Electric accessory connector for cap lamp battery

<td> United States Patent Lozeau</td><td> [19]</td><td> [H] 3,723,947 [45] Mar. 27, 1973</td>

<td colspan="2"> [54] ELECTRIC ACCESSORY CONNECTOR FOR CAP LAMP BATTERY [75] Inventor: Homer A. Lozeau, Worcester, Mass. [73] Assignee: Koehler Manufacturing Company, Marlboro, Mass. [22] Filed: May 14,1971 [21] Appl.No.: 143,417 [52] U.S. Cl...........339/91 R, 240/10.6 R, 339/176 L [51] Int. Cl............................ HOlr 13/54</td><td rowspan="2"> 2,727,981 12/1955 Carpenter........................240/10.6 R 3,017,469 1/1962 Giller..................................339/75 R 3,601,595 8/1971 Kivela..............................240/10.6 R Primary Examiner— Joseph H. McGlynn Attorney—Munroe H. Hamilton [57] ABSTRACT Electric connector means for a miner’s cap lamp battery includes a plug receptacle component supported on the battery and connected to the positive and negative electrodes of the battery. A plug component is slidably engageable with the receptacle and includes positive and negative contacts for contacting recessed contacts in the receptacle. The negative contact of the receptacle is internally housed in a concealed position to be engaged by a negative contact of the accessory plug only when the plug is in a fully advanced position. A trap plate and spring arrangement protects the negative contact from tampering by an object inserted through the slideway of the plug contact. 8 Claims, 13 Drawing Figures</td>

<td colspan="2"> [58] Field of Search......339/75, 91, 176; 240/10.6 R, 240/10.61, 10.68 [56] References Cited UNITED STATES PATENTS 1,088,531 2/1914 Callier............................240/10.6 R 3,408,490 10/1968 Lozeau............................240/10.6 R 3,020,513 2/1962 Quackenbush.....................339/91 R 2,093,677 9/1937 Hickman et al...................339/176 S 2,721,929 10/1955 Schwartz et al..................240/10.6 R</td>

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Patented March 27, 1973

3,723,947

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Patented March 27, 1973

3,723,947

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Patented March 27, 1973

3,723,947

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3,723,947

ELECTRIC ACCESSORY CONNECTOR FOR CAP LAMP BATTERY

This invention relates generally to electric connector means of the class employed in connecting an electrically operated device to a source of electric power. More specifically the invention is concerned with electric connector means which can be used with a miner’s cap lamp battery for supplying power to an electrically energized device operated independently of the miner’s cap lamp, but within the safety standards commonly required in miners’ cap lamp operation.

At the present time, electrically operated devices have been developed for use by miners, examples of which are methane gas detectors, mine dust samplers and the like. These electrically operated devices usually require, under existing safety Standards, that the miner wear a second battery for their operation, thus creating another burden for the miner to bear.

It is, therefore, a chief object of the invention to provide an improved electrical connector means.

Another object is to devise an electrical connector means which can be used with a miner’s cap lamp battery independently of the operation of the cap lamp itself.

Still another object of the invention is to devise an electrical connector which can be combined with a miner’s cap lamp battery in a manner such that it is tamper proof in either a fully assembled position or in a partially disengaged position.

The nature of the invention and its other objects and novel features will be more fully understood and appreciated from the following description of a preferred embodiment of the invention selected for purposes of illustration and shown in the accompanying drawings, 35 in which:

FIG. 1 is a perspective view illustrating a miner’s cap lamp battery and cap lamp and further indicating the electrical connector device of the invention attached thereto;

FIG. 2 is an exploded view of the battery top and plug receptacle components separated from one another;

FIG. 3 is another exploded view of accessory plug components in operative relationship;

FIG. 4 is a detail fragmentary view of the battery and electrical connector device installed and shown partly in cross section;

FIG. 5 is an elevational view of the electrical connector plug component of the invention;

FIG. 6 is a cross sectional view taken on the line 6—6 of FIG. 5;

FIG. 7 is an end elevational view of the structure shown in FIGS. 4 - 6;

FIG. 8 is a perspective view of the plug components illustrating a spring contact element;

FIG. 9 is a fragmentary plan view of a receptacle component of the electrical connector means;

FIG. 10 is a cross section taken on the line 10—10 of FIG. 9;

FIG. 11 is an end elevational view of an open end of the receptacle;

FIG. 12 is a perspective view of the plug receptacle base illustrating in more detail a trapping recess and a negative contact supporting ramp;

FIG. 13 is a detail plan view of a plate component also shown in FIG. 2.

The principal parts of the connector means of the invention include a plug receptacle and an accessory plug constructed and arranged to slidably engage in the plug receptacle together with locking means for adjustably ⁵ holding these parts together. The receptacle component is designed to be secured at the top of a battery and connected to positive and negative electrodes at points within a battery top section in a completely concealed manner. Positive and negative contacts are ar^υ ranged in recessed relation such that only a specially formed L-shaped plug contact structure can be moved into a fully connected position, and novel trapping means prevents tampering by means of any object not j₅ L-shaped and which may be forced into the plug receptacle opening.

Referring more in detail to the structure shown in the drawings, numeral 2 denotes a miner’s cap lamp battery of the class worn by miners for operating a cap 20 lamp 6 which is connected by conductor 8 to a battery top 4. The electric connector means of the invention, in one preferred form, may for example be mounted at one end of the battery top 4 as shown in FIG. 1. Arrows 10 and 12 denote, respectively, a plug receptacle com25 ponent and an accessory plug component of the invention fitted together in an operative position. FIGS. 3, 5, 6 and 8 illustrate details of the accessory plug and FIGS. 2, 9, 10, 11 and 12 illustrate details of the plug receptacle.

As shown in FIG. 2, the plug receptacle is constructed with a base 14, arranged to be secured to the battery top 4 which is formed with openings such as 16, 18 and 20, through which may be located threaded fastenings as 22, 24 and 26. As shown in FIGS. 9, 10 and 11, the threaded elements 22 and 24 are made of a length suitable for projecting downwardly through the battery top to provide threaded extremities on which are internally threaded screws 23 and 25 to provide a ₄₀ positive terminal for the battery conductor 28 and a negative terminal for the battery conductor 30. The conductors 28 and 30 are detachably secured by means of suitable washer and small screw elements as 32 and 34. In the arrangement described, the exposed head of 45 fastening 22 functions as a positive contact while the fastening 24 serves to support a concealed negative contact 36, shown in FIGS. 9 and 10 as hereinafter described.

In FIG. 3, the accessory plug components are shown 50 in separated relation and included therein is an accessory plug casing formed with a top 12, side walls 13 and 15, and an end wall 17, through which is received the conductor 8. Solidly secured inside the casing 12 by screws 37 and 39 is a negative contact element 19 55 which is shaped as shown in FIG. 8 and formed with Lshaped slide portions 19α and 19b. Located against an inner side of the contact 19 is an insulator member 33 on which is secured a positive contact element 35 by means of a cap screw 37. A positive lead 8a from conductor 8 is retained by the screw 37 as shown in FIGS. 5 and 6. A negative lead 8b from conductor 8 is held by a threaded fastening 39, as shown in FIGS. 4, 5 and 6.

An important feature of the invention is the com₆₅ bination with the receptacle base 14 and its electrical connections of support means for holding an end 36α of the resilient negative contact 36 in a position to yieldably engage with one of the L-shaped slide por3,723,947 tions of the accessory plug. The support means includes a trapping plate and a cooperating trapping recess together with a novel trapping element. The trapping plate is arranged to support both the negative contact 36 and the trapping element in such relative positions as to protect the negative contact against tampering or accidental engagement with other objects.

Considering these parts in further detail, the plug receptacle base 14 is constructed with side walls 38 and 40 and a connecting end wall 42, thus defining an enclosure which is open at one end and at its top side for receiving the accessory plug 12. I further form the base 14 with a flat bottom surface area 44 which is recessed adjacent the side wall 38 throughout a portion of its length to provide a trapping recess 44α and a contact support block 47. The contact support block 47 has its upper surface lying in the plane of the bottom surface 44 and thus constitutes an extension of the slide surface 48 adjacent side wall 38.

The surface 44 together with the recess 44α and the contact support block 47 are shown in more detail in FIG. 12. As shown in FIG. 12 there is located on the surface 44 a plate supporting pad 46 whose edges, as shown in FIG. 12, occur in spaced relation to the side walls 38 and 40 to define slide surfaces 48 and 50. One edge of the supporting pad 46· adjacent the trapping recess 44α is also recessed at 46α, as indicated.

Mounted on the pad 46 is a trapping plate member 52 having a shape, as generally indicated in FIG. 9. FIG. 13 also shows the plate 52 as viewed from its underside. Side edges of the plate 52 are arranged to lie in spaced relation to the side walls 38 and 40. However the width of the plate 52 is constructed slightly greater than the width of the pad 46, as shown in FIG. 11, with the result that side edges of the plate overlie respective edges of the pad, thereby to define, in combination with the slide surfaces 48 and 50, a pair of slideways 54 and 56 as shown in FIG. 11. These slideways are of Lshaped cross section and are of a size suitable for receiving the L-shaped portions of the accessory plug element 19.

The trapping plate 52 as shown in FIGS. 9 and 13 has located therethrough an opening 52α for receiving the fastening 24, earlier described. Immediately adjacent the opening 52α there is provided a slot 52b which is located immediately above the contact support block 47. In the contact slot 52b is received the negative contact 36. FIG. 13 shows the bent end 36α of the contact 36 in the position assumed when the accessory plug 12 is not inserted, and as will be observed, the bent end 36α projects downwardly and resiliently engages against an upper surface of the support block 47.

Directly in front of the negative contact 36 and its contact slot 52b, as indicated in FIG. 13, is still another slot 70 through which is received a resilient trapping element 72 which is of a width exceeding the width of the negative contact, as noted in FIG. 13, and which as further shown in FIG. 10, projects angularly downwardly into the trapping recess 44α in a position to extend through the slideway and below the upper surface of the support part 47. In this position, the trapping element functions as a barrier to an object such as a wire inserted through the slideway from the open end of the plug receptacle and operates to deflect an object downwardly against the recessed edge 74 and thus a trapping or blocking effect is realized to completely guard the negative contact against tampering. The plate 52 is firmly held against the pad 46 by means of an insulator element 61 and a cover plate 63, through which fastenings 22 and 26 extend.

With the arrangement described, it will be observed that the L-shaped portions 19α and 19b of the negative contact in the accessory plug 12 can readily move through respective slideways 54 and 56, and upon coming into contact with the resilient trapping element 72, forces the bent end of this trapping element upwardly into a position as shown in FIG. 4, and simultaneously the bent end 36α of the negative contact 36 is forced upwardly as shown in FIG. 4. In this position, the accessory plug and receptacle are electrically connected for operation.

I may also desire to provide a means for releasably holding the accessory plug in a fully engaged position in the plug receptacle as above described. As one suitable means of accomplishing this, I may provide a spring clip 78 which is solidly fastened to the battery top 4 by fastening 80 as shown in FIGS. 1 and 2. As shown in these Figures, the spring clip is formed with a raised extremity whose edge is located normally at a level such that it engages with a rear side of the accessory plug and holds it in a locked position. Depressing the spring clip permits withdrawal when desired.