US 3147055 A
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Description (OCR text may contain errors)
Sept. 1, 1964 G. J, RUBENS 3,147,055
RESILIENT SAFETY SLEEVE FOR ELECTRICAL PRONGS Filed Dec. 11, 1961 IN V EN TOR.
BY gangs United States Patent 3,147,055 RESILENT SAFETY SLEEVE FQR ELECTRICAL PRONGS George J. Rubens, 6460 Penfield Ava, Woodland Hills, Calif. Filed Dec. 11, 1961, Ser. No. 158,254 3 Claims. (til. 339-36) This invention relates to safety devices, and more particularly to 'a safety sleeve for insulating the exposed energized prongs of a male electrical plug or the like and preventing electrical shock during use.
During the connection and removal of male plugs, night lights etc. from mating receptacles, it can be observed that the prongs thereof are energized at a time when the body of the male plug is momentarily spaced from the receptacle. This space is of sufficient dimension, i.e. approximately one-half inch, to enable the fingers of the user to be accidentally inserted therein to engage the bare hot prongs.
This condition is especially dangerous to young children who are naturally attracted to electrical plugs connected to wall receptacles normally installed close to the floor. The burns and electrical shocks resulting from contact with bare conductors can be critical, and especially painful to a childs tender skin.
The present invention provides a safety device for the exposed portions of the energized prongs of an electrical plug or the like to prevent contact, accidental or otherwise, by the fingers of the user. The safety device comprises a highly resilient sleeve of insulating material adapted to be mounted on one of the connector halves, preferably the male plug, to completely surround the prongs thereof.
The sleeve can be made of any insulating elastomeric material having a high degree of compressibility and resilience, in other words, a low compression set, to allow the sleeve to be squeezed between the connector halves, and to remain thusly during engagement, and yet be quickly restored to its original thickness when the plug is disconnected to be available for ready reuse. A suitable material, among others, is polyvinyl chloride, neoprene, sponge rubber etc. The sleeve may be provided with one or more longitudinal openings extending therethrough' to receive the prongs, and which can resiliently grip the male prongs; or the sleeve may be adhesively secured, or otherwise connected, to the connector body.
One object of this invention is to provide a safety device for insulating the bared energized prongs of a separable electrical connector.
Another object is to provide a protective device for such prongs which will insulate the energized prongs throughout the connecting and disconnecting operation.
A further object is to provide an insulating device that can be easily installed on existing connectors, male or female, without the need of modifying the connector.
Still other objects are to provide an insulating means for electrical connectors which is simple and inexpensive.
Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:
FIG. 1 is an exploded side elevation view of a conventional male electrical plug in a position aligned with an insulating device of this invention and a conventional wall receptacle of said plug;
FIG. 2 is a similar view of the assembled male plug and uncompressed insulating device of FIG. 1 initially inserted into the receptacle, the latter shown in section;
FIG. 3 is a completely installed connector assembly of FIG. 2 with the male plug fully inserted into the receptacle to complete the electrical connection, the insulating device being squeezed therebetween;
FIG. 4 is a cross-sectional view of the assembled plug and safety device taken along line IVIV of FIG. 2 before compression;
FIG. 5 is a longitudinal sectional view of a modified safety device; and
FIG. 6 is a similar view of still another modified safety device.
Referring to the drawing where like reference numerals refer to similar parts throughout the drawing there is shown in FIG. 1 a conventional male plug 10 comprising a body 12 of insulating material that supports two or more electrical prongs 14 connecting to the ends of conductor 16 in the usual manner. This type of plug is em ployed in a multitude of applications for connecting an electrical device, not shown, to a conventional female receptacle 18 usually installed in a wall 20 or other supporting structure. To insulate the exposed hot prongs 14 when the plug is connected, a safety device 22 constructed according to the teaching of this invention is adapted to fit around the prongs in a manner illustrated in FIGS. 2 to 4. Safety device 22 is constructed in form of a sleeve having any suitable outer configuration, and in FIGS. l5 is similar in configuration to the plug. The sleeve is molded or otherwise formed of an insulating elastomeric material having a high degree of compressibility and resiliency, in other words, a low compression set. Suitable materials among others are polyvinyl chloride, neoprene, sponge rubber, etc. The sleeve is provided with at least one longitudinal opening 24, only one central opening being illustrated in FIGS. 1-4, extending from one end to the other and of a diameter to receive prongs 14 that project therethrough when the sleeve is slipped over the free ends of the prongs during installation. Thus a single opening can accommodate plugs having two or three prongs. Opening 24 of this modification is barrel shaped to provide neck portions 26 at one or both ends to resiliently grip prongs 14 and v prevent accidental separation of the sleeve during use. The intermediate enlarged portion of the opening at 28 provides space to accommodate the excess resilient material that becomes present when the sleeve is squeezed by the complete insertion of the plug into the receptacle, as is illustrated in FIG. 3. The resiliency of the material is not of such a character as to accidentally separate the connector halves.
The length of the sleeve in the relaxed condition is such as to insulate the energized prongs in the initial position of FIG. 2, and it is desirable, but not necessary, that the sleeve be slightly less in length than the prongs to permit the latter to protrude therebeyond to aid the user in aligning the prongs with the receptacle. Body 12 may also be formed with one or more projections 30 on the periphery to aid in alignment, which would be helpful when visibility is restricted.
FIG. 5 is another modification of a safety device 50 having a resilient body 52 formed of the same material as previously described. The principal difference in construction is that two or more longitudinal openings are provided at 54 in the body, each opening to receive a corresponding prong 14. Each opening may be uniform in diameter except for the end 56 where the opening may be restricted at 58 to resiliently engage the prongs similar to neck portions 26 of the previous modification. The remaining portions of openings 54 are sufliciently spaced from the prongs to permit the sleeve to be assembled thereover and accommodate the squeezed material during connection of the plug to the receptacle. The obvious disadvantage of this modification over the former is that a separate opening is required for each prong, and the three prong plug is coming into wide use. Thus, different safety devices would be needed for the different plugs currently used.
FIG. 6 discloses another modification of a safety device 60 according to the invention, a body portion 62 being made of the same material described with reference to the modification of FIGS. 1-4. Similar to the modification of FIGS. l-4, body 62 is formed with one central opening 64 to accommodate both the two or three prongs that the plug may be provided with. Opening 64 is of uniform diameter to loosely receive the plug prongs and to accommodate the bunched material when the plug is inserted into the receptacle. The exterior periphery of body 62 is provided with an annular recess 66 also to accommodate the bunched material.
To retain safety device 60 on the plug, the end 68 of the safety device that engages the plug is coated or otherwise provided with a layer of a suitable pressure-sensitive adhesive 70 adapted to adhere to the face of the plug. A protective sheet 72 may be employed to cover the adhesive until use, the sheet 72 being provided with a pull tab 74 for quick removal.
According to the present invention, a protective safety device is provided for the exposed prongs of an electrical connector half throughout the connecting or disconnecting operation. Such prongs may be of the type on a conventional plug provided for lamps and the like, the prongs mounted on an iron, or the exposed prongs on any other similar type of separable connector. The protective safety device may be easily attached to any existing plug either by resiliently or adhesively attaching the device thereto. If desired the plug and protective device may be fabricated with mating mechanical fasteners for attachment together. The protective device may be provided with one central opening to house all of the prongs or separate openings of the individual prongs, suitable provision being made to accommodate the compressed material of the safety device.
1. The combination of a male electrical connector plug having a body with exposed prongs extending from one end wall thereof adapted to be manually connected with a female socket and a safety device supported by said prongs to insulate the prongs when energized from contact with the fingers of a person holding said plug, said device formed as a sleeve having at least one aperture extending therethrough to receive said prongs, said sleeve circumventing only the exposed prongs of the connector and extending from said plug wall for at least a major portion of their exposed length, said sleeve frictionally engaging the prongs sufiicient to retain the sleeve on the prongs, said sleeve being made of an insulating material having a high degree of compressibility capable of being squeezed by the plug around the prongs increasing said frictional engagement when the plug is inserted into the socket, said sleeve precluding contact between the energized prongs and the persons fingers throughout the electrical connection, said material being capable of remaining in a compressed condition when squeezed by the plug until the plug is manually disconnected from the female socket.
2. The combination of claim 1 wherein said sleeve has a single aperture to receive said prongs.
3. The combination of claim 1 wherein said aperture has a restricted portion to provide said frictional engagement.
References Cited in the file of this patent UNITED STATES PATENTS 2,281,739 Wright May 5, 1942 2,458,153 Festge Jan. 4, 1949 2,632,789 Modrey Mar. 24, 1953 2,759,160 Kelley Aug. 14, 1956 FOREIGN PATENTS 480,619 Italy May 3, 1953