US2970286A - Continuous outlet strip - Google Patents

Description

Jan. 31, 1961 H. J. MODREY CONTINUOUS OUTLET STRIP Filed March 19, 1957 JNVENTOR. HENRY J. MOORE? A r To/Ews Y6 hired C(DNTlNUOUS UUTLET STRIP Henry J. Modrey, Eagle Drive, Stamford, Conn.

lFiled Mar. 19, 1957, Ser. No. 647,108

7 Claims. (Cl. 33914) The present invention relates to a continuous electrical outlet for receiving the connector plugs of appliances as used in homes, stores, plants and the like, and more particularly to a continuous outlet of strip form having exposed slots for receiving the two prongs or pole elements of one or several standard plugs to be connected through the slots to bus bars disposed in ducts formed within the strip body.

One object of the invention is to provide a novel and improved continuous outlet strip which is capable of receiving both standard plugs and plugs with a grounding contact element and in which either kind of plugs or both kinds of plugs may be inserted at selected points along the length thereof.

Another object of the invention is to provide a novel and improved continuous outlet strip in which one or more grounding contacts may be installed, either before the strip is mounted or after the mounting of the strip.

The aforedescribed versatility of the outlet affords the advantage that the same type of outlet may be used for various kinds of new installations and that an existing installation may be readily and inexpensively converted from an installation employing standard plugs to an installation involving the use of plugs with grounding contacts, and vice-versa.

Still another object of the present invention is to provide a novel and improved continuous electrical outlet design which affords the advantage of retaining with adequate mechanical strength and good contact quality the pole elements of several comparatively narrowly spaced plugs.

A further object of the invention is to provide a novel and improved continuous outlet strip design which re tains inserted plugs in a substantially rigid and upright position thereby assuring a constant contact engagement between the pole elements and the bus bars.

A still further object of the invention is to provide a novel and improved outlet strip which can be bent in one plane and also coiled. As a result of such flexibility, the strip is capable of being mounted on surfaces meeting at an angle and also of accommodating itself to the specific requirement of an installation. Furthermore, the storage and shipping of the strips are greatly facilitated as the same may be stored and shipped in coiled condition, and the manufacture of the strips is simplified as the same may be produced in a continuous operation and rolled up on storage reels.

Yet a further object of the invention is to provide a novel and improved outlet, the design of which can be conveniently adapted to receive elements of either flat or round cross section.

Also an object of the invention is to provide a novel and improved outlet the slots of which are designed to accommodate the pole elements of a plug in a predetermined position only relative to the bus bars in the outlet whereby the outlet becomes a polarizedoutlet.

A further object of the invention, allied with the preceding ones, is to provide an inexpensive and easily mountable locating means which when inserted in the slots of the outlet aligns and retains the bus bars therein in the correct positions for coaction with the pole ele ments or contact blades of a plug. Such alignment and retention of the bus bars are particularly useful for outlets designed to receive multiple-pole plugs. The locating means affords the further advantage that it can serve as an outlet point and provides a steady platform for a plug.

Other further objects, features and advantages of the invention will be pointed out hereinafter and set forth in the appended claims.

In the accompanying drawings several embodiments of the invention are shown by way of illustration and not by way of limitation.

In the drawing:

Figure l is an isometric View of an outlet strip with grounding contacts according to the invention, a two pole connector plug with a grounding pole element being shown inserted therein.

Figure 2 is an isometric view of a grounding contact component of the kind mounted in the outlet of Figure 1.

Figure 3 is a view similar to Figure 1 showing a locating clip attached to the outlet strip.

Figure 4 is a section of the outlet clip taken on line 44- of Figure 3.

Figure 5 is an isometric view of two contact strips designed for coaction with pole elements of round cross section.

Referring first to Figures 1 and 2 in detail, the exemplification of the outlet according to these figures, comprises a strip ill made of suitable insulation material. The properties of this material and the general dimensions of the strip are such that the strip can be bent in one plane for mounting of the outlet and also coiled for storing and shipping. The strip may have any desired length, and the outlet may be manufactured in a continuous operation, that is, a supply of the strip material is stored on supply reels from which it is fed to one or several machining stations. Finally, the completed outlet may be wound upon a take-up reel for future consumption. Insulation materials suitable for the purpose of, for instance, plastics known as polyethylene, nylon or Teflon.

The strip has, preferably, a generally rectangular cross section and is formed with two parallel continuous, narrow outer slots or slits 11 and 12, thereby longitudinally dividing the strip, to the extent of the depth of the slots, in two outer sections 13 and 14 respectively and a middle section 15. The rim portions of these sections are re-entrant to form at least approximately self-closing lips at 16 and 17. The middle portion of the outer sections is preferably curved at 18 toward the opposite wall of the middle section which is kept smooth.

Each of the slots serves to receive a contact strip or bus bar 19 and Ztl respectively. The thickness and the hardness of the material of the contact strips should be such that the same can be conveniently bent or coiled along with the insulation strip. Each of the contact strips has on its side facing the respective outer section of the insulation strip, a plurality of longitudinally spaced transverse ribs 231. These ribs are shown as being formed out of the material of the strips. The width of each contact strip is less than the depth of the slots, the upper rim of the inserted strips being preferably below the lip portions 16 and 17. As may be observed, the strips abut with their flat sides against the corresponding flat wall surfaces of the middle section. Each two adjacent ribs on the other side of the strip in conjunction with the: fiat strip sections between each two ribs and the corresponding wall portions of the outer sections define a pocket for receiving therein a pole element of a connector plug 22. The plug is shown as a conventional plug having two fiat pole elements or blades 23 and a round grounding element 35. To accommodate the grounding element, a third slot 37 is provided intermediate of slots 11 and 12 and parallel thereto. In contradistinction to slots 11 and 12, slot 37 does not have reentrant lips 16 and 17, but is open at its upper rim. Slot 37 serves to accommodate a receiving contact member 38 and the grounding element 35 of each plug 36.

Member 38 is shown as a springy contact clip 39 suitably secured to a metal base 49, as can best be seen in Figure 2.

Slot 37 further serves to accommodate in a transverse enlargement provided for this purpose a grounded bus bar 41 which may be of a length co-extensive with that of bus bars 19 and 20 or of any other desired length. Bar 41 may be inserted when bars 19 and 253 are fitted in the outlet strip, it may be inserted when tthe outlet strip is mounted or it may be subsequently inserted.

As is apparent, a plug 22 is applied to the outlet by forcing the pole elements 23 past the expandable lips 16 and 17 and simultaneously inserting grounding element 35 in contact clip 39. The pole elements, when the plug is pressed home, are parallel of the contact strips 19 and in engagement therewith and end at or near the bottom of the slots 11 and 12. They are frictionally retained in the slots by the pressure between lips 16 and 17 and the further pressure between the strips and the curved portions 18 of the outer sections. This latter pressure may be further increased and the contact engagement between the contact strips 19 and 20 and the pole elements 23 may be improved by providing bulges or pips 24 in the strips at a point just opposite the apex of the curved section 18. The pips engage holes in the pole elements when the plug is fully inserted.

As a result of the guidance of each pole element 23 in the pocket formed by two adjacent ribs 21 and the frictional retention of each pole element 23 at two spaced points (16, 1'7 and 18, 24), the plug is held steady and upright in the outlet strip. This affords the advantage that good and substantially constant contact conditions are maintained and that the plugs can be comparatively closely spaced in the outlet without the danger of at least some of the plugs becoming loose due to a spreading of the slots 11 and 12 caused by closely adjacent plugs.

In the event the ground bar 41 is in position when the outlet strip is mounted, the screws or nails used for mounting the outlet strip may be driven directly through the bar. If the nails or screws should touch a pipe or other conductive component connected to the ground this is electrically of no importance as the bar 41 itself is grounded. One or several contact clips 39 may be inserted in slot 37 and fastened to bar 41 at points selected for the insertion of plugs 22. To facilitate attachment of a clip 39, the same is shown as having a mounting hole 43. In the event the clips are inserted when the outlet is mounted the same screws or nails 42 that are used to attach a clip to bar 41 may also be used to fasten the outlet proper by extending the screws or nails through hole 43 of clip base 41), hole 43' of ground bar 41 and the base of the insulation strip proper, so that there are practically no increased installation costs. If the clips or bar 41 have to be mounted at a later date, all that is necessary is to drive in a few nails or screws through the ground bar so that the installation costs are also negligible.

The outlet of Figure 1 is capable of receiving plugs having two pole elements 23 only and/or plugs of the kind shown in Figure l. The latter kind of plug may be employed with or without the use of the ground bar 41. Furthermore, an installation initially laid out without ground connection can be readily and inexpensively converted into aninstallation employing ground connection completely or in part, or vice-versa.

As is now evident,the described versatility of the outlets according to the invention greatly simplifies the initial installation and later modifications thereof.

Furthermore the inventory that has to be maintained by suppliers of installation material can be greatly reduced as one kind of outlet is suitable for a wide variety of installations.

As previously explained, the transverse ribs 21 of the contact strips 19 and 2t) define guide pockets in the outer slots 11 and 12 which serve to receive and steady the contact blades 23 of inserted plugs. To permit a smooth insertion of the plugs, the pockets must be aligned relative to each other and to the contact blades of the plugs. It has been found that there is a tendency of the contract strips to become displaced relative to each other. While it is possible to attach the contact strips directly to the insulation material of strip 11 such attachment of the contact strips is comparatively expensive. According to the invention the contact strips are retained in correct alignment by providing a locating means or clip 60. As shown in Figures 3 and 4 the clip comprises an insulation plate 61 to which are attached by any suitable means such as upset ears 62, depending arms 63 which straddle insulation strip 10 and preferably end in lateral lugs 64. These lugs may be used to fasten the clip and with it the outlet strip to a support wall by driving a screw or nail through holes 65 provided in lugs 64 for the purpose. Two dummy blades 66 depend from plate 61 suitably secured to the plate for instance by molding the hooked ends of the blades into the material of the plate. Each of the dummy blades extends into a pocket formed by the respective one of the contact strips 19 and 2% thereby preventing a misalginment of the same.

The clip can further be used as an outlet point. its plate 61 constitutes a steady platform for a plug and is provided with two suitable spaced slots 67 to accommodate the blades 23 of a plug. The clip is mounted by simply pressing it upon the outlet strip and into the position of Figure 3.

Finally, Figure 5 shows a connector plug 45 having round pole elements 46. To accommodate these pole elements and to guide the same, the contact strips and 20a inserted in outer slots 11 and 12 have an undulated or corrugated configuration. The corrugations form in effect guide pockets as previously described. The contact strips of Figure 5 should be visualized as being inserted in the outer slots 16 and 17 of Figure 1. The function of the contact strips is obvious from the previous description.

While the invention has been described in detail with respect to certain now preferred examples and embodiments of the invention, it will be understood by those skilled in the art after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended, therefore, to cover all such changes and modifications in the appended claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A continuous electrical outlet adapted to receive connector plugs having pole. elements and connector plugs having pole elements and a grounding contact element, said outlet comprising a strip of insulation material having in one of its surfaces three parallel continuous longitudinal slots, a continuous contact strip inserted in each one of the two outer slots parallel to the lateral boundary walls thereof, said outer slots being adapted to receive the pole elements of said plugs in contact with the contact strips therein and having rims forming at least approximately self-closing lips expandable for frictionally retaining the pole elements, a flat grounding contact strip placed flat upon the base of the center slot, and a grounding contact member for receiving the grounding contact element of a plug insertable in said center slot and attachable to the gr unding strip therein at any selected point along the length thereof.

2. A continuous electrical outlet adapted to receive connector plugs having pole elements and connector plugs having pole elements and a grounding contact element, said outlet comprising a strip of installation material having in one of its surfaces several parallel continuous longitudinal slots, a continuous contact strip inserted in some of said slots parallel to the lateral boundary walls thereof, the slots having the contact strips therein being adapted to receive the pole elements of said plugs in contact with the contact strips in the slots and having rims forming at least approximately self-closing lips expandable for frictionally retaining the pole elements, an-

other one of said slots being adapted to receive upon its base a flat grounding contact strip in longitudinal arrangement and a grounding contact member, a grounding contact strip insertable in said latter slot, and a grounding contact member for receiving the grounding contact element of a plug insertable in the slot receiving the grounding contact strip and attachable to said strip at any selected point along the length of the grounding strip.

3. A continuous electrical outlet adapted to receive connector plugs having pole elements and connector plugs having pole elements and a grounding contact element, comprising a strip of insulation material having in one surface three parallel longitudinal continuous slots, the rims of the two outer slots forming at least approximately self-closing re-entrant lips expandable for frictionally retaining pole elements of a plug inserted in said outer slots and the center slot being of substantially uniform width, a continuous contact strip of a width less than the depth of the outer slots inserted in each one of the said slots parallel to the lateral boundary walls thereof and each of said contact strips having longitudinally spaced transverse guide ribs, each two adjacent ribs in conjunction with the portion of the respective contact strip therebetween and the adjacent wall portion of the insulation strip forming a guide pocket for an inserted pole element to steady the same, a grounding contact strip inserted in the center slot, and a grounding contact member for receiving the grounding contact element of a plug insertable in said center slot and attachable to the grounding strip therein at any selected point along the length thereof.

4. An outlet according to claim 3, wherein said grounding contact member comprises a springy contact clip and a base plate mounting said clip.

5. A locating means for a continuous outlet strip of the kind having three parallel longitudinal continuous slots in one surface and contact strips inserted in the outer ones of said slots parallel to the lateral walls thereof, each of said strips having longitudinally spaced transverse guide ribs to define longitudinally spaced guide pockets in said slots each for receiving a pole element of a connector plug inserted in the outlet and a grounding strip placed flat upon the base of the center slot, said locating means comprising a carrier member attachable to said outlet strip at any selected point of the length thereof, and dummy blades, one for each outer slot, mounted on said carrier member, each of said blades extending into one of said pockets of the outer slots upon attachment of the carrier member to the outlet strip thereby retaining the contact strips in substantially fixed relative positions in the slots.

6. A locating means according to claim 5, wherein said locating means is in the form of a clip comprising an insulation plate and arms depending from said plate and adapted to straddle the outlet strip, said dummy blades being mounted on said plate depending therefrom for engagement of said slots when said arms straddle the outlet strip.

7. A locating means according to claim 6, wherein said plate includes slots disposed in registry with the slots in the outlet strip in the straddling position of the clip, said plate slots constituting passage slots for the pole elements and the grounding contact element of a plug.

References Cited in the file of this patent UNITED STATES PATENTS 1,588,183 Goddard June 8, 1926 2,062,752 Kindberg Dec. 1, 1936 2,105,833 Feuer et al. Jan. 18, 1938 2,108,031 Acuff Feb. 15, 1938 2,175,245 Brockman Oct. 10, 1939 2,216,765 Clayton Oct. 8, 1940 2,218,545 Morten Oct. 22, 1940 2,254,280 Gottheimer Sept. 2, 1941 2,267,745 OBrien et a1. Dec. 30, 1941 2,361,721 Van Deventer Oct. 31, 1944 2,441,461 Wayne May 11, 1948 2,781,497 Sheskier Feb. 12, 1957 FOREIGN PATENTS 930,770 France Aug. 25, 1947

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