US255224A - Charles s - Google Patents

Description

0's. WESTLAND. EXTENSIB'LB DROP LIGHT.

(No Model.)

Patented Mar. 21,1882.

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PETERS. Mme-Lithographer. Washingtom D4 C.

UNITED STATES PATENT OFFICE.

. GHARLES \VESTLAND, OF PROVIDENCE, R. I., ASSIGNOR TO ADDISON'H. WHITE AND HENRY L. FAIRBROTHER, OF SAME PLACE.

EXTENSIBLE DROP-L|GHT.

SPECIFICATION forming part of Letters Patent No. 255,224, dated March 21, 1882. I

' Application filed October 12. 1881. (No model.)

To all whom it may concern:

Be it known that I, CHARLES S. WEsrLAND, of the city and county of Providence, and State of Rhode Island, have invented a new and uset'ul Improvement in Extensible DropLights; and I do hereby declare that the following specification, taken in connection with the accompanying drawings, forming a part of the same, is a full, clear, and exact description thereof.

My improvement is intended to enable a drop-light provided with a kerosene or other fluid burning lamp to be conveniently adj usted and held to anyposition from the ceiling of the room within the limits proper for such domestic conveniences; and the invention con sists generally in such a construction of the extensiblesupportingmember of t-helamp that the resistance of a confined cushion of air can be made available for aiding in supporting the weight of the lamp and its attachments and the degree of such resistance be conveniently regulated to meet vary ing requirements.

- Referring to the drawings, Figure 1 represents my improved drop-light in elevation and partly in section. Fig. 2 shows a section on line a: 00 of Fig. 1. Fig. 3 represents in section a portion of the supporting-tube and the interior pipe.

A is a tube properly secured to and pendent from the ceiling of the room. B represents a kerosene-burning lamp, which in this instance is mounted in a harp-shaped frame or support, 0. This frame, or at least one side of it, is tubular, and is connected by a suitable coupling, 0, to the pipe I). This pipe is somewhat smaller in external diameter than the interior diameter of the pendent tube A, as indicated in dotted lines in Fig. 1, and shown in section in Fig. 3. The drawing Fig. 1 represents the drop-light as standing near its highest elevation. The pipe D should be of sufficient length and extend enough into the tube A to permit the full amount of downward extension required. The upper end of the pipeD is (urnished with a piston, D, the sides of which should fit closely the interior bore of the tube A, so as to prevent the passage of air; and it will be found desirable in practice to pack the piston with some suitable fibrous. packing, as shown in Fig.3. The lower end of thetube A is provided with a stuffing-box,A, Fig. 1, of wellknown construction, so as to exclude the passage of air from within the tube A around the pipe 1). It is obvious that if the drop-light be lowered the air within the tube A below the piston will be compressed and the reactionary force caused by such compression, unless balanced by the weight of the lamp and its attach- 6oments, would cause the piston D to be forced upward. In order, therefore, to regulate the air-resistance consequent upon the formation of an air-cushion between thelowerface of the piston and the stutfing-box A, so that it will be just equal to or but slightly in excess of the weight of the lamp, 1 perforate the pipeD with a sufficient number of holes, d, close adjoining the piston, as shown in Fig. 3, to enable the compressed air to enter through the same and pass down the pipe into the frame 0. To enable the excess of pressure to be relieved, I place at an y convenient point-as, for instance,

at the place usually occupied by the cock in a gas drop-light-a spring check-valve, E. This 5 valve is opened by means of a rod connected thereto, and furnished with a button-head, E, and is kept closed by the pressure of a spring,

6, or it may be constructed in any other convenient way, so long as it will enable the excess of air-pressure beyond what is required to sustain the lamp and its attachments at the desired height to escape until any tendency of the lamp to creep upward is relieved. When the lamp is to be raised toward the ceiling the valve E should be again opened, so as to allow the external air to enter and supply the partial vacuum in the tube A, which otherwise would occur.

In order to prevent the air above the piston from being compressed when the drop-light is elevated and from being attenuated when the light is lowered, a series of holes, a, are made at any convenient place in the tube A above the range of movement of the piston D, the air 5 entering or discharging through which maintains always above the piston simple atmospheric pressure. The friction occasioned by i i I the packing around the piston D and in the lamps, is-

1. The combination, substantially as above set forth, ofa pendent tube, a pipe arranged to slide within the bore of said tube, a piston attached to said sliding pipe, a stuffing-box preventing the escape of air from the mouth of the pendent tube, apertures in the sliding pipe connecting the annular space within the tube with the interior of the sliding pipe, and a relief-valve to permit the escape of any excess of air-pressure when the drop-lightislowered, and to permit the admission of air when the light is elevated.

2. The combination, substantially as above set forth, of a pendent tube, a sliding piston attached to a pipe arranged to move within the bore of the pendent tube, air-apertures to maintain an equilibrium of pressure located in the pendent tube above the range of movement of the piston, a stufiing-box to prevent the escape of compressed air at the mouth of the tube when the drop-light is extended downward, apertures in the sliding pipe connecting the annular space within the tube with thcinterior of the sliding pipe, and a relief-valve to permit the escape of any excess of air-pressure when the drop-light is lowered, and to permit the admission of air when the light is elevated.

O HARLES S. WESTLAND.

Witnesses W. H. THURSTON, I. KNIGHT.

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