US 2729797 A
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Description (OCR text may contain errors)
Jan. 3, 1956 v. KOBLER ETAL PLUG FOR ELECTRICAL APPARATUS Filed Sept. 20, 1954 IN VE N TORS United States Patent PLUG FOR ELECTRICAL APPARATUS Victor Kobler and Werner Kobler, Zurich, Switzerland Application September 20, 1954, Serial No. 456,899
Claims priority, application Switzerland September 29, 1953 3 Claims. (Cl. 339-36) The present invention relates to plugs for electrical apparatus, and more particularly to such plugs, which are provided with a protection cap for sensitive parts of the apparatus.
Such plugs often have the disadvantage, that due to the protection cap, which usually is fixed within the range of the plug contacts, they may not be inserted into the corresponding sockets. This disadvantage occurs not only with plugs having pins, which are to be inserted into the bushings of countersunk sockets, but particularly with plugs having so-called bayonet armatures, as they are common in certain countries.
The present invention has as its object the provision of a plug, with which the disadvantage mentioned is avoided.
According to the invention the plug is characterized in that the protection cap and the insulating body of the plug, having at its one end the plug contacts, form two separate parts, a support being slidable on the insulating body and on the current supply cable leaving the latter.
By displacing the support of the protection cap on the insulating body it is possible to provide for the distance between these contacts and the protection cap, which is necessary for the proper insertion of the contacts into the corresponding socket.
If necessary the protection cap with its support can he slid back completely onto the current supply cable,-
which is led into the insulating body at the end thereof facing away from the plug contacts.
The accompanying drawing shows two embodiments of the plug according to the invention.
Figs. 1 and 2 show perspectively the first embodiment, the protection cap being in its position of use and its out of-use position respectively.
Figs. 3 and 4 the second embodiment in analogous positions to Figs. 1 and 2, and
Fig. 5 the insulating body of the second embodiment with a fragmentary axial section.
The plug shown in Figs. 1 and 2 has an insulating body 1, carrying in a known manner the plug pins 2 as well as a protection cap 3 being formed as a separate part, which in the present case serves for the protection of the cutter-head of an electrical dry-shaver. The protection cap, being integral with a sliding sleeve 4, suitably consists of a soft rubber, while the insulating body 1 consists of a hard insulating material e. g. synthetic material. The sleeve 4 carrying the protection cap is slidably guided on the insulating body 1 and on the cable 5, emerging from the latter. Therefore the protection cap 3 extending at right angles from one of the longitudinal sides of the insulating body, can be displaced from its position of use (Fig. 1), in which it is placed in the range of the face side of the plug body 1 carrying the pins 2, into its out-of-use position (Fig. 2) at the lower end of the insulating body 1, where obviously it will not hinder in inserting the plug also into a countersunk socket.
2,729,797 Patented Jan. 3, 1956 The plug shown in Figs. 3-5 is one serving for connection to connecting sockets having bayonet armatures as they are usual in different countries, e. g. Australia. Also here, the plug body 6a, 6b and the protection cap 7 with its support 8 are formed as separate parts. The plug body, for instance consisting of electrically properly insulating, hard synthetic material comprises a cylindrical head portion 6a, having at its face side the two contacts 9 and at its circumference two bayonet engaging pins 14, and a flat shaft portion 6b. In the latter the terminals 10 are provided, in which the strands of the current supply cable are held by means of screws 12. The shaft portion 6b and the cable end emerging from the latter are enclosed by a cover 13 of insulating material. With its shaft portion 6b enclosed by the cover 13, the plug body is inserted in a corresponding opening 15 of the protection cap-support 8 in the position of use of the protection cap 7, in which the latter according to Fig. 3 protects the cutter head of an electrical dry-shaver. This support 8 can be slid back from the shaft portion 6b of the plug body onto the cable 11 together with the protection cap 7. As shown in Fig. 4, the protection cap 7 can no more obstruct the insertion of the contact carrier 6a into the connecting socket in this position. Thereby the cover 13 prevents the user from getting into contact with the current carrying parts of the shaft 6b.
By means of the described arrangement plugs are provided, the contact carriers of which, taking up relatively little space when the plug is not in use, form a compact unit with the protection cap, while the latter, when using the plug, can he slid back to such an extent over the cable that the plug may be properly applied.
It should of course be understood that modifications may be made in the illustrated and described embodiments without departing from the invention as set forth in the accompanying claims.
1. A plug for electrical apparatus comprising an insulating body, plug contacts at one end of said insulating body, a protection cap for sensitive apparatus parts and a cap support slidably arranged on said insulating body, said protection cap and said insulating body being formed as separate parts, said cap support having a recess, said protection cap and its support being movable from one position in which the insulating plug body is nested within said recess in said cap support and said cap is arranged adjacent the contact carrying portion of said body to a second position away from said contact carrying portion of said insulating body.
2. A plug according to claim 1, wherein said insulating body is provided with plug pins for insertion in corresponding bushings of a socket and said support of the protection cap having sleevelike configuration is slidable on the insulating body such that the protection cap extending at right angles from said support, in its position of use is arranged in the range of the face side of the insulating body carrying the plug pins.
3. A plug according to claim 1, wherein the insulating body is provided with a cylindrical contact-carrier having bayonet engaging pins for insertion into a bayonetsocket and with a shaft portion, said shaft portion and the cable end emerging from the latter being enclosed by a cover of insulating material, on which the support of the protection cap is slidably arranged.
Kolbert et al. May 30, 1944 Wilson Aug. 21, 1945