WO2001017398A1

WO2001017398A1 - Adjustable back support device

Info

Publication number: WO2001017398A1
Application number: PCT/US2000/023648
Authority: WO
Inventors: John M. Sundheim; Greg S. Sundheim
Original assignee: Ourbod Research Corporation
Priority date: 1999-09-10
Filing date: 2000-08-29
Publication date: 2001-03-15
Also published as: AU7084100A

Abstract

The adjustable back support device (20) has a generally U-shaped base (22) and a pivoting back portion (24) which can be adjusted to a forward/upright position, a backward/reclining position and any angle of inclination thereinbetween. An adjustment and retaining mechanism connects the base and the back portion to permit adjustment to and/or retention in a desired position and includes an inflatable bellows (28), a forward biasing spring (34, 35), an airflow passageway (33) and an airflow activating valve assembly (56). When the valve assembly activates the airflow, the forward biasing spring forces the back portion (24) to a forward position in the absence of any counter force. When the valve assembly is activated simultaneously with a user-applied backward force on the back portion, the back portion pivots to a backward position.

Description

ADJUSTABLE BACK SUPPORT DEVICE

This invention relates to devices that support a person while sitting or reclining. More particularly, the present invention relates to a new and improved apparatus for comfortably supporting a person's back while sitting on a surface such as a floor, a lawn, a bed mattress or other relatively flat surface. The apparatus is easily and quickly adjustable by the user in a range of angles of reclination.

Background of the Invention Seating comfort is a major concern of many people. Thus, many furniture pieces are designed with a wide variety of features developed for the comfort of the user, such as backrests, armrests, lumbar supports, footstools, the padding arrangements on each of these features, and many others. The number and variety of such furniture pieces have grown around the desire for comfortable furniture in a wide variety of situations and physical needs. For the convenience of a user, some of these pieces involve only a back support, a kind of "pseudo- chair," that is primarily only the backrest portion of a chair. Some of these back support devices can be transported to and set up at almost any place, so the user can sit and rest or recline comfortably on a relatively flat surface, such as the floor in a living room, a lawn at an outdoor concert, a mattress on a bed, the sand at a beach, or other place where there is normally no comfortable support for a person's back when sitting or reclining.

The variety of back support devices ranges from simple ergonomically- shaped pillows to complex mechanical devices having various levers, braces, hinges, support webbing and/or padding, and a wide assortment of adjustment and position-locking components. The adjustability of these devices significantly impacts on comfort and convenience for a user who may want to shift positions while using the device. Also, the ease of adjustment or use, convenience of storage or setup, and ease of lifting or transporting are important considerations relating to the portability and use of the device. Adjustability typically involves, among other possible features, a forward and backward tilting of the back support portion of the device to one or more desired positions. Many back support devices incorporate adjustment mechanisms that permit positioning of the back support portion in only a few discreet angles of inclination, thereby considerably limiting the adjustability. Many of these devices further require that the user get up from the device and manipulate the adjustment mechanism in order to change the inclination of the back portion. Thus, the device may be difficult or frustrating to use in addition to having limited adjustability. Other back support devices incorporate adjustment mechanisms that permit the position to be continuously variable, thereby providing greater adjustability. These devices, however, may involve electro-mechanical apparatus, such as pumps for pneumatic devices or motors for other assemblies, to perform the adjustments. Thus, although these types of devices may be easy to use due to the automation, they are expensive and prone to breakdown. Additionally, they can be bulky and heavy, so they cannot be easily lifted or transported and may not collapse to a conveniently small configuration for easy storage and may require lengthy assembly and setup procedures. Other back support devices with continuously variable positioning may involve manual-manipulation of the back portion which is inconvenient to perform. Some continuously adjustable back support devices incorporate an inflatable bag, bladder or bellows to make the adjustments. The adjustment mechanism is inflated and deflated to raise and lower, or pivot back and forth, the back portion. Inflation is performed by pumping air into the inflatable member with an external electro-mechanical pump or hand pump or by manually lifting up on the back portion to extend the inflatable member. Thus, the inflatable devices require the expense, bulk or inconvenience of the means for inflating them, requiring tradeoffs between ease of use and ease of storage, lifting, setup or transport. Additionally, the bag or bladder types of inflatable devices tend to bulge outward, unless restrained, resulting in a very inefficient use of the air pressure used to inflate the device and tilt the back portion.

It is with respect to these and other considerations, that the present invention has evolved. Summary of the Invention One of the improvements available from the present invention involves a comfortable and adjustable back support device that is easy to adjust back and forth, does not incorporate expensive or bulky adjustment mechanisms, is collapsible to a convenient storage configuration, is relatively lightweight for lifting and carrying and permits simple and quick setup. A consequence of the ease and convenience of transporting, setting up and adjusting the device is that the user may have a comfortable back support in almost any situation at almost any time. For example, when a person is hosting a party and there are insufficient chairs for the guests, the back support device may be brought out of storage and quickly set up to provide the guest with a back support that is adjustable to his or her most comfortable position. Likewise, a person who wants to sit up and read or watch television in bed may slide the back support device out from under the bed, where it may be conveniently stored, and quickly set it up on the bed mattress. Additionally, the back support device can be easily carried to a park or beach and quickly set up on the grass or the sand. The back support device can be quickly and easily adjusted to a reclined position for relaxing or sunbathing, or to a more straight-up position for reading or watching television, or to any angle of reclination desired by the user. The back support device includes a base, a back portion and an adjustment mechanism connected there between. The back portion is hinged to the base for adjustability in forward and backward pivoting or tilting movement. The base has a closed rear portion and an open forward portion, at least part of which extends forward of the back portion to define a sitting space for the user to sit and lean comfortably back onto the back portion. The adjustment mechanism connects to the closed rear portion of the base and to about a midpoint of the rear side of the back portion. The adjustment mechanism also extends and collapses to tilt the back portion forward and backward, respectively. The base is preferably U-shaped. The closed rear portion is the curved part of the U-shape, and the open forward portion is the linear portions of the U-shape.

A forward biasing member may be employed to apply a forwardly pivoting bias force to the back portion. The biasing member may be a hinge spring at a hinged connection between the base and the back portion, or it may be a compressed spring connected between the rear side of the back portion and the rear of the base. The biasing member can cause the back portion to pivot forward without the user having to apply any force to the back portion or to manipulate the back support device in any way. Backward adjustment is also easily accomplished, except that the user applies simple back pressure on the back portion to make it pivot backwards against the bias of the biasing member.

The adjustment mechanism preferably includes an inflatable or pneumatic device that extends upon inflation. The forward bias force can cause the inflatable or pneumatic device to extend and thereby inflate. Inflation or extension of the adjustment mechanism and forward pivoting of the back portion may be performed by permitting air to enter the inflatable device and allowing the bias force to act on the back portion. In one preferred embodiment, the adjustment mechanism includes a bellows and a spring as the inflatable device and biasing member, respectively. An activator, such as an air valve interconnected to the bellows to open and close an air passageway thereto, may permit the spring to extend and inflate the bellows and pivot the back portion forward or permit a user to apply a backward force to overcome the spring bias, collapse and deflate the bellows and pivot the back portion backward. When the valve is closed, the bellows retains its position against the bias force and holds the back portion in the desired position.

A more complete appreciation of the present invention and its scope, and the manner in which it achieves the above noted improvements, can be obtained by reference to the following detailed description of presently preferred embodiments of the invention taken in connection with the accompanying drawings, which are briefly summarized below, and the appended claims.

Brief Description of the Drawings Fig. 1 is a perspective view of an adjustable back support device incorporating the present invention with a back portion shown in an upright position. Fig. 2 is a perspective view of the adjustable back support device shown in Fig. 1 with the back portion adjusted to another reclined position and without padding on the back portion.

Fig. 3 is a rear perspective view of the adjustable back support device shown in Fig. 1 with the back portion shown in an upright position.

Fig. 4 is a rear perspective view of the adjustable back support device shown in Fig. 1 with the back portion pivoted forward in a low-profile configuration.

Fig. 5 is an enlarged cross section view of a bellows and a portion of the back portion which is incorporated within the adjustable back support device shown in Figs. 1-4, and taken generally in the plane of line 5-5 in Fig. 1.

Fig. 6 is an enlarged cross section and elevation view of a valve assembly incorporated within the adjustable back support shown in Figs. 1-4 and taken generally in the plane of line 6-6 in Fig. 1. Fig. 7 is an enlarged cross section and elevation view of a hinged connection between the back support and the base portion of the adjustable back support shown in Figs. 1-4, taken generally in the plane of line 7-7 in Fig. 1.

Fig. 8 is an enlarged cross section and elevation view of the hinged connection taken in the plane of line 8-8 in Fig. 7.

Detailed Description An adjustable back support device 20 incorporating the present invention is shown in Fig. 1. The device 20 generally has a base 22 and a back portion 24. The base 22 rests on a surface on which the user wants to sit, such as a floor, a lawn, a beach, a bed mattress or any other generally flat surface. The back portion 24 pivots about a hinged connection 26 to the base 22, so that the user can adjust the back portion 24 to any desired position of tilt, or reclination, as exemplified by Figs. 1 and 2. Fig. 1 shows the back portion 24 in a generally upright position, and Fig. 2 shows the back portion 24 in a generally more reclined position. Additionally, the user may adjust the back portion 24 to any useful position for the user's comfort. An adjustment and retaining mechanism, such as one or more air-inflatable bellows 28, or other appropriate pneumatic device, attaches between a curved rear portion 30 of the base 22 and a rear side 32 of the back portion 24. An airflow passageway 33, shown in dashed lines in Fig. 3, allows air to enter and exit the bellows 28 to permit the bellows 28 to be extended and collapsed, or inflated and deflated, as the back portion 24 is moved forward and backward, respectively. A forward biasing member, such as a hinge spring 34 (Figs. 7 and 8) at the hinged connection 26, or a compression spring 35 disposed within the bellows 28 (Fig. 5), or other appropriate biasing device, applies a forwardly pivoting bias force to the back portion 24, such that when the bellows 28 are free to extend or collapse, the bias force causes the back portion 24 to pivot more forward or upright.

Backward pivoting adjustment is accomplished by the user applying a backward force, sufficient to overcome the forward bias force of the hinge spring 34 (Figs. 7 and 8) or the compression spring 35 (Fig. 5), to the back portion 24. When the airflow passageway 33 (Fig. 3) is closed, or sealed, the bellows 28 hold their shape and longitudinal length to retain the back portion 24 in the desired position. Thus, the device 20 is adjustable to almost any practical angle, and the adjustment of the device backward and forward and its retention in the desired position are easily accomplished by admitting air into, releasing air out of and trapping air in the bellows 28, respectively. Additionally, the back portion 24 can be pivoted all the way forward as shown in Fig. 4. Each bellows 28 can snap into and out of retaining recesses 36 in a bulging rear protrusion 38 of the back portion 24 so that the back portion 24 can pivot all the way forward as shown, when the bellows are disconnected from the back portion 24. As shown in Fig. 4, the device 20 is collapsed to a low-profile space-saving configuration for convenience of storage or transport. Each of the elements of the device 20 may be made of any suitable relatively lightweight material. For example, the base 22 and back portion 24 may be blow-molded plastic. The bellows 28 may also be hollow flexible plastic material. A plastic construction of this nature permits the device 20 to be made relatively lightweight for further convenience of transport.

Padding 40 (Fig. 1 ) covers a front side 42 of the back portion 24 for comfort when the user's back contacts it. Fig. 2, not showing the padding 40, shows recesses 44 in the front side 42 for mounting the padding 40 (Fig. 1) to the back portion 24. Additionally, an anchor flap 46 attaches to the back portion 24 or the padding 40. Typically, the anchor flap 46 extends forward of the back portion 24 into a sitting space 48 where the user can sit on the anchor flap 46 to anchor the device 20 from sliding away from the user when the user leans back onto the back portion 24.

The base 22 is preferably U-shaped, with the curved rear portion 30 and generally linear forward portions 50. The forward portions 50 form armrests and generally define the sitting space 48 thereinbetween. The forward portions 50 also have recesses 52 (Figs. 2, 3 and 4) into which armrest padding 54 (Fig. 1 ) may be mounted to cushion the user's forearms. One of the forward portions 50 has an activator button 56 (Figs. 1 , 3 and 6) for activating and deactivating, or opening and closing, the airflow passageway 33 (Fig. 3) to the bellows 28. The airflow passageway extends from the activator button 56 to both of the bellows 28 through an interior cavity 57 (Figs. 5 and 6) in the base 22. The forward portions 50 also have holder recesses 58 for the convenience of holding a cup, glass, can or bottle of a beverage, or other item, for example.

More details of the bellows 28 are shown in Fig. 5. One or more (two are shown in Figs. 1-4) bellows 28 is attached at its opposite ends to extend between the back portion 24 and the base 22. A top end 60 of the bellows 28 fits into the matching retaining recess 36 in the back portion 24. Opposite sides 62 of the top end 60 have recesses 64 formed therein. Facing sides 66 of retaining recess 36 have detents 68 that receive and retain the matching recesses 64 to hold the top end 60 in the retaining recess 36. Because of the connection provided by the detents 68 and the recesses 64, the top end 60 can be snapped into and out of the retaining recess 36 of the back portion 24. A slight taper to the top end 60 facilitates snapping the top end 60 into and out of the retaining recess 36. A support protrusion 70 extends from the front side 42 of the back portion 24 toward and almost touches the retaining recess 36 to provide additional support to the rear protrusion 38. When the bellows 28 is inserted into the retaining recess 36 or when a load is placed on the front side 42 of the back portion 24 through the padding 40 (Fig. 1 ), the protrusion 70 relieves some of the stress on the rear protrusion 38 of the back portion 24 by contacting the retaining recess 36 and transferring some of the load to the front side 42.

A bottom end 72 of the bellows 28 is attached to a pivoting connector 74, which permits the bellows 28 to pivot as necessary as the back portion 24 moves. Additionally, the connector 74 permits the bellows 28 to pivot downward into the low-profile configuration shown in Fig. 4. Opposite sides 76 of bottom end 72 have recesses 78, and facing sides 80 of connector 74 have detents 82 for receiving and retaining the recesses 78. The recesses 78 and the detents 82 permit the bellows 28 to be snapped into the connector 74 and held in place by the matching recesses 78 and detents 82. The connector 74 is attached to hinge 84, which is attached to the curved rear portion 30 of the base 22. When the connector 74 is pivoted all the way down to the base 22 (clockwise as shown in Fig. 5), the connector 74 fits into the hole 86 and rests on shoulders 88 above hole 90. The bottom end 72 of the bellows 28 has an opening 92 that protrudes therefrom and receives a tube 93 in an airtight connection. The tube 93 joins with a similar tube 94 from the other bellows 28 (Fig. 3), and both tubes 93 and 94 connect to another tube 95 which connects to the valve assembly 96 (Fig. 6) to form the airflow passageway 33 for air to enter and exit the bellows 28. The opening 92 and tube 93 extend into the hole 90, and the tube 93 extends therefrom through an underside cavity 57 under the base 22 to the other tubes 94 and 95 which extend through the underside cavity 57 to the other bellows 28 and to the valve assembly 96.

In one embodiment for a forward biasing member that applies a forwardly pivoting bias force to the back portion 24, the compression spring 35 is disposed inside the bellows 28 as shown in Fig. 5. The compression spring 35 causes the bellows 28 to expand in a lengthwise direction when the airflow passageway 33 (Fig. 3) is open and air is free to move into or out of the bellows 28, thereby pivoting the back portion 24 forward. A force against the back portion 24 sufficient to overcome the biasing force of the compression spring 35 will cause the back portion 24 to pivot backwards. In another embodiment, the compression spring 35 is disposed between the back portion 24 and the base 22 outside of the bellows 28. For example, the compression spring 35, in this alternative embodiment, may be connected to the back portion 24 and the base 22 between the two bellows 28. Another embodiment for providing a forward biasing member is shown in Figs. 7 and 8 and involves the hinge spring 34 as described below.

The adjustable positioning function provided by the bellows 28 is achieved as a result of controlling the amount of air which is trapped within both bellows 28, thereby establishing the extent to which the bellows 28 is inflated or deflated. The valve assembly 96 (Fig. 6) is pneumatically connected to both of the bellows 28, and the valve assembly 96 is controlled by depressing the activator button 56 exposed at the top of one of the forward portions 50 of the base 22. Depressing the activator button 56 opens the valve assembly 96 to permit air to flow into both bellows 28 or to flow out of both bellows 28. Air flows into both bellows 28 as a result of applying a separating force between the back portion 24 and the base 22, thereby expanding both bellows 28. Air flows out of both bellows 28 as a result of applying a compression force between the back portion 24 and the base 22. Once the desired position of the back portion 24 has been achieved, the activator button 56 is released and the valve assembly 96 is closed to trap the desired amount of air within both bellows 28. The trapped air resists further expansion or compression of the bellows 28 and thereby retains the bellows 28 in the desired position established by the user. The desired position is selected by the user to achieve the convenience of use, comfort and ergonomic positioning desired.

The valve assembly 96 is shown in Fig. 6 in its position in the forward portion 50 of the base 22. The valve assembly 96 has a generally cylindrical housing 100 that fits into a hole 102 in the base 22. The housing 100 has an annular recess 104 which receives and engages an annular protrusion 106 protruding from the side of the hole 102, to hold the valve assembly 96 in place in the hole 102. A slight taper in the housing 100 permits the valve assembly 96 to be snapped into the hole 102. When snapped into the hole 102, the valve assembly 96 positions the activator button 56 at the top of the hole 102. The activator button 56 has a stem 108 with an annular flange 110 at the end. The housing 100 has a top end portion 112 which holds the activator button 56 in the assembly 96. The housing 100 has a mid portion 114 below the recess 104 which holds a valve tube 116. The valve tube 116 surrounds a valve stem 118 which extends upward to engage the flange 110 of the activator button 56. The valve stem 118 also has a cap 120 that engages a bottom valve seat end 121 of the valve tube 116 to form an airtight seal for the valve assembly 96. The housing 100 also has a bottom portion 122 below the mid portion 114 which engages the tube 95 in an airtight connection. The tube 95 connects the valve assembly 96 to the other tubes 93 and 94 (Fig. 3) and to the bellows 28 through the underside cavity 57. A tension spring 124 surrounds the valve stem 118 and connects to the valve stem 118 near the cap 120 and to the tube 116 at the top end to bias the cap 120 against the bottom valve seat end 121 of the tube 116 to form the airtight seal. The spring 124 which biases the cap 120 and valve stem 118 also applies bias force on the activator button 56 upward at the flange 110. When the activator button 56 is pressed down, the cap 120 is unsealed from the valve seat end 121 and an airflow passageway is created through the tube 116, past the cap 120 and to the tube 95 which forms part of the airflow passageway 33 (Fig. 3) that connects to the bellows 28. In this manner, the adjustment of the device 20 is activated by pressing the activator button 56 to open the airflow passageway 33 (Fig. 3) and is deactivated by releasing the activator button 56 to seal the airflow passageway 33.

The hinge spring 34 that applies a forward biasing force to the back portion 24, in one embodiment of a forward biasing member, is shown in greater detail in Figs. 7 and 8. The hinge spring 34 is located at one or more of the hinged connections 26 between the seat back and the base. The hinge spring 34 has a center coil 125 that wraps around an inner hinge rod 126. The inner hinge rod 126 is attached to an outer hinge rod 128 of a greater diameter than the inner hinge rod 126. The outer hinge rod 128 is attached to the side 130 of the back portion 24. The end of the inner hinge rod 126 has a tapered annular flange 132 for holding the hinge spring 34 on the inner hinge rod 126 and against the outer hinge rod 128. The hinged connection 26 attaches to the base 22 through an outer base wall 134 and an inner base wall 136 and is held in place by the opposing engagements of the annular flange 132 with the inner base wall 136 and the outer hinge rod 128 with the outer base wall 134. An outer end 138 of the wire forming the center coil 125 engages a lower base wall 140 of the base 22, while an angled end 142 of the wire forming the coil 125 engages side 144 of protrusion 146 of the outer hinge rod 128. Outer base wall 134 has an opening 148 (Fig. 8) to accommodate the protrusion 146 throughout the range of movement of the back portion 24. For example, for the position of the back portion 24 shown in Fig. 1 , the protrusion 146 and hinge spring 34 are in about the position shown in Fig. 8. For the position of the back portion 24 shown in Fig. 2, the protrusion 146 abuts against end 150 of the opening 148. For the position of the back portion 24 shown in Fig. 4, the protrusion 146 abuts against end 152 of the opening 148. The hinge spring 34 is constantly maintained in tension throughout at least the range of desired positions of the back portion 24 from the position shown in Fig. 1 to the position shown in Fig. 2. The tension of the hinge spring 34 applies a biasing force between the lower base wall 140 and the protrusion 146. In this manner, when the bellows 28 are free to extend and collapse, the biasing force of the hinge spring 34 will cause the back portion 24 to pivot forward in the direction of arrow 154. A force against the back portion 24 in the opposite direction of arrow 154 sufficient to overcome the biasing force of the hinge spring 34 will cause the back portion 24 to pivot backwards.

Although the device 20 is shown incorporating either the compression spring 35 or the hinge spring 34 for a forward biasing member, it is understood that the invention is not so limited. Rather, any other apparatus for biasing the back portion 24 forward may also be used. For example, the bellows 28 may also have some springiness or resilience that inherently forwardly biases the back portion 24. Furthermore, it is understood that the invention is not limited to the specific embodiment of the adjustment mechanism shown herein (i.e. the bellows 28, the valve assembly 96, the airflow passageway 33, the spring 34 or 35 and their interconnections), but may incorporate other elements that can serve the functions of adjusting and retaining the back portion 24 relative to the base 22 without departing from the broader aspects of the invention.

In operation, the user places the back support device 20 on the desired sitting surface, preferably with the anchor flap 46 forward, and attaches the bellows 128 to the back portion 24. The user sits within the sitting space 48 and on the anchor flap 46 and leans his or her back against the back portion 24. The user presses the activator button 56 to open the valve assembly 96. The user leans forward to allow the device 20 to position the back portion 24 forward automatically, or leans backward to apply a force to the back portion 24 to adjust it backward. When the user achieves the desired position, the activator button 56 is released to retain the back portion 24 at the desired position. At any time, the user may readjust the back portion 24 to a new desired position by simply pressing the activator button and leaning either forward or backward.

The adjustable back support device 20 shown herein has the advantage of being very easy for almost any person to adjust, but without a heavy, expensive or complicated adjustment mechanism. Rather, the bellows/spring/valve adjustment and retaining mechanism is simple, lightweight and durable. Since the base 22, back portion 24 and paddings 40 and 54 may also be made of lightweight material, the entire device 20 is not too heavy for almost any person to carry, so the device 20 has the further advantage of easy portability. The low-profile to which the device 20 can be collapsed enhances the portability of the device 20 and also provides the advantage of being able to store the device 20 in a relatively small space. The device 20 also has the advantage of quick and easy setup by simply snapping the bellows 28 into the rear side 32 of the back portion 24.

Presently preferred embodiments of the invention and its improvements have been described with a degree of particularity. This description has been made by way of preferred example. It should be understood that the scope of the present invention is defined by the following claims, and should not be unnecessarily limited by the detailed description of the preferred embodiment set forth above.

Claims

The Invention Claimed Is:

1. An adjustable back support device for use on a support surface, comprising: a base having a rear portion and a forward portion extending from the rear portion, the base adapted to contact the support surface; a back portion hingedly connected to the base between the forward and rear portions; and an adjustment mechanism connected between one of the portions of the base and the back portion to move the back portion in forward and backward tilting movements relative to the base when the base contacts the support surface.

2. An adjustable back support device as defined in claim 1 wherein: the adjustment mechanism is extendible and contractible to move to the back portion in the forward and backward tilting movements.

3. An adjustable back support device as defined in claim 2 wherein: the adjustment mechanism comprises a pneumatically operable element.

4. An adjustable back support device as defined in claim 3 wherein: the pneumatically operable element comprises a bellows.

5. An adjustable back support device as defined in claim 1 wherein: the base further includes a pair of forward portions connected on opposite sides of the rear portion; and the back portion is hingedly connected between the pair of forward portions.

6. An adjustment mechanism as defined in claim 5 wherein: a space between the pair of forward portions and adjacent to the back portion constitutes a location for the user to sit and lean against the back portion.

7. An adjustable back support device as defined in claim 6 further comprising: a flap connected to the back portion and extending into the space between the forward portions upon which the user may sit while leaning against the back portion.

8. An adjustable back support device as defined in claim 5 wherein: the rear portion is generally curved from one side to the other side; the pair of forward portions project forwardly from the rear portion; and the pair of forward portions and the curved rear portion generally define a U-shaped configuration of the base.

9. An adjustable back support device as defined in claim 8 wherein: the back portion is selectively pivotable forward into and occupies the space between the pair of forward portions to establish a collapsed position of the device.

10. An adjustable back support device as defined in claim 5 wherein: the adjustment mechanism comprises an expandable and contractible bellows connected between the rear portion and the back portion; and further comprising: a valve assembly connected to one of the forward portions and pneumatically connected to the bellows to selectively admit, release and trap air within the bellows; the amount of air trapped within the bellows controlling the degree of forward and backward tilt of the back portion relative to the base portion.

11. An adjustable back support device as defined in claim 10, further comprising: a biasing member connected between the base and the back portion for applying a bias force to move the back portion in a forward tilting movement.

12. An adjustable back support device as defined in claim 11 , wherein: the biasing member comprises a hinge spring disposed at the hinged connection to engage the base and the back portion.

13. An adjustable back support device as defined in claim 11 wherein: the biasing member comprises a compression spring connected between the rear portion and the back portion.

14. An adjustable back support device as defined in claim 13 wherein: the compression spring is located within the bellows.

15 An adjustable back support device as defined in claim 11 wherein: the forward portions of the base form armrests.

16. An adjustable back support device comprising: a base; a back portion pivotally connected to the base; an extendible inflatable adjustment mechanism connected to the base and the back portion to extend and compress with pivoting of the back portion; and an inflation mechanism connected to the base and the back portion to apply a bias between the base and the back portion which extends the adjustment mechanism and inflates the adjustment mechanism upon an activation.

17. An adjustable back support device as defined in claim 16 wherein: the back portion is connected to the base at a hinge connection; and the inflation mechanism is disposed at the hinge connection.

18. An adjustable back support device as defined in claim 17 wherein: the inflation mechanism is a hinge spring which applies a forward pivoting bias between the base and the back portion.

19. An adjustable back support device as defined in claim 16 wherein: the inflation mechanism is disposed internally in the adjustment mechanism.

20. An adjustable back support device as defined in claim 19 wherein: the adjustment mechanism is an extendible and collapsible bellows; and the inflation mechanism is a compression spring which provides an extension bias force to the bellows.

21. An adjustable back support device as defined in claim 16 further comprising: an activator in fluid contact with the adjustment mechanism to activate and deactivate fluid flow through a fluid passageway into the adjustment mechanism, activation and deactivation of the activator respectively permitting and prohibiting inflation of the adjustment mechanism to permit adjustment of the back portion and to retain the back portion.

22. An adjustable back support device as defined in claim 21 wherein: the adjustment mechanism comprises an extendible and collapsible bellows; the inflation mechanism comprises a spring which applies a bias force between the base and the back portion; the activator comprises an air valve which permits air to flow into and out of the bellows when open and which seals the bellows when closed; when the valve is open, the spring pivots the back portion which extends and inflates the bellows; and when the valve is closed, the bellows retains its position against the bias of the spring.

23. An adjustable back support device as defined in claim 16 wherein: the adjustment mechanism is air-filled; the inflation mechanism comprises a bias spring; and the back portion is retained in the desired position by air compression and spring compression when a user rests against the back portion.

24. An adjustable back support device comprising: a base; a back portion pivotally connected to the base against which a user can rest in a sitting or reclined position; an adjustment mechanism connected to the base and the back portion to permit adjustment of the back portion when activated and to retain the back portion in a desired position when deactivated; a forward biasing member connected to the base and the back portion to provide a forward bias force to the back portion to pivot the back portion forward when the adjustment mechanism is activated; and an activator interconnected to the adjustment mechanism to activate and deactivate the adjustment mechanism; and wherein simultaneous activation of the adjustment mechanism with application of a backward force counteracting the forward bias force permits backward adjustment of the back portion.

25. An adjustable back support device as defined in claim 24 wherein: the adjustment mechanism comprises an air inflatable bellows; the forward biasing member comprises a spring biased to pivot the back portion which extends the bellows; and the activator comprises an air valve, the activation of which opens an airflow passageway into the bellows permitting air to enter and inflate the bellows when the forward bias force pivots the back portion forward to extend the bellows and permitting air to exit and deflate the bellows when the backward force is greater than the forward bias force.

26. An adjustable back support device as defined in claim 24 wherein: a portion of the base extends forwardly of the back portion to form an armrest; the activator comprises a button disposed on the armrest, the activator being activated by the user pressing the button; the back portion is adjusted backward by the user simultaneously pressing the button and applying the backward force on the back portion; and the back portion is adjusted forward by the user pressing the button without applying force on the back portion.