US 3578926 A
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Description (OCR text may contain errors)
United States Patent lnventor George Obermann Niles, 11].
Dec. 4, 1969 May 18, 1971 Controls Company of America Melrose Park, Ill.
App]. No. Filed Patented Assignee SNAP SWITCH 3 Claims, 3 Drawing Figs.
US. Cl 200/67 Int. Cl H01h 13/36 Field of Search 200/67 (D), 67; 74/100 (P) References Cited UNITED STATES PATENTS 8/1951 Van Ryan et al. 200/67D(UX) 2,571,453 10/1951 Jackson ..200/67D(UX) Primary Examiner-David Smith, Jr.
Attorneys-John W. Michael, Gerrit D. Foster, Bayard H.
Michael, Paul R. Puerner, Joseph A. Gemignani, Andrew 0. Riteris, Daniel VanDyke and Spencer B. Michael ABSTRACT: The compressed tongue of the switch blade is pivoted on the fixed support member while the side tails are under tension. The actuated end of the blade has integral pivot arms bent at 90 from the plane of the blade and pivoted on ears projecting from the support member. When the plunger is depressed, the side rails pass the pivot point of the tongue and cause the contact carrying end of the blade to snap downwardly. The construction affords considerable overtravel with no adverse effect on contact pressure. The switch provides a high degree of contact wiping.
Patented May 18, 1971 3,578,926
/mb7w SNAP swrrcn BACKGROUND OF INVENTION This general type of switch has been known for its long life, high reliability, high contact wiping, siderable overtravel. The closest prior art would be Kaminky U.S. Pat. No. 2,486,033 but that construction, while successful, had more parts and was considerably more difficult to assemble than the present design.
' SUMMARY OF INVENTION DESCRIPTION OF DRAWINGS FIG. I is a vertical view with one side of the case removed. FIG. 2 is a plan view of the blade and its support. FIG. 3 is a perspective view of the blade per se.
DESCRIPTION OF PREFERRED EMBODIMENT The housing supports two fixed terminals l2, l4 respectively provided with silvered contacts l6, 18. Also mounted in the housing is a fixed terminal which includes a support member 22, the' upper end of which is received in a cooperatrelative to the housing and, of course, relative to the contacts 16 and 18. The support member 22 is provided with laterally projecting pivot cars 24 upon which the blade pivot arms 26 are mounted. The pivot arms are integral with and bent down from the blade member 28, the actuated end of which (the left end in the drawings) has a crosspiece acted upon by the balllike end of plunger 30. The side rails 32 of the blade 28 pass on either side of the support member 22 and at the moving end (the right end) are joined by a crosspiece upon which the blade contact 34 is mounted. The compressed, bowed tongue 36 extends from the contact end of the blade back towards the support member and is pivoted in a suitable notch in the support member.
As can be seen in the drawings, the side rails normally lie above the pivot point of torque 36. The rails are in tension. The tongue and arms 26 are in compression. This results in a force on the pivot arms 26 tending to move the arms upwardly or clockwise about pivot 24, moving the plunger to its uppermost position. Also, the tongue, being under compression, exerts a force tending to move the free or contact end of the blade upwardly and thus holding the blade contact 34 against the upper fixed contact 18. As the plunger 30 is depressed, the actuated end of the blade moves down about pivot 24 and the rails move past the plane of the pivot of tongue 36. Once past and provision of coning slot in the interior of the housing to locate the member the centerline, the rails will cause the force developed by the compressed tongue to move the blade contact 34 away from the upper contact and down to the lower contact with a snap action. The rails never move below the pivot 24 so the force on the plunger is always upward and .the switch must be held in the actuated position. As the rails go towards the overcenter position, the torque must be bowed more and this causes a wiping action between the moving contact and the fixed contact which acts to break any weld.
Since the pivot anns are integral with the blade, the distance between the arm pivot point (24) and the actuating point can be accurately controlled. Pivots 24 are formed in stamping the support member. The positioning of the support member in the housing insures accurate location of the pivot. Arms 26 operate in unison to eliminate or minimize any twisting tendency of the actu'ated end of the blade. There are but eight parts in the entire assembly. Assembly is very simple.
After the rails pass over center as the plunger IS depressed,
considerable further movement (overtravel) can occur without any adverse effect on contact pressure, the contact pressure being developed by the compressed tongue. The switch will, of course, always tend to return to the illustrated position.
Greater accuracy is possible than in the prior art while realizing lower costs and high reliability.
l. A snap switch comprising:
a support member mounted in the housing and including projecting ears,
an overcenter blade including a compression tongue and spaced tension members, said tension members being interconnected at opposite ends,
a contact carried at one of the interconnected ends of the tension members and being free to move between preselected positions with a snap action, the other interconnected ends of the tension members being the actuated end of the blade,
said tongue being integral with the contact end of the blade and projecting toward and being pivoted on said support,
arms integral with the actuated end of the blade and being bent down at about to the plane of the blade and projecting from the blade end parallel to the tension members with holes pivotally mounted on said support ears, said arms being in compression and functioning in unison as a rigid beam pivotally supporting said blade, and
a plunger in the housing acting on said actuated end to move the tension members relative to the tongue pivot whereby the free end of the blade moves between said preselected positions with a snap action.
2. A snap switch according to claim 1 in which the preselected positions are determined by contacts carried by terminals fixed in and projecting from the housing.
3. A snap switch according to claim 3 in which the support is integral with a terminal fixed in and projecting from the housing.