Piston actuated lumbar stimulation device for a chair

A chair is disclosed including a seat and a back that is adapted to tilt back with the seat when a user of the chair leans back. A lumbar stimulation device having pairs of massage rollers is attached within the chair back to a gas cylinder bracket that extends vertically through the chair back for attachment to a chair base lying below the chair seat. A push-button actuated gas cylinder is connected to the gas cylinder bracket inside the chair back. A push-button located on one arm of the chair is connected to the gas cylinder by a cable. When the push-button is depressed, the gas cylinder is actuated to generate a pushing force for pushing the pairs of massage rollers of the lumbar stimulation device in a substantially horizontal direction through the chair back to apply a pressure against the user's back.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a piston actuated lumbar stimulation device that is located inside the back of a chair that rocks back and forth between upright and reclined positions as a user shifts his weight in the chair. The lumbar stimulation device is attached to a gas cylinder bracket that extends vertically within the back of the chair. A push-button controlled gas cylinder is attached to the gas cylinder bracket, and a retractable piston is forced outwardly from the gas cylinder to generate a pushing force for causing the lumbar stimulation device to move towards a user's back to apply a focused massage pressure thereto.

2. Background Art

An individual who is seated in a chair may wish to have a focused pressure applied from the back of the chair to a lower (i.e., lumbar) region of his back to enhance his comfort while seated. In addition to enhancing his comfort, applying a focused pressure to the lower back may stimulate or increase the circulation of blood flow. A conventional chair has no moving parts in the back and, therefore, is incapable of generating a focused pressure to be applied to the lower back of the seated individual. That is, because of the static nature of a typical chair back, especially those common to chairs having a back which reclines when the individual shifts his weight backwards, the individual may experience discomfort in his lower back when he remains seated for a long time. Although electrically powered external attachments are known to be used in combination with a chair back to massage an individual's back, such attachments are frequently expensive, require a source of electrical power to operate, and can become separated from the chair back and misplaced.

Therefore, what would be desirable is a chair having a back that tilts back when a user shifts his weight backwards and within which a lumbar stimulation device is located to apply a focused pressure to the user's lower back without first having to be attached to the chair back or operated from an electrical power source. What would also be desirable is to enable the user to selectively actuate the lumbar stimulation device by depressing a manually accessible push-button.

Reference may be made to my patent application Ser. No. 14/959,994 filed Dec. 4, 2015 for an example of a lumbar stimulation device that is located within the back of a chair and is capable of applying a focused massage pressure against the back of one seated in the chair.

SUMMARY OF THE INVENTION

In general terms, a piston actuated lumbar stimulation device is disclosed to be located inside the back of a chair that rocks back and forth between upright and reclined positions as a user shifts his weight back and forth in the chair. The lumbar stimulation device is capable of applying a focused pressure and improving the circulation of blood flowing through the lower back of the user seated in the chair and leaning backwards. The chair with which the lumbar stimulation device is associated includes a seat that is held above the ground by a base. A gas cylinder that extends between a gas cylinder receiver of the base and a seat plate at the bottom of the seat is operable to adjust the elevation of the seat above the base. The chair also includes a rigid (e.g., plywood) backing that runs through the rear of the chair back and a soft cover that lies opposite the rigid backing at the front of the chair back.

The piston actuated lumbar stimulation device that is located inside the back of the chair includes upper and lower roller carriages that are held one above the other by means of a pair of oppositely aligned carriage coupling plates. Each of the upper and lower miler carriages has a first pair of rollers at the top thereof and a second pair of rollers at the bottom. The upper and lower roller carriages are rotatable relative to one another to conform to the shape of the user's back. The lumbar stimulation device is also rotatable as a unit at an intermediate coupling rod that extends between the opposing carriage coupling plates. Upper ends of a pair of wheel positioning arms are pivotally coupled to the intermediate coupling rod, and the opposite lower ends of the wheel positioning arms are attached to wheels that lie against and roll on the rigid backing at the rear of the chair back.

A Y-shaped gas cylinder bracket extends vertically through the chair back so as to lie between the rigid backing at the rear of the chair back and the soft cover at the front. The bottom of the Y-shaped gas cylinder bracket is connected through the bottom of the chair back by an attachment strap to the gas cylinder below the seat of the chair. The top of the gas cylinder bracket is affixed to the intermediate coupling rod that extends between the carriage coupling plates of the lumbar stimulation device. Therefore, the position of the gas cylinder bracket and the lumbar stimulation device affixed thereto will remain substantially stationary in a vertical direction within the back of the chair. The top of a push-button controlled gas cylinder is connected to the pair of wheel positioning arms by means of a pin that runs through the gas cylinder and between the arms. A threaded retractable piston extends outwardly from the bottom of the push-button controlled gas cylinder to be connected to a gas cylinder support at the gas cylinder bracket. A push-button that is accessible to the user at one of the arms of the chair communicates with the gas cylinder by way of a cable.

When the push-button is depressed, the cable causes the piston to be forced outwardly and downwardly from the bottom of the push-button controlled gas cylinder against the gas cylinder support of the stationary gas cylinder bracket. The gas cylinder moves upwardly to cause a corresponding upward pushing force to be applied to the pair of wheel positioning arms. The wheel positioning arms are thusly rotated upwardly within the chair back and around the intermediate coupling rod to cause the pairs of rollers of the upper and roller carriages to be pushed in a substantially horizontal direction towards the soft cover at the front of the chair back so as to move into contact with the lower back of the user and apply a massage pressure thereto. When the user reclines in the chair and the seat and back tilt back with one another, the chair back will move downwardly relative to the lumbar stimulation device towards the chair base below the seat. Accordingly, the wheels carried by the pair of wheel positioning arms will roll on the downwardly moving rigid backing at the rear of the chair back so that the pairs of rollers of the upper and lower roller carriages of the lumbar stimulation device will appear to the user to be moving upwardly along his back.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially toFIGS. 1-5of the drawings, a preferred embodiment is described for a piston actuated lumbar stimulation device1for a chair in accordance with the present invention. As will soon be explained, the lumbar stimulation device1is capable of applying a focused pressure and improving the circulation of blood flowing through the lower back (e.g. the lumbar area) of one seated in a chair with which the lumbar stimulation device of this invention is associated. Thus, the well-being of the individual seated in the chair may be improved.

The chair3with which the lumbar stimulation device1is associated is preferably one that tilts as the user shifts his weight in the chair. The chair3is of the kind that would commonly be found in a home or office. As in many chairs, the chair3includes a seat5that is held above the ground by a base7having a set of legs9to which rollers10are attached to permit the chair3to be rolled over a flat surface. A gas cylinder12extends between a gas cylinder receiver14that stands upwardly from the base7and a seat plate16that lies below the seat5of the chair3. A lever arm (designated17and shown inFIG. 5) cooperates with the gas cylinder12to enable the elevation of the seat to be adjusted above the base7to suit the needs of the user. An adjustment knob18which is accessible below the seat plate16is rotated to adjust the spring tension of the seat5depending upon the size and the weight of the user.

The chair3also has a back20which stands upwardly from the seat5. The chair back20includes a rigid (e.g., plywood) backing22at the rear of the back20, intermediate filler material (not shown), and a soft (e.g., mesh-like) cover24at the front of the back20that lies opposite the rigid backing22. The back20is connected to the seat by a pair of arms (designated26and best shown inFIG. 5). As the user shifts his weight and leans back against the back20of the chair3, the seat5and back20of the chair will simultaneously tilt back and rotate around a pivot28that runs through the seat plate16. Thus, the chair back20rocks back and forth between an upright position shown inFIG. 1and a reclined position shown inFIG. 3depending upon whether the user shifts his weight backwards or forwards in the chair3.

The piston actuated lumbar stimulation device1of this invention is located inside the chair back20between the rigid backing22at the rear of the chair back20and the soft cover24at the front. Referring concurrently toFIGS. 1-5of the drawings, the lumbar stimulation device1is shown having an upper roller carriage30and a lower roller carriage32. The upper roller carriage30of the lumbar stimulation device1includes a first pair of (e.g., plastic) rollers34and35located at the top thereof and a second pair of rollers36and37located at the bottom. The first pair of rollers34and35are connected in spaced axial alignment to one another by a shaft38which extends therebetween. The second pair of rollers36and37are also connected in spaced axial alignment to one another by a shaft40which extends therebetween. A set of (e.g., hard plastic) nubs42projects outwardly from each roller34-37of the first and second pairs of rollers.

Like the upper roller carriage30, the lower roller carriage32of the lumbar stimulation device1includes a first pair of (e.g., plastic) rollers44and45located at the top thereof and a second pair of rollers46and47located at the bottom. The first pair of rollers46and47are connected in spaced axial alignment to one another by a shaft48. The second pair of rollers46and47are also connected in spaced axial alignment to one another by a shaft50which extends therebetween. A set of (e.g., hard plastic) nubs52projects outwardly from each roller44-47of the first and second pairs of rollers.

As is best shown inFIG. 4, the first pair of rollers34and35at the top of the upper roller carriage30is held above the second pair of rollers36and37at the bottom by a pair of opposing side plates54and58that extend therebetween. That is, first ends of the shafts38and40of the rollers34and36are rotatably coupled to respective opposite ends of one side plate54, and the opposite ends of the shafts38and40of the rollers35and37are rotatably coupled to respective opposite ends of the other side plate55. In this manner, the first and second pairs of rollers34,35and36,37of the upper carriage assembly30are adapted to rotate with one another relative to the opposing side plates54and55in response to a rotational force applied to the rollers34-37.

The first pair of rollers44and45at the top of the lower roller carriage32are held above the second pair of rollers46and47by a pair of opposing side plates58and59that extend therebetween. That is, first ends of the shafts48and50of the rollers44and46are rotatably coupled to respective opposite ends of one side plate58, and the opposite ends of the shafts48and50of the rollers45and47are rotatably coupled to respective opposite ends of the other side plate59. In this manner, the first and second pairs of rollers44,45and46,47of the lower roller carriage32are adapted to rotate with one another relative to the opposite side plates58and59in response to a rotational force applied to the rollers44-47.

The upper and lower roller carriages30and32of the lumbar stimulation device1are interconnected and held one above the other by a pair of oppositely aligned carriage coupling plates62and63that are located at opposite sides of the device1. That is, one end of an upper coupling rod66runs through one of the side plates54of the upper roller carriage30(so as to lie between the first and second pairs of rollers34,35and36,37thereof) and the top of a first of the pair of carriage coupling plates62. The opposite end of the upper coupling rod66runs through the other side plate55of the upper roller carriage30and the top of the opposite one of the pair of carriage coupling plates63. One end of a lower68coupling rod68runs through one of the side plates58of the lower roller carriage32(so as to lie between the first and second pairs of rollers44,45and46,47thereof) and the bottom of the first carriage coupling plate62. The opposite end of the lower coupling rod68runs through the other side plate59of the lower carriage assembly30and the bottom of the opposite carriage coupling plate63.

An intermediate coupling rod70extends between the pair of oppositely aligned carriage coupling plates62and63so as to lie between the upper and lower roller carriage30and32. By virtue of the opposing carriage coupling plates62and63and the upper, lower and intermediate coupling rods66,68and70that extend therebetween, the upper and lower roller carriages30and32of the lumbar stimulation device1are adapted to rotate relative to one another at the upper and lower coupling rods66and68. Likewise, and to provide one seated in the chair3with maximum lumbar stimulation, the upper and lower roller carriages30and32are also adapted to rotate together as a unit at the intermediate coupling rod70depending upon the forces that are applied to the lumbar stimulation device1. In this manner, the roller carriages30and32can be positioned within the chair back20to conform to the shape of the back of the user seated in the chair.

As is also best shown inFIG. 4, the lumbar stimulation device1includes a pair of wheel positioning arms72which lie within the chair back20between the pair of side plates58and59of the lower roller carriage32. The tops of the wheel positioning arms72are pivotally coupled in surrounding engagement with the intermediate coupling rod70that extends between the oppositely aligned carriage coupling plates62and63. A wheel74is rotatably coupled to the bottom of each wheel positioning arm72. As will soon be disclosed, depending upon a gas cylinder generated pushing force to be applied thereto, the wheel positioning arms72are adapted to rotate around the intermediate coupling rod70to correspondingly cause the lumbar stimulation device1to move through the chair back20and towards the back of the user.

To this end, and continuing to refer toFIGS. 1-5of the drawings, a flexible, generally Y-shaped gas cylinder bracket78is shown located between the piston actuated lumbar stimulation device1within the back20of the chair3and the bottom of the seat5of chair3. As is best shown inFIGS. 1-3, the gas cylinder bracket78runs vertically through the chair back20alongside the rigid backing22. Located below the seat plate28of the chair3is a relatively stiff attachment strap80. One of the attachment straps80is connected to the base7below the seat5of chair3in surrounding engagement with the gas cylinder12. The opposite end of the attachment strap80turns upwardly above the chair seat5so as to be connected through the bottom of the chair back20to the bottom of the Y-shaped gas cylinder bracket78by which the bracket78is held in place within chair back20.

As is best shown inFIG. 4, the top of the Y-shaped gas cylinder bracket78includes a pair of upstanding spaced, parallel aligned bracket arms82that lie within the chair back20between the rigid backing22and the soft cover24. The bracket arms82are affixed (e.g., welded) to the intermediate coupling rod70that extends between the carriage coupling plates62and63at opposite sides of the lumbar stimulation device1. Thus, the lumbar stimulation device1is held in place within the chair back20by the connection of the bracket arms82to the intermediate coupling rod70. The spaced bracket arms82run downwardly through the chair back20and come together at a point where the top and the bottom of the Y-shaped gas cylinder bracket78join one another.

Located adjacent the point where the bracket arms82at the top of the gas cylinder bracket78join the bottom of the bracket is an outwardly (i.e., forwardly) extending gas cylinder support84. A push-button controlled gas cylinder86is connected to the gas cylinder bracket78at the gas cylinder support84thereof. The gas cylinder86is also connected to the pair of wheel positioning arms72to impart an upward pushing force thereto for causing the lumbar stimulation device1to be moved in a generally horizontal direction through the back20of the chair3and towards the back of one seated in the chair so that the rollers34-37and44-47of the upper and lower roller carriages30and34of device1will press against and roll on the user's back to apply a focused massage pressure thereto.

The push-button controlled gas cylinder86is conventional, and the operation thereof is similar to the operation of the gas cylinder12that is located below the seat plate16to elevate the seat5of the chair3. Referring now toFIGS. 5-9of the drawings, the gas cylinder86is shown having a tubular body88that is pressurized by air. A threaded retractable piston90extends outwardly from the bottom of the tubular body88to be fixedly attached to the gas cylinder bracket78at the gas cylinder support84thereof. The top of the tubular body88of gas cylinder86is received between and coupled to each of the pair of wheel positioning arms72by means of a pin92that runs through the cylinder body88and between the arms72.

As is best shown inFIG. 5, a push-button94is accessible to the user seated on the chair3. By way of example, the push-button94is mounted on one of the arms26at one side of the seat5of chair3. The push-button94communicates with a switch valve96of the push-button controlled gas cylinder86(best shown inFIGS. 6 and 7) by way of a cable100that runs through the chair arm26and into the chair back20. When the user depresses the push-button94, the cable100, which is coupled to the pressurized gas cylinder86by way of the switch valve96, causes a pin (not shown) to be displaced, whereby the retractable piston90is forced outwardly and downwardly from the bottom of the cylinder body88.

FIGS. 1 and 6show the piston actuated lumbar stimulation device1at rest with the back20of the chair3tilted forward and standing erect prior to the depression of the push-button94(ofFIG. 5). The piston90is retracted within the cylinder body88, and the lumbar stimulation device1is spaced rearwardly from each of the soft cover24at the front of the chair back20and the back of the user seated on the chair. InFIGS. 2 and 7, with the chair back20still tilted forward and standing erect, the push-button94is now depressed. Accordingly, the piston90is forced outwardly from the tubular body88of the gas cylinder86, and the pair of wheel positioning arms72rotate upwardly and around the intermediate coupling rod70so that the lumbar stimulation device1is pushed towards the soft cover24and pressed against the user's back.

More particularly, and as was previously described, the piston90is fixedly connected to the Y-shaped gas cylinder bracket78at the gas cylinder support84thereof. The gas cylinder bracket78, which stands upwardly and is held in place within the chair back20by its attachment to the gas cylinder12at the chair base7below the chair seat5by way of the attachment strap80(ofFIG. 2), remains at all times substantially stationary in the vertical direction within the chair back20. Likewise, the lumbar stimulation device1which is connected to the top of the gas cylinder bracket78(at the intermediate coupling rod70) remains substantially stationary within the chair back20in the vertical direction. As the piston90is driven outwardly and downwardly from the bottom of the cylinder body88, an opposite upward driving force causes the cylinder body88to move upwardly towards the pair of wheel positioning arms72. Thus, a linear pushing force is applied from the top of the cylinder body88to the wheel positioning arms72at the pin92that extends through the cylinder body88and between the wheel positioning arms72. The wheel positioning arms72are therefore caused to rotate (in the direction of the reference arrow98ofFIG. 7) upwardly and around the intermediate coupling rod70.

Accordingly, the wheels74that are carried at the bottoms of the wheel positioning arms72are pushed against the rigid backing22at the rear of the chair back20. At the same time, the upper and lower roller carriages30and32of the lumbar stimulation device1that are coupled to the top of the wheel positioning arms72at the intermediate coupling rod70are pushed in a substantially horizontal direction towards and against the soft cover24at the front of the chair back20at which to engage the user's back and apply a focused pressure thereto.

When the user shifts his weight and leans back against the back20of the chair3(best shown inFIG. 3), the back20and seat5of chair3tilt back with one another around the pivot28through the seat plate16below seat5. In this regard, the back20and the seat5will remain aligned perpendicular to one another whether the chair back20is tilted forwards or backwards. As the chair back20tilts back, the flexible gas cylinder bracket78is bent back. The force generated by the user's back will cause the chair back20to be pushed downwardly towards the chair base7. In other words, the rigid backing22and the soft cover24of the back20of the chair3will move downwardly together relative to each one of the substantially stationary (in the vertical direction) gas cylinder bracket78and the piston actuated lumbar stimulation device1that is attached to the bracket78within the chair back20at the intermediate coupling rod70that extends between the oppositely aligned carriage coupling plates62and63.

In this case, the wheels74that are carried at the bottoms of the wheel positioning arms72will roll on the rigid backing22which moves downwardly with the chair back20when the user leans back in the chair3. Although the rollers35-37and45-47of the upper and lower roller carriages30and32of the lumbar stimulation device1are held within the chair back20by the stationary gas cylinder bracket78and do not actually move in the vertical direction, it will appear to the user as if the rollers35-37and45-47are otherwise moving upwardly along his back to enhance his comfort.

As was explained above, when the chair back20stands erect and the user depresses the push-button94so that the pressurized air within the body88of the gas cylinder86is released to cause the retractable piston90to move outwardly and downwardly from the cylinder body88, the lumbar stimulation device1is moved horizontally towards and against the back of the user. When the chair back20tilts back, the user can once again depress the push-button94as his back moves rearwardly and pushes against the upper and lower roller carriages30and31of the lumbar stimulation device1by which the gas cylinder86will be recharged (i.e., repressurized) with air and the retractable piston90thereof will be retracted inwardly of the piston body88.

It may be appreciated that the position of the rollers35-37and45-47of the upper and lower roller carriages30and32within the chair back20as well as the pressure being applied by the lumbar stimulation device1against the back of the user can be selectively controlled depending upon the time during which the push-button94is depressed and the upward travel of the body88of the push-button controlled gas cylinder86. That is to say, as long as the push-button94is depressed, the piston90will continue to be pushed outwardly and downwardly from the cylinder body88, and the pair of wheel positioning arms72will continue to be rotated upwardly for causing the lumbar stimulation device1to be advanced towards and into contact with the back of the user.