Caster-borne step stool with positionable lights and rechargeable battery

A step stool with positionable lights and a rechargeable battery is carried upon retractable casters for suitable positioning and utility. A motion and timer switch is interposed between the battery and the positionable lights to allow the positionable lights to be illuminated only for a fixed period of time following movement of the step stool. The lights may be positionable as by adjustable brackets or by a cord reel assembly. The step stool has contact bands thereabout that are adapted for engagement with contacts in a charging station that is specifically configured to receive the step stool. Receipt of the step stool by the charging station activates a battery charger that serves to charge the battery of the step stool thereafter. A solenoid switch disconnects the lights of the step stool upon commencement of the charging operation.

TECHNICAL FIELD

The present invention generally resides in the art of step stools and lighting devices. In particularly preferred embodiments, the present invention resides in the art of caster-borne step stools and lighting devices.

BACKGROUND OF THE INVENTION

Step stools are well-known and are employed for various reasons in both domestic and industrial settings. In the broadest sense, a step stool can be virtually any readily portable physical structure that can rest on a horizontal or ground surface and provide a support surface raised from the ground surface at a distance suitable for stepping up to the support surface. There are many physical structures that can provide such a support surface.

To improve the utility of the basic step stool, many manufacturers have designed their step stools with auxiliary features. For instance, some step stools provide an intermediate support surface that is maintained below the main support surface. Such an intermediate support surface could be used as an aid to reaching the higher elevated main support surface, or the intermediate support surface could serve as a platform of support when the additional height provided by the main support surface is not needed. Some step stools are designed to fold to a storage position to increase portability and facilitate storing the stool. Yet others include tool box type compartments to increase the utility of the step stool. Clearly, in the step stool arts, there is a drive to increase the utility of the step stool so that it does more than simply provide an elevated support surface to stand upon.

A particularly desirable type of step stool, especially in industrial settings, includes retractable casters. The step stool rides on spring-loaded casters, wherein the springs are sufficiently strong to force the base of the step stool off of the ground surface so that the step stool may ride on the casters, but are sufficiently weak so that, when an individual steps onto or sits upon the step stool, the lift of the springs is overcome and the base of the step stool engages the ground surface to remain stationary and provide a stable support. Such step stools may be moved simply by pushing them along the ground with one's foot, eliminating the need to bend down and pick up the step stool to place it where it is needed. A step stool of this type is produced by Cramer, Inc., under the brand name Kik-Step®. In industrial settings, such a step stool can be kicked around the work area, allowing the worker to carry additional needed items in his hands.

In many industrial or service settings, step stools are employed to aid a worker in reaching and working on a workpiece. For example, a mechanic may employ a step stool to stand on to work on portions of a car supported on a hydraulic lift. The mechanic may choose to sit on the stool while working on other parts of the car, such as the wheels and brakes, with the car only slightly elevated on the lift. In any event, for the example given, the need for additional or focused light on the work area of the car is always problematic. The present invention seeks to improve the common step stool for such applications, although it will be appreciated that the applications for the step stool disclosed herein are not limited to such industrial settings. Moreover, the invention herein is also directed to transportable and positionable lighting devices to illuminate work areas.

SUMMARY OF THE INVENTION

The present invention seeks to increase the utility of the common step stool. More particularly, the present invention incorporates at least one light source into a step stool design. In particularly preferred embodiments, the light source is powered by a rechargeable power source retained within the step stool. In yet other embodiments, the rechargeable power source can be recharged at a charging station. In particularly preferred embodiments in accordance with the best mode of this invention, the step stool rides on casters and may simply be rolled along the ground surface into the charging station. The step stool may also be rolled into a desired location, and the light adjusted, so that adequate light is available for the area being worked upon, while providing a surface for sitting or standing, as desired.

Thus, the present invention provides a step stool comprising a base, a support surface, a light source, and a rechargeable power source retained within the base and powering the light source.

In accordance with a particular embodiment, the light source is secured to the step stool in a manner that permits selective positioning of the direction of illumination provided by the light source. In other embodiments, multiple light sources are provided, preferably with each being selectively positionable to change the direction of illumination.

In some embodiments, the lights are enabled by movement of the step stool, and remain so enabled for a set period of time in the absence of subsequent movement.

In some embodiments, the rechargeable power source retained within the base can be recharged by contacting external charging contacts on the step stool with complimentary charging structures at a charging station. In particularly preferred embodiments, these recharging means may be employed without the need for positioning the step stool relative to the charging station in a specific mating orientation.

In certain embodiments, the lights are disabled during any period of recharging of the power source.

In other embodiments, the step stool feature of the invention is abated, and the invention is directed to a transportable lighting device for illuminating work areas.

PREFERRED EMBODIMENT FOR CARRYING OUT THE INVENTION

Referring now toFIGS. 1 and 2, a preferred embodiment for a step stool in accordance with this invention is shown and designated by the numeral10.FIG. 2is slightly different thanFIG. 1in that a particular light source has been removed inFIG. 2. It will be appreciated that this helps demonstrate that the present invention is concerned with the provision of at least one, and not necessarily two, three, or more light sources in a step stool.

Step stool10includes base12, which is elevated off of ground surface G and supported by spring-loaded retractable casters14. Generally, at least three casters14would be provided, to effect a stable three-point support system. In the present invention, base12is circular, and three casters14are positioned at points of an equilateral triangle to provide adequate support. Additional casters may be employed, if desired, or if base12takes a different configuration.

Retractable casters are well known, and include biasing means16secured between the axle brackets18for wheels20and a stationary caster support22secured to base12. Biasing means16exerts a force on axle bracket18and, thus, wheel20, to lift base12on stationary caster support22, to raise bottom edge24of base12off of the ground surface G. Thus, base12, and the entire step stool10, can freely ride on the ground surface on retractable casters14. However, when sufficient force is applied downwardly on base12, the force of biasing means16is overcome, and bottom edge24contacts ground surface G, making step stool10stationary so long as the downward force on step stool10remains. Such a step stool may be moved to a desired location simply by kicking or pushing it along the ground, allowing it to roll on the retractable casters. This function is particularly useful in an industrial or shop setting. Additionally, it is particularly useful in the present invention, wherein additional elements added to the step stool increase its weight beyond that which is practical for carrying the step stool to the desired location.

A plurality of supports26extend upwardly from base12to a primary support surface28, and maintain primary support surface28above and substantially parallel to ground surface G at a height that is suitable for common step stool embodiments. The desired height for primary support surface28may be tailored to any desirable height for a given step stool, and the present invention is not limited to or by any particular dimensions. In this particular embodiment, supports26extend between primary support surface28and intermediate support surface30, which may be considered as the top surface of base12. Intermediate support surface30can serve as an intermediate step for accessing primary support surface28, or may serve as the support surface employed when the extra height offered by supports26and primary support surface28is not needed.

Base12houses a battery32that serves to power light sources. In the embodiment ofFIG. 1, three light sources are shown, including first light source34, second light source36(not shown inFIG. 2) and remote light source38. Each of these light sources is electrically connected to battery32by appropriate wiring. The wires associated with first and second light sources34and36are designated by the numerals40and42, respectively. Remote light source38is connected to battery32through wire44. Before connecting to light source38, wire44winds around a retractable spool46so that light source38may be extended away from step stool10by pulling a desired length of wire44off of retractable spool46. Retractable spool46is preferably configured to retract automatically, as known in the spool arts, and stopper48is provided on wire44between light source38and spool46to limit the extent to which wire44is drawn into spool46. A separate switch, such as switch50, is associated with each light source. Here, switch50is shown associated with light source34, and this switch serves to turn light source34on and off. A similar switch would be provided for light source36. Light source38carries a switch52on a handle portion54thereof.

Light sources such as light sources34and36may be secured to step stool10in fixed position and orientation, but may also be secured to step stool10in a manner that permits selective positioning of the direction of illumination provided by the light sources. InFIG. 1, it can be seen that light source36is secured to a movable toothed cam56that rotates relative to and selectively engages stationary tooth cam58. The teeth of these respective cams are caused to engage each other through the tightening of bolt60. Bolt60may be loosened so that the teeth on movable tooth cam56may be disengaged from the teeth on stationary tooth cam58and light source36may be pivoted around the axis of cams56,58. When the desired radial position is achieved, bolt60may be tightened to re-engage the teeth of the cams and secure light source36in a desired position. Thus, the interaction of cams56and58allows one to reorient the direction of illumination of light source36in a first, here vertical, plane. Light source34is secured to step stool10through a similar movable cam, stationary cam, and bolt mechanism, designated by the numeral62inFIG. 1. The cam and bolt mechanism62is secured to a movable post64that rides on and rotates relative to a support post66that is secured to step stool10at the support26shown. Wire40feeds up along support26and into support post66and movable post64. It will be appreciated that movable post64rotates relative to support post66to reorient the direction of illumination of light source34in a second plane that is substantially normal to the plane of movement established by cam and bolt mechanism62. Together, movable post64and cam and bolt mechanism62allow light source34to be positioned to direct its illumination in almost any given direction.

Remote light source38preferably includes at least one hook70for hanging remote light source38at a desired location. In the embodiment shown, light source38further includes a second hook72, provided for the same reason. In the particularly preferred embodiment, supports26include at least a metal portion, and light source38includes a magnet74that can be used to secure light source38to step stool10, at that metal portion. It will be appreciated that, as shown, light source38is a retractable work light or “trouble light.”

As mentioned above, the invention also contemplates the inclusion and utilization of fixed lights in place of, or in addition to, adjustable lights. In that regard, lights34,36of the unit10may be fixed as to position and orientation. Any number of lights may be employed as a bank of fixed lights to provide illumination to a desired work region or area. A single fixed light may be used where the routinely encountered work area is specific and finite, while a bank of such lights may be used where a flood light effect is desired.

As mentioned, base12retains battery32, for powering the various light sources that may be employed in accordance with this invention. Preferably, battery32is rechargeable, particularly without having to remove battery32from step stool10. This is achieved by operatively connecting battery32to external charging contacts on step stool10. Here, as shown inFIGS. 1 and 3, external charging contacts are generally shown and designated by the numeral80. External charging contacts80include a positive conductive band82and a negative conductive band84.

With reference now toFIGS. 3 and 4, an appreciation can be obtained of the circuitry and associated elements of the step stool10. As shown therein, a charging station108is provided to nestingly receive the step stool10to effect the charging of the battery32. A charger92is received within the charging station108, and may be of any of various types, suitable for recharging a battery. Typically, the charger92would comprise an AC to DC converter suitable for providing a charging current to batteries of the type employed. The charger92has an electrical plug94adapted to engage a jack96that is interconnected with a wall plug102through an appropriate contact switch98having a switch arm100. Those skilled in the art will readily appreciate that the wall plug102is adapted for connecting to any appropriate AC power source. Actuation of the switch arm100closes the switch98to activate the charger92, as will be readily understood by those skilled in the art.

The positive output terminal of the charger92is connected to a spring biased contact104, while the negative terminal of the charger92is connected to a spring biased terminal106. The terminals104,106are positioned to make contacting engagement with respective positive and negative conductive bands82,84of the charging contacts80that are circumferentially provided about the base12of the step stool10. Accordingly, when the step stool10is nestingly received in the arcuate opening124of the charging station108, the contacts104,106are positioned to respectively engage the bands82,84which, as shown inFIG. 3, are respectively provided in contact with the positive and negative terminals of the battery32.

With particular reference now toFIG. 3, an appreciation of the battery charging and operational circuitry90of the step stool10can be obtained. As shown, a series of light emitting diodes110, interconnected with respective current limiting resistors112, are interposed between the bands82,84and positive and negative terminals of the battery32. Accordingly, because of the presence of the blocking diode114, the light emitting diodes110illuminate only when the step stool10is nestingly received by the charge station108such that the charger92is activated to place a voltage potential across the bands82,84and, accordingly, across the terminals of the battery32. The light emitting diodes110are, as shown inFIG. 1, uniformly spaced about the periphery of the base12of the step stool10for ease of observation. Accordingly, the user of the step stool10can visually determine that the battery32is being recharged.

A solenoid switch116is interposed across the bands82,84such that, in the charging mode, the solenoid switch116, which is a normally closed switch, is opened to disconnect power to the lights34,38as shown inFIG. 3. Accordingly, while the battery32is being charged, there is assurance that the battery is not being drained by the lights, which are disabled by the switch116.

Interconnected across the terminals of the battery32is a motion switch118and a timer switch120. The motion switch118is closed upon sudden movement of the step stool10and serves to apply power to the timer switch120. Accordingly, when a user moves the step stool10, the motion switch118actuates the timer switch120to begin a time period of, for example, 15 minutes. The timer switch120stays closed for that period of time. If no further movement is made of the step stool10during that period of time, the switch120opens at the end of that time period, preventing the user from inadvertently leaving any of the lights on for a substantial period of time while they are not required, thus draining the battery32. Any appreciable movement of the step stool10, however, serves to actuate the motion switch18and reset the timer switch120, such that the lights34,38are available as needed. In the event the lights are left on for a period of time sufficient for the timer switch120to time out and open, any jarring or movement of the step stool10will cause the motion switch118to actuate and reset the timer switch120to again enable the lights by closing the line of power to the lights.

It will be appreciated, as shown inFIG. 3, that the light34has an associated switch50, while the trouble light38has an associated switch32and cord reel46. In the preferred embodiment, additional lights, such as the light36, may also be employed. However, for purposes of simplicity, only the lamp34and associated switch50has been shown. Additional lights, such as the light36and associated switch can be place in parallel with the light and switch34,50, as will readily be appreciated by those skilled in the art.

As shown inFIG. 4, the charging station108has an arcuate opening124of a curvature consistent with the base12of the step stool10, and with the spring biased contacts104,106extending in alignment with the respective bands82,84, about the base12of the stool10. Also received within the arcuate opening124is a spring loaded arm122which is actuated by the base12when it is pushed into the opening124. The spring loaded arm122is positioned to make contacting engagement with the contact switch arm100of the contact switch98such that the battery charger92is turned on only when the step stool10is received within the opening124such that contacting engagement is made between the bands82,84and the spring biased contacts104,106.

It should now be appreciated that, with the step stool10having a rechargeable battery32therein, the user may employ various lights, both stationary such as the lights34,36or movable such as the light38, to illuminate a work area of interest. The lights34,36may be adjusted from horizontal to vertical, and any position in between, to illuminate, for example, the brakes of a car or its undercarriage and exhaust system. The lights are enabled by means of a motion switch118which energizes a timer switch120to allow for continued use of the lights during a period of time established by the timer switch120. Each time the motion switch118is activated, the time period of the timer switch120is begun anew. Light emitting diodes110indicate sufficient contact engagement between the contacts104,106and bands82,84to effect the desired charging of the battery32. In standard fashion, the charger92may be of the type that automatically terminates application of power to the output terminals of the charger when charging is complete. At such time, the light emitting diodes110will turn off, indicating that the battery32has been fully charged.

Not only does the step stool10provide desired positionable light for a work area, but it also continues to serve as a place on which a worker can sit or stand, as desired, to perform a work function. The lights are peripherally positioned so as not to interfere with that function.

In light of the foregoing, it should thus be evident that the structure of the present invention, provides a substantial improvement in the art. While the invention has been presented and described with regard to a step stool, the concept of the invention is not so confined. The invention extends to a transportable temporary light source that may be employed to illuminate any of numerous work areas, as small as the brake assembly on the wheel of an automobile, or as large as the interior of a building under construction. While, in accordance with the patent statutes, only the preferred embodiments of the present invention have been described in detail hereinabove, the present invention is not to be limited thereto or thereby. Rather, the scope of the invention includes all modifications and variations that fall within the scope of the attached claims.