US1727347A - Electrical plug connection - Google Patents

Description

Sept. 10, 1929. E. KNICKERBOCKER ELECTRICAL PLUG- CONNECTION Filed July 5, 1927 Patented Sept. 10, 1929.

UNITED STATES EARL KNICKERBOCKER, OF MOLINE, KANSAS.

ELECTRICAL PLUG CONNECTION.

Application filed July 5, 1927.

This invention relates to plugs for connecting sources of electrical energy to electrical current consuming apparatuses and the primary object thereof is to provide a plug including a switch which will close the circuit when the plug is fastened to the socket, the switch being so arranged that the circuit must be broken before the plug can be removed from the socket, thus reducing the liability of arcing between the contacts which tends to burn the terminals.

The novelty of the invention will be clearly understood by reference to the following description in connection with the accompanying drawings in which:

Fig. 1 is a perspective view of an iron to which my invention is applied.

Fig. 2 is an enlarged sectional view through the socket, the plug being shown partly in section and partly in elevation.

Fig. 3 is a rear elevational view of the plug and socket in interengagement and Fig. 4 is an end view ofthe same.

The electrical device, containing a heating element, is illustrated as an iron 1, having an upstanding socket 2 to receive a plug 3. Within the socket 2 are two pins or con tacts 4 and 5 to be received in the socket contacts 6 and 7 in the plug. One end of the socket 2 is provided with a rectangular opening 8. The other diametrically opposite end wall of the socket 2 is provided with an inverted T-shaped slot 9. The plug 3 carries a push-switch, comprising a transversally reciprocatory bar 10 having on one end a T-shaped head 11. The plug can be fastened in any appropriate manner to a conductor or cable 12 supplied with the elec trical current from any suitable source. When the switch bar 11 is in the position shown in Fig. 2, the circuit will be open. The plug may now be forced into the socket so that the contacts 4 and 5 are received in the contacts 6 and 7. At this time the bar can pass through the narrow part 13 of the slot 9. The end 14 of the bar will be sub stantially flush with one edge of the plug 3. When the plug is seated down in the socket 2, the operator will push the bar 10 tlansversally in the plug so that the end 14 Serial No. 203,565.

will engage the opening 8 and the head 11 will be received in the enlarged portion 15 of the slot 9. Since the horizontal dimension of the head 11 is greater than the narrow portion 13 of the slot 9 and since the end 14 of the bar engages the opening 8, it will be impossible to accidentally withdraw the plug since the bar constitutes both a switch operating element and a fastening means or latching means between the plug and the socket. In other words, when the bar is in the position shown in Fig. 2, the circuit in the plug is open and when it is in the positions shown in Figures 3 and 4, the circuit is closed.

From the foregoing it will be apparent that the plug cannot be inserted in the socket 2 with the switch closed, but that the closing must take place after the contacts 4, 5, 6 and 7 are in interengagement and that the plug cannot be removed until the switch in the plug is opened. Consequently, danger of arcing and burning the contacts 4, 5, 6 and 7 will be eliminated. Another advantage is that danger of injury to the per ends of the contacts 4 and 5 and the upper edge of the socket 2. Therefore, if the circuit in the plug is closed before it is put in the socket, the head on the bar 10 will act as a stop for the full insertion of the plug because the head 11 cannot pass through the slot 13. Consequently, the plug will not touch the short contacts 4 and 5. As a result the iron cannot be heated until the bar 10 is moved to the position shown in Fig. 2, at which time the circuit in the plug is broken. This is an important fea ture because if the contacts 4, 5, 6 and 7 could be brought together while the switch in the plug is closed, arcing would take place. The short contacts eliminate t possibility of the contacts being brought together while the switch is closed in theplug.

What I claim and desire to secure by Letters-Patent is 1. An electrical plug connection comprising a socket having a slot with an enlarged portion in its edge, a plug, cooperative con tacts in the socket and in the plug and a switch element carried by the plug having a head movable into the enlarged portion of the slot to latch the plug "to the socket when the switch is closed and movable out of engagement with enlarged portion of the slot when the switch is open.

2. An electrical plugconnectionicomprising a socket having a key-hole shaped slot in one wall thereof, a plug, -cooperating contacts in the socket and in the plug'anc'l a switch carried by the plug having aheaded reciprocatory bar, the smaller end of which is projectable through an opening in the wall of the socket opposite the slot, the head of the bar being larger than the narrow part of the key-hole shaped-slot so that when the small end of the bar is in the opening in the socket, the head of the bar will be in the large part of the key-hole shaped slot to prevent withdrawal ofthe plug. 7

3. An electrical plug connection comprising a socket having akey-hole shaped slot in one wall, a plug having contacts adapted to contact with complementary contacts in the socket and a switch having a reciprocatory bar provided with a head movable into and out of the enlarged portion of the keyhole shaped slot, e i

4. An electrical plug connection comprising a socket and a plug having co-operating contacts and a reciprocatory latching 'bar carried by the plug for engaging the socket when the switch is on and disengaging the socket when the switch is off.

In testimony whereof I affix my signature.

EARL KNICKERBOCKER.

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