US2443442A

US2443442A - Lamp cutout

Info

Publication number: US2443442A
Application number: US730850A
Authority: US
Inventors: Henry E Butler
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1947-02-25
Filing date: 1947-02-25
Publication date: 1948-06-15
Anticipated expiration: 1965-06-15

Description

June 15, 1948. 'H. E. BUTLER 2,443,442

LAMP cur-our Filed Feb. 25, 1947 2 Sheets-Sheet 1 Invehtor: H envy E. Butler,

by His Attorn ey.

June 15, 1948. H. E. BUTLER 2,443,442

LAMP CUT-OUT Filed Feb. 25, 1947' 2 Sheets-Sheet 2 Ifiventow": Henry E. But/19.1,

H IS Attorney.

Patented June 15, 1948 LAMP CUTOUT Henry a. miner, Seotia, N. Y m to am Electric Company, a nflation New York Application February as, an, seem No. msso 1 My invention relates to electric lamp cut-outs,

and more particularly tomagazine rod type film cut-outs for electric lamp shunting contacts.

In series electric lighting circuits and the like. it is usual to provide in each lamp base a pair of resilient lamp shunting prongs, or contacts, arranged normally to be insulated from each other by a cut-out element including a film of copper oxide or other voltage-limiting dielectric medium which is subject to electrical break-down upon the occurrence of a predetermined excessive voltage. A typical lamp base with such shunting contacts is illustrated in Patent 2,078,793, issued to H. J. Flaherty on April 27, 1937. The type of cut-out element currently generally used is a small disk or wafer-like element comprising a pair of conducting buttons normally separated by a copper oxide film. Such wafer-like cut-out elements, while highly effective and satisfactory in operation, are generally rather difilcult to handle because of their small size. These elements are commonly about the size of a five or ten cent piece, and must often be handled by a linesman wearing a pair of bulky insulating gloves.

Accordingly, it is a principal object of my. in-- vention to provides. new and improved magazine rod type electric lamp cut-out which may be readily removed and replaced without individual handling of the separate cut-out elements.

It is a particular object of my invention to provide a new and improved, sectionalized rod type, magazine cut-out element which may be readily handled by an operator wearing bulky insulating gloves.

My invention itself will be more fully understood and its various objects and advantages further appreciated by referring now to the following detailed specification taken in conjunction with the accompanying drawing in which Fig. 1 is a cut-away perspective view of a magazine type cut-out embodying my invention; Fig. 2 is a crosssectional view taken along the line 2--2 of Fig. 1; Fig. 3 is an end view of a single contact element of the cut-out shown at Figs. 1 and 2; Fig. 4 is a cross-sectional view taken along the line 4-4 of Fig. 3; Fig. 5 is a perspective view illustrating the manner in which the cut-out elements of Figs. 1 to 4 are inserted between lamp prongs; Fig. 6 is a cross-sectional view of a film cut-out rod similar to that of Fig. i but illustrating another embodiment of my invention; Fig. 7 is a side view ofa film cut-out rod illustrating a further embodiment of my invention; Fig. 8 is a cross-sectional view taken along the lines 8-. of Fig. 7; Fig. 9 is a side view of a film cut-out rod 4 Claims. (Cl. sot-11s) 2 illustrating still another embodiment. of my invention; m. 10 is a emu-sectional view taken along the line l'l-ll of Fig. 9; Fig. 11 is a perspective view showing the film cut-out of Fig. 9 inserted between a pair of lamp shunting prongs: Fig. 1-2 is a side view of. a film cut-out rod illustrating still mother embodiment of my invention; and Fig. 13 is a cross-sectional view taken along the line lI-II of '18. 12.

Referring now to the drawins. and particularly, to Figs. 1-5, inclusive, I have there shown one embodiment of my invention comprising a plurality of film cut-outs I formed as sections of a rigid sectionalized rod of moulded insulating material 2, the rod being substantially cylindrical in cross-section and having spaced apart portions 3 of reduced cross-sectional area. The sectionalizing portions 8 or the insulating rod, being of reduced cross-sectional area, are of less mechanical strength than e intermediate sections of th rod. and thus facilitate separation of the various sectional cut-outs. The insulating rod is preferablyof oblate cross-sectional eonfigm'ation, as illustrated at Figs. 1. 2 and 5, to facilitate proper positioning of the cut-out between a pair of lamp shunting prongs 4 and i, as illustrated at Fig. 5.

The individual cut-outs are formed by setting into each rod section I, as by moulding or the like, a pair of electric conducting imerts or conso tact bri ging pins 8, the pins being disposed transversely'of the rod 2 in end-to-end relation with their outer ends protruding slightly on opposite sides of the insulating rod. The protruding outer ends of the pins 8 provide contact with the lamp prongs 4 and I. The adjacentinner ends of the contact bridging pins 0 are normally insulated from each other by a thin film l of copper oxide or other suitable voltage-limiting dielectric medium characterized by electrical breakdown at a predetermined voltage. To ensure retention of the pins I in the moulded rod 2, the inner ends oi the pins 0 are flanged as at I.

At Figs. 3 and 4, I have shown detailed views of a single bridging pin 6. It will be observed that in the embodimentfof the invention shown at Figs. 1-5, each pin 6 is formed as a flanged cup having its inner surface coated with a thin film I of copper oxide. The bridging pins 3 are moulded into the rod 2 with their flanged ends adjacent and their closed ends protruding from opposite sides'of the rod.

At Fig. 5, I have illustrated the manner in which a film cut-out section such as shown at Figs. 1-4 is positioned between a pair of resilient lamp shunting prongs 4 and I. In inserting a cutment'with opposite prongs! broken oil at the next sectionalizlng portion 3,

4 derstood that I intend in the appended claims to cover all such modifications which fall within the true spirit and scope of my invention.

leaving the inserted cut-out in place between prongs. It is evident from Fig. 5, that in replacing a used or defective cut'out, the end 01 the sectionalized rod or cut-outs may itself be used to eject the old cut-out while inserting the new 1 cut-out;

AtFig. 6, Ihave shown a cross-sectional view shown at Fig. 1, but in which the contact bridg 'ing pins 6 are set into the 'rod sections with their flanged ends outward and their'closed' ends ad-" What I claim as new and desire to secure by Letters Patent oi the United States, is:

1. A magazine rod type cut-out for insertion between electric lamp shunting prongs comprisor a sectionalized cut-out rod similar to that cular cross-section and provided at one side with a radially protruding positioning flange 9. The

, conducting inserts or brid ing pins 0 are inserted with their flanged ends outward as at Fig. 6, and are of rectangular rather than circular crosssection, as illustrated at Fig. 7.

At Figs. 9 and 10, I have illustrated still a further embodiment of my invention in which the sectionalized rod of insulating material 2 has a cross-sectional configuration similar to the rod of Figs. 7 and 8, but in which the bridgin inserts or pins 8 are or circular cross-section and moulded into the rod in the manner ot-the. pins 8 at Fig. 8.

At Fig. 11, I have shown a fragmentary perspective view of a pair of lamp shunting prongs I and 5 having clamped therebetween a sectional protect the oxide coating 13 from damage by en-- gagement with the contact prongs I provide outer sectional electrode coating it of metal on opposite sides of each rod section. The sectional metallic electrode coatings it serve to protect the copper oxide film-from adverse weather conditions and irom chipping by abrasion. The sectionalized cut-out of Figs. 12 and 13 may be used in conjunction with shunting prongs or the type shown at Figs. 5 and 11. In this' form of the invention a positioning flange l or a position determining configuration or the cut-out is desirable to ensure that the electrode coatings ll engage the prong contacts 4 and 5.

While I have described'only certain preferred embodiments of my invention by way or illustration; many modifications will occur to those skilled in the art and I, therefore, wish to have it immg a rigid sectionalized rod of insulating material substantially cylindrical in cross-section having set into each section a transverse bridging pin formed of a pair of electrically conductive inserts normally insulated from each other by a voltage-limiting dielectric medium.

2. A magazine rod type cut-out for insertion between electric lamp shunting prongs comprising a rigid sectionalized rod of moulded insulatin material, said rod having spaced apart separating portions or reduced cross-sectional area and being or substantially uniform cross-sectional configuration between said portions, and a pair 01' electric conducting bridging inserts set into each section or said rod transversely in end to end relation and normally insulated from each other solely by a voltage-limiting dielectric film, said inserts having head portions protruding from opposite sides of said rod for engagement with said prongs.

3. A magazine rod type film cut-out for insertion between electric lamp shunting prongs comprising a rigid sectionalized rod oi moulded insulating material, said rod having spaced apart separating portions of reduced cross-sectional area and being of substantially uniform crosssectional configuration between said portions, each section of said rod having set therein a pair of contact bridging pins disposed transversely in end-to-end relation and having head portions protruding from opposite sides of said rod for engagement with said prongs, the adjacent ends or said pins being normally insulated from each other by a film of copper oxide. I

4. A magazine rod type cut-out for insertion between electric lamp shunting prongs comprising asubstantially cylindrical rigid sectionalized rod or moulded insulating material having spaced apart separating portions of reduced mechanical strength, each section of said rod having moulded therein a pair oi transversely disposed electric conducting inserts in end-to-cnd relation, the ad- Jacent ends or said inserts being normally insulated from each other by a film of copper oxide and the remote ends of said inserts protruding from opposite sides of said rod for engagement with said prongs.

HENRY E. BUTLER.

narnnancns man The followingv references areof record in the file or this patent:

UNITED STATES PATENTS" ,Swartz Sept. 19, 1939