US3447121A

US3447121A - Electrical connectors particularly for electric resistance heating elements

Info

Publication number: US3447121A
Application number: US592484A
Authority: US
Inventors: George Edward Ammerman; Donald M Cunningham
Original assignee: Edwin L Wiegand Co
Current assignee: Edwin L Wiegand Co
Priority date: 1966-11-07
Filing date: 1966-11-07
Publication date: 1969-05-27
Anticipated expiration: 1986-05-27
Also published as: GB1160654A

Description

G. E. AMMERMAN ET CONNECTORS PARTICULARLY FOR ELE 3,447,121 CTRIC May 27, 1969 ELECTRICAL RESISTANCE HEATING ELEMENTS Sheet Filed Nov. 7, 1966 M \w w www INVENTOR5 ERM AN GEORGE E AMM ad DQNALD M. CUNN\NGHAM ATTo/elvsys May 27, 1969 .E. AM-MERMAN ET AL 3,447,121 ELECTRICAL CONNECTORS PARTICULARLY FOR ELECTRIC RESISTANCE HEATING ELEMENTS Filed Nov. 7, 1966 Sheet 2 of2 Fla 21 INVENTORS GEORGE. E. AMMERMAN i DONALD M. CUNN\NGHAM United States Patent 3,447,121 ELECTRICAL CONNECTORS PARTICULARLY FOR ELECTRIC RESISTANCE HEATING ELEMENTS George Edward Ammerman, Murfi'eesboro, Tenn., and Donald M. Cunningham, Pittsburgh, Pa., assignors to Edwin L. Wiegand Company, Pittsburgh, Pa.

Filed Nov. 7, 1966, Ser. No. 592,484 Int. Cl. H01r 33/72, 9/08; Hb 3/68 US. Cl. 339-192 16 Claims ABSTRACT OF THE DISCLOSURE An electrical connector assembly in which one or more elongated, resilient electrical contact strips are disposed in respective slots formed in a dielecetric body and wherein each strip has a portion cooperable with one of its slot walls to resiliently receive and grip a respective electrical contact prong therebetween.

Abutments are spaced longitudinally of a body slot to maintain the strip portion aforesaid adjacent its slot wall, such abutments comprising a projection extending toward one slot wall from an opposed slot wall and the other comprising an angularly disposed contact strip end portion resiliently engaged with such opposed slot wall.

The present invention relates to electrical connectors particularly adapted for use with electric resistance heating elements and the principal object of the invention is to provide new and improved devices of the character described.

Heretofore, the connection of electric power and ground leads to electric resistance heating elements of the range, or surface type, has presented a problem in achieving an acceptable balance between manufacturing cost considerations, ease of assembly and disassembly, safety in the hands of a not always careful user, and of course, the basic requirement that any such device must function efficiently for long periods with no attention.

In the past, the leads aforesaid have been attached to the heating element by means of screws; however, such structure has not been satisfactory in that a user of the range could not readily detach the leads from the element to facilitate cleaning of the range and the element assembly. Moreover, factory assembly costs were high since each lead had to be individually fastened.

Going to a near-opposite extreme, the prior art has provided surface elements of the so-called, plug-in type wherein a heating element had its electric terminals inserted into a suitable receptacle in which the electrical connections were automatically made upon element insertion. Many of such plug-in elements have been satisfactory in that a user could readily remove and replace an element; however, such assemblies have not always functioned properly and they have invariably been quite expensive to manufacture and assemble with the range.

The present invention provides a low-cost, simple and efficient device for connecting power and ground leads to a surface-type, electric resistance range element, such device also providing for ready disconnection and reconnection of the element by one of little mechanical aptitude. These and other advantages will readily become apparent from a study of the following description and from the appended drawings.

In the drawings accompanying this specification and forming a part of this application there is shown, for purpose of illustration, an embodiment which the invention may assume, and in these drawings:

FIGURE 1 is a sectional view through a range top in which is mounted a surface-type electric resistance heating element assembly embodying the invention,

Patented May 27, 1969 ice FIGURE 2 is a separated perspective view of certain parts seen in FIGURE 1,

FIGURE 3. is a fragmentary, enlarged plan view generally corresponding to the line 3-3 of FIGURE 1, portions on the near side being broken away to show the underlying structure,

FIGURE 4 is an enlarged sectional view generally corresponding to the line 4-4 of FIGURE 1,

FIGURE 5 is a view similar to FIGURE 3, but showing certain parts in separated relation,

FIGURE 6 is a view similar to FIGURE 5 but showing certain parts at an earlier stage of assembly,

FIGURE 7 is an enlarged perspective view of a detail seen in FIGURES 3, 5 and 6, and

FIGURE 8 is a fragmentary, enlarged perspective view of a modified detail.

With reference first to FIGURE 1, there is shown the well-known, surface-type heater assembly 10 mounted on the top panel 11 of an electric range or the like. Briefly, such assembly comprises a trim ring having a tubular portion 12 fitting within an aperture 13 in the range top panel 11, a radially outwardly projecting flange 14 which rests upon the stove panel top, and a radially inwardly turned flange 15. Seated upon the flange 15 is a radially outwardly turned flange 16 of a drip pan 17. The latter has a portion of its wall cut away at 18 for a purpose to appear.

Mounted within the trim ring is the usual enlongated tubular sheathed electric resistance heating element 19 whose intermediate, heat-generating portion 19.1 is convoluted to provide a generally plane heating surface on which a vessel to be heated may be disposed. Terminal ends 20, 21 of the element 19 are bent to project beneath and to one side of the heating surface provided by the element intermediate portion 19.1. Element terminal ends 20, 21, as best seen in FIGURE 2, are disposed in side-by-side relation for a purpose to appear. Underlying and suitably secured to the convoluted element intermediate portion 19.1 is a metallic supporting member 23 known in the trade as a spider. Spider member 23 provides a plurality of legs which rest upon the upper surface of the flange 16 of pan 17, such spider in turn supporting the overlying element. 1

As best seen in FIGURE 2, the element terminal ends 20, 21 terminate in exially extending, electrically conductive terminal pins 20.1, 21.1, respectively, such pins being electrically connected to respective ends of the usual, heat-generating resistor conductor member (not shown) disposed within the intermediate portion of the element 19. It will be appreciated that pins 20.1 and 21.1 are of relatively low electrical resistance to provide for conduction of electrical energy to the resistor aforesaid at the intermediate element portion.

Still referring to FIGURE 2, an apertured, metal plate 24 extends between the

element terminal ends

20, 21 and is crimped or otherwise afiixed to at least one of such ends to maintain the latter in the desired spaced relationship. Welded or otherwise mechanically and electrically secured to the plate 24 is one end of a metal pin 25 whose opposite free end 25.1 is flattened and doubled over on itself to provide a ground prong between the

element terminal ends

20, 21 whose transverse size at its free end is materially greater than the transverse size of the terminal pins 20.1, 21.1. It is also to be noted that the free end of prong 25 projects a substantial distance beyond the free ends of the terminal pins for reasons to appear.

A female electrical connector assembly 26 provides a quick attachab1e-detachable means for connecting the element terminal pins 20.1, 21.1 into an electrical power circuit and for connecting the ground pin 25 into a grounding circuit. As herein disclosed, assembly 26 comprises a dielectric body 27 having an end with a recess 28 in which the free ends of the element terminal ends 20, 21 may be inserted. As will later appear, electrical connectors within the body 27 make contact with the terminal pins 20.1, 21.1 and the ground pin end 25.1 to place such parts into their respective circuits.

With reference first to FIGURE 4, body 27 is provided with three

elongated slots

29, 30 and 31 extending therethrough in side-by-side relation of respectively receiving the terminal pin 20.1, grounding pin 25, and terminal pin 21.1. Slot 29 is in part defined by a side wall 32 while slot 31 is in part defined by a side wall 33. As herein disclosed, walls 32, '33 are in oppositely facing relation and are disposed adjacent the slot 30. Similarly, slot 30 is in part defined by a wall 34; however, wall 34 preferably forms the bottom of slot 30. As will later be disclosed in greater detail, the terminal pin 20.1 is adapted to be gripped between the wall 32 and a resilient electrical contact member 35, the terminal pin 21.1 is adapted to be gripped between the Wall 33 and another resilient electrical contact member 36, and the ground pin and 25.1 is adapted to be gripped between the wall 34 and still another resilient electrical contact member 37. Since the

contact members

35, 36 and 37 are preferably identical and function with their respective slots in an identical manner, only the contact 35 and the slot 29 will hereinafter be disclosed in detail.

As best seen in FIGURE 7, contact member 35 comprises a resilient metal strip of a width to closely fit within the slot 29 and having a rectilinear, main portion 35.1 and an integral, angularly disposed end portion 35.2. At the opposite end of the contact member, the latter is bent transversely at 35.3 to mechanically and electrically connect with a flexible, insulated lead wire 38. Contact member portion 35.3 forms a lateral extension on the same side of said contact strip as said angularly disposed end portion 35.2 for a purpose to appear. On the same side of the contact strip as the lateral extension 35.3 and the angularly disposed end portion 35.2, a tongue 35.4 is struck from the contact strip. The free end of tongue 35.4 is directed toward the extension 35.3 but is spaced therefrom, longitudinally of the strip, a short distance for a purpose to be disclosed.

Turning now to FIGURE 6 where the contact strip 35 is shown at an early stage of assembly with the dielectric body 27, it is to be noted that the slot wall 32 is provided with an integral projection 39 while the opposite wall is provided with a similar projection '40;

Projections

39, 40 are spaced longitudinally of the slot from each other as shown, the former being adjacent the end of the body having the recess 28 and the latter being adjacent the opposite body end.

In assembly of the contact strip 35 with the body 27, the strip will be inserted in the slot 29 from the right as shown in FIGURE 6 with the strip main portion 35.1 adjacent the slot wall 32 and the angularly disposed strip end 35.2 bearing against the opposite slot wall. To dispose the contact strip in this position, the angularly disposed strip end 35.2, of course, will have been threaded past the projection 40 and between the latter and the projection 39, this operation being facilitated by the inclined surfaces on respective projections. Further move ment of the contact strip into the body slot 29 will first spring the angularly disposed strip end 35.2 past the projection 39 while continued strip movement will spring the tongue 35. 4 past the projection 40 to dispose the latter between the strip lateral projection 35.3 and the free end of the tongue 35.4 as shown in FIGURE to thus retain the contact strip against disassembly form its slot.

With the contact strip 35 completely assembled with the body 27 as shown in FIGURE 5, it is to be noted that the main portion 35.1 of the contact strip is maintained adjacent the slot wall 32 by virtue of it being sprung between the abutments provided by the projection 40 and the angularly disposed strip end 35.2. The projection 39 functions to maintain a minimum spacing between the contact strip main portion 35.1 and the slot wall 32, such spacing being somewhat less than the transverse size of the terminal pin 20.1 as shown.

Upon relative movement of the element terminal ends 20, 21 into the body recess 28, the terminal pin 20.1 will be guided into the slot 29 by means of the angularly disposed contact strip end 3'5.1. As the body 28 and the heating element are further forced together to the position seen in FIGURE 3, the terminal pin 20.1 will force the contact strip main portion 35.1 away from the slot wall 32 and the slot projection 39, the resiliency of the contact strip 35, however, tightly gripping the terminal pin 20.1 between the contact strip main portion and the wall 32 to establish a low-resistance electrical connection between the terminal pin and the contact strip. To separate the body 27 from the element terminal ends merely require that the body be pulled away from the latter in a reversal of the assembly operation.

While only the contact strip 35 and the associated parts of the dielectric body 27 have been described in detail, it is to be understood that not only are the contact strips 36 and 37 identical therewith and have identical

respective leads

138, 238 secured thereto, the contact strip 36 is disposed in the body slot 31 which is identical to slot 29 and has identical projections therein for engagement with the terminal pin 21.1. As hereinbefore pointed out with respect to FIGURE 4, the wall 33 of slot 31 faces in the opposite direction from the corresponding wall 32 of slot 29. Additionally, and while the slot 30 in which the contact strip 37 is disposed is considerably wider than the

slots

29, 31 to accommodate the greater size of the ground pin 25 and while the wall 34 corresponding to the

slot walls

32, 33 is at the bottom rather than at the side, the slot 30 is nevertheless similar to the

slots

29, 31 and is provided with similar wall projections for engagement with the contact strip 37 in the manner heretofore disclosed with respect to contact strip 35 and its body slot 29.

It is an important safety feature of the present invention that the grounding pin end 25.1 is slightly larger than the

slots

29, 31 to exclude its disposition therein and engagement with their contained, contact strips. Moreover, since grounding pin 25 projects beyond the projecting ends of element terminal pins 20.1, 21.1, entry of such terminal pins into engagement with their contact strips can only be efiected if grounding pin 25 is first properly entered into its body slot 30.

While the element terminal pins 20.1, 21.1 have thus far been disclosed as being simple, straight members, it may be desirable to provide them with projecting ends which will increase their area contact with the contact strips.

In the embodiment seen in FIGURE 8 wherein corresponding parts are identified with the same reference characters as before but with the suffix a added, only the element terminal end 20a is shown in the interest of simplicity. In this embodiment, the terminal pin 20.1a has its end formed to provide a loop 41 which is adapted to cooperate with the previously disclosed body slot 20 and contact strip 35 in the same manner as the straight terminal pin. Obviously, loop 41 will be oriented to lie flat along the slot wall 32 upon its insertion into body slot 29.

In view of the foregoing it will be apparent to those skilled in the art that we have accomplished at least the principal object of our invention and it will also be apparent to those skilled in the art that the embodiments herein described may be variously changed and modified, without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described; hence it will be appreciated that the herein disclosed embodiments are illustrative only, and that our invention is not limited thereto.

We claim:

-1. An electrical connector assembly comprising a dielectric body having an elongated, internal slot in part defined by opposed walls and one end of said slot being adapted to receive an electrical contact prong,

elongated, resilient electrical contact strip disposed in said slot and having a main portion cooperable with one of said walls to resiliently receive and grip said contact prong therebetween,

and two abutment means spaced longitudinally of said slot for maintaining said contact strip portion adjacent said slot one wall, one of said abutment means being a projection within said slot spaced from said slot one end and connected to and extending from said slot other wall toward said slot one wall, and the other of said abutment means being a contact strip portion resiliently engaged with said slot other wall adjacent said slot one end.

2. The construction of claim 1 wherein a second projection is disposed in said body slot intermediate said first projection and said slot one end for engagement with said contact strip, and wherein such second projection extends from said slot one wall toward said slot other Wall to engagement with said contact strip main portion prior to disposition of said contact prong in said body slot to maintain a minimum spacing between said contact strip and said slot one wall that is less than the transverse size of said contact prong.

3. The construction of claim 2 wherein disposition of said contact prong in said body slot biases said contact strip away from said second body projection so that said contact strip is sprung between said first-mentioned body projection and said contact strip portion engaged with said slot other wall.

4. The construction of claim 1 wherein said other abutment means is an angularly disposed contact strip end portion.

5. The construction of claim 4 wherein said body has identical slots formed therein in side-byside relation,

wherein said slots are arranged with their ends aforesaid the same direction, wherein said one wall of respective slots are in facing relation,

and wherein identical contact strips are disposed in respective body slots with their angularly disposed end portions turned away from each other.

6. The construction of claim 5 wherein a third slot is formed in said body in coextensive relation with and disposed between said first-mentioned slots,

wherein said third slot has one wall corresponding to the one wall aforesaid of respective first-mentioned slots and lying in a plane normal thereto,

and wherein an identical contact strip is disposed in said third slot for engagement with a grounding contact prong.

7. The construction of claim 4 and further comprising retaining means carried by said contact strip and disposed on opposite sides of said body projection for engagement therewith to retain said strip within said body slot.

8. The construction of claim 7 wherein said retaining means in part comprises a lateral extension formed at an opposite end portion of said contact strip and wherein a lead wire is secured to such strip opposite end portion.

9. The construction of claim 8 wherein the remaining part of said retaining means is a resilient tongue having a free end directed toward but spaced from said lateral extension an amount to closely receive said body projection therebetween.

10. An electric connector assembly, comprising a dielectric body having an elongated internal slot in part defined by opposed body walls, one end of said slot being adapted to receive an electrical contact plug,

a normally generally flat resilient metal contact strip moved to assembled position within said slot by endwise movement of the latter through an opposite end of said slot,

an abutment on one of said slot walls and extending therefrom toward but short of engagement with the other slot wall to form a narrow passageway for said contact strip,

the leading end of said contact strip having a portion laterally ofiF-set from its flat portion in a direction for pressure engagement with said one slot wall after it has been moved through said narrow passageway to thereby resiliently urge that portion of said contact strip between it and said abutment in a direction toward said other slot wall.

11. The construction of claim 10 wherein said contact strip has another offset portion which engages behind said abutment when said contact strip has been moved to fully assembled position to prevent withdrawal of said contact strip from said slot.

12. The construction of claim 10 wherein said electrical contact plug is in the form of a stiff Wire-like member having an end of button-hook shape, said end being disposed flatwise between said contact strip and said one slot wall.

13. An electrical connector assembly, comprising a dielectric body having an elongated internal slot, one end of which is adapted to receive an electrical prong,

an elongated resilient contact strip disposed in said slot and having a main portion cooperable with a wall of said slot to resiliently receive and grip said contact prong therebetween,

said contact prong comprising a stiff wire-like member having an end of loop shape, in assembly said loop shape being projected through said slot opening and into said slot to position between said slot wall and said contact strip.

14. The construction of claim 13- wherein said loop is of button hook shape and disposed flatwise between said slot wall and said contact strip.

15. An electrical plug-in connector assembly including the combination of a sheathed electric heating element and a terminal block, said block having an internal cavity opening at an end thereof, a metal contact strip within said cavity and adapted to be connected to a source of electrical energy, said heating element having an internally disposed heating resistor and a terminal pin electrically connected to said resistor and having an exterior portion extending outwardly of an end of the element sheath, the end of said exterior portion being in the form of a loop, said loop being projected through said block opening and into said cavity. and having spring engagement with said contact strip to provide for flow of electrical energy from said contact strip to said heating resistor.

16. The construction of claim 15 wherein said loop is button hook-like in shape and has flatwise engagement with said contact strip.

References Cited RICHARD MOORE, Primary Examiner.

US. Cl. X.R. 219-451; 339-217 Hanson 219451