US2773954A

US2773954A - Snap action switch

Info

Publication number: US2773954A
Application number: US362505A
Authority: US
Inventors: Arthur W Haydon
Original assignee: HAYDON SWITCH Inc
Current assignee: HAYDON SWITCH Inc
Priority date: 1953-06-22
Filing date: 1953-06-22
Publication date: 1956-12-11
Anticipated expiration: 1973-12-11
Also published as: US2773955A; DE1075705B; GB779942A; CH317270A

Description

Dec. 11, 1956 A. w. HAYDON SNAP ACTION SWITCH Filed June 18, 1953 R m M A:olllllrrillolllllll!llv ATTORAEYS United States Patent '0 SNAP ACTION SWITCH Arthur W. Haydon, Cheshire, Conm, assignor to Haydon Switch, Incorporated, Waterbury, Conn., a corporation of Connecticut Application June 18, 1953, Serial No. 362,505

2 Claims. (Cl. 200-67) This invention relates to snap action switches, and more particularly to modifications of the snap action switch disclosed in copending application Serial No. 363,107 filed June 22, i953.

In the aforementioned application there is fully disclosed and claimed what may be termed 'a'single pole double throw hermetically sealed switch useful for the control of two interdependent electric circuits or for the control of a single electric circuit. For certain applicationsit is desirable to provide a "switchto control two completely independent electric circuits. "For other applications it is desirable toprovide 'a switch capable of controlling three interdependent 'electrical circuits. The primary object of this invention "is therefore to provide snap action switches, of the general type disclosed in the aforementioned copending application, which are suitable for use in the control of -two independent electrical circuits or for use in the control of three interdependent electrical circuits.

The snap action switch of the aforementioned copending application comprises a casing in which are mounted three terminal rods, two adjacent one end thereof and the third adjacent the other end thereof. To the third terminal is secured one end of a spring blade, the other end of which supports apair of contacts, one on either side, and extends between the remaining two terminal rods. The spring blade is normally supported so that one of the contacts on its free end engages a contact on one of the last mentioned terminal rods. When the switch is actuated by means of an actuating member mounted in the wall of the casing the spring blade is moved with a snap action from its normal position with its free .end in contact withone of the terminal rods of the pair to a position in which the other contact on its free end engages a contact on the other terminal rod of the pair.

The present invention contemplates :modifications of the above snap action switch in which the free end of the spring blade is mounted to move back and forth upon actuation of the switch from contact with a pair of terminal rods supported on one side thereof to a single terminal rod supported on the other side. The free end of the spring blade is provided with a contact on its side adjacent the single terminal rod adapted to engage a contact mounted on said terminal rod. Upon the other side of the free end of the blade is supported what may be termed a connecting bar, each end of which is adapted to engage a contact mounted on one of the pair of terminal rods on that side of the blade when the free end of the blade is moved toward said pair of terminal rods. In the modification useful in controlling two independent circuits, the connecting bar is supported from the free end of the blade by dielectric material electrically insulating it from the blade. In the modification useful for controlling three interdependent circuits, the contact bar is supported from the free end of the blade by conducting material electrically connecting it to the blade.

For a more detailed understanding of the invention and the advantages thereof, reference may be made to the following .more specific description taken in connection with the accompanying drawingin which:

Fig. l is a perspective of a switch according to this invention;

Fig. 2 is a sectional view thereof taken along line 2-2 of Fig. 1;

Fig. 3 is aplan view of the switch, partly-in section and with a portion of the casing removed; and

Fig. 4 he sectional view taken along line 44 of Fig. 2 illustrating more clearly the construction of the connecting 'bar support means.

The switches of this .application each comprise, as does that of "the aforementioned copending application Ser. No. 363,107, a cup-like casing member 10 having anopen side surrounded by a flange 11 and adapted to be closed for hermetic sealing by a casing closure 12 which is received within flange 11 and secured to the casing member 10 .by a fluid tight seal. A spring blade supporting terminal rod 13 supported in a glass sealing compound support 14 extends through closure member 12 having its inner end flattened at 13 to support a spring blade 16 and apa'irofiblade supporting members I7 and 18 which varesecure'd thereto by rivets19. A pair of 'tubuIarSmembersZt) extend completely through the switch casing and are sealed at opposite ends by fluid tight sealing means, .such as solder, to .the bottom of casing member IOand .to closure vmemberlZ. An auxiliary support member 21 of cylindrical form for aiding in the positioning and support .o'f'blade support member '18 is mounted on a tubular member 22 which is supported in a glass sealing compound support 23 in closure member 12. The interior of the switch 'is adapted to be evacuated through tube 22 and filled, if desirable, with inert gas and the tube thenpinched off and sealed.

The spring blade 16 includes a central compression member 16' normally arched out of the plane of the blade and a pairof tension members 16" on either side thereof. Blade support member 18 engages the convex side of compression member 16 while blade support member 17 having depending blade-engaging portions 17' engages tension members 16" of the blade, the latter being crimped, as indicated, to shorten their lengths and improve their resiliency under longitudinal tension. The outer end 17 of blade support member 17 supports a button 3% of material such as nylon engaged by a switch actuating pin 31 mounted in a flexible support member 32. Flexible support member 32 is preferably made of a silicone rubber compound and is supported in an opening in one wall of casingmember 10. The flexible support 32 for the actuating pin 31 is secured thereto by a fluid tight seal and further is secured by a fluid tight seal to a flange 33 bounding the opening through the side wall of casing 10.

As thus far described, switches of this invention are identical to the switch disclosed in copending application Ser. No. 363,107 and reference to that application is suggested for a more complete description of the elements of this switch as described so far, as well as for a complete description of the operating characteristics of those elements.

In the switch of the copending application, the spring blade 16 was provided at its outer end with a pair of silver contacts, one on either side thereof, these contacts being adapted to alternately engage a pair of contacts similar to

contacts

40 and 41 of the present switch which are mounted on

terminal rods

42 and 43, respectively, supported in the casing closure member 12 by two glass

sealing compound seals

44 and 45. In the switches of this invention, however, a single silver contact 50 is secured as by welding to the upper face of the outer end of spring blade 16 and is adapted, when the switch is in normal condition, to engage with a positive pressure contact 40 to complete a circuit including

terminal rods

13 and 42 and spring blade 16. On the other side of the free end of spring blade 16, instead of a second silver contact comparable to contact 50, there is mounted a shorting or connecting bar 60. When the switch is actuated and the contact between

contacts

40 and 50 is broken, connecting bar 60 is adapted to electrically connect contact 41 on terminal rod 43 to a contact 62 secured to a terminal rod 63 mounted in closure member 12 by a glass sealing compound support 64. Connecting bar 60 is preferably made of silver and is supported from the end of the spring blade by support member 70 partially surrounding the end of the spring blade, as illustrated most clearly in Fig. 4, and having a post 71 of square or non-circular cross section depending therefrom and extending through an opening of similar cross sectional shape in connecting bar 60, the bottom end of the post 71 being flared out to prevent removal of the connecting bar therefrom.

Supporting post 71 is located substantially centrally of the end of the blade and is of smaller cross section than the opening 72 in the connecting bar whereby the connecting bar is very loosely supported by the post and may rock to a limited extent. Support member 70 is additionally provided with a ridge 73 extending transversely of the blade between connecting bar 60 and the end of the blade, ridge section 73 acting as a fulcrum substantially to limit rocking movement of the connecting bar to a direction longitudinally of the blade. The mounting of connecting bar 60 by support member 70 for rocking movement longitudinally of the blade is' essential in order that tight contact be effected between connecting bar 60 and contacts 41 and 62 when the switch is actuated.

In a switch suitable for controlling two independent circuits, support member 70 and its components are made of any suitable dielectric material capable of withstanding the heat generated at the free end of the spring blade during operation of the switch. Hence the connecting bar is fully insulated from the spring blade. One of the circuits controlled will be that previously indicated including

terminal bars

13 and 42 and the switch blade. The other circuit that may be controlled is entirely independent and includes

terminal members

43 and 63 and connecting bar 60.

in a switch for controlling three interdependent circuits, the support member 70 may be made of an electrically conductive material such as silver. In this case, of course, the connecting bar 60 is electrically connected to spring blade 16 and the three circuits that may be controlled each include terminal rod 13 and spring blade 16 and one of

terminal rods

42, 43 or 63.

In a switch of this category, the support member need not be as large in volume as is shown, and in fact it is desirable that it not be so, because of the weight that would be involved. In this instance, the post 71 and the connecting bar rocking ridge 73 may be secured directly to the end of the spring blade 16 as by welding.

Certain changes and modifications in the switches of this invention may readily occur to those skilled in the art, but it should be understood that the scope of the invention should not be limited by reason of this fact but rather only to the extent set forth in the appended claims.

I claim:

1. A snap action switch comprising a spring blade supported at one end, the other end being free to move when the switch is actuated, a switch contact mounted opposite one side of the free end of the blade, a pair of switch contacts mounted opposite the other side of the free end of the blade, a support member of a dielectric material mounted on and substantially surrounding the free end of the blade, said support member having a depending post extending in the direction of said pair of switch contacts, a connecting bar loosely mounted on said post against rotation relative thereto, said connecting bar being adapted to engage and electrically connect said pair of switch contacts when the switch is actuated and the free end of the blade is moved toward said pair of switch contacts, pivot means associated with said support adjacent said post to provide for pivotal movement of the connecting bar about a lateral axis when it is moved into contact with said pair of switch contacts, and a contact mounted on the free end of the blade in electrical contact therewith and on the opposite side thereof from said post, said lastmentioned contact being adapted to engage the switch contact mounted opposite said one side of the free end of the blade when the switch is actuated and the free end of the blade is moved toward said switch contact.

2. A snap action switch according to claim 1 in which the support member of dielectric material includes a ridge extending transversely of the free end of the blade, said ridge being laterally aligned with said post and maintaining said connecting bar spaced from the free end of the blade, said ridge also providing a fulcrum for pivotal movement of said connecting bar in a direction longitudinally of said blade.

References Cited in the file of this patent UNITED STATES PATENTS 2,202,440 Beach May 28, 1940 2,238,621 Bletz Apr. 15, 1941 2,446,961 Sherlock Aug. 10, 1948 2,649,520 Hartz Aug. 18, 1953 2,662,941 Fisher Dec. 15, 1953