US 3665373 A
Description (OCR text may contain errors)
United States Patent Voglesonger 1 May 23, 1972 1541 PUSH-IN CONNECTOR swi'rcn 3,l35,822 6/l964 Baran et al ..339/95 D FOREXGN PATENTS OR APPLICATIONS 1,251,400 l0/l967 Gemlanyum 339/950 Primary Examiner-Joseph H. McGlynn Anomey-Harbaugh and Thomas 1511 ABSTRACT An appliance switch including a push-in electrical terminal safety assembly in which a bared conductor wireis simply insened endwise in guided relationship transversely through an insulating side wall to be received nonnal to a spring metal base element held in place by a cover where the bared wire is clamped between the ends of two cooperating aligned and converging spring metal tongues in the base element that are disposed against the opposite side of the wall.
llClains,6Drawingfigum Patented May 23, 1972 3,665,373
INVENTO/P. HARRY M. VOGLESO/VGER By /W/ M Attorneys PUSH-IN CONNECTOR swrrcn CROSS-REFERENCE Swanke Ser. No. 813,957, now US. Pat. No. 3,596,161, a related case and disclosure owned by the same assignee.
BACKGROUND OF THE INVENTION Although appliance manufacturers endeavor to safeguard the users of their products against electrical shocks, among other dangers, there generally are only one or two screws employed to hold dielectric housing members in assembled relation to prevent a user contacting electrically live connector elements in household appliances powered by multi-circuit arrangements. With the screws and dielectric housing members removed, conventional bare terminal clips and bare wire portions can be touched. Thus, the provisions of conventional terminal clips, soldered joints and component assemblies not only encounter the usual expense of additional connectors, labor, time and materials, but conventional dangers exist and a desired safety is still not attained because users still take appliances apart for any one of a number of reasons, regardless of offers of manufacturers to service and overhaul appliances and their warnings to discourage this for safetys sake.
There appears to be only one essentially important way to provide desired extra safety shocks and that is a two-fold action. Not only protect against bare wire contact by providing a main insulating housing that is not readily dismantleable but also to protect by providing insulated elements with all wiring and connections isolated from contact within the control components themselves that are in the main housing.
Accordingly, it is an object of the invention not only to provide structure whereby there are no bare metal parts exposed outside of any dielectric component members even when the main housing members are removed, but also to provide such structure and arrangements which are inexpensive and greatly reduce space requirements and the cost of assembly and production of components and appliances.
SUMMARY OF THE INVENTION In the present invention all metal that conducts electrical current is at least double insulated, both by the main housing, and additionally within the main housing by either an insulation covering or by being confined within dielectric component housings, or both. Electrical connections outside of the motor frame are confined to springlike connectors that have a small hole punched in them slightly smaller than the bare wire diameter and with two tabs that are lanced in the base of a conductor body when formed which yield to permit the bare wire to pass through the punched hole and be The arrangement has advantages with all conventional bare wire forms. When using stranded wire it can either be soldertinned after stripping, or it can be stranded wire which is hot tinned after stranding, or it can be stranded wire with extra heavy tin on the individual strands which can be induction fused in the stripped area only. All provide adequate dual contact areas with the tab endsl The contacts are held in place by snapping or screwing a DESCRIPTION OF THE DRAWINGS In the drawings, a liquidizer or blender is shown embodying the invention, in which 7 FIG. 1 is a fragmentary perspective view of the base and control construction embodying the invention,
FIG. 2 is a section taken on line 2-2 in FIG. 1,
FIG. 3 is an enlarged section view through the switch control,
FIG. 4 is an enlarged perspective view of a spring switch blade'and connector embodying the invention,
FIG. 5 is an enlarged perspective view of a stationary contact construction embodying the invention, and
FIG. 6 is an enlarged section illustrating the connectorclarnping relationship.
THE PREFERRED EMBODIMENT By way of illustrating the invention a liquidizer 10 is shown in FIG. 1 having a housing 14 enclosing an open frame universal motor 16, and a speed selector switch embodiment 12 con nected thereto by insulated wires 18. References is made to Swanke Ser. No. 813,957 for a further detailed description of the circuits involving field coils of different irnpedances and the switching thereof in various permutations. As viewed in Swanke, a permutation switch had electrical current bearing bare metal parts exposed to contact by a person's fingers when the lower cover is removed by the release of several screws.
This is eliminated in this invention.
In the present invention all electricity conducting metal parts are not only easily and quickly assembled but also are enclosed in the main housing and in the switch housing for double isolation against contact by anyone dismantling the base assembly and cannot be reached or tampered with without dismantling the component housing.
More particularly, the liquidizer 10 shown in FIG. 1 is one having the well known clover leaf shaped jar 20 supported on the housing 14in operative position in a well known manner by four upstanding guide supports 21. The panel 22 supports the multiple push button switch 12 embodying the invention and has either one or two rows of push buttons 24 extending More particularly all wire connections are end stripped of insulation and inserted through an insulating hole in the housing of a component up to the limit of insulation on the wire. The bare wire end passes between contiguous free ends of spring tabs at right angles to their plane of alignment. They flex away from the wall to permit the ready passage of the wire end and then clamp the wire end between their ends against withdrawal, the wall supporting the tabs. The wire is easily inserted and then held by spring tension of the formed tabs firmly locked against withdrawal. The molded or drilled hole in the case not only prevents buckling of the bare wire end, but serves to guide the wire into the clip and prevents sideway motions that might cause severance of the wire once the connection is made.
through the panel for selective actuation by the user. The general versatility of the invention is illustrated with a switch which includes two rows of push buttons 24 devoted to speed selection with a plurality of switches per-mutated thereby for the purpose. One button 248 is a composite button and serve as a stop button.
The multiple switch 12 as shown in FIGS. 2, 3 and 5 has a hollow elongated housing 26 molded of suitable insulating material having'an upright central portion 28 defining a slider chest 30 and adapted at its ends to receive mounting screws 32 (FIG. 1). The side walls 34 support the sliders 36 in an assembly for relative longitudinal reciprocation. Opposing vertical grooves 38 in the side walls 34 receive push rods 40 supporting the buttons 24 in guided relation where they extend upwardly from the slidechest through narrow slots 42 in the top of the central'portion 28 .for purposes of selective actuation. a
located below the sliders and comprise a row 'of stationary base terminals 44 having downwardly facingfixed contacts 43 resilientlysupported on 'a shoulder 45 in the housing. Along the other side are otherfixed base terminals 46 resiliently sup-' porting one end of bridging conductors 48 whose other ends provide contact areas 47 urged to close against the stationary contacts 43 in an upward direction when free to do so. A flat cover plate 50 of insulating material is secured to the housing 26 by suitable means to close the switch chamber with sufficient clearance to permit operation of the bridging conductors 48, to support the sliders with respect thereto and secure the base portions 44 and 46 of the terminals in supported relationshi /ells 52 are provided along the outer housing walls 34 on opposite sides of the sliders to receive the base portions 44 and 46 of the switch parts in supported relation. Switch spring brass blanks having a thickness of approximately 0.020 inch in a width of 0.375 inchare stamped and formed to the shapes shown. The blank base 46 portion (representative of base 44 also) is substantially flat and has a U-shaped cut 54in it with a bight portion 56 of the cut adjacent to the contact 47. The
central portion 58 of the cut is left flat and coplanar with the uncut base portion while the spaced strips that are severed into two parallel spring elements 60 are reversely-bent at 62 to provide resilient support adjacent to the bight 56 of the cut for the contact 47 that is carried on the other end of the blank formed to cooperate with the sliders 36.
Thus, observing the resulting form, the flat base portion 46 v is receivable to the depth of the well and against the outer wall 34 of the well 52 in a fixed relations secured by the cover 50.
Where the open space 54 between the reversely bent springs 60 is opposite the base 46, a generally H-shaped cut 64 is made to provide two spring tongues 66 and 68 with concave ends and extending towards each other and free at their edges 70' to move out of the plane of the base 46 to receive a bare wire element 72 forced endwise between their ends whereupon they cooperate to clamp the wire in place against removal.
Where the cross portion 74 of the H-cut 64 is located, the
housing wall 34 of the well 52 is ap'ertured as shown in FIG. 6
at 76 to receive the bare wire 72 therethrough perpendicular to the base portion 46 and its thrust force is divided between the two tongues 66 and 68 to move the tongues away from the face of the wall 34 with the free end of the bare wire extending into the open space between the spring elements 60 for com- The switch elements that are actuated by the sliders 36 are pactness of assembly. Manually pushing the wire as far as the insulation 78 thereon will go because of the size or shape of v the hole whereby it either abuts against the exterior of the wall 34 or against the shoulder 77, provides an electrical connec tion with which thereare no bare parts exposed to cause electrical shocks. The two deflected tongues 66 and 68 are supported at their base by the wall 34 of the well 52 and cannot be pulled back through the wall by pulling on the wire 18. It is only when the cover 50'of the switch housing is removed and the two tongues 66 and 68 are mechanically lifted that the bare wire 72 connection can be released, thus preventing inadvertent loosening of a connector by vibration, strain, or other means, and, if the bare wire is broken where it is clamped, the end exposed will be quite short and probably be protected by the remaining insulation.
In this connection it is to be noted that the resistance to flexure by the tongues is related to the cross-sectional area and the flatness of the spring stock at their bases. This can be regulated by the width of the H-cut 64, somewhat by the length of the tongues and the stiffness of the wire. Whatever resiliency is designed into the tongues, there will be little deviation of the wires because the wires are directed by the aperture 76 disposed vertically to the tongues 66 and 68. The conditions of assembly are substantially the same for all connectors with predictably repeatable results and most strand, solid, or soldered wires can be accommodated. Furthermore, the support of the contact by the spring parts are augmented rather than diminished in the embodiment.
What is claimed is:
1. An electrical connector comprising a housing having a wall of insulating material defining a pocket having a bare wire receiving opening through one of two opposite sides thereof,
a spring metal switch member having a temiinal base portion element of resilient electrically conductive material resting against said one side and an intermediate resilient portion against the other side supporting the remaining portion for movement,
a pair of clamping tongues cut from said base element and extending temiinally toward each other at said opening to flex away from the wall to receive and hold in clamped relationship between the ends of said tongues a bared wire inserted through said opening in alignment therewith, said base element and tonguesbeing assembled in said housing in electrically isolated and shielded relationship, said resilient portion being reversely bent upon the base element and overlying said opening and defining a space clearing the end of the bared wire inserted a-distance beyond the resilient portion. 2. The connector called for in claim 1 in which the severance of the tongues defines an H-cut in the base element with the center of the crosscut portion of the H-cut at said' 3. The connector called for in claim 1 in which the tongues curve away from said wall adjacent to their bases towards each other to engage said bared wire between them, said opening supporting said bared wire against flexing at'the point of said engagement.
4. The combination called for in claim I in which the adjacent ends of said tongues normally. define between them an opening of a size less than the size of said bared wire.
5. In an electric wiring device, a conductive member having a base member of switch spring material approximately 0.020 inch thick and 0.375 inch wide with an elongated slot therethrough,
a plurality of resilient tongues within the slot extending towards each other from opposite ends ofthe slot to flex in the same direction and increase the distance between their adjacent ends to receive a bared wire transversely therebetween in dual sharp edge electrically conductive 7. The combination called for in claim 6 including insulating means enclosing said base member and resilient means and having a wall supporting said base member in close proximity thereto with an aperture for receiving the bared wire therethrough in alignment with the ends of said tongues.
8. The combination called for in claim 7 including a dielectric switch housing. enclosing said conductive member in which the size of the aperture is approximately the size of a bared wire.
9. In an electrically powered housing a control device including a housing having spaced inner and outer walls on one side of insulating material defining a well with an aperture through the outer wall,
an electrical connector comprising a base portion. engaging said outer wall in supported relationship and having a reversely bent intermediate portion engaging the inner wall under pressure holding the base portion and intermediate portion in place, and v a terminal portion supported on the intermediate portion carrying a contact,
said base portion having a slot in alignment with said aperture, a plurality of tabs extending towards each other in said slot and terminating in close proximity to each other in alignment with said aperture to clamp a bared wire inserted through said aperture.
10. A combination switch element and connector comprising an end portion of resilient conductive material having a U- shaped cut defining a flat base portion and reversely formed spring strips defining a space with the bight of the cut,
said flat portion of said base being in juxtaposition to said