US2280680A - Synchronous simplex telegraph system - Google Patents

Description

A ril 21, 1942.

R. C. WITTMAN ELECTRIC LIGHT CORD EXTENSION Filed March 21, 1941 2 Sheets-Sheet l a 4.5, ATTORNEYS April 21, 1942. R c. WWTMAN 2,280,680

ELECTRIC LIGHT CORD EXTENSION Filed March 21, 1941 2 Sheets-Sheet 2 INVENTOR wrrucsszs Rwhard 6'. 2011612116211 4/ I f/igww q 6, @m afy Patented Apr. 21, 1942 U N i T E D STA-ii" iii ELECTRIC LIGHT CORD EXTENSION Richard C. Wittman, Emporium, Pa.

Application March 21, 1941, Serial No. 384,488

3' Claims.

This invention relates to extension cords, and more particularly to an apparatus designed to handle electric light cord in such a way that the cord may be extended and retracted automatically.

An object of the invention is to provide a device of the character described, which may be simply and easily positioned on the walls or roof of a garage, factory, or other building, and from which an electric light cord may be extended or retracted at will.

A further object is to provide a device of the same general description, in which the cord may be extended to any desired point within limits, and in which the cord will remain at said desired point until retracted.

A further object is to provide a device of the character described, in which the cord will be protected against undue wear or injury, and in which the current flowing through said cord will be automatically shut off when the device is in its fully retracted position.

Various other objects and advantages of my invention will be apparent as the description proceeds.

In the drawings-- Fig. 1 is a side elevation showing my device with the cord retracted;

Fig. 2 is a front elevation in the same position;

Fig. 3 is a fragmentary side view showing the positioning of the upper pulley;

Fig. 4 is a rear view of the same portion shown in Fig. 3;

Fig. 5 is a cross-sectional view taken on the line 5-5 of Fig. 4;

Fig. 6 is an enlarged view of the lower end of the device showing the operation oi the switch with the circuit open;

Fig. 7 is a view similar to Fig. 6 with the circuit closed;

Fig. 8 is a view taken on the line B8 of Fig. 6.

I provide a frame l0 having two upright members II and I2. While the uprights ii and i2 may be of any suitable material, I have found that tubular steel is best adapted for the purpose.

The uprights are Joined at their upper portion by the cross piece [3 and at their lower portions by a cross member I t. The bracket it extends from the cross piece I3 to engage the light cord iii. A conventional mounting attachment. such as the bracket H or iii, may be applied to position the device with relation to the building in which it is mounted.

Mounted in the upper portions of the upright by means of the axle 20 is a pulley ii. A suitable 55 bearing 22 may be provided for smooth operation and the axle 20 may consist of a. bolt extending through the uprights. The pulley 2! is provided with a groove 23.

Slidably mounted on the uprights ii and I2 is a pulley carriage 25 having spaced members 26 adapted to engage the upright ii, and similar members 21 adapted to slidably engage the upright I2.

Mounted in the pulley carriage 25 is a pulley 28 provided with a groove 29 and pivoted 011 the axle member 30. Suitable bearings 38 may be provided for the pulley, and the axle 30 may consist of a bolt extending beyond the sides of the carriage. Removable weight members 32 may be positioned on the bolt axle 30 so that the weight of the carriage may be adjusted to compensate for different conditions.

The electric light cord I 6 is positioned on the bracket 15 by means of the clamp 35 or by any other suitable means. The cord is spliced at 36 to provide an extension 31 extending through the upright l2 to the base 38.

Mounted in the base 38 is a mercury switch 40 to which the wires 4| and 42 of the cord 31 lead and engage contacts 43 and N. The mercurs switch 4!! is pivoted at 45 and a stop 48 is provided to limit its movement. A depending member 41 is fastened to the sliding member 21 and is provided with shoulders 48 and 48 adapted to engage the side walls 50 and 5| of the base 38 when the carriage is in its lowest position. This will allow the end 52 of the depending member 41 to contact the end 53 of the mercury switch 40 to uncover the contact point 43 and break the flow of current through the cord 31 and IS.

The cord I 6 extends from the bracket l5 down under the pulley 28 and up over the pulley 2|. .A light bulb socket is fixed to the end of the cord It.

In operation it will be seen that the device in the fully retracted position shown in Fig. 6, will be without current due to the action of the depending member 41 on the mercury switch 40. However, as the cord is pulled out the pulley carria e 25 will be raised allowing the weighted member 54 to pivot the switch 40 on the pivot 45 and bring the mercury about the points 43 and 44, thus closing the circuit. As the cord is extended, the carriage 25 will slide upwardly on the uprights. Since the weight of the cord and the weight of the pulley carriage 25 will be balanced due to the addition or subtraction of the plates 32, the carriage will maintain its position along the uprights and the cord may be left in any extended position. When it is desired to retract the cord, it may be fed into the device and the weight of the carriage 25 will cause it to be retracted. When the cord is fully retracted and out of use, the current will be completely shut 011 by the switch 40.

I claim:

1. A cord extension device comprising a pair of members spaced in parallel relationship, a pulley mounted between said members at one end thereof, a pulley carriage member slidably mounted between said members, said pulley carriage member comprising a pair of sliding members having relatively widely spaced flanges engaging said first-mentioned members, a pulley mounted between said sliding members, an axle extending through said pulley and engaging said members, and means on said axle for varying the weight of said pulley carriage.

2. In a device of the character described, a pair of spaced rigid members, a pulley mounted between said members at one end thereof. a pulley carriage slidably mounted between said members, an electric cord extending from adjacent said fixed pulley around said pulley carriage and around said pulley, a pair of wires engaging said first-mentioned cord and extending through one of said rigid members to the opposite end oi said device, a pivotal switch cooperating with said wires, and a member on said pulley carriage adapted to engage said switch to open said switch when said carriage is at the point farthest from said fixed pulley.

3. In an electric cord extension device, a pair of rigid members joined at either end, a fixed pulley between said members at the top thereoi and a base at the oppositeend, a pulley carriage slidably mounted between said rigid members, said pulley carriage comprising a pair of supporting members having flanges [or slidable engagement with said rigid members, a pulley mounted between said supporting members. weight members removably mounted on said supporting members, a depending member havin shoulders adapted to engage the base to limit the downward motion of said pulley carriage, a pivotal switch mounted in said base, and an extension on said depending member adapted to open said switch when said carriage is in its downward position.

RICHARD C. WITTMAN.

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