Patent Publication Number: US-3878346-A

Title: Combination electrical switch

Description:
111 3,878,346 [4 1 Apr. 15, 1975 United States Patent [191 Green COMBINATION ELECTRICAL SWITCH [76] lnventor: Franklin L. Green, Box 77, Primary Examirier RoPe.rt schziefer Machias, NY Assistant ExammerW1ll1am J. Smith Attorney, Agent, or Firm-Bean &amp; Bean [22] Filed: Mar. 28, 1974 21 Appl. No.: 455,662  
  Related U.S. Application Data Continuation-impart of Ser. No. 376,695, July 5, 1973, Pat. No. 3,801,761.  
 assembly including a combination dial rotatably coupled with a push button, which is mounted for independent reciprocating movements to successively po- [52] U.S. Cl. 200/43; 70/302; 70/311 [51] Int. Cl. H01h 27/10 sition an operator in driving association with each of [58] Field of Search............. the tumblers. The tumblers serve to drive contact elements along annular paths into circuit closing engagement with blade contacts establishing plural switch operating combinations one or more of which may be changed by selectively changing the position of the blade contacts. An improved latch device is provided for releasably retaining the switch in circuit completed 9 Claims, 7 Drawing Figures nn 00 SS mM VV aa DD 2,797,271 Augustine 2,934,615 4/1960 Goral....... 2,984,717 5/1961 Davidson. 3,192,331 6/1965 PATENTEU PR1 75 sum 1 er 3 COMBINATION ELECTRICAL SWITCH REFERENCE TO RELATED APPLICATION This application is a continuation in part of my copending application Ser. No. 376,695, filed July 5, 1973 now US. Pat. No. 3,801,761, Apr. 2, 1974.  
 BACKGROUND OF THE INVENTION In my copending application Ser. No. 376,695, filed July 5,1973 now US. Pat. No. 3801761, Apr. 2, 1974, there is disclosed a switch construction including a combination dial rotatably coupled to a push button,  
 which is in turn mounted for reciprocating movements in order to successively position an operator in driving association with each of a plurality of tumblers such that rotations of the combination dial are imparted to the tumblers through the operator. Each of the tumblers serves in turn to drive a bridging contact along an annular path within the confines of a combination contact housing non-rotatably fixed within a switch casing. The contact housings and the casing are formed with annularly spaced, radially aligned openings through which combination or blade contacts may be removably inserted for the purpose of changeably defining a single switch operating combination.  
  The combination dial is depressable to selectively release a latch device employed to normally retain the operator in its successive tumbler driving positions.  
 SUMMARY OF THE INVENTION The present invention relates to improvements in the switch construction disclosed by my above mentioned copending application. More specifically, the present invention provides a modified combination contact housing construction, which permits the switch to be operated by using any of two or more combination setting operations, and an improved latch device, which prevents retrograde rotations of the tumblers during the combination setting operation and negates the need for depressing the combination dial to return the switch to its initial condition.  
 DRAWINGS FIG. 6 is a sectional view taken generally along line 66 in FIG. 4; and  
  FIG. 7 is a fragmentary view similar to FIG. 6, but showing the latch in inoperative position.  
 DETAILED DESCRIPTION able mounting/security plate 12. To this end, plate 12 may be formed with an aperture 14 and switch 10 may be held in place therewithin by threadably or otherwise. suitably connected outer and inner clamping ring devices 16 and 18, respectively, as shown in FIG. 4. If required, access to portions of switch 10, which are disposed rearwardly of plate 12, for the purpose of changing the switch operating combination or combinations in-the manner to be described, may be normally prevented by enclosing same within an additional plate mounted security box, not shown.  
  By again referring principally to FIGS. 2 and 4, it will be understood that switch 10 generally includes a dial 20; a cup shaped push button 22; movement transmitting assembly 24; a switch casing 26; a plurality of tumblers 28-31; a plurality of combination contact housings 32-35, which are associated one with each of the tumblers; one or more sets of combination contacts eg. contacts 36-39 and contacts 36 &#39;39&#39;, wherein one contact of each set is removably associated with each of housings 32-35; a tumbler operator 40; and a reset latch device 42.  
  Dial 20 is best shown in FIG. 4 as including a body portion 50, an annular rear flange or rim portion 52 and a front face or rim portion 54, which may be interconnected in any desired manner. Body portion 50 is formed with a stepped through opening 56 having a reduced diameter front end portion 56a dimensioned to slideably receive assembly 24, and an enlarged diameter rear end portion 56b dimensioned to receive an annular flange 60 of outer clamping ring 16; rim portion 52 serving to retain flange 60 within end portion 56b and rotatably support the dial on ring 16 and thus plate 12.  
  As indicated in FIG. 1, the front face of rim portion 52 bears combination indicia, which upon rotation of dial 20 may be individually placed in registration with a reference mark 66 applied to plate 12. In the illustrated switch construction, the indicia includes an 0&#34; position and counterclockwise arranged numerical or combination setting positions 1 through 11.  
  The front surface of body portion 50 is formed with inner and outer annular recesses 72 and 74, respectively, which are disposed concentrically of bore opening 56. Inner recess 72 is dimensioned to accommodate a rear end ofa coil or other suitable compression spring 76, whereas other recess 74 is dimensioned to slideably receive an enlarged annular rim portion 78 of push button 22.  
  Movement transmitting assembly 24 includes an outer member 80, which has its front or outer end movably supported within dial bore opening portion 56a and an aligned through bore opening 82 formed in outer clamping ring 16 and has its rear or inner end movably supported by a casing carried guide pin 84 received within a rear opening cavity 86; and an inner or stem member 88&#39;, which is slideably supported within a from opening cavity 90 defined by outer member 80. Members and 88 are coupled for simultaneous rotary movements and for limited relative axial movements by means of an outer member carried pin 92, which is slideably received within inner member slot opening 94; pin 92 additionally being received within a slot 96 formed in body portion 50 for the purpose of coupling assembly 24 for rotation with dial 20, while providing for limited axial movement therebetween.  
  Outer member 80 is additionally formed with an enlarged front or head end portion 98, which is engaged by the front end of spring 76; a pair of side opening apertures 100, which are disposed in communication with the base or closed inner end 102 of front opening cavity 90; and an axially extending slot or recess 104, which is adapted to slideably receive a pin 106 carried by tumbler operator 40 for the purpose of coupling the tumbler operator for rotation with the outer member, while providing for limited axial movement therebetween. By this arrangement, pairs of apertures 108, 110 and 112, which are formed in tumbler operator 40 are maintained in radial alignment with outer member apertures 100, during relative axial movement between the outer member and tumbler operator in the manner to be hereinafter described.  
  lnner member 88 has an enlarged head end portion 114 fixed to its outer end and a pair of operating or pusher fingers I 16 pivotally supported on its inner end, as by means of a pin shaft 118. Head end portion 114 is preferably fixed to the inner surface of push button 22, but may be merely retained in engagement therewith by means of a coil or other suitable compression spring 120, which bears upon theouter end of outer member 80 and is relatively weak, as compared to spring 76.  
  Outer member 80 is normally maintained in its normal extended or outer position shown in FIG. 4, wherein an outer member carried abutment, such as a snap-on C-ring 122, engages with the inner face of outer clamping ring 16, by the cooperative action of springs 76 and 124; spring 124 bearing on the inner end of tumbler operator 40, which in turn bears upon C- ring 122. An inner or operating position of outer member 80, not shown, may be variously defined as for instance by engagement of the closed end or base 125 of rear opening cavity 86 with the front end of pin 84.  
  Inner member 88 is normally maintained in an extended or outer position relative to outer member 80 by spring 120, wherein the free ends of fingers 116 extend into but not through outer member apertures 100, as shown in FIG. 4. An inner or operating position of inner member 88 relative to outer member 80, not shown, may be variously defined as for instance by engagement of the inner end of inner member 88 with base 102 of front opening cavity 90. As will be apparent, movement of inner member 88 inwardly relative to outer member 80 against the bias of spring 120 serves to force fingers 116 to move outwardly through apertures 100 for receipt within tumbler operator apertures or openings 108, 110 and 112 when aligned therewith; such apertures preferably not being aligned with any of the above mentioned numerical positions of dial 20.  
  Again referring to FIGS. 2, 4 and 6, it will be understood that tumbler operator 40 is additionally formed with four axially spaced, frusto-conically shaped annular recesses 126, 128, 130 and 132; three axially spaced, ratchet toothed annular surface portions 134,  
 136 and 138; a smooth or non-toothed front surface&#34; portion 140; and a pair of radially extending tumbler driving pins 142, which are dimensioned to be slideably received within a pair of axially extending slots 144 formed on the cylindrical inner surface of each of tumblers 28-31. While pins 142, and thus slots 144, are preferably annularly spaced apart through about 120&#34;, they are shown in FIG. 4 as having a 180 spacing in order to facilitate identification of parts.  
  As best shown in FIG. 2, rearward and forward facing surfaces of adjacent tumblers are relatively inclined and cut away to define cooperating ratchet teeth 146 and 148, respectively, whereas the forwarding facing surface of frontmost tumbler 28 and the rearwardly facing surface of rearmost tumbler 31 are planer and essentially parallel, except for the provision of a forwardly extending release-stop lug 150 on the front face of tumbler 28, which is best shown in FIGS. 6 and 7 as cooperating with latch device 42. Lug 150 may be considered as defining a latch release or cam surface 150a and a stop surface 150b. It will be understood that when ratchet teeth 146 and 148 of any pair of adjacent tumblers are engaged, slots 144, as well as pairs of slots 152 formed on the outer cylindrical surface of each tumbler are maintained in relative axial alignment. With teeth 146 and 148 of adjacent tumblers engaged, driven rotation of first tumbler 28 in a clockwise direction (such direction corresponding to the direction dial 20 is rotated to successively position numeral positions 1 through 11 in alignment with reference mark 66) will produce like rotations of tumblers 29-31. Conversely, when the teeth of all of the tumblers are engaged, driven rotation of tumbler 31 in a counter-clockwise direction will produce like rotations of tumblers 28-30.  
  Tumblers 28-31 are normally biased into face to face abutting engagement and frontmost tumbler 28 biased into axial bearing engagement with the inner end of a cylindrical front part 154 of casing 26 by means of a coil spring 156 acting through a bearing sleeve 158. The front end of front part 154 may be clamped between ring devices 16 and 18 in order to support casing 26 on plate 12.  
  In that contact housings 32-35 are of identical construction, only first or frontmost housing 32, which is associated with tumbler 28, will be described in detail with reference to FIGS. 3 and 5, and like parts of housings 33 through 35 will be identified by like numbers. Housing 32 is best shown in H0. 3 as including an insulated bridging contact ring 162, which is coupled for rotation with tumbler 28 by a pair of projections 164 slideably fitted within tumbler slots 152 and carries a transversely extending bridging or through electrical contact pin 166 and a peripherally extending contact band 168; an insulated front housing ring 170, which is formed with a plurality of annularly spaced, rearwardly and radially outwardly opening positioning slots or openings 172, and has a radially outwardly projecting positioning lug 174; and an insulated rear housing ring 176, which is formed with an annular recess 178 whose base or radial surface is coated or covered with an electrical contact ring or bane 180 and with a plurality of annularly spaced, radially inwardly and outwardly opening positioning slots or openings 182 and has a radial outwardly projecting positioning lug 184. Contact band 168 is recessed below the peripheral surface of contact ring 162 except for a contact area 168a, which is disposed essentially flush with or projects slightly above such surface. First and second circuit contact pins 186 and 188, which extend radially outwardly through rear housing ring 176, have their inner ends electrically coupled with contact bands 180 and 168, respectively. In this connection, it will be understood that the inner end portion 188a of second circuit pin 188 is radially spring biased in order to permit it to ride over contact area 168a during rotation of contact ring 162 and be likewise radially displaced during assembly of its associated contact housing.  
  When housing rings 170 and 176 are clamped in engagement, contact ring 162 is rotatably received in recess 178 and housing ring 176 rearwardly closes slots 172. When the contact housing is assembled, its bridging contact 166 has its rear end arranged in sliding electrical contact with electrical contact ring 180 and has its front end arranged to slightly project into lower or radially inner end portion of slot openings 172. Also, contact band 168 is disposed in radial alignment with second circuit pin 188 and slot openings 182.  
  For any given construction, the number of slot openings 172 formed in each front housing ring and the annular spacing therebetween corresponds to the number and relative annular placement of numeral positions 1 through 11 of dial positioning lug 174 of each front housing ring corresponding to the 0 position of the dial 20 and being disposed in alignment therewith when the 0 position of the dial is disposed in registry with reference mark 66. Preferably, slot openings 182 correspond in number and annular orientation to slot openings 172. However, in the presently preferred construction, slot openings 172 are elongated in an annular direction and slot openings 182 are elongated in an axial direction relative to contact housing 32-35.  
  Casing 26 additionally includes an insulated central or main part 190, which is dimensioned to slideably accommodate housings 32-35; and a rear or cap part 192, which serves both to mount guide pin 84 and to axially clamp housings 32-35 in assembled condition within central part 190. Housing part 190 is formed with two sets of radially opening stepped apertures 192 and 192; and an elongated slot opening 194, which serves to receive ring positioning lugs 174 and 184 in order to prevent rotation of rings 170 and 176 of the contact housings relative to the casing. It will be understood that casing apertures 192 and 192&#39; are arranged as axially spaced, groups of apertures corresponding in number to the number of contact housings and that the apertures of each group of apertures 192 and 192 are arranged in radial alignment one with each of slot openings 172 and 182, respectively, of an associated contact housing.  
  In accordance with one form of the present construction, switch 10 is capable of two separate combination settings, which are selectively determined by inserting combination contacts 36-39 and contacts 36&#39;-39&#39; into one aperture of each group of apertures 192 and 192&#39;, as generally indicated in FIG. 1. This form of the invention has particular utility as a door lock control for multiple unit building installations, eg. motels, apartment houses and office buildings, wherein a custodian requires access to each unit and tenants are permitted access to only their assigned units. In this connection, the switch employed to control locking of the door of each unit would have a first operating combination determined by the setting of contacts 36-39 and known only to the tenant to which such unit is assigned, whereas all of the switches would have an identical second operating combination determined by the setting of contacts 36&#39;39&#39; and known only to the custodian. Moreover, this plural combination form of switch 10 may be used together with an otherwise similar single combination switch in various types of installation, such as with plural record storage files wherein certain individuals are entitled to have access to all files, whereas other individuals are entitled to gain access to only one or more specified files or for automobile ignition and trunk lock controls, wherein a parking attendant or mechanic is informed as to only the first operating combination of the ignition switch and the second operating combination of such switch corresponds to the single combination setting of the trunk lock control switch.  
  Contacts 36-39 each include an insulated pull 198 serving to mount a metal contact blade 200, an associated lead wire to be described and a pair of metal mounting fingers 202, which are resiliently deformable to permit a contact to be removably snap-fitted into one of apertures 192. Contact blade 200 is dimensioned to be removably inserted through one of apertures 192 for snug sliding fit in an aligned slot opening 172 for electrical contact with the front end of bridging contact pin 166. As will be apparent, various wear compensating means may be provided to insure proper electrical contact between blade 200 and contact pin 166 over an extended period of use, such as by constructing the blade to resiliently deform when contacted by the forward end of the contact pin.  
  Contacts 36&#39;39&#39; may be identical in construction to contacts 36-39 and thus like parts are designated by like primed numbers. Contact blade 200 is, however, dimensioned to be removably inserted through one of apertures 192&#39; for snug sliding fit in an aligned slot opening 182 and such that its inner end either slideably bears on or is in close proximity to the peripheral surface of contact ring 162 depending on the radial height of contact area 168a. As will be apparent, contact blades 200&#39; are disposed in electrical contact with bands 168 only when contact rings 162 are rotated such as to position their associated contact areas 168a in radial alignment therewith. Of course. various wear compensating means may be provided to insure proper electrical contact between blades 200&#39; and contact areas 168a and between pin end 188a with ring 168 over an extended period of use.  
 Latch device 42 also departs from that illustrated in my above mentioned patent application, in that it includes an inverted, essentially h-shaped operator member 210, having a latch leg portion 212 and a releasestop leg portion 214, which freely project through apertures formed in casing front part 154; a connecting portion 216; a suitable resilient device, such as coil spring 218, for biasing the operator member 210 inwardly for engagement with tumbler operator 40 and release-stop lug a resiliently deformable ratchet tooth member 220 carried by latchleg portion 212; and a connecting portion guide device 222 fixed to casing front part 154. By viewing FIG. 6, it will be appreciated that the mounting of tooth member 220 is such as to permit it to deflect only in a direction permitting clockwise or combination setting rotations of operator member 40 and thus dial 20 when tooth member 220 is engaged with any of ratchet toothed portions 134, 136 or 138.  
  Operation of switch 10 will now be described, it being assumed for purposes of illustration that contacts 36-39 have been positioned to establish a first switch operating combination of 6-9-7-11; that dial 20 is initially set with its 0 position in registration with reference mark 66; and that assembly 24 and tumbler operator 40 occupy the positions illustrated in FIG. 4. Also, in this condition lug stop surface l50b is disposed in sidewise engagement with the free or inner end of release-stop leg portion 214 thereby to constrain tumbler 28 and thus its associated contact ring 162 against retrograde rotations, ie., rotations in a counter-clockwise sense past an initial position wherein contact pin 166 and contact area 168a are disposed in an position in essential radial alignment with positioning lugs 174 and 184. Further, it will be understood that in this condition lug cam surface 150a has been underengaged with the lower end of leg portion 214 whereby to lift or vertically displace latch leg portion 212 from within recess 126 and lift tooth member 220 from engagement with ratchet tooth portion 134 against the return bias of spring 218, as indicated in FIG. 7.  
  A person having knowledge of the first combination may operate switch 10 by first rotating dial in a clockwise direction until numeral position 6 is positioned in registry with reference mark 66; this operation serving to drive contact ring 162 associated with contact housing 32 in a clockwise direction to bring the front end of its associated bridge contact pin 166 into electrical contact with blade 200 of contact 36, which is positioned in the 6 position of the first group of apertures 192. During this operation, contact ring 162 of contact housing 32 is&#39;coupled for rotation with dial 20 via tumbler 28, tumbler operator 40 and outer member 80; tumblers 29-31 rotating with tumbler 28 due to the coupling effect of ratchet teeth 146 and 148 in order to maintain their respective slots 144 in axial alignment. Also, it will be understood that as dial 20 is moved from its 0 position, lug 150 is moved from engagement with leg portion 214 thereby to permit spring 218 to position leg portion 212 within recess 126 and to position tooth member 220 in engagement with ratchet tooth portion 134 such that retrograde rotations of dial 20 are prevented.  
  After this initial setting of dial 20, push button 22 is momentarily depressed for the purpose of stepping pins 142 of tumbler operator 40 into operative engagement with slots 144 of tumbler 29. Upon initial depression of push button 22, relatively weak spring 120 is compressed to allow movement of inner member 88 inwardly relative to outer member 80; such relative movement serving to cam fingers 116 outwardly through outer member openings 100 for receipt within tumbler operator openings 108 and terminating upon engagement of inner member 88 with base end 102 of outer member front cavity 90. Thereafter members 80 and 88 and tumbler operator 40 are coupled for continued inwardly or rearwardly directed axial movement against the bias of springs 76 and 124 until movement thereof is arrested by engagement of the forward end of pin 84 with the base 125 of outer member rear opening cavity 86. When this movement is completed, tumbler operator 40 has been moved axially through a distance sufficient to position pins 142 within slots 144 of tumbler 29 and to position recess 128 and ratchet toothed portion 136 in radial alignment with leg portion 212 and tooth member 220, respectively; the radial displacement of leg portion 212 occasioned by riding out of recess 126 being sufficient to remove tooth member 220 from engagement with ratchet toothed portion 134 and prevent engagement thereof with ratchet toothed portion 136 until seating of such leg portion in operator recess 128. Upon release of push button 22, engagement of leg portion 212 with the rear wall of recess 128 serves to retain tumbler operator 40 in its first depressed position, not shown, against the bias of spring 124. Springs 120 and 76 are, however,  
 effective for removing fingers 116 from within tumbler operator openings 108 and then returning outer mem-- ber and inner member 88 to their initial positions shown in FIG. 4. When this is accomplished, outer member apertures are positioned in radial alignment with operator member apertures 110 and the switch is ready for the step of setting the next number of the first combination.  
  Dial 20 is again rotated in a clockwise direction until numeral position 9 is placed in registry with reference mark 66; this operation serving to drive contact ring 162 associated with contact housing 33 in a clockwise direction to bring its associated bridging contact pin into electrical engagement with blade 200 of contact 37 positioned in the 9 position of the second group of apertures 192. During this operation, tumblers 30 and 31 remain coupled for clockwise rotation with tumbler 29, while tumbler 28 remains at rest; spring 156 yielding sufficiently to permit slight axial movement of tumblers 29-31 relative to tumbler 28 as a result of camming engagement between the relatively inclined facing surfaces of tumblers 28 and 29. Retrograde rotation of dial 20 is again prevented by engagement of tooth member 220 with ratchet toothed portion 136. Suitable friction forces or detents, not shown, within housing 32 are relied upon to prevent movement of the bridging contact pin from registry with the contact blade of contact 36, as tumbler 29 is moved relative to tumbler 28.  
  After this second setting of dial 20, push button 22 is again momentarily depressed for the purpose of stepping pins 142 of tumbler operator 40 into operative engagement within slots 144 of tumbler 30. Upon release of the push button, members 80 and 88 are again returned to their initial positions in the manner described above, but tumbler operator 40 is retained in its second depressed position, not shown, due to engagement of leg portion 212 within recess 130. In this position of the tumbler operator, its apertures 112 are automatically aligned with apertures 100 of outer member 80 when the latter is returned to its initial or rest position. Also, tooth member 220 is arranged for engagement with ratchet toothed portion 138.  
  The third combination number is set by again rotating dial 20 in a clockwise or combination setting direction until numeral position 7 is placed in registry with reference mark 66; this operation serving to drive the contact ring associated with housing 34 in a clockwise direction to bring the front end of its associated bridging contact pin into electrical contact with the blade of contact 38, which is positioned in the 7 position of the third group of apertures 192. During this movement, tumbler 31 is coupled for rotation with tumbler 30 and spring 156 again deforms to permit relative axial movement of tumblers 30 and 31 with respect to now sta tionary tumblers 28 and 29.  
 To complete the combination setting operation, push button 22 is again depressed for the purpose of stepping pins 142 of the tumbler operator into operative engagement with slots 144 of tumbler 31; leg portion 212 being cammed out of recess and then being re ceived within recess 132 in order to prevent disengagement of pins 142 with tumbler 31 when the push button is thereafter returned to its normal extended position by springs 76 and 120. When this step is completed, tooth member 220 is arranged in sliding engagement with the smooth or non-tooth front surface portion 140.  
  The combination may now be completed by merely rotating dial 20 in a clockwise direction until numeral position 11 is in registry with reference mark 66&#39;, this serving to place the bridging contact pin of contact housing 35 in contact with the contact blade of contact 39, which is inserted through the 11 position of the fourth group of apertures 192. During this operation, spring 156 further deforms to permit slight axial movement of tumbler 31 relative to now stationary tumblers 28-30.  
  With the whole of the first combination set, a series circuit through the switch is completed for the purpose of completing a control circuit with which the switch is associated. As generally indicated in FIG. 1, the circuit would include lead wires 240 and 242, which are connected to contact pin I86 associated with contact housing 35 and combination contact 36 associated with contact housing 32, respectively. The circuit between contact housings of the switch may be suitably established, as by bridging wires 244, 246 and 248, which are provided to connect the contact pin associated with contact housing 32 to combination contact 37, the contact pin associated with contact housing 33 to combination contact 38, and the contact pin associated with contact housing 34 to combination contact 39, respectively.  
  If desired, contact housing 35 and combination contact 39 may be employed as a short throw ON- OFF&#34; switch in order to permit a device with which the present combination switch is associated to be turned ON and OFF without the necessity of reworking the whole combination. In this arrangement, the 11 position of the dial would be the ON position and the position would be the OFF position; smooth front surface 140 permitting combination setting and retrograde rotations of dial 20 between these positions. The remaining contact housings 32, 33 and 34 would of course be employed to form the combination and be uneffected by ON and OFF rotations of dial 20.  
  When desiring to relock the switch for the purpose of interrupting the control circuit, it is necessary to first rotate dial 20 in a counter-clockwise direction until all of the associated pairs of ratchet teeth 146 and 148 are brought into driving engagement with the result that tumblers 28-30 are driven in a counter-clockwise direction by tumbler 31 and slots 144 of all of the tumblers are again aligned. The operator of switch will be automatically advised when this operation is completed by engagement of frontmost tumbler carried lug 150 with latch leg portion 214, which serves both to prevent further tumbler rotation in a counter-clockwise direction and to release latch leg portion 212 from latching engagement within recess 132 and raise same above the surface of operator member 40, whereby to permit spring 124 to return the operator member to its initial position shown in FIG. 4. It will be noted that the relative positioning of latch leg portion 214 and lug 150 is such that the 0 position of the switch elements is in registry with reference mark 66.  
  When switch 10 is provided with a second operating combination, such as defined by the positioning of contacts 36&#39;39 arranged for instance in the combination 4-11-10-9, a separate, second electrical circuit can be completed through the switch by one having knowledge of the second combination; the manipulation of dial 20 and push button 22 being similar to that described above. This circuit would include lead wires 240&#39; and 242, which are connected to contact pin 188 associated with contact housing 35 and combination contact 36&#39; associated with contact housing 32, respectively, and bridging wires, not shown, would be provided to connect contact pin 188 associated with contact housing 32 to combination contact 37, the contact pin 188 associated with contact housing 33 to combination contact 38&#39;, and contact pin 188 associated with contact housing 34 to combination contact 39.  
 I claim:  
 1. A combination electrical switch comprising in combination:  
 a manually rotatable combination setting dial;  
 a manually depressable push button;  
 a plurality of, spaced devices each including at least one combination contact for establishing a combination setting of its associated device;  
 a plurality of axially aligned tumblers arranged one in association with each of said devices, each of said tumblers being rotatable relative to its associated device for driving a tumbler associated contact into electrical contact with said combination contact associated with its device whereby to complete an electrical circuit through its device, said devices being arranged within a series circuit completed by the completion of said electrical circuit through each of said devices, adjacent tumblers having cooperating means for coupling said tumblers for rotation in a first combination setting direction when a first of said tumblers is driven in said first direction, whereas when an additional tumbler other than said first tumbler is driven in said first direction said first tumbler and tumblers intermediate said first tumbler and said additional tumbler are uncoupled while other ones of said tumblers remain coupled for driving by said additional tumbler in said first direction, and for coupling said tumblers for rotation in an opposite direction when a last of said tumblers is driven in said opposite direction, each of said tumblers is formed with at least one axially extending drive slot, and the drive slots of adjacent tumblers when coupled being disposed in alignment;  
 a tumbler operator being formed with at least one tumbler engaging drive pin slideably received for movement lengthwise within said drive slot of each tumbler, said tumbler operator having a normal first position wherein said drive pin is disposed in driving engagement with said first tumbler and successive axially spaced positions wherein said drive pin is disposed in driving engagement with successive ones of said tumblers;  
 a latch device operable to releasably retain said tumbler operator in each of said successive positions and to prevent tumbler driving rotations thereof in said opposite direction in all positions excepting a last of said successive positions wherein it is drivingly engaged with said last of said tumblers, said latch device being releasable to permit return of said tumbler operator to said first position when said drive slot of a tumbler with which said tumbler operator is presently engaged is aligned with said drive slots of said first tumbler and tumblers intermediate said first and presently engaged tumblers;  
 and  
 a motion transmitting assembly for coupling said tumbler operator with said dial whereby to impart rotations of said dial to a tumbler with which said tumbler operator is drivingly engaged whereby to drive its associated contact and for coupling said tumbler operator with said push button whereby successive depressions of said push button serve to step said tumbler operator between said positions thereof in a direction axially away from said first position.  
  2. A combination electrical switch according to claim I, wherein said first tumbler carries means engageable with said latch device whereby to release said tumbler operator for return to said first position upon driven rotation of coupled tumblers by said last tumbler in said i said tumblers while coupled are driven by said last tumbler in said opposite direction, whereby in succession to release said tumbler operator for return to said first position and to define the limit of rotation of said tumblers in said opposite direction.  
  4. A combination electrical switch according to claim 1, wherein said tumbler operator is normally biased in a relatively forward direction into said first position thereof and includes an axially extending front opening. a plurality of axially spaced radially directed openings communicating with said front opening, a plurality of annular recesses spaced apart axially of said tumbler operator for cooperating with said latch device to releasably retain said tumbler operator in each of said successive positions and a plurality of ratchet toothed surface portions arranged intermediate adjacent annular recesses for cooperating with said latch device to prevent tumbler driving rotation of said tumbler operator in said opposite direction, said movement transmitting assembly includes an outer member received within said tumbler operator front opening for relative axial sliding movement and keyed to said tumbler operator for conjunctive rotary movements and an inner member supported concentrically within said outer member for relative axial sliding movement, said outer and inner members being keyed for rotation with said dial. said outer member having at least one radial opening disposable in radial alignment with a first of said tumbler operator radial openings when said tumbler operator is in its first position and successive ones of said tumbler operator radial openings when said tumbler operator is in said successiveipositions excepting said last of said successive positions, said&#39;inner member having an outer end engaged with said push button and an inner end carrying at least one pusher finger projectable outwardly through said outer member opening and into an aligned radial opening of said operator member when said push button is depressed&#39;whereby to couple said push button, said inner member, said outer memher and said tumbler operator for axial movement whereby to move said tumbler operator in a relatively rearward direction into said successive positions for engagement with successive ones of said tumblers, and said latch device cooperating with said ratchet toothed surface portions in all positions of said tumbler operator excepting said last of said successive positions 5. A combination electrical switch according to claim 4, wherein said first tumbler carries means engageable with said latch device whereby to release said tumbler operator, for return to said first position upon driven rotation of coupled tumblers by said last tumbler in said opposite direction.  
  6. A combination electrical switch according to claim 4, wherein said latch device includes a latch portion, a release-stop portion, a toothed member, and spring means for biasing said latch portion for insertion into said annular recesses and said toothed member for engagement with said ratchet toothed surface portions, and said first tumbler carrying a lug, said lug being arranged to engage said release-stop portion to remove said latch portion from insertion and said toothed member from engagement against the bias of said spring means upon driven rotation of said tumblers in said opposite direction by said last tumbler.  
  7. A combination electrical switch comprising in combination:  
 a manually rotatable combination setting dial;  
 a manually depressable push button;  
 a plurality of axially aligned stationary contact housings;  
 at least one set of electrical contacts, each said set including a plurality of combination contacts associated one combination contact with each of said housings for establishing a combination setting thereof;  
 a plurality of axially aligned tumblers arranged concentrically within and associated one with each of said housings, each of said tumblers being rotatable relative to its associated housing for driving a tumbler associated contact into electrical contact with said combination contact associated with its housing whereby to complete an electrical circuit through its housing, said housings being arranged within a series circuit completed by the completion of said electrical circuit through each of said housings;  
 a tumbler operator arranged concentrically within and engageable with said tumblers for effecting driven rotation thereof, said tumbler operator having a normal first position wherein it is disposed in engagement with a first of said tumblers and successive axially spaced positions wherein it is engaged with successive ones of said tumblers;  
 a latch deviee for releasably retaining said tumbler operator in each of said successive positions and for constraining said tumbler operator from rotation in a direction opposite to a given combination setting direction for all positions thereof excepting a last of said successive positions wherein it drivingly engages a last of said tumblers, said latch device being releasable to permit said tumbler operator to return to said first position from said last of said successive positions; and  
 a motion transmitting assembly for coupling said tumbler operator with said dial whereby to impart rotations of said dial to a tumbler with which said tumbler operator is engaged whereby to drive its associated contact and for coupling said tumbler operator with said push button whereby successive depressions of said push button serve to step said tumbler operator between said positions thereof in a direction axially away from said first position. 8. A combination electrical switch according to claim 7, wherein each of said stationary contact housings includes two sets of radially directed openings wherein the openings of each set correspond in number to the number of combination settings provided on said dial, said switch has two sets of electrical contacts. a combination contact of each set is associated with each said housing and removably insertable inwardly through a selected one of the openings of each set of said openings to selectively determine two separate combination settings of said housing, each of said tumblers drives two separate associated contacts one for electrical circuit completing engagement with an inserted combination contact of each set of electrical contacts thereby to selectively complete two separate electrical circuits through each housing, and said housings are arranged within two separate series circuits wherein only combination contacts of one set of electrical contacts are arranged in each series circuit.  
 9. A combination electrical switch according to claim 8, wherein each of said stationary contact housings defines an annular recess, said sets of openings being movably insertable selectively into one of said openings associated with said one set of electrical contacts to extend into a front portion of said recess, one of said tumbler associated contacts being a bridging contact extending through a contact ring, said contact ring being rotatably disposed within said annular recess and being coupled for rotation with its associated tumbler, one end of said bridging contact being disposed in continuous electrical contact with said ring of electrically conductive material and an opposite end of said bridging contact being movable into electrical contact with said combination contact extending into said front portion of said recess upon conjunctive rotation of said tumbler and contact ring, a combination contact of an other of said sets of electrical contacts arranged in an other of said series circuits being removably insertable selectively into one of said openings associated with said other set of electrical contacts to extend into a rear portion of said recess forwardly of said ring of electrically conductive material, another of said tumbler associated contacts being a band of electrically conductive material extending peripherally of said contact ring in radial alignment with said other set of openings for establishing electrical contact with an inserted combination contact of said other set in only one rotatable position of said contact ring, and said band is continuously connected into an other of said series circuits by a second connector extending outwardly through said contact housing and having its inner end disposed in sliding engagement with said band.