Abstract: A pair of lamps are mounted on either side of a protective helmet on indexing tables that permit each lamp to be independently directed at a different target. Each lamp table is slidably received within a base section so that the lamp can be easily removed from the helmet. A utility band passes between the two base sections and is held therebetween by gripping bars mounted in each base section. The band is adapted so that articles can be carried thereupon.

Abstract: This invention is directed at a light box comprising a box-like base member and a cover. The base member has a storage compartment and a series of light chambers which are aligned with the storage chamber. The storage chamber includes a means of providing power to the source of light mounted in the light chambers. The cover is pivotally engaged to the base member by an L hinge and has an adjustable connector extending therefrom which is engageable with the base member. Each of the secondary walls has an upper side edge and a lower side edge. The upper side edge is positioned in close proximity to the opening of the base member and the lower side edge is positioned in spaced parallel relation to the upper side edge and has a notch formed therein. The notches of the secondary walls are in aligned, spaced relation to each other. A first channel is mounted in a shoulder formed at the opening to the base member and faces into the light chambers.

Abstract: An auxiliary visor light includes a visor body coupled to a vehicle and including a light housing coupled to the visor body and movable between a stored position substantially flush with the visor body and a use position projecting from the visor body and which is laterally directable to provide selective illumination to the interior of a vehicle.

Abstract: A lamp and filter mounting assembly includes a lamp holder with a lamp mounting plate and a back wall for pivotal mounting to a bracket. The back wall of the lamp holder includes an inclined adjustment stop that engages the bracket upon rotation of the lamp holder through a predetermined angle. The assembly also includes a filter holder with side rails and a filter stop to hold a filter. The side rails include extensions that overlie the lamp holder to provide a sliding attachment to the lamp holder. The bracket is secured to an aperture pan that is rotatably mounted within a trim assembly. A light shield is secured to the aperture pan and surrounds the lamp holder.

Abstract: A self-housed rectangular lamp assembly with a replaceable halogen bulb lamp unit. A cup-shaped housing, having a pivotal mounting bracket, receives a lamp unit that has a pair of integral threaded bosses on its rear surface receiving fasteners extending through the rear of the housing to releasably attach the lamp unit within the housing.

Abstract: A lamp bulb mount for axially mounting two lamp bulbs into a light for selective operation in relation to a combination flood and spot light is disclosed. The mount includes a forward base and a rearward base selectively connectable to each other. The forward base is conformable to a reflector member of the light and has an opening formed therein which receives the lamp bulbs supported by the rear base. Interconnection of the forward and rearward base and placement of the forward base against the reflector member projects the light bulbs through the reflector member in a predetermined relationship. A socket of each base of the mount is convertible between flanged lamp bulbs and twin pin lamp bulbs through alternative spring mountings. A carrying case for the mount includes a fan adapted to maintain air flow throughout the light, cooling the battery, control circuitry and lamp bulbs.

Abstract: An articulated task lamp for exemplary use as a counterbalanced drafting table lamp including pivotally interconnected base assembly, lower support arm, upper support arm, and lamp head, and counterbalance linkage operable within said lower support arm and base assembly and provided a novel connection to the upper support arm. The counterbalance linkage includes a torsion counterbalance spring in the base assembly having a force transmitting connection to a link member which is pivotally interconnected to a compensating link pivotally mounted intermediate its ends to the base assembly, the other end of said compensating link being pivotally connected to an elongated link member carried and operable within the lower support arm and having its other end pivotally connected to a crank member enclosed within a mid joint means providing a pivotal connection and force transmitting connection between the upper and lower support arms.

Abstract: A support device for a vehicle headlamp that consists of a wire shaped so as to have a gripping engagement with the peripheral portion of the headlamp adjacent the lens and that includes formed wire sections which rotatably carry adjusting screws which connect the support device to a frontal portion of the vehicle.

Abstract: A novel portable light beam projector device, related system apparatus, and attendant novel method for wide variety use in conjunction with military vehicles, to establish optimum placement of optical fire detection sensors relative to installation of the vehicle's fire suppression system. These inventions are similarly usable to novelly establish corresponding optimum placement of various optical type intrusion and/or fire-detection sensors to similarly protect various confidential areas including storage facilities and attendant personnel/equipment/data and the like whether of a military, industrial or commercial character.Each light projector device has an adjustable tubular shroud to adjustably focus the light beam cone angle. The desired cone angle of the light beam is initially set by use of associated system apparatus including an associated light beam calibration chart and some optional projector support stands.

Abstract: A portable lighting apparatus having a lamp assembly attached to the top of an elongated mast, preferably formed of interconnectable relatively short sections. The lamp assembly includes at least one electric lamp affixed to a horizontal shaft for rotation about a horizontal axis. Associated with the horizontal shaft are a pair of gears, suitably a vertical rack and a pinion engaged therewith, the pinion being operatively attached to the horizontal shaft. A spring associated with the pinion tends to rotate the gear in a direction which biases the engaged rack downwardly. The lower end of the rack abuts a movable pushrod generally centrally located within the hollow mast and running the length thereof. The lower end of the mast is telescopically mounted on a mast support provided with a fixed vertical stoprod which abuts the lower end of the pushrod.

Abstract: A panel includes a mirror surrounded on three sides by a generally U-shaped light source for providing illumination of the mirror for use as a vanity mirror under low ambient light conditions. The panel, in one embodiment of the invention is an integral portion of a body of a visor or a panel which is slidably extended from a visor. The U-shaped light and mirror panel can be pivoted when in an extended position such that the light and mirror can be utilized while the visor is in a raised, stored position or in a lowered use position. The panel is, in one embodiment, coupled to an X-shaped bracket with the legs forming the bracket pivotally coupled to one another. One end of each leg is pivotally coupled to one of an anchoring member or the visor panel and the opposite end pivotally and slidably mounted to one of the anchoring member or the visor panel.

Abstract: The present invention relates to auxiliary spotlights (headlamps) for automobile vehicles, for example fog and spot lamps. Such auxiliary spotlights generally comprise a sealed beam unit, i.e. a reflector-light source-glass assembly, housed in a casing forming a protective housing. A system of articulated assembly connects the casing to the automobile vehicle on which the spotlight is thus fixed by the outside.

Abstract: An apparatus containing a headlight gimballed for rotation within the enclosure of the apparatus. The headlight is capable of exposure through an opening in the enclosure, and is capable of directional adjustment in accordance with signals produced at a remote location. A cover is provided for selectively enclosing the opening which exposes the headlight, and is capable of selectively enclosing or exposing the opening in accordance with signals produced at a remote location.

Abstract: An annular illumination device comprising a tubular light transmitter, a light source means able to project parallel light rays onto an entrance end face of the tubular light transmitter from a direction intersecting diagonally with the entrance end face and a light collecting lens collecting conical light bundle coming out of an exit end face of the tubular light transmitter to form an image of an annular light in order to make it possible to make a bright efficient annular illumination. The angle formed by the parallel light rays with the entrance end face of the tubular light transmitter can be varied in order to vary the diameter of the image of the annular light.

Abstract: A headlight apparatus for a motorcar including a headlight and a mechanism for protruding and retracting the same above and below, respectively, the upper front portion of the car body. The mechanism includes a pair of parallel links on each side of the headlight pivotally attached at one end to the car body and at the other to the headlight, a crank having a pin and being driven by an electric motor and a connector connecting the pin to one of the pair of parallel links intermediate the ends thereof.

Abstract: A vehicle body taillamp assembly includes a taillamp finishing panel mounted to the rear end panel of a vehicle body and having spaced pintle portions in its upper edge. A taillamp structure fits within the finishing panel and includes hinge pins received through apertures in the hinge pintle portions to mount the taillamp structure to the finishing panel for movement between a closed position within the finishing panel and an open position outwardly and upwardly of the finishing panel wherein the housing reflector portion and the wiring to the bulbs with the housing reflector portion are exposed for servicing.

Abstract: A kinematic lamp mount for mounting a spectral source lamp (3) such as a hollow cathode lamp accurately with respect to an optical axis of, for example an atomic absorption spectrophotometer comprises a base member (100), a lamp holder (1) and two spring means (120, 121) which urge the holder (1) into contact with the base member (100). The holder (1) is provided with three ball ended feet (6,8,10) two of which (6,8) are adjustable. Two feet (6 and 10) engage in an arcuate V-groove (102) while the third engages in a radial V-groove (103) giving kinematic connection between the holder (1) and base member (100).By providing kinematic connection between the holder (1) and base member (100) the lamp holder (1) and hence the lamp (3) may be removed from and later replaced sufficiently accurately on the base member (100) that no re-adjustment is necessary.

Abstract: An improved shop light for being releasably mounted in a desired location for illuminating a work area. The shop light (10) comprises a handle member (12) provided with a light bulb socket (16) for releasably receiving a light bulb (18). Electricity for powering the light bulb (18) is supplied by a cord (20) received in handle member (12). A guard member (34) is releasably engaged to the handle member (12) in order to protect the light bulb (18) from damage. Magnetic mounting means (52) are provided for selectively mounting the shop light (10) on a metalic surface, such means being capable of selectively pivoting the shop light (10) to most desirably illuminate a preselected work area. The shop light (10) is further provided with a hook member (50) for hanging the shop light (10) at a desired location.

Abstract: An adjustable photographic light stand includes a base supported on rolling casters, and a column extending upwardly therefrom. An extendable boom arm is joined to the column by an adjustable carriage assembly which maintains the boom at any elevation along the column. A handle stored within the boom arm is extendable to raise or lower the carriage assembly and the boom arm. An L-shaped gimbal arm member is rotatably joined to the distal end of the extendable boom. A yoke member is rotatably joined to the distal end of the gimbal arm member, and is adapted to support a lamp head, X-ray unit, or the like. The yoke member provides rotational adjustment of the lamp head about two orthogonal axes, while the gimbal arm member provides for revolving adjustment about a third axis. The extendable boom arm provides lateral positioning of the lamp head, and the adjustable carriage assembly enables height adjustment of the unit.

Abstract: Disclosed is a lighting fixture which is primarily adapted for removable attachment to modular office furniture and for adjustable, substantially glare-free illumination of a work surface. The lighting fixture has a substantially elongated housing for a ballast, and a pair of holders for fluorescent tubes which are pivotably attached to a lower surface of the housing. A fastening device is attached to the housing which enables removable attachment of the lighting fixture to the underside of a shelf or the like, preferably without physically altering or changing the shelf. A channel shaped member having an upwardly open face is attached to and is disposed substantially along the entire length of the housing in order to unobtrusively accommodate at least a portion of a cable which connects the lighting fixture with an electric outlet. A user may adjust the positioning of each tube holder relative to the housing in order to obtain an optimal lighting effect on the work surface.

Abstract: A reflector for supporting a tungsten-halogen lamp assembly having a light bulb connected to a plurality of terminals. The reflector includes a parabolic section the rear central portion of which is integrally formed with a boss. At least two slots are formed in the boss for receiving the terminals, and each slot is located in a cavity which is adapted to be filled with an adhesive for fixing the terminals to the reflector after the lamp assembly is optically aimed.

Abstract: A flashlight has a battery housing and a head on which is mounted a bulb socket. Forwardly directed legs on the housing pivotally engage forwardly directed legs in the head so as swivelly to mount the head to the body.

Abstract: A boat light is especially adapted to be mounted upon the transom or stern of a cabin cruiser, speedboat, small yacht, or the like. A holder for a lamp unit has a spherically curved outer surface engaging a complementary inner surface of a housing attachable to the hull of the boat. The holder is universally adjustable to selected angular positions of adjustment relative to the housing. In a typical adjustment, the beam of the lamp unit may be projected horizontally despite the inclination of the transom from the vertical. In the selected position of adjustment, the tightening of screws by which the device is assembled and mounted on the transom is effective to preserve the lamp unit holder adjustment. This occurs when a shield closing the inner end of the housing is caused to bear against a rearwardly projecting surface of the holder. The holder, or at least the shield-engaging surface thereof, is of a deformable material.

Abstract: A portable auxiliary light having a case, a battery positioned within the case, and a light house on the end of the case. The light also has bellows interattaching the case and the light house and a related circuitry positioned in the case. The method for lighting includes locating the light behind a rear view mirror such that a recess in the case straddles the support post of the rear view mirror, and securing the light to the mirror. A switch on the case is activated to furnish lighting to the inside of the automobile.

Abstract: A flexible electric lighting strip is disclosed that can be utilized in various lengths, is capable of three dimensional movement, and provides evenly distributed illumination. The lighting strip is formed by an adhesive tape having a plurality of light emitting diodes thereon connected in parallel with each other with each light emitting diode being connected in series with a resistor also mounted on the tape.

Abstract: A retractable headlamp assembly for automobiles in which a headlamp, pivotally mounted on the automobile frame, is operatively coupled to the rotatable shaft of a motor by a link mechanism. The motor, operating through the link mechanism, is energizable to cause the headlamp to be moved angularly between a first position at which the headlamp projects out of the front hood of the automobile, and a second position at which the headlamp is retracted within the front hood. An adjustable stop is provided to stop the headlamp at the first position, which adjustable stop is adjusted to bring the first position into conformity with an angularly displaced position of the rotatable motor shaft, which is displaced through a slip angle from a normal stopping position. Such an arrangement assures that the headlamp can be stopped at a fixed position at all times for emitting a correctly directed beam of light irrespective of the varying positions at which the motor can stop.

Abstract: A height-adjustable support arm with a parallelogram linkage has a stationary first articulated head and a second articulated head which is movable relative thereto, the second articulated head having a support bar connected thereto for mounting a device such as a hanging lamp. In order to avoid gaps in the exterior portion of the second articulated head, the movable parts thereof are surrounded by a flexible covering mounted on a tubular parallelogram leg at one end and at the free end of the support bar at its other end. The exterior dimensions of the covering correspond substantially to the tubular parallelogram leg and the interior dimensions are selected such that the second articulated head can move freely therein within an adjustment range.

Abstract: A book-light characterized by its small size and light weight is formed from suitable plastic material with a base supporting a vertical lamp-bearing arm and an integral clamp consisting of a U-shaped frame having side arms rigidly attached to the base and a central plate flexibly attached to the base so that the entire book-light may be attached to a book or other publication by inserting the cover or pages between arms and the central plate. The vertical lamp-bearing arm is mounted at one end in a transverse slot in the base, while the other end supports the lamp proper in a manner to permit both circular and vertical motions.

Abstract: A retractable head lamp structure for automobiles in which a head lamp assembly is mounted on the automobile body for pivotable movement about a pivot axis between an extended position and a retracted position. In the retracted position, the lens surface of the head lamp assembly is located along the body surface. The pivot axis is inclined downwardly and rearwardly with respect to a horizontal transverse line as seen in transverse outward direction of the body so that the lens surface is substantially flush with the body surface in the retracted position.

Abstract: Safety lamp apparatus, suitable for use as a miner's cap lamp, includes a housing body closed at one side by a plastic light transmitting member. A bulb member is yieldably received in the housing body and is operable, when energized, to provide a filament in a state of incandescence for emitting visible radiation. During use of the apparatus in an explosive atmosphere conditions may arise where deformation of the light transmitting member from external impact forces directed thereagainst may drive deformed portions of the light transmitting member against the bulb member with sufficient force to cause bulb breakage and resulting explosion of the atmosphere.In the present invention protective means is provided comprising an arrangement of parts defining an oblique angular relationship between the central longitudinal axis of the bulb member and the impacting surface of the deformed portion of the light transmitting member.

Abstract: A solar simulator includes a lamp array of solar lamps pivotally connected to an array frame. The array frame is rotatably and pivotally mounted on a gantry crane, the elevation and lateral position of which are adjustable relative to the position of a solar collector to be tested. The solar simulator maintains the plane of the lamp array parallel to the plane of the test device for all elevations, lateral positions and rotational positions of the lamp array, and controls tilting of the lamps relative to the array frame to any desired angle of incidence. The solar simulator is operated to control the angle of incidence of radiation received by the solar collector to be tested and to vary the distance from the array of lamps to the solar collector in such a manner that the intensity of received radiation along the surface of the test device is uniform, thereby avoiding undesirable lateral gradients in temperature along the surface of the test device.

Abstract: A mobile lighting unit which includes a plurality of lighting fixtures, each utilizing high-wattage, high-intensity lamps. The fixtures comprise a socket and hemispherical reflector assembly which are vertically and horizontally adjustably mounted to a lighting rack by an adjustable elbow member. The lamps are positioned in said fixtures so that their longitudinal axis is parallel to the light beam formed by the reflector, requiring one end of the lamp to be inserted in the socket and the other end to extend to the center of the hemispherical reflector. The lamps are cooled by pressurized air produced by a fan and transported through air tight channels in the lighting rack. The lamps are shock-dampened by mounting their socket end to a metal spring located on the interior wall of the socket and by attaching wires to the front end of the lamp, which are in turn attached to metal springs on the interior surface of the reflector. Thus, the lamp is fully shock absorber protected.

Abstract: A control system for positioning a searchlight (2) in azimuth and elevation including an upper torque tube (34) and a lower torque tube (39) which are coupled together; an upper push rod (46), push rod coupling (50) and lower push rod (54) which are coupled together; and control elements (65, 90 & 93, 100) operative to rotate the lower torque tube and also operative to reciprocate the lower push rod.

Abstract: A spring clip which is removably attached to a retainer member for maintaining a headlamp within a housing and includes a pair of leg sections carried by the housing that cooperate with a flange on the retainer member for locking the retainer member to the housing.

Abstract: A high intensity lamp system for fireman's use and similar users provides a specially shaped base with an angle-adjustment of a reflector-equipped high intensity lamp extending from a junction box on the base; the base special shape includes at one end a "J"-section channel hook for hanging the system on a door or the like free of twisting; an arcuate cutout centrally in the edge of "J"-section channel hook provides for hanging the system on a nail or the like; at the opposite end of the base a planar projection of the base beyond the junction box provides for mounting the system by clamping or by slipping into a slot. The junction box receives a twist-lock type electrical supply plug in a socket for power input and provides two output sockets, eliminating need for extra extension cords. Special provisions permit adjusting the angle of the lamp head without danger of burning the hands of the user.

Abstract: A support housing for a vehicle headlamp that includes a pair of pivotally interconnected ring members adjustable about a pair of mutually perpendicular pivot axes by a pair of vertically oriented adjustment screws which are located to the rear of the headlamp and within the peripheral confines of the headlamp lens.

Abstract: A support housing for a vehicle headlamp that includes a pair of pivotally interconnected ring members adjustable about a pair of mutually perpendicular pivot axes by a pair of vertically oriented adjustment screws which are located to the rear of the headlamp and within the peripheral confines of the headlamp lens.

Abstract: A trunnion degree marker and reset stop for a luminaire indicating the angle of aim and providing a positive stop to facilitate resetting after service. It comprises a flat plate having a trunnion bolt hole, an arcuate slot around it with angle markings, and a screw extending therethrough for locking the plate to the trunnion bracket independently of the trunnion bolt. The plate has a foot protruding at an angle and turned toward the housing for engaging a shoulder stop cast as an integral part of the housing.

Abstract: Decorative lights are mounted on trees such as Christmas trees or the like by positioning a crown at the top of the tree with the crown including a closed loop collar to which a plurality of elongated tracks are pivotally mounted with a pulley associated with each track and being secured to the collar so that a string of lights may be guided by the track by use of a cord tied to the string and extending over the pulley.

Abstract: To permit adjustment and ready removal of a halogen lamp from an operating room light so that the halogen bulb (3) can be positioned with respect to a dome-shaped reflector (1) to control the light distribution therefrom while being readily removable for bulb replacement and cleaning, a pivot arm (5) is hinged at a circumferential point to the outer circumference of the reflector (1) and held in horizontally extended position across the reflector by a latch (16, 20; 18, 19, 19'; 21, 27). The other end of the latch is in engagement with a vertically positionable adjustment sleeve or rod (7) to adjust the position of the latch arm, and hence of the lamp bulb (3) with respect to the apex of the reflector (1) by pivoting of the pivot arm (5) about its pivot point (6) adjacent the circumference of the reflector. A plurality of such lamps may be combined in a common housing (H), and adjustment can be carried out conjointly, for example by a drive (11, 23) common to all the adjustment elements.

Abstract: A hanger arm mechanism to hold a lamp head vertically rotatably in dental lighting equipment is directed to a mechanism designed to rotate the lamp head around the axis shaftline of the hanger arm and to stop the same in a desired position, with the result that the field of lighting of the shadowless lamp mounted inside the lamp head can freely be changed in the range of rotation of the lamp head without making the patient turn his head.

Abstract: A precise lamp positioner for moving a lamp relative to a lens. The lamp is carried at one end of an L-shaped pivot plate which is pivoted at its corner to the free end of a pivot arm. The pivot arm is pivoted at its other end to a base. The pivot plate is pivoted about its pivotal connection at its corner by a plate position adjustment means. The pivot arm is pivoted about its pivotal connection to the base by an arm position adjustment means. By adjusting both adjustment means, the lamp position relative to the lens can be precisely set. The pivot plate also pivots about the pivotal connection at its corner so it can swing relative to the base to allow replacing the lamp if it fails.

Abstract: A lamp swivel composed of two main coaxial members, which are at least partially rotatable relative to each other. An inner pin extends from one member to a circular inner groove in the other member, the groove being coaxial with the members. However, the other member, usually composed of a metal such as brass, copper or aluminum which may be anodized, is coined so as to prevent egress of the pin from the groove. Thus the two members are semi-permanently attached to each other and can rotate, by less than 360 degrees, relative to each other. The invention is especially applicable to provide an articulated lamp mounting for a swing arm lamp or the like, the lamp swivel being a swivel connector or coupling means which provides an articulated mounting attachment for the lamp.

Abstract: This invention is a pivot mounting for a lamp (12) comprising a pair of journal bearings (30) and two parallel semi-circular springs (14, 16) urging the bearings towards one another, the bearings having gripping surfaces (56) for the mirror. The springs (14, 16) allow the bearings to be separated to admit the mirror which is then held by the resilience of the springs.

Abstract: This invention relates to a novelty or foldable toy light having an appearance similar to that of a switchblade knife. The light includes a housing with an extensible element which rotates from a position within the housing to a position extending away from the housing. A lamp within the extensible element powered by batteries within the housing illuminates the extensible element which is made of light conveying material. The lamp is activated by a rotary switch within the housing so that the extensible element is illuminated in response to outward rotation of the extensible element.

Abstract: A portable emergency lighting system includes a base that has an upwardly directed socket with a post adapted to be received in the socket and an elongated bar having a second socket received on the upper end of the post and having one or more lights supported thereon. The first socket on the base has a pin extending across the opening and the post has a plurality of angularly related recesses respectively adapted to receive the pin while the opposite end has a like number of angularly related recesses which are angularly offset from the lower set and cooperate with a second pin in the second socket so that the light can be held in a plurality of distinct positions on the upper end of the post for each distinct position between the lower end of the post and the base.

Abstract: A rectangular seal beam lamp and single-point universal support assembly for vehicles that is replaceable as a unit and that has high shock-absorbing characteristics. The lamp includes a rectangular plastic paraboloidal reflector having an integral single polygonal support post that carries a slotted rubber ball member which forms part of the mount for the lamp. The ball is compressed and clamped against the post by a pair of mating semi-spherical cooperating fastener elements that support the lamp unit and permit adjustment of the lamp beam in any direction by a single adjustment.

Abstract: A fairing and headlight assembly for a motorized two wheel vehicle is disclosed, in which the headlight is carried by a yoke which is removably received within grooves in a recess of the fairing and is detachably secured within the fairing by a single screw threaded member which extends to the exterior of the fairing through an aperture therein. The yoke carries a lamp-supporting gimbal mount which is separately adjustable about horizontal and vertical axes, movement of the gimbal about a horizontal axis being under the control of an adjustable member which extends to the exterior of the fairing through said threaded member.

Abstract: An adjustable lamp mounting assembly for two lamps 12, 12A, which are each connected to a body 10 by a pair of arcuate rods 14. The arcuate rods 14 of lamp 12 each fit snugly into one of a pair of slots 16 formed in a face 18 of the body 10. The rods are retained in the slots 16 against the ends of the slots by a single resilient spring strip 20, which lies on the opposite side of the face 18 to the lamp 12. The resilience of the spring strip 20 holds the arcuate rods 14 against the ends of the slots. The arcuate members 14 can slide in the slots 16, in the direction shown by arrow 26 to rotate the lamp 12. The arcuate rods 14 are connected to the lamp 12 by a pair of housings 22, and the lamp 12 is mounted to turn about bearings in the housings 22 about the pivot axis 24.

Abstract: A drive mechanism for revolving the turret of a searchlight assembly. The turret is rotated in an oscillating manner over an arc of less than 360.degree.. It is particularly characterized by smooth reversal allowing the driving of a high inertia turret without rapid motor overload and failure as characterized by other prior art methods of driving such mechanisms. A partial cylindrical track is concentrically disposed about the axis of rotation and attached to the turret. In the preferred embodiment, a link chain is welded along the bottom of the track, being folded back on the ends in a tear-drop shape. A drive sprocket on a swing arm is held into engagement with the chain and driven by a constant speed motor. The sprocket alternately drives along the inside of the chain and the outside of the chain smoothly traversing between the positions around the tear-drop ends to cause a smooth deceleration and acceleration.