US803212A - Switch for electric circuits. - Google Patents

Switch for electric circuits. Download PDF

Info

Publication number
US803212A
US803212A US18219603A US1903182196A US803212A US 803212 A US803212 A US 803212A US 18219603 A US18219603 A US 18219603A US 1903182196 A US1903182196 A US 1903182196A US 803212 A US803212 A US 803212A
Authority
US
United States
Prior art keywords
blades
switch
wedges
pairs
contact
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US18219603A
Inventor
Frank Conrad
Arthur B Reynders
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CBS Corp
Original Assignee
Westinghouse Electric and Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Westinghouse Electric and Manufacturing Co filed Critical Westinghouse Electric and Manufacturing Co
Priority to US18219603A priority Critical patent/US803212A/en
Application granted granted Critical
Publication of US803212A publication Critical patent/US803212A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H21/00Switches operated by an operating part in the form of a pivotable member acted upon directly by a solid body, e.g. by a hand
    • H01H21/02Details
    • H01H21/18Movable parts; Contacts mounted thereon
    • H01H21/36Driving mechanisms
    • H01H21/40Driving mechanisms having snap action
    • H01H21/42Driving mechanisms having snap action produced by compression or extension of coil spring

Definitions

  • WILKINSBURG PENNSYLVANIA
  • ASSIGNORS TO WESTINGHOUSE ELEC- TRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.
  • FRANK CONRAD residing at Edgewood Park
  • REYNDERs residing at Wilkinsburg, in the county of Allegheny, State of Pennsylvania, citizens of the United States, have invented a new and useful Improvement in Switches for Electric Circuits, of which the following is a specification.
  • Our invention relates to manually-operated switches for electric circuits.
  • the object of our invention is to provide a switch of the character indicated which shall be adapted for use in circuits carrying heavy currents; and it consists in means whereby adjustment of the contact-terminals may be made after the switch is closed in order to increase the intimacy of contact between the movable and stationary contact members and whereby the parts may be loosened when it is desired to open the switch.
  • Figure 1 is a front elevation f a switchembodying our invention.
  • Fig. 2 is a side elevation of the same.
  • Fig. 3 is a detail sectional view, and
  • Fig. 4 a view, partially in side elevation and partially in section, of a portion of the movable member of the switch shown in the preceding gures.
  • the invention is shown as embodied in a single-pole switch of the quickbreak type, but it may also be embodied in a multiple-pole switch either with or without a quick-break attachment.
  • One of the terminal blocks 1 is provided with two forwardly-projecting plates 2 and with two rearwardly projecting screwthreaded studs 3'f0r attachment to a circuitterminal at the rear of the switchboard.
  • the other terminal block 4 is also provided with two forwardly-projecting plates 5 and with two rearwardly projecting screw threaded studs 6, to which another circuit-terminal is.
  • the contact portions of the movable member of the switch consist of two outer blades 7 and 8 and two shorter inner blades 9 andlO. Riveted to the inner faces of the hinged ends of the blades 9 and 10 are wedge-shaped blocks 11 and 12, the thicker edges of the blocks being at their outer ends, and riveted to the inner faces of the other-ends of the blades 9 and 10 are similar wedge-shaped blocks 13 and 14, these blocks being so disposed that the inner faces incline oppositely to those of the blocks 11 and 12.
  • the blades 7, 8, 9, and and the blocks 11 and 12 are hinged upon a bolt 15,having bearings in the plates 2, which project from the terminal block 1.
  • the ends of the blades 7 and 8 are seated in suitable recesses in a head 16 and are fastened therein by means of bolts 17, which extend through the head 16 and the ends of the said blades.
  • rIlie cylindrical portion 19 is provided with a screwthreaded recess or socket, in which is screwed a rod 20, the handle being securely fastened to said rod by means of pins 2l.
  • rlhe other end of the rod 20 is provided with an annular groove 22 and projects into a cylindrical recess in a wedge 23, the form and size of which is such that it will accurately iit within the space between the inclined inner faces of the blocks 1l and 12.
  • the wedge 23 is provided with a set-screw 24, the inner end of which is seated in the groove 22 in the rod 20, so that the rod may be readily rotated; but if moved lon itudinally the wedge will be moved wit it.
  • a Wedge 25 similar to the wedge 23 is located between the blocks 13 and 14 and is rovided at its inner thicker end with a screwthreaded bush 26, that is fastened in position by means of a set-screw 27.
  • the bore of the bush 26 is of such diameter that its internal screw-thread makes operative engagement with the screw-thread on the rod 20.
  • the wedge 25 is provided with a lateral opening 28 at approximately its middle part, and a sufficient 4portion of the thinner edge is cut away to permit of the location and operation therein of the rod 2O without engagement with the adjacent edges.
  • a bolt 29 projects through the blades 7, 8, 9, and 10, and between the inner faces of the blades 9 and 10 ⁇ it is enlarged to form a cylindrical block 30, which is of less diameter than the opening 28 in the Wedge 25 and is provided with a lateral bore 31 to receive the rod 20.
  • the plates 5 are provided with slots 32., which are either inclined at a suitable angle or are cut upon the arc of a circle having the axis of the bolt 15 as its center in order to rebolts 36 and the inner ends of which are at- ⁇ tached to the blades by similar pins or bolts 37, the frictional engagement between the free ends of the blades and the plates 5 being such that when the switch is opened the supplemental blades will be held in their closed position until the beveled edges 38 at their pivoted ends engage the inner edges of the corresponding main switch-blades.
  • the parts will be so designed that at the time when this engagement is effected the main blades will have become separatedy from the plates 5, and consequently any arcing which takes place will be between the supplemental blades and the main contact-plates, and on account of the action of the springs 35 the iinal opening of the circuit will be effected so quickly as to promptly extinguish any arc which may be formed, this being a usual device and well known in the art.
  • thel handle 18 in order to open the'switch thel handle 18 will be turned in such direction, depending upon whether the screw-thread upon the rod 20 is of the right-hand or left-hand variety, as to tend to move the wedges 23 and 25 toward each other, and therefore out of engagement with the corresponding blocks A11 and 12 and 13 and 14. Since the pressure is exerted in opposite directions, the wedge will first move which has the least frictional engagement with the corresponding blocks, and this movement will continue until the bolt 15 or the cylindrical block 30, as the case may be, comes into engagement with the side of the opening in which it is located. This movement will be suflicient, however, to free the wedge from the adjacent wedge shaped blocks.
  • This action serves, in conjunction with the bolts 15 and 29, to draw the blades 7 and 9 and 8 and 10 into close contact with the corresponding plates 2 and 5, and thus insures a maximum carrying capacity for the amount of metal embodied in the switch.
  • a switchfor electric circuits the combination with two pairs of stationary contactterminals, of a movable member comprising contact blades having inclined surfaces, bolts, oppositely-acting wedges and means for actuating said wedges to engage said inclined surfaces and clamp said blades to both pairs of stationary terminals.
  • a switch for electric circuits the combination with two pairs of stationary contactterminals, of a movable member comprising contact-blades having lateral projections, clamping-wedges and means for moving said wedges in opposite directions to engage said projections.
  • a movable member comprising inner and outer blades the former of which have wedge-shaped blocks, wedges located between said blocks and means for forcing said wedges in opposite directions into and out of engagement vwith said blocks.
  • a switch for electric circuits the combination with two stationary terminals, of a movable member comprising contact-blades having inclined surfaces, wedges for engaging said inclined surfaces to clamp said blades to the contact portions of said stationary terminals and a single means for actuating said wedges in opposite directions.
  • a switch for electric circuits the combination with two stationary terminals, of a movable member comprising contact-blades, connectiiig-bolts and wedge-shaped blocks, wedges located between said blocks and means for moving said wedges in opposite directions to clamp the contact portions of both stationary terminals between the blades of the movable member.
  • a switch for electric circuits the combination with two pairs of stationary contactterminals, of a movable member hinged or pivoted to one of said pairs of terminals and comprising contact-blades having oppositelyinclined surfaces which are in lateral alinemeiit with the stationary terminals when the switch is closed, wedges located between said inclined surfaces and means for moving said wedges in opposite directions to clamp and release the contact-blades.
  • a switch for electric circuits the combination with two stationary terminals, of a movable member pivoted or hinged to one of said terminals and comprising contact-blades having lateral projections,wedges for engaging said projections to clamp said blades to the contact portions of said stationary terminals and a single means for actuating said wedges in opposite directions.
  • a switch for electric circuits the combination with two stationary terminals, of a movable member hinged or pivoted to one of said terminals and comprising con- A tactblades, connecting bolts and wedgeshaped blocks, wedges located between said blocks and means for moving said wedges in opposite directions to clamp the contact portions of both stationary terminals between the blades of the movable member.
  • a switch for electric circuits the combination with two pairs of stationary contact-terminals, of a quadruple-blade member having two pairs of wedge-shaped blocks attached to the inner faces of the inner blades, a rotatable handle having a screw-threaded rod and oppositely-disposed wedges mounted upon said rod and adapted to be forced in opposite directions between the respective pairs of blocks when the handle is rotated in the proper direction.
  • a switch for electric circuits the combination with two pairs of side-by-side, stationary contact-terminals, of a movable contact-terminal comprising two pairs of blades having inclined surfaces, two oppositely-acting wedges to engage said surfaces, an operating screw-rod therefor and an actuating-handle for said rod.
  • a quadruple-blade member pivoted to one of said IOO pairs of terminals and having wedge-shaped f blocks attached to the inner faces of the inner blades, two wedges and means for forcing them in opposite directions between said blocks.
  • arotatable handle having a screw-threaded rod and oppositely-disposed wedges mounted upon said rod and adapted to be forced in opposite directions between the respective pairs of blocks when the handle is rotated in the proper direction.
  • a switch for electric circuits the combination with two pairs of side-by-side, stationary contact-terminals, of a movable contact-terminal hinged or pivoted to one of the pairs of stationary terminals and comprising two pairs of blades having oppositelyinclined faces, two oppositely-acting wedges to engage said faces, an operating screw-rod IIO IZO

Description

No. 803;'212. PATENTED OGT.31, 1905. F. CONRAD & A. B. RBYNDERS. SWITCH FOR ELECTRIC GIRGUITS.
APPLIOATION FILED NOV. 21, 1903.
2 SHEETS--SHBET l.
No. 803,212. PATENTED CCT. 3l, 1905. P. CONRAD & A. BpREYNDERS. SWITCH FOR ELECTRIC CIRCUITS.
APPLICATION FILED NOV. Z1, 1903.
2 SHEETS-SHEET 2.
W/TNESSES: @i N. www.
TINTTED STATES PATENT orricn.
FRANK CONRAD, OF EDGEWOOD PARK, AND ARTHUR B. REYNDERS, OF
WILKINSBURG, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELEC- TRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.
SWITCH FOR I-:LECTRIC CIRCUITS.
Patented Oct. 31, 1905.
Application led November 21, 1903. Serial No. 182.196.
To all whom t may concern:
Be it known that we, FRANK CONRAD, residing at Edgewood Park, and ARTHUR B. REYNDERs, residing at Wilkinsburg, in the county of Allegheny, State of Pennsylvania, citizens of the United States, have invented a new and useful Improvement in Switches for Electric Circuits, of which the following is a specification.
Our invention relates to manually-operated switches for electric circuits.
The object of our invention is to provide a switch of the character indicated which shall be adapted for use in circuits carrying heavy currents; and it consists in means whereby adjustment of the contact-terminals may be made after the switch is closed in order to increase the intimacy of contact between the movable and stationary contact members and whereby the parts may be loosened when it is desired to open the switch.
In the accompanying drawings, Figure 1 is a front elevation f a switchembodying our invention. Fig. 2 is a side elevation of the same. Fig. 3 is a detail sectional view, and Fig. 4 a view, partially in side elevation and partially in section, of a portion of the movable member of the switch shown in the preceding gures.
As here indicated the invention is shown as embodied in a single-pole switch of the quickbreak type, but it may also be embodied in a multiple-pole switch either with or without a quick-break attachment.
One of the terminal blocks 1 is provided with two forwardly-projecting plates 2 and with two rearwardly projecting screwthreaded studs 3'f0r attachment to a circuitterminal at the rear of the switchboard. The other terminal block 4 is also provided with two forwardly-projecting plates 5 and with two rearwardly projecting screw threaded studs 6, to which another circuit-terminal is.
attached.
The contact portions of the movable member of the switch consist of two outer blades 7 and 8 and two shorter inner blades 9 andlO. Riveted to the inner faces of the hinged ends of the blades 9 and 10 are wedge- shaped blocks 11 and 12, the thicker edges of the blocks being at their outer ends, and riveted to the inner faces of the other-ends of the blades 9 and 10 are similar wedge-shaped blocks 13 and 14, these blocks being so disposed that the inner faces incline oppositely to those of the blocks 11 and 12.
The blades 7, 8, 9, and and the blocks 11 and 12 are hinged upon a bolt 15,having bearings in the plates 2, which project from the terminal block 1. The ends of the blades 7 and 8 are seated in suitable recesses in a head 16 and are fastened therein by means of bolts 17, which extend through the head 16 and the ends of the said blades.
A handle 18, which is provided foropening and closingthe switch, has a cylindrical portion 19, that projects through a corresponding opening in the head 16 and makes a suficiently loose iit therein, so that it maybe turned readily upon its axis. rIlie cylindrical portion 19 is provided with a screwthreaded recess or socket, in which is screwed a rod 20, the handle being securely fastened to said rod by means of pins 2l. rlhe other end of the rod 20 is provided with an annular groove 22 and projects into a cylindrical recess in a wedge 23, the form and size of which is such that it will accurately iit within the space between the inclined inner faces of the blocks 1l and 12. The wedge 23 is provided with a set-screw 24, the inner end of which is seated in the groove 22 in the rod 20, so that the rod may be readily rotated; but if moved lon itudinally the wedge will be moved wit it.
A Wedge 25 similar to the wedge 23 is located between the blocks 13 and 14 and is rovided at its inner thicker end with a screwthreaded bush 26, that is fastened in position by means of a set-screw 27. The bore of the bush 26 is of such diameter that its internal screw-thread makes operative engagement with the screw-thread on the rod 20. The wedge 25 is provided with a lateral opening 28 at approximately its middle part, and a sufficient 4portion of the thinner edge is cut away to permit of the location and operation therein of the rod 2O without engagement with the adjacent edges.
A bolt 29 projects through the blades 7, 8, 9, and 10, and between the inner faces of the blades 9 and 10`it is enlarged to form a cylindrical block 30, which is of less diameter than the opening 28 in the Wedge 25 and is provided with a lateral bore 31 to receive the rod 20.
IOO
The plates 5 are provided with slots 32., which are either inclined at a suitable angle or are cut upon the arc of a circle having the axis of the bolt 15 as its center in order to rebolts 36 and the inner ends of which are at-` tached to the blades by similar pins or bolts 37, the frictional engagement between the free ends of the blades and the plates 5 being such that when the switch is opened the supplemental blades will be held in their closed position until the beveled edges 38 at their pivoted ends engage the inner edges of the corresponding main switch-blades. The parts will be so designed that at the time when this engagement is effected the main blades will have become separatedy from the plates 5, and consequently any arcing which takes place will be between the supplemental blades and the main contact-plates, and on account of the action of the springs 35 the iinal opening of the circuit will be effected so quickly as to promptly extinguish any arc which may be formed, this being a usual device and well known in the art.
As regards the operation of the main switch, it will be understood that in order to open the'switch thel handle 18 will be turned in such direction, depending upon whether the screw-thread upon the rod 20 is of the right-hand or left-hand variety, as to tend to move the wedges 23 and 25 toward each other, and therefore out of engagement with the corresponding blocks A11 and 12 and 13 and 14. Since the pressure is exerted in opposite directions, the wedge will first move which has the least frictional engagement with the corresponding blocks, and this movement will continue until the bolt 15 or the cylindrical block 30, as the case may be, comes into engagement with the side of the opening in which it is located. This movement will be suflicient, however, to free the wedge from the adjacent wedge shaped blocks.
When the movement of either wedge is stopped by the means referred to, the other wedge must necessarily begin to move, and
its movement will continue until its bQlt 15 or cylindricalblock 30, as the case maybe, comes into engagement with the adjacent wall of the opening in the wedge, and vthus prevents further movement. The switch may then be opened by pulling outward upon the handle 18, since the blades 7, 8, 9, and 10 are pivotally mounted upon the bolt 15 and the slots 32 in the plates 5 afford passage-ways for the ends of the bolt 29. The friction between the supplemental blades 33 and the plates 5 will serve to maintain the engagement between the said parts until the beveled edges 38 engage the adjacent edges of the main blades, and thereafter the main and supplemental blades will move together until the latter are nearly freed from'contact with the plates 5, when the springs 35 will effect a quick separation of said parts and will move the supplemental blades into their normal edge-to-edge engagement with the main blades. When the switch is again closed, by moving the handle inward until the blades occupy the positions indicated in Fig. 2 the handle may be rotated in the opposite direction to that above described, so as to move the wedges away from each other into engagement with the faces of the corresponding wedge-shaped blocks. This action, as will be readily understood, serves, in conjunction with the bolts 15 and 29, to draw the blades 7 and 9 and 8 and 10 into close contact with the corresponding plates 2 and 5, and thus insures a maximum carrying capacity for the amount of metal embodied in the switch.
The form and dimensions of the several parts may obviously be varied from what is shown', and we therefore do not intend to limit our invention to details of construction, except as limitations may be imposed by the state of the art.
Ve claim as our invention- 1. In a switchfor electric circuits, the combination with two pairs of stationary contactterminals, of a movable member comprising contact blades having inclined surfaces, bolts, oppositely-acting wedges and means for actuating said wedges to engage said inclined surfaces and clamp said blades to both pairs of stationary terminals.
2. In a switch for electric circuits, the combination with two pairs of stationary contactterminals, of a movable member comprising contact-blades having lateral projections, clamping-wedges and means for moving said wedges in opposite directions to engage said projections.
3. In a switch for electric circuits,the combination with two pairs of stationary contactterminals, of a movable member pivoted to one of said pairs of terminals and comprising contact -blades having inclined surfaces, clamping-wedges and means for moving said wedges in opposite directions against said in clined surfaces.
4. In a switch for electric circuits, the combination with two pairs of stationary contactterminals, of a movable member comprising contact blades having oppositely -inclined surfaces which are in lateral alinement with the stationary terminals when the switch is TOO IIO
closed, wedges located between said inclined surfaces and means for moving said wedges in opposite directions to clamp and release the contact-blades.
5. In a switch for electric circuits, the coinbination with two pairs of stationary contactterminals, of a movable member comprising inner and outer blades the former of which have wedge-shaped blocks, wedges located between said blocks and means for forcing said wedges in opposite directions into and out of engagement vwith said blocks.
6. ln a switch for electric circuits, the combination with two stationary terminals, of a movable member comprising contact-blades having inclined surfaces, wedges for engaging said inclined surfaces to clamp said blades to the contact portions of said stationary terminals and a single means for actuating said wedges in opposite directions.
7. In a switch for electric circuits, the combination with two stationary terminals, of a movable member comprising contact-blades, connectiiig-bolts and wedge-shaped blocks, wedges located between said blocks and means for moving said wedges in opposite directions to clamp the contact portions of both stationary terminals between the blades of the movable member.
8. ln a switch for electric circuits, the combination with two pairs of stationary contactterminals, of a movable member hinged or pivoted to one of said pairs of terminals and comprising contact-blades having oppositelyinclined surfaces which are in lateral alinemeiit with the stationary terminals when the switch is closed, wedges located between said inclined surfaces and means for moving said wedges in opposite directions to clamp and release the contact-blades.
9. In a switch for electric circuits, the combination with two pairs of stationary contactterminals, of a movable member hinged or pivoted to one of said pairs of terminals and 4 5 omprising inner and outer blades the former of which have wedge-shaped blocks, wedges located between said blocks and means for forcing said wedges in opposite directions into and out of engagement with said blocks.
10. In a switch for electric circuits, the combination with two stationary terminals, of a movable member pivoted or hinged to one of said terminals and comprising contact-blades having lateral projections,wedges for engaging said projections to clamp said blades to the contact portions of said stationary terminals and a single means for actuating said wedges in opposite directions.
11. In a switch for electric circuits, the combination with two stationary terminals, of a movable member hinged or pivoted to one of said terminals and comprising con- A tactblades, connecting bolts and wedgeshaped blocks, wedges located between said blocks and means for moving said wedges in opposite directions to clamp the contact portions of both stationary terminals between the blades of the movable member.
12. In a switch for electric circuits, two pairs of stationary contact-termiiials,a quadruple-blade member having wedge-shaped blocks attached to the inner faces of the '1nner blades, two wedges and means for forcing them in opposite directions between said blocks.
13. ln a switch for electric circuits, the combination with two pairs of stationary contact-terminals, of a quadruple-blade member having two pairs of wedge-shaped blocks attached to the inner faces of the inner blades, a rotatable handle having a screw-threaded rod and oppositely-disposed wedges mounted upon said rod and adapted to be forced in opposite directions between the respective pairs of blocks when the handle is rotated in the proper direction.
14. In a switch for electric circuits, the combination with two pairs of side-by-side, stationary contact-terminals, of a movable contact-terminal comprising two pairs of blades having inclined surfaces, two oppositely-acting wedges to engage said surfaces, an operating screw-rod therefor and an actuating-handle for said rod.
15. In a switch for electric circuits, the combination with stationary contact-terminal lates and contact-terminal blades having ateral projections and engaging both faces of said plates, of bolts, wedges for engaging .the projections on said blades and means for adjusting the wedges to increase or decrease the clamping action.
16. In a switch for electric circuits,`two pairs of stationary contact-terminals, a quadruple-blade member pivoted to one of said IOO pairs of terminals and having wedge-shaped f blocks attached to the inner faces of the inner blades, two wedges and means for forcing them in opposite directions between said blocks.
17. In a switch for electric circuits, the combination with two pairs of stationary contact-terminals, of a quadruple-blade member pivoted to one of said pairs of terminals and having two pairs of wedge-shaped blocks attached to the inner faces of the inner blades, arotatable handle having a screw-threaded rod and oppositely-disposed wedges mounted upon said rod and adapted to be forced in opposite directions between the respective pairs of blocks when the handle is rotated in the proper direction.
18. ln a switch for electric circuits, the combination with two pairs of side-by-side, stationary contact-terminals, of a movable contact-terminal hinged or pivoted to one of the pairs of stationary terminals and comprising two pairs of blades having oppositelyinclined faces, two oppositely-acting wedges to engage said faces, an operating screw-rod IIO IZO
combination With tWo pairs of stationary contacteterminals, of a movable member having a pair of oppositely-acting Wedges and contact-blades so formed and arranged as to be clamped to the stationary contact-terminals by the said Wedges.
In testimony whereof We have hereunto subscribed our names this 6th day of November, 1903.
FRANK CONRAD. ARTHUR B. REYNDERS. Witnesses:
H. N. BARTLETT, BIRNEY HINEs.
US18219603A 1903-11-21 1903-11-21 Switch for electric circuits. Expired - Lifetime US803212A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US18219603A US803212A (en) 1903-11-21 1903-11-21 Switch for electric circuits.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US18219603A US803212A (en) 1903-11-21 1903-11-21 Switch for electric circuits.

Publications (1)

Publication Number Publication Date
US803212A true US803212A (en) 1905-10-31

Family

ID=2871696

Family Applications (1)

Application Number Title Priority Date Filing Date
US18219603A Expired - Lifetime US803212A (en) 1903-11-21 1903-11-21 Switch for electric circuits.

Country Status (1)

Country Link
US (1) US803212A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2845512A (en) * 1955-03-30 1958-07-29 Kelek Company Pressure switch

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2845512A (en) * 1955-03-30 1958-07-29 Kelek Company Pressure switch

Similar Documents

Publication Publication Date Title
US2308026A (en) Load break disconnect
US803212A (en) Switch for electric circuits.
US2449479A (en) Electrical contacts
US2286131A (en) Disconnecting switch
US3646294A (en) Switch
US2710897A (en) Switch construction
ES2941310T3 (en) Spring-loaded auxiliary contact system for bus transfer switching in a central breaker
US570418A (en) wurts
US1914924A (en) Switch
US2456502A (en) Double throw switch
US704202A (en) Switching apparatus.
US771989A (en) Electric switch.
US2613291A (en) Auxiliary contact construction for load interrupter switches
US633771A (en) Switch for electric circuits.
US888760A (en) Circuit-breaker.
US1551279A (en) Mamgr
US1913309A (en) Disconnecting switch
US1212125A (en) Switch for heavy alternating currents.
US570419A (en) Alexander jay wurts
US691766A (en) Electric switch.
US1123283A (en) System of electric distribution and circuit control.
US2599242A (en) Rotary circuit interrupter
US500629A (en) Electric switch
US3646299A (en) Pole mechanism for double-throw pressure contact switch
US578643A (en) Electric cut-out