US2922980A - Current tap - Google Patents

Description

L. CAPLAN CURRENT TAP Jan. 26, 1960 2 Sheets-Sheet 1 Filed Dec. 5, 1957 FIG I. RENCE CAPLAN IN TOR PATENT AGENT L. CAPLAN CURRENT TAP Jan. 26, 1960 2 Sheets-Sheet 2 Filed Dec. 5, 1957 FIG.6

FIG.4 F|G.5.

LAWRENCE CAPLAN m ENTOR BY M FIG.3

PATENT AGENT United States Patent CURRENT TAP Lawrence Caplan, Toronto, Ontario, Canada Application December 5, 1957, Serial No. 700,900

1 Claim. (Cl. 339-157) This'inve'ntion relates to electrical connectors and more particularly to a current tap adapted to receive a plurality of plugs for connection to a source of electric current.

United States Patent No. 2,723,382 to Lawson discloses a form of current tap which presents definite advantages over prior practice, and the tap described and claimed therein has enjoyed substantial commercial success.

Prior to the said US. patent, there were two principal disadvantages to the prior forms namely (a) The fact that the plugs were relatively large and bulky, and

(b) The fact that the internal contacting means was complicated and correspondingly expensive to manufacture.

The construction disclosed in the Lawson patent overcame many of the disadvantages of the prior art by providing a current tap adapted to receive three plugs in which two plugs were insertable on opposite sides of the plug housing and the third from the free end, thereof, the two plugs on opposite sides being 90 out of alignment with each other. This mi s-alignment permitted the opposite plugs to overlap when their prongs were inserted, and two unitary contact strips were provided each contact being adapted to contact one of the three prongs in each of the three plugs for connection to the source of current.

While the Lawson patent did achieve several notable advantages, I have found that an improved arrangement of the plug receiving openings will permit an even greater reduction in the size of the overall unit, and the use of an internal contact means of greater simplicity and efl'icacy.

It is an object of this invention therefore to provide a current tap adapted to receive a plurality of plugs which will be of minimum dimensions and bulk.

It is a further important object of the invention to provide such a current tap as will include a contact means of simple and inexpensive design which will frictionally contact the prongs of one or more service plugs with constant pressure regardless of the number of plugs actually inserted. V V I I These and other advantageousobjects will become apparent through a consideration of the following detailed description taken in conjunction with the attached drawings in which:

Figure 1 is an exploded perspective view of all the components of the connector tap which form this invention in which three plugs are shown as outlined in their inserted position and one internal contact means has been removed to show its precise configuration.

Figure 2 is a perspective view showing a single contact means in contacted position with one prong of each of the three plugs adapted to be inserted into the tap.

Figure 3 is a schematic view showing an alternative arrangement of the tap openings. I

ICC

arrangement of parts specifically illustrated in Figures I 1 and 2. p e

The invention consists broadly in the provision of an electrical connector adapted to be connected to a source of electrical current and to receive a plurality of pronged V attachment plugs, the connector comprising an insulated housing with a plurality of pairs of openings therein adapted to receive prongs of such plug, the openings on opposite sides of the connector being in longitudinal alignment but in staggered relationship to each other together with a pair of internal contact members located in the housing, each such contact member being so disposed with relation to the openings as to be contacted by one of the 'prongs of each plug when said plug is in fully inserted position in the connector.

In greater detail and referring now to the drawings, the electrical connector' or current tap which forms the subject matter ofthis invention is indicated generally as at l and comprises an insulating housing, formed of a lower portion 2 and an upper portion 3. These two portions are adapted to be joined bya fastening means such as bolt 4 which is threaded into a suitably threaded hole 5 provided in the lower portion 2. I

In the embodiment shown, the electrical connector or current tap is provided with three pairs of openings, 6 A

6A; 7, 7A; 8,8Arespectively. These openings are adaptedtoreceive the prongs of three plugs 9, 10 and 22 respectively.

As may be seen by reference to Figures 1 and 2, the openings 6, 6A and 7, 7A which are provided on op v of plug 9 and the prongs 12, 12A of plug 10 are in fully inserted'position in the housing 1 the prongs by-pass each other by a distanceequal to the extent by which the plug openings 6, 6A and 7, 7A are displaced transversely. 1

In the embodiment shown, the third plug 22 with its depending prongs 13, 13A is inserted from the free end of the housing through the openings 8, 8A and assumesv providedwith aslot 17.. through which the rivet shank.

passes thus permitting a longitudinal adjustment of the contact member relative to the housing 1. Each contact member .comprises a terminal portion 18, ad apted for connection to a current carrying wire. Thispo'rtion may conveniently be 'cri'mped onto the wire as shown'by reference figures l and 2. The contact member is desirably formed of conductive strip material of substantial uniform thickness. The contact member is mounted on the lower portion 2 of the housing 1 within the area of the openings 6, 6A; 7, 7A; and 8, 8A so that when the prongs 11, 11A; 12, 12A; and 13, 13A of the plugs are in inserted position frictional contact between the ends of the prongs and the contact member.

In the preferred embodiment of the contact members shown in Figures 1 and 2, the contact member is pref- When the prongs 11, 11A

These contact members are fitted into slots J erably provided with a contact portion 19 and 20 on opposite sides thereof, this portion being cut from the perimeter of the contact means towards the longitudinal axis thereof at two points and. then bent relative to the longitudinal axis of the member to provide aprojecting portion 19' and 20 as may be seen: by references to Figures land 2. These bent portions whichextend in opposite d rections from the member are adapted toscontactr one of the prongs of eachiplug, in frictional engagementand.

electrical conductivity. The end of the contact member 21 may similarly be bent. to provide a close frictional contact with one of the prongs 13 of the plug 11.

The contacting portions 19, 20 and 21 ofthe'contac't members are thus formed so that they will lie across the area of the prong receiving openings 6, land 8 respectively aifording three separate circuits which may be connected by means of this tap across the power supply.

It will be seen that the formation of the contact memher as described herein will insure close contact of the prongs of all the plugs independently of each other. Thus contact between any plug and the power supply is independent of the existence or absence of other plugs in the tap.

The tap may easily be connected toa power supply by removal of the insulation from the wire and attachment to the current carrying wires of two terminals 18, 18A of the contact members 14 and 15 either by crimping or by any other means.

The upper and lower portions may then be serviced together, and one or more service plugs inserted as required.

It will be appreciated that the invention in addition to forming the terminal of an extension cord could equally be incorporated as a service block having prongs adapted to be inserted to a wall or other electrical receptacle and presenting a head adapted for connection to three separate loads.

The fact that the prongs on opposite sides of the housing are in longitudinal alignment permits the design of an-overall'housing of minimum width. The fact that the prongs of plugs inserted are in staggered relationship to each other and overlap each other when in the inserted position permits the design of a housing of minimum thickness.

The invention lies in the provision of a current tap in which the prong receiving openings are in longitudinal alignment but in a staggered relationship and the other embodiments of this invention may be seen by reference to the schematic Figures 3 to 6 inclusive. In

Figure 3 the side openings 6F, 6G and 7F, 7G are in longitudinal alignment and displaced relative to each other in the same manner as shown in detail in Figures 1 and 2 but the end prongs 8F and 8G overlap and bypass these prongsaffording the minimum length. possible. In Figure 4 the side openings 6B, 6C, 7B and 7C are in both longitudinal and transverse alignment and the prongs inserted in end openings 8B and 8C overlap and by-pass both side prongs resulting in a substantial reduction of the length of the tap over the embodiments shown in Figures 1 and 3. In Figure 5 the- side openings 6D, 6E and 7D, 7E while again in longitudinal alignment are staggered with respect to each other and the end prongs 8D and 8E again overlap and by-pass both pairs of side prongs when in inserted position. Figure 6 is a schematic similar to Figures.3v to 5 illustrating the arrangement of parts specifically described in detail with relation to Figures 1 and 2.

These possible variations are all characterized in that the side prongs while remaining in alignment, are displaced relative to each other to permit overlapping of the prongs when inserted from opposite directions. When here and elsewhere in this specification and claim I use the term in alignment, it is to be understood as meaning that the openings or prongs as the case may be are parallel in the plane of the housing. Similarly when I use the term staggered relationship," it is to be understood that the prongs or openings, as the case may be, on opposite sides of the housing are displaced relative to each other to permit the prongs inserted into the openings to by-pass each other in the interior of the housing.

An important feature of the invention lies in the fact that but two contact members are required, and that these contact members are contacted on opposite sides by prongs inserted from opposite sides of the housing but by-pass each other in the interior of the housing.

In addition, the fact that the inclined contacting poitions 19 and 20 are formed by cut-out portions on opposite edges of the contact member oppositely bent, and that the contact portion 21 is similarly formed, means that contact is made between the prongs and the contact members towards the end of the prongs. This feature not only provides a guide for the entry of theprongs, but also permits a wide tolerance in the thickness of the prongs which may be accepted into the unit.

While the invention has been described with referenceto preferred embodiments, it is to be understood that the invention is not limited to precise constructional detail. Such embodiments of the invention as come within the scope and purview of the appended claim are to be considered as part of this invention.

What. I claim as my invention is:

An electrical connector adapted to receive a plurality of pronged attachment plugs comprising an insulating housing having a plurality of pairs of openings therein, each such pair of openings being adapted to receive the prongs of a plug, the openings on opposite sides of the receptacle being in longitudinal alignment but in .a transversely staggered relationship to each other, whereby the prongs of plugs inserted from the opposite sides of the receptacle by-pass each other inside the housing and a pair of prong receiving openings in the end of the housing so located that the prongs of a plug inserted thereinto overlap and by-pass both said prongs inserted from opposite sides of the receptacle; a pair of contact members located in said housing each contact member I being disposed with relation to the openings as to be contacted by one of the prongs of each plug when said plug is in fully inserted position in said openings.

References Cited in the file of this patent UNITED STATES PATENTS 1,940,942 Dohrwardt Dec. 26, 1933 2,714,713 Parajon Aug. 2, 1955 2,799,839 Weiss July 16, 1957 2,878,457 Weiss Mar. 17, 1959

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