tends to Fig. .4 is a fragmentary sectional View of a modification of the switch according to Fig. 3. Fig. 5 is a section taken on line.55 of Fig. .4 on an enlarged scale. Fig. 6 is a sectional view of another modifi'ca tion of the switch according to the invention. and Fig. 7 is a sectional view of still another modification of the switch. according to the invention. Referring firstto Figs. I and 2 in detail, the switch according to these figures is shown asbeing mounted in a panel It or other suitable sup- The switch comprises a stationary means which serves to connect or disconnect the contact terminals. Experience shows that the wear out much faster than the stationary contact means, primarily by reason of spring fatigue.

parable size emp'l'oyingra leaf spring and a rubbingfor. sliding. contact.

The use or a leaf spring and of a rubbing. or sliding' contact invery small switches creates a further" problem in that the: contact" component otjthe switch. is usually'th'e' part thatw'ears'out first. With switch designs as. hitherto known, a replacement of" the contact component is frequently .difiicult or at least entails a tedious rewiring as does also the installation of a new switch when a replacement of th'e contact" com ponent only is not practicali Accord-ing1y,-- anbth'er object cf'the present inventien, allied witl 'i the preceding cnes; is to ofv the contact component without requiring. a rewiring?ofithe smtch. a still a-n'otla-ar object or the invention: an etl le swit nr acsignwhich: is: 225 5133 11 vim-gs titn proon The movable contact means comprises a metal guide sleeve H open on one end and closed at the other end by a wall member. 42 having an opening therethrough. Sleeve H is set on to form. a shoulder I31 This shoulder serves as a limit means to limit the depthv of insertion of guide sleeve. H inv the stationary contact means of the narrow sleeve portion Ill. The opposite-end of rod I4 is fixedly secured to a sleeve I6 guided in sleeve ll. Sleeve I6 supports a switch actuating knob I7. This knobjis shown as having a lug fastened" to sleeve It by any suitable means such as a punched manta: A'SWHI be obvious. various'other means can be employed to secure knob I-l to rod 14-, either permanently or d'etachably. A compressed coil spring t9 within sleeve l ibiases contact head i 5 toward sleeve wall l2.

The movable contact means comprise a receiving sleeve 20. The inner cross-sectional outline of this sleeve fits the outer peripheral outline of sleeve portion II and also of contact head l5 and the axial length of the sleeve is slightly in excess of the axial length of sleeve portion I l' for a purpose which will be more fully explained hereinafter. Sleeve 20 is fastened to or. as shown, integral with an externally threaded shell 2|. This shell serves to mount the switch in a corresponding opening of panel H1. The shell is secured in its position by means of a flange 2| and a counter-nut 22.

The receiving shell 20 supports the contact elements of the switch. These elements are shown as a contact strip 23 secured to one end face of sleeve 20 and a contact strip 24 secured to the other end face of the sleeve.

Contact element 23 coacts with shoulder 13 of sleeve H. It may occupy either the entire periphery of sleeve 20 or only part thereof as it will be in contact engagement with shoulder I3 in each rotational position of sleeve I l.

Contact element 24 coacts with the bent back tip of head [5. The switch is designed to interrupt the circuit connections at contact element 24. Accordingly, this contact element should occupy only a part of the periphery of sleeve 23. As can best be seen in Fig. 2, contact element 24 comprises a springy contact strip 25 resting upon the respective end face of sleeve 20, and a tail 26. This figure also shows that the face end of sleeve 28 is formed with two detent notches 21 and 28. The contact element 24 is fitted in one of these notches by bending contact strip 25 accordingly. It is secured to sleeve 20 by means of a hookshaped nose 29 which engages a corresponding slot 30 in sleeve 20.

As appears from the previous description, the switch is in its on position when contact head l5 rests in notch 21 and is in its off position when head it engages notch 28. The two detent notches are pifefprably so spaced and shaped that there is no intermediate position for the contact head but that the always occupies either the on. position ontlfe off position.

To simplify the illustration, only one on position and one off position are shown but it will be apparent that several on and off positions may be provided-in a similar manner whereby the switch becofnes a .multi-position switch.

It is possible to omit the detent notches 21 and 28 and to provide a hat contact element 24. However, a switch designed hasno'clearly defined on and off positions so 'that the illustrated arrangement is preferableki It will be evident that contact elements 23 and 24 must be electrically ins iflated one from the other. This can be most conveniently accomplished by making sleeve 28 and preferably also its extension shell 2| of insulation material as is shown but it is also possible to employ a metal sleeve in which case contact elements 23 and 24 and the detent notch 28 must be insulated from each other by interposing insulation ma.

terial.

Sleeve 20 and its extension shell 2| may be made of a single piece reasons it is generally preferable to make the sleeve and the shell of two halves which aresecured together by cementing, clamping or any other suitable means after insertion of the contact components. Fig. 2 shows a sleeve composed of two halves, and slot 30 is so Pltlfid 21 4 it extends into the two halves.

but for manufacturing length is considerably tact means.

The assembly and operation of a switch, as hereinbefore described, are as follows:

Shell 2! and with it the receiving sleeve 20 are inserted in the opening of panel ID. The shell is then secured in its position by means of nut 22. As is apparent from Fig. 1, the soldering tails of the contact elements 23 and 24 are so designed that they permit passage of the nut.

The movable contact means of the switch is now mounted by inserting contact head 15 in receiving sleeve 20. During the initial part of this insertion, wall l2 of sleeve portion H abuts against contact element 23 so that sleeve H is pushed back relative to head 15 and the latter protrudes further from the wall 12. When the head has penetrated sleeve 20 the initially eccentrally disposed sleeve portion H can be moved into axial alignment with sleeve 20, the width of sleeve 2! permitting the required lateral displacement of sleeve H, H'. The sleeve portion II can now enter sleeve 20. Finally, the head and sleeve portion ll' occupy positions as shown in Fig. 1 in which the bent-back tip of head it: abuts against the outer end face of sleeve 20 and shoulder l3 against contact element 23. By virtue of the aforementioned relative axial length of sleeve 20 and sleeve portion H, contact head I5 is retained in a protruding position in which spring i9 is stronger than initially compressed. As a result, shoulder 13 is held by the constant pressure of the coil spring against contact element 23 and head I5 is also held by the constant spring pressure against the outer end face of sleeve 23 thereby assuring a good constant contact quality and low resistance between the coacting contact surfaces and engagement of the head with the detent nothes 21 and 28.

The switch is moved into its on position by turning knob l'I into the position in which head 15 engages contact strip 25 and into its off position by turning the knob into the position in which the contact head occupies detent notch 28.

The movable contact means of the switch may be replaced by removing knob 11 if theknob is detachably fastened to rod (4 or more specifically to sleeve 16, and then lifting guide sleeve H, for instance by tools specifically designed for this purpose. Sleeve H or more specifically sleeve portion H, when sufficiently lifted, leaves receiving sleeve 21] thereby making space available for withdrawal of the contact head [5. The entire movable contact means can now be withdrawn and a new contact means inserted in the manner previously described. As all the wire connections lead to the contact elements which are mounted on the stationary contact means, no rewiring of any kind is necessary when the switch is rejuvenated by replacement of the movable contact means. As previously mentioned, the useful lifetime of the stationary contact means generally far exceeds the useful lifetime of the movable contact means.

In case knob 11 is fixedly secured to rod H, the release sleeve H is inaccessible. The movable contact means may then be replaced by cutting off contact head 15 for instance by pliers. The entire movable contact means can then be conveniently withdrawn from the stationary con- Generally, the spring l9 which is now released will propel rod l4 and. the knob out of the switch? A switch according to Figs. 1 and 2 can be conveniently. so manufactured that its overall less than an inch and its diameter approximately one-quarter of an inch.

it was hithenln ingly; corresponding: pants are! designatedx by:

similan referencenumerals.

In: contrast to, the. switch-of; Fig, the switch at Eig; 3\is, designedzasl a moisture-moot switchz Fen this. purpose, shell: 20 is. fiastened; te= or in tegr-ale with a; generallycup-i shaped: housing; or shell 35nvl1-i'clm encloses. contact. hea l:5;. and! a resilient. sealing: washer; 39, is; intenposeil between knob ti and. flan e 2.1:. Shelli; aches, preferably a. knocl-:-.-out bottom portion indicated at 36. the {impose of; which; willbe subsequently explained;

Bus to: the. presence ct shell 35; it is 1101111395.:- sible tozcut; elf heaeli I15 for: purpose: ofremoving the. movable: contact means il'i'z caseiit. is: desired to; neplace the same. eonseqlientltn, it is; 658613." tial. for. the design} of. Fig. 3 thatknobz his is re.- mclwable. This is accomplished by! joining: the knob:- to shell k6.- by the punched; indentation 3J- whioh, joins the; two: components suificientl-y strongly tor. operationah purposes but". pcmmi-ts tapul-L knob I] out of sleeve. l 6,.

As; has be-em explaineds in? connection. with; Fi s. 1-,. the loading. of spring: its effects a; pressure contact. between contact elements 23v and. t4 and shoulder t3 and; head. I15, liespectively. when it is desired; to increase this pressure? contact; without strength 01% I-S:-Whi(2hr is; undesirable as it; generally entails an: incseasezim the overall dimensions of the; switeh-a resilient disks-shaped member- 38.-islplacediupon.the bottom of shell. 35= member may forinstance be as tubhen or silicone As is.obwio;us.-,, ciislsv fitwhon, EDGE/- el-ly tlimensionedpresses heads [5 againstcontaet element. 211. and: into. detent notch. 28s. In; addiincreasing the tion, disk 38 affords the advantage thatit coimr teractsthe efiectoi vibrationato which theswitch may. be subjected vibsationsjt not: 0.01111?" teracteel;v result-in a serious: deterioration. oi the contact qualities; of theswitch.

As isr apparent, rod l t is in effect supported 5 by twoindependent spring systems. one, fomnecl byspring. l9 andthe other by resilientmemben 38 These two. spring. systems have obviouslst totally difierent. characteristics-in negaizditel autcvibration and critical amplitudes. Pisactical' tests have shown that. in. most; instances one: systemwillv damp. out a-ny tenelency to autorvibration of: the other system; because.- the critiea1 amplitudes of the. two.- systems do not coincide. Asa. result. the. switch is. practically vibration-proof, which. is,- most desirableiorma-ny fields. oi application}.

The resilient washer between shell M and; knob: L1. is. preferably so dimensionedr that. in addition to serving as. a moistureseal; it coac-ts with disc as. to suppress. vibrations. It will be: apparent; that washer. as also acts as. a vibration suppressing componentwhem disc 3.3;isemi-ttec1'.

The operation: of the switch. will be obymus tromthe previous. description:. of, Figs; 1 and; 2.. It. sufiices to state that the; by rotating knob: It.

With the hereinbefore described: switches, the; circuit-connection is closed by engagement oi the spring loaded contact. head with; contact.- stripl Pilot contact element 24... contact; arrangethe stsength oi switch is actuated:

i 21 i is; neplacea knock-out portion ment; with contac Howcaen. enea-tercucnent carnyins': capacity;

is: wanted larger matine contactsurfaces: are: desirable; Eissus and; Whi0hlShQu1d.bceE visualized: as a; fmagmentary of, the; switch: accordin SPShQ-Vi a, contact; element,v providing, largezz mating contact surfaces.

According: to: thesefigures: the; contact element by; a. contact. element generally; designated byrill This-contact.elementcomprises in; addition: to: a curvacli and preferablynspningy: contact strip 4! similar: to contact;- strip; 25s a: contact strim 42-: hugging the; innensitiiee walli of shell; 3%: @bntact: element.- is is secured; to e comings sleeve- ;23 shell l5; respectsvely; bysiiiliablemeans: such. as a hook-shaped, nosfr Z9: engaging a, ccrsrespcmiing slot sleeve- Z-flci. shell; 35.

as result, contact head Irtl when in: its; on position: engages. its bent back; end; contact. stsip; My and; with its; side. wall; contact strip is; thereby coilresponclingly. increasing; the, mating: contact surfiaces and. the currentcarnying:

: capacity of the; switch;

Fig; 6; shows a. switch; which: is; similar in. most. irespectsztmtheswitchaccordtmg to.- 3.. Ace cordingly, the same reteaencenumesals; are; used; to; designate corresponding Li ht/51;. As; will be observed; washes 3:9: is omitted: This has; the: advantagethat by: using; the same..- comgaonents. as; forthe; switch; of Eig;.. it the: switch of. Big. 61 can. beoperated; by eitherrotating; knob.- lll on depressing; the; same. In other words, the! switch becomes! a push-button switch. In; the embodiment. of Big. 6 the contact; recess. coacting with the head: is: peeienably deeper; in. the sin bodiment. of Figs. 2. to, assume, that. the: al.- ways; returnslinto-the on position even if displaced by nearly one-half circle.

Contact. connection. between head t5* and; contact element as can be permanently intesrnpted. by rotating; head to into its positiilm occupying, cletent. notch, 2.8; or it: can; be; tempeaasily inten Hunted; by depressing knobs l 7..

atoresaiel; switch arrangement: further a totals the possibility ct controlling additional. Gill cuit connectionsiby. fitting aath-ircl-centact. element 4:5 in the. bottom. oi, shell. as removing he piir gaose.v

As a result, the switch can. functionas at break.- a-nclrmake switch when the: contact head is in thepesitienot Big; 6 EZQQxdBPllEfiSEd intoensageelement; is; as indicated by? dottedilinesi It can also-function. as a make osa bseak switch when head: at: is, rotated; into ens easement with} clete it notch: 23 and" then; @33 psessesl. into; engagement with contact. element.

as.a has been mentioned? connection. with. Fig}. 11.. sexiesalcontact elements 24: and several: on? positions 2.8. may be: crow/aides; Accoroinely-,, the simple switch, arrangement ct Fig. 6,. to,

contzzola; plurality of circuit, connections ap pncpxziatte: A. multiple. switch c this; type isusetul. in fields.- of application ion instance. in, measuring; inStiEllFfiBIl-t-S and; test circuits.

In case; it is desired to move contact. he d: onlybetween. its position. in contact.' element asand its. men; with contact element, keyect to: shell; as indicat s at as to: assets that the: lways retains from; its eesitiee in. nga m nt with contact elem nt 4.5.; into its is engagement. with: position: engce-- 4,5,, leach: ti; may be;

36 provided in the shell for,

position in engagement with contact element 24. In case a circular contact element 24 is provided, guide means such as key 45 may be omitted.

The switch according to Fig. 7 also uses substantially the same components as the switch according to Figs. 3 and 6. Accordingly, corresponding parts are designated by the corresponding reference numerals.

While the switch of Fig. 3 is operated only by rotation of knob ll and the switch of Fig. 6 either by rotation or depression of the knob, the switch according to Fig. 7 can be only operated by depression of the contact head.

Accordingly, knob I1 is omitted and replaced by an actuating means for effecting the required axial displacement of rod Hi. This actuating means is shown as a toggle cam 50 the camming surface of which coacts with the end face of rod [4, preferably enlarged for this purpose. As will be apparent, pivoting of cam 59 from its position shown in full lines into the position shown in dotted lines effects disengagement of contact head I from contact element 24 against the action of spring l9 and resilient disk 38. The two spring systems formed by the spring is and disk 38 again coact with each other in the manner of a damping device as has been explained in detail in connection with Fig. 3.

To assure that contact head always returns from its depressed or disengaged position into engagement with the contact strip of contact element 24, cam 50 is pivoted to shell 29 by means of a pivot pin 5| and engages a transverse slot 52 in the end face of rod l5 thereby preventing an accidental rotation of the rod and, hence, of head [5. Other suitable means to prevent a rotation of head l5 may of course also be employed, such as guiding the head in a groove in shell 35 but the illustrated arrangement is the preferred one.

While the invention has been described in detail with respect to certain now preferred examples and embodiments of the invention it will be understood by those skilled in the art after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended, therefore, to cover all such changes and modifications in the appended claims.

What is claimed as new and cured by Letters Patent, is:

1. An electric switch comprising a movable contact means including an electrically conducdesired to be setive guide sleeve having limit means on an intermediate part of its outside wall, an electrically conductive rod movably disposed within said sleeve in sliding electric contact therewith, said rod having an enlarged contact head on one end protruding from the sleeve and one-sidedly overhanging the peripheral outline of the sleeve, spring means within the sleeve coacting with the rod so as to bias the head thereof toward said sleeve; and a stationary contact means including a receiving sleeve having an inner configuration permitting passage of said head through the receiving sleeve and insertion of the guide sleeve in the receiving sleeve, one end of the receiving sleeve forming an edge abutment for said limit means and the other an edge abutment for said head, a contact member on one end of said receiving sleeve for contact engagement with said limit means, and a second contact member on the other end of the said sleeve electrically insulated'from the first contact member for contact engagement with said head whereby the said head and the said limit means abut against the respective ends of the receiving sleeve and electric connection is established between said contact members and, upon movement of the said head into a position disengaged from the said contact member, said electric connection is interrupted.

2. An electric miniature switch comprising a movable contact means including an electrically conductive guide sleeve having limit means on an intermediate part of its outside wall, an electrically conductive rod movably disposed within said sleeve in sliding electric contact therewith having an enlarged contact head on one end protruding from the sleeve and one-sidedly overhanging the peripheral outline of the sleeve, coil spring means within the sleeve coacting with the rod so as to bias the head thereof toward said sleeve; and a stationary contact means including a receiving sleeve having an inner configuration fitting the outer configuration of said enlarged head and said guide sleeve respectively for passage of said head through the receiving sleeve and insertion of the guide sleeve in the receiving sleeve, one end of the receiving sleeve forming an edge abutment for said limit means and the other an edge abutment for said head, the axial length of said receiving sleeve being slightly in excess of the axial of the guide sleeve portion between said limit means and the sleeve end from which said head protrudes, a contact member on one end of said receiving sleeve for contact engagement with said limit means, and a second contact member on the other end of the said sleeve electrically insulated from the first contact member for contact engagement with said head whereby the said head and the said limit means abut under spring tension against the respective abutment ends of the receiving sleeve and electric connection is established between said contact members and, upon movement of the said head into a position disengaged from the said contact member, said electric connection is interrupted.

3. An electric miniature switch comprising a movable contact means including an electrically conductive guide sleeve having electrically conductive limit means on an intermediate part of its outside wall, an electrically conductive rod axially slidable and rotatable within said sleeve in sliding electric contact therewith having an enlarged contact head on one end protruding from the sleeve and one-sidedly overhanging the peripheral outline of the sleeve, coil spring means within the sleeve coacting with the rod so as to bias the head thereof toward said sleeve; and a stationary contact means includin a receiving sleeve having an inner configuration fitting the outer configuration of said enlarged head and said guide sleeve respectively providing for passage of said head through the receiving sleeve and insertion of the guide sleeve in the receiving sleeve, one end of the receiving sleeve forming an edge abutment for said limit means and the other an edge abutment for said head, the axial length of said receiving sleeve being slightly in excess of the axial length of the guide sleeve portion between said limit means and the sleeve end from which said head protrudes, a contact member on one end of said receiving sleeve for contact engagement with said limit means, and a second contact member on the other end of the said sleeve electrically insulated from the first contact member for contact engagement with said head, said second contact member occupying part of the periphery of the respective sleeve end, whereby the said head and the said limit means abut under spring tension against the respective abutment ends of the receiving sleeve and in one rotational position of the said head electric connection is established between said contact members while in another rotational position of the said head the same is disengaged from the respective contact member and said electric connection is interrupted.

4. An electric miniature switch comprising a movable contact means including an electrically having electrically conan intermediate part of its outside wall, an electrically conductive rod on one end protruding from the sleeve and one-sidedly overhanging the peripheral outline of the sleeve, coil spring means within the sleeve coacting with the rod so as to bias the head thereof toward said sleeve; and a stationary contact means including a receiving sleeve having an inner configuration fitting the rupting said electric connection.

5. A switch according to claim 4, wherein the said limit means are in form of an annular shoulder on the outside of the guide sleeve.

6. A switch according to claim 4, wherein the said receiving sleeve is made of insulation material, the said second contact member comprising a contact strip fitted in one of the recesses of the sleeve, the said recess constituting the "on position and the other the "off position of the switch.

7. A switch according to claim 6, wherein the said receiving sleeve is continued in an open shell extending from the sleeve end engageable with said limit means and attachable to a. support for the switch, said shell housing the part of the guide sleeve between said limit means and the sleeve end opposite to said head.

8. A switch according to claim 7, wherein an actuating member is secured to the rod end opposite to said head, the said member protruding from the shell and covering the open free end 01' the same.

with said limit means and attachable to a port for a switch, said 9. A switch according to claim 4, wherein a generally cup shaped shell is secured to the end of the receiving sleeve engageable with said head for encompassing the same.

10. A switch according to claim 9, wherein the said head is in form of a rod portion bent back against said rod, and wherein the said second contact member is in form of a contact strip having a portion substantially transversely to the rod axis and a portion substantially parallel thereto, the said two strip portions being simultaneously engageable with the face end of the bent back rod portion and a side wall portion of said head.

to the second contact member, member occupying part of the respective end of the receiving periphery of the sleeve.

actuating member and the respective end of said shell.

l7. A switch according to claim 15, wherein the said receiving sleeve is continued in an open shell extending from the sleeve end engageable supshell housing the part of the guide sleeve between said limit means and the sleeve end opposite to said head, and whereand being in form of a knob mounted on said rod.

HARVEY HUBBELL. HENRY J. MODREY.

No references cited.

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