Counterbalanced Lamp

Abstract

A lamp having an elevated, freely movable light boom counterbalanced, by a weight located adjacent the lamp base. The weight is attached to a lever pivotally mounted on the lamp base. The lever is connected to an end of the light boom by means of a cable and pulley arrangement. Thus, inadvertent disengagement of the weight or its movement presents an optimum, minimum safety hazard.

Description

The present invention relates generally to lamps, and more particularly to an improved counterbalanced lamp.

A lamp using a light boom having a large reach requires a counterbalance to facilitate movement and positioning of the boom. However, a counterbalancing weight on the elevated free end of the boom, i.e., the end opposite the light, is a potential safety hazard if it should become inadvertently disconnected and thus fall from its elevated position, or if during movement at this elevation, which is head level, it strikes someone. Counterbalancing in the aforesaid manner, as is done in the prior art, also produces a lamp which is top-heavy and contributes to a situation in which it is difficult for the boom to hold its position without drifting.

Broadly, it is an object of the present invention to provide a counterbalanced lamp overcoming the foregoing and other shortcomings of the prior art. Specifically, it is an object to effectuate the counterbalancing relation between the weight and boom through a pulley means in an interposed position therebetween, thereby permitting the advantageous location of the weight adjacent the base of the lamp, and thus not in an elevated, hazardous position.

An improved counterbalanced lamp demonstrating objects and advantages of the present invention includes a relatively large boom having a light on one end and having an upright body or support connected to support the boom in an elevated position. A cable of a pulley means interconnects, in counterbalancing relation, the other free end of the boom with a counterweight supported adjacent the base of the lamp. Thus, movements of the counterweight corresponding to positioning movements of the light occur in an out-of-the-way area.

The above brief description, as well as further objects, features and advantages of the present invention, will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevational view illustrating the counterbalanced lamp hereof, in which positions of movement thereof are illustrated in full line and phantom line perspective; and

FIG. 2 is a plan view illustrating further structural details and also rotative movement of the lamp.

In the drawings, there is shown a counterbalanced lamp, generally designated 10, demonstrating objects and advantages of the present invention. By counterbalanced is meant that the lamp 10 and, more particularly, a boom 12 having a relatively large reach which is the major component thereof, is counterbalanced by a counterweight 14 in a noteworthy manner, all as will be described in detail subsequently herein. It is because of the counterbalancing relation between the weight 14 and boom 12, with the lamp 16 appropriately mounted thereon, that a position of equilibrium is achieved in each position of movement of the boom 12, i.e., that nothing is required to maintain or hold the position of the boom against drifting movement. Another consequence of the counterbalance is that it is relatively simple to move, without exertion or much physical effort, the boom 12 in opposite directions along the path of pivotal movement 18 into the various positions illustrated in full line and phantom line perspective.

In addition to the boom 12, lamp 10 includes an upright support 20 which has a pivotal connection, as at 22, to the boom 12 at a point between the boom operative ends 24, 26, said connection as clearly illustrated, being decidedly closer to the end 26 remote from the lamp 16. In this manner, support 20 normally provides sufficient elevation to the light 16 on the far, overhanging end 24 of the boom 12.

In contrast to prior art counterbalanced lamps, the lamp 10 hereof does not have the counterweight 14 at the boom operative end 26, since this elevated location is hazardous if the weight should become inadvertently disconnected from the boom and, since it is also at head level, it is dangerous should it strike someone while being urged through movement which occurs during adjustments in the position of the light 16. Additionally, the concentration of weight which would occur by supporting counterweight 14 adjacent the boom operative end 26 renders the upright support 20 top-heavy, and thus more susceptible to tipping or falling. Additionally, while an angular traverse in the light 16 by reason of the considerable length of the boom 12, as measured between the pivotal connection 22 and the light 16, does not significantly change the tipping moment about the vertical axis of the upright support 20, the corresponding angular movement produced in the considerable shorter length of the boom, as measured from the connection 22 to the operative end 26, does materially affect said tipping moment. This difference in length segments of the boom also has a tendency to interfere with the ability of the boom 12 to achieve equilibrium in all positions of pivotal movement thereof. Stated another way, as a consequence of positioning light 16, there is a significant difference in the extent to which the boom operative end 24 is moved closer to the vertical axis of the upright support 20 as compared with the boom operative end 26 and this has been found to contribute to drifting in the position of the light 16 unless effectively counteracted.

In accordance with the present invention, the aforesaid and other problems and shortcomings heretofore characteristic of counterbalanced lamps having a boom with a considerable reach are solved, in large measure, by locating the weight 14 which counterbalances the weight of the reach of the boom 12 and its light 16 on a lever 28 pivotally located, as at 30, at a selected position well below the pivot connection 22 and adjacent the upright support base 32. This location, in an obvious manner, lowers the elevation of the counterweight 14, bringing it closer to the floor 34 and thereby minimizing the safety hazard previously referred to. Also, by separating the counterbalancing operative components 12 and 14 at the respective upper and lower ends of the upright 20, the previously noted instability due to top-heaviness of prior art counterbalanced lamps is obviated.

As illustrated in FIG. 1, advantageous use is made of the length portion of the upright 20 between the connections 22 and 30, more particularly designated 36, for the location of pulley means, generally designated 38, to operatively interconnect in counterbalancing relation the boom operative end 26 and the counterweight lever 28. Specifically, upright 20 preferrably consists of two panels 40 and 42 connected on opposite sides of spacing blocks or the like so as to bound a rectangular compartment 44 therebetween, as shown in FIG. 2. Mounted in compartment 44 is the previously noted pivotal connection 22 for the boom 12, and also a pair of upper pulleys 46 and lower pulleys 48. Pulley means 38 is completed by a cable 50 appropriately connected at one end to the operative boom end 26, extended therefrom about the lower pulleys 48 up along the support 20 and over the upper pulleys 46, and then connected at its opposite end, as at 52, to the counterweight lever 28.

It has been found that as a result of the looping of the medial portion of the cable 50 about the pulleys 46, 48, there is sufficient friction resulting from the wrap of the cable about the pulleys to provide a useful, selected amount of resistance to movement of the pivotally movable components of the lamp 10, namely the boom 12 and lever 28. As a consequence, drifting in position of the light 16 is minimized; in fact, use of the lamp 10 contemplates the need on the part of the user to actually grasp the boom 12 and push or pull it through pivotal movement about the pivot 22 in order to overcome the slight frictional resistance inherent in the pulley means 38.

In addition to pivotal movement 18, lamp 10 is also advantageously provided with rotative movement 54 about the vertical axis of the upright 20. To this end, base 32 includes an outer ring 56 having ball bearings or the like in contact with an inner disc 58 connected to the bottom of the upright 20.

From the foregoing, it should be readily appreciated that there has been described herein a counterbalanced lamp with noteworthy features of safety and simplicity of construction, all of which further contributes to a desirable aesthetic appearance in the lamp in that it permits use of a counterbalanced boom with a comparatively large reach and yet has none of the disadvantages attendant to prior art lamps of a similar classification.

A latitude of modification, change and substitution is intended in the foregoing disclosure, and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.

Claims

What is claimed is:

1. A lamp comprising a boom having opposite first and second operative ends, a light supported adjacent said first boom operative end, an upright support in supporting connection beneath said boom at a location between said boom first and second operative ends so as to maintain said light normally in an elevated position, a counterweight to said boom supported on said upright support at a remote location below said supporting connection to said boom adjacent the base of said upright support, and a pulley means operatively arranged on said upright support between said counterweight and said boom operatively interconnecting in counterbalancing relation said counterweight and said boom second operative end, whereby movement of said counterweight caused by boom movement is confined to an optimum safe area adjacent the base of said upright support.

2. A lamp as defined in claim 1 wherein said counterweight includes a pivotally mounted lever and a weight supported on the free end of said lever.

3. A lamp as defined in claim 2 wherein said pulley means includes upper and lower pulleys journalled on said upright support and a cable connected at one end to said boom second operative end, threaded about said pulleys, and connected at said other end to said lever of said counterweight.

4. A lamp as defined in claim 3 wherein said cable is disposed in looped arrangement about said pulleys so as to maximize frictional engagement therewith, to thereby contribute to maintaining the equilibrium of said boom in each position of movement thereof.