US 3263306 A
Description (OCR text may contain errors)
1966 H. R. CHAPlN ETAL 3,263,306
METHOD OF MAKING A SNAP ACTION SWITCH Original Filed May 27, 1959 2 sheets sheet l I j I a E J" HEW ll. m m I In M W I 11 I FIG. 2 L
4-: 43 Q Fae. l0 F16. H (16.12 INVENmg How? I?!) E. 63 Tdsiiw CIT M 684 Aug. 2, 1966 Original Filed May 27, 1959 H. R. CHAPIN ETAL METHOD OF MAKING A SNAP ACTION SWITCH 2 Sheets-Sheet 2 Fla. 7
ATTORNEY United States Patent 3,263,306 METHOD OF MAKING A SNAP ACTION SWITCH Howard R. Chapin, Park Ridge, and Joseph J. Kaleba, Roselle, Ill., assignors to Controls Company of America, Schiller Park, Ill., a corporation of Delaware Application Aug. 27, 1962, Ser. No. 219,790, now Patent No. 3,189,703, dated June 15, 1965, which is a continuation of abandoned application Ser. No. 816,189, filed May 27, 1959. Divided and this application Apr. 26, 1963, Ser. No. 280,487
3 Claims. (Cl. 29-1555) This invention relates to electrical switches and more particularly to an improved snap action precision switch and a process for mass-producing such switches.
This application is a division of Serial No. 219,790, filed August 27, 1962, and now Patent No. 3,189,703, which is a continuation of Serial No. 816,189, filed May 27, 1959, now abandoned.
Precision snap action switches require accurate pivot and anchor points to assure proper alignment of the parts to provide precise operation of the switch. Formerly switches of this nature had relied on a combination of stamped and formed parts to complete the finished product. While accuracy and uniformity are inherent in stamped parts over extended production, forming tools are relatively inaccurate and do not have precision necessary to provide consistent snap action in the switch.
The primary object of this invention is to provide a switch which is fabricated largely of stamped parts which are so arranged as to lend themselves readily to high production Without adjustment.
Another object of this invention is to provide a switch in which all of the critical parts are inherently properly aligned.
A further object of this invention is to provide a process for fabricating a snap action switch which will insure the accurate location of contacts and supports during final assembly.
A still further object is to provide a .switch in which the base of the housing is molded around the blade contact supports and can be molded in multiple units to greatly decrease fabricating costs.
A final object of this invention is to provide a switch which can be easily ganged.
Other objects and advantages will be pointed out in, or be apparent from, the specification and claims, as will obvious modifications of the single embodiment shown in the drawings in which:
FIG. 1 is a side elevation partly in section of a complete snap action switch;
FIG. 2 is a plan view of a switch with the cover removed;
FIG. 3 shows the first step in the process showing the terminal strip;
lFIG. 4 shows the terminal strip with the contacts in p ace;
FIGS. 5 shows the terminal strip with the upper portion trimmed oft;
FIG. 6 shows the terminal strip with the plastic body molded thereon;
'FIG. 7 shows the terminal strip with the lower portion trimmed off;
FIG. 8 is a view taken on line 8--8 of FIG. 1;
FIG. 9 shows a plurality of switches mounted on a single bar;
FIG. 10 is taken on line 10-10 of FIG. 1;
FIG. 11 shows a modified form of contact; and
FIG. 12 shows another modified form of contact.
Referring to the drawings, FIGS. 1 and 2 show the complete switch contemplated by the invention. The switch includes terminals 10, 12 and 14, plastic body 16,
blade 18, stationary contacts 20 and 22, and a cover 24 supporting an actuating button 26.
The terminals 10, 12 and 14 are first stamped in a unit which is part of a metal strip in which any number of units can be stamped simultaneously. The units are retained in strip form to reduce handling and thereby eliminate individual fabrication. Each unit includes terminals 10, 12 and 14, upper web 28, lower web 30, anchor 32 and pivot 34. Contact supporting slots 36 are also stamped in each unit.
Silver contacts 20 and 22 are then mounted (FIG. 4) in the slots 36 by peening the divergent portion of the contact into the slot. This provides a rigid fit that will not be easily displaced. Where a lower amperage operation is contemplated the contacts may be modified to use brass points 40 (FIG. 11) stamped with the original strip or circular slugs 43 (FIG. 12) also peened into appropriate curved slots. These contacts can be peened simultaneously along an entire strip of units without distorting the contact points due to the presence of the web 28 and 30.
The upper web 28 is then trimmed (FIG. 5) from each unit in a single operation on the strip. The upper ends of the terminals 10, 12 and 14 are then separated one from the other with the blade anchor and pivot being an integral part of terminal 10. Upper contact 20 is integral with terminal 14 and lower contact 22 is integral with terminal 12.
The terminal strip is set in a multiple mold and the body 16 is molded to each unit in the strip. The terminals are still connected by web 30 and need not be separately jigged during the molding operation. Each unit is provided with a number of holes 42 for the plastic to flow through to hold the terminals in place.
The lower web is then trimmed, FIG. 7, from the unit, leaving the terminals 10, 12 and 14 insulated one from the other. Simultaneously with this step the adjacent body units are separated from each other leaving each switch an independent unit.
Blade 18, FIG. 2, which has been separately stamped is next secured to the anchor and pivot. Anchor 32 is inserted through slot 44 in the mounting tongue 46 and is swedged to make a rigid fit. The compression tongue 48 is then inserted into pivot 34 so that the contact end 50 is forced against upper contact 20. The accuracy of the switch is increased because the anchor, pivot, contacts and terminals are all in one plane omitting the necessity of providing for side forces.
An actuating button 26 is inserted through a hole 52 in cover 24 and retained in the cover by head 54. The cover, preferably a resilient thermoplastic, is then snapped onto rail 56 provided along the sides of the body 16, FIG. 8, and slot 58 formed on the inside of the cover fits over the contact end of the terminal '14 to prevent it from being misaligned.
To operate the switch, the button 26 is depressed against bridge 60 of he blade. The rails 62 will move downward until a point is reached where the force of the compression tongue on the contact end will be reversed to snap the contact end down against the lower contact, closing the circuit through terminal 12 and opening the circuit through terminal 14. When the button is released, the bridge will move upward, again reversing the force of the compression tongue on the contact end and snapping the end up against the upper contact, opening the circuit through terminal 12 and closing the circuit through terminal 14.
Where a multiple switch installation is required, the switches can be easily ganged by sliding a bolt or bar 66 through hole 68 provided in the body. A lug 69 and recess 70 provided on the sides of the body will interlock to form a unitary ganged structure as shown in 3 FIG. 9. Thus the locating lug and recess arrangement permits gauging the switches with use of only one bolt or the like.
Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims We claim:
1. A process for making a snap action switch terminal unit body comprising the steps of stamping a multiplicity of switch terminal units in a continuous metal strip, each of said units including the terminals, a blade anchor and a set of contact supports for a single switch each of said contact supports being provided with contact receiving means in confronting edges thereof, each terminal being connected to an adjacent terminal by webbing at the conclusion of the stamping operation, peening a set of contacts into the contact receiving means of contact supports, molding a continuous body strip of electrical insulating material on the terminal strip, removing the webbing interconnecting the terminals whereby the terminals are electrically insulated, and separating the said continuous body strip into individual bodies for each unit.
2. A process for making a snap action switch including a switch body and a movable switch blade and comprising the steps of providing a movable switch blade; stamping a planar switch terminal unit from a metallic strip, said terminal unit including the terminals, switch blade support and at least one switch contact support for a single switch, each terminal being connected to an adjacent terminal by webbing at the conclusion of the stamping operation to hold said terminals, blade support and contact support in the desired operational relationship during subsequent processing; molding a switch body of electrical insulating material on said terminal unit to hold said terminals, switch blade support and switch contact support assembled in said switch body in said operational relationship; removing the Webbing interconnecting the terminals so that said terminals are electrically insulated one from the other and fixedly securing one end of said movable switch blade onto said switch blade support with the other end of said switch blade extending from said switch blade support to position a portion of said switch blade in confronting relationship with an edge of said contact support and for movement of said switch blade portion relative to said switch blade support and said one end to move .said switch blade portion toward and away from said contact support edge.
3. The process of claim 2 wherein said terminal unit includes a pair of contact supports each provided with contact means on confronting edges thereof, and wherein said movable switch blade portion extends between said contact means for movement therebetween.
References Cited by the Examiner UNITED STATES PATENTS 2,406,281 9/1946 Dahl 29155.55 2,438,046 3/1948 Giannuzzi et al. 29155.54 2,954,469 9/1960 Gelzer 2504O 2,988,606 6/1961 Allison 20011 FOREIGN PATENTS 201,092 7/1923 Great Britain.
695,683 8/ 1953 Great Britain.
699,199 10/ 1953 Great Britain.
JOHN F. CAMPBELL, Primary Examiner.
WHITMORE A. WILTZ, Examiner.
R. W. CHURCH, Assistant Examiner.