US367840A - Parlor extension-lamp - Google Patents

Description

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. v 1). W. PARKER.

PARLOR EXTENSION LAMP.

No. 367,840. PatentedAug. 9,1887..-

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D. W. PARKER;

PARLOR EXTENSION LAMP.

Patented Aug. 9

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UNITED STATES PATENT OFFICE.

DEXTER W. PARKER, OF MERIDEN, CONNECTICUT.

PARLOR EXTENSION-LAMP.

SPECIFICATION forming part of Letters Patent No. 367,840, dated August 9, 1887.

Application filed July 10. 1886. Serial No. 207,647. (No model.)

To all whom it may concern:

Be it known that I, DEXTER W. PARKER, a citizen of the United States, residing at Meriden, in the'county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Parlor Extension- Lamps; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

' This invention relates to that class of extension-lamp fixtures known as piano-lamps or parlor-lamps and provided with two telescoping parts, the lower resting on the floor or on some supporting article or object, while the other, which bears thc'lamp, is vertically ad justable.v p

The object of the present invention is to improve parloi'lamps which are extensible upward from the [1001' by providing them wit-l1 more reliable and satisfactory devices for holding them in any position of vertical extension to which they may be adjusted.

To this end my invention consists in a mov- V able parlor-lamp having asupport consisting of a vertically-extensible upper part, a counterbalance weight or spring therefor, and an automatic friction-brake, which prevents the descent of the latter, and a relatively fixed lower part, substantially as hereinafter set forth and claimed.

In the accompanying drawings, Figure 1 represents a vertical section of a parlor-lamp fixture embodying my invention. Fig. 2 represents an enlarged side elevation of the friction-brake and proximate devices, some of the .thelamp-iixture; B,the upper tube, verticallymovable therein; C, the lamp, supported on the top of this upper tube; and D, Fig. l, the cord, which is attached to the lower end of said up-. per tube, passes over a pulley, E, journaled in the upper part of said lower tube, and then down to a spring-drum, F, on which it is ;to descend.

wound. The spring G within said drum acts as a counterbalance to said upper tube, 13, and the lamp supported thereby. This spring is preferably only-strong enough to balance the said parts when they are in their lowest position. Of course as the I lamp is raised the tension of the spring diminishes. An auto matic friction-brake is therefore employed to hold the lamp at any desiredelevation. This consists ofa peripherally-ratchettoothed friction-disk, H, forced against one end of said spring-drum by a spring, I, which is in contact with said disk, the latter being free to slide on the shaft F of the drum. 7 A pawl, J,

engages with the ratchet-teeth on said disk and preventsv the latter from turning with the drum when the upper tube or section, B, begins The disk H under suchcircumstances applies friction to said drum, so as to prevent the descent of said tube and lamp under the influence of gravity alone. Of course it is aided in this by the coiled spring G, which always partly counterbalances said of the lower tube, A. A guide-pulley, M, j0ur-- naled in a slotted part of said extension, Fig. 3, or of the casing itself, Figs. 1 and 2, is in contact with cord D and serves to prevent friction at the point where the said cord leaves gitudinally slotted at b, to pass over the shaft of pulley E aforesaid. Both sides of said tube are thus slotted at points corresponding to the ends of the shaft, though only one slot appears in Figs. 1 and 4, owing to the plane on which the section is taken in each instance.

As shown in Fig. 7, this may be avoided by placing the counterbalance-spring G at the top of the upper tube, B, where it and the drum and friction-brake are j ournaled in a suitable frame, 9, and causing the cord to pass under a pulley, z, in the lower end of the said upper tube, and thence to the top of the fixed lower tube, A, to which saidcord is attached at a.

Sometimes i employ a spring having strength enough to more than counterbalance the lamp and movable tube or section B at any point of vertical adjustment. Under such circumstances I pivot a cam, N, as shown in Fig. 4, within the upper tube, 13, and arrange it to extend through a slot in said tube and bear against the lower tube, A. A rod, 0, extends upward from the inner end of this pivoted cam to a collar, N, loose on said upper tube. The cord Dis also attached to the inner end of said cam and passes up over the pulley E aforesaid, and then down to and around the spring-drum F. The cam is so shaped that the draft of spring E holds it in contact with the lower tube, A, and thus prevents the upper tube, 13, and the lamp carried thereby from rising above a certain point. In this way the action of the elevatingspringG on the cam N compensates for its own excess of strength. The collar N has an incline, a, formed on its upper edge. Vhen said collar is turned in one direction, this incline comes in contact with a stud, p, on tube B. The result is to force downward said tube and rod and the inner end of said cam, thereby freeing the latter from tube A. The spring G then raises tube B and the lamp. By turning said collar back to its former position the cam is once more put i 11 position for clamping. The turning of said collar N is most conveniently effected by hand.

Of course my vertically-extensible support and counter-balance may be used for elevating other articles besides lamps.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A eounterbalance-spring and stationary lower tube, in combination with a verticallymovable upper tube, a cord, and an automatic friction-brake, which prevents the descent of the said movable tube, substantially as set forth.

2. In a lamp, the combination of a fixed lower part with a movable upper part, acord, a couuterbalanee-spring, and a cam pivoted in said movable part and operating against the fixed part to automatically hold. the movable part at any desired elevation, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

DEXTER XV. PARKER.

\Vi tnesses:

J. H. BueKu'r'r, RALPH A. PALMER.

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