SPECIFICATIONExercise chairThis invention relates to exercise apparatus and more particularly to exercise apparatus for exercising the upper body whilst in a sitting position.
There are currently available a number of forms of exercise apparatus in which the user may perform exercises on the upper half of his or her body. Of these, there are some in which the user performs the exercises in a sitting position. One of the disadvantages of such apparatus is that it can only realistically be sited in gymnasia or other such premises more or less designed around the exercise equipment.
We have appreciated that the major factor which influences whether or not a person will continue to indulge in exercises designed to develop the body is the ease of access to suitable facilities. Having to make the effort of seeking out a gymnasium often stifles a person's desire for body development and exercise before they have had a chance to feel the benefits.
Thus, it is an object of the present invention to provide exercising apparatus for exercising the upper body in the structure of a chair which is constructed so as to be usable in applications and settings in which an equivalent ordinary chair would be used.
According to the present invention there is provided a chair for exercising the upper body, the chair comprising a seat portion mounted on a support structure, a back support extending generally upwardly from the rear of the seat portion, an arm extending generally upwardly from each side of the seat portion and pivotably attached thereto, and resilient means mounted on the chair to resist the movement of each arm about its corresponding pivotal attachment.
A specific embodiment of the present invention will now be described by way of example, with reference to the accompanying drawings in which:Figure 1 is a side elevation of an office chair incorporating the present invention.
Figure 2 is a detailed diagram illustrating a method of mounting arms of the chair of Figure 1.
Figure 3 is a vertical section through the arm of the chair of Figure 1.
Figure 4 illustrates the base of a gauge mounted in the arm of the chair of Figure 1.
Figure 5 is a diagram of an electrical circuit incorporating a strain gauge for measuring arm movement.
Referring to Figure 1, a seat portion 10 is secured to a seat base 11. A single centrally mounted leg 12, which is terminated at a lower end in a plurality of feet 14 equally radially spaced about the leg 12, rotatably supports the seat base 11. Extending upwardly from the rear of the seat base 11 is a back support 16 which holds in position a back rest cushion 18.
On each side of the seat portion 10, extending generally upwardly, is a tubular metal arm 20. Each arm 20 is secured to the seat base 11 by means of a pair of coil springs 22 spaced longitudinally with respect to the seat base 11. As shown in more detail inFigure 2, the coil springs 22 are each housed in a recess in the lower horizontal strut of its corresponding arm 20. In this embodiment the recesses are located on an outer face of each arm 20, but they could belocated on an inner face thereof to equal effect.
Furthermore, the coil springs 22 could be replaced by a suitably resilient sheet of material, such as metal, aplastics material or carbon fibre, secured between theseat base 11 and an arm 20.
Each coil spring 22 is fixedly secured to a corresponding arm 20 by means of a threaded extension 24of a last turn at one end of the spring 22 projectingupwardly through an upper and a lower hole 26, 28 in the pressed recess of the tubular metal arm 20. One end of a sleeve 30, fitting over the threaded extension 24, bears on an inner face of the upper hole 26, the opposite end of the sleeve 20 being provided with a flange 32 which bears on an outer face of the lower hole 28, such that an upper and lower nut 34, 36, on the threaded extension, may be drawn together thus clamping the arm 20 in position relative to the spring 22. On an opposite end of each spring 22 to that bolted to the arm 20 a further threaded extension 38 projects downwardly into a hole in the seat base 11.
Nuts, located above and below the seat base 11; on the threaded extension 30 are similarly drawn together in order to clamp the arm 20 in position with respect to the seat base 11.
On an outer face of an upper horizontal strut of each arm 20 is located a pair of pressure pads 40, 42, one pad 40 being positioned toward the rear of the arm 20 and the other pad 42 being positioned toward the front of the arm 20. The pads 40, 42 are screwed into the metal of the arm 20. In an arm made of a moulded plastics material the pads could be formed as an integral part of the moulded shape. The contours of the pads 40, 42 are generally complementary to the contours of the palms of the hands in attitudes that would be adopted by palms of a user's hands when seated in the chair. Thus, the pads 40, 42 provide a comfortable area on which to apply pressure exerted by the arms and upper body muscles through the palms. By grasping the front pads 42 and pressing inwardly, the fore-arms and chest muscles may be exercised.By grasping the rear pads 40 and pressing inwardly, the shoulders and chest muscles may be exercised.
In order to monitor the user's progress when using the exercise facility within the chair, a gauge 44 is located in the middle of an upper face of each arm 20, as illustrated in Figures 3 and 4. The gauge comprises a spindle 46 which is geared to convert a small linear pull on a pair of wires onto an appreciable angular movement of a needle 48. One of the wires 50 associated with a gauge 44 is secured to the spindle 46, by means of a lever 51 and anchored to a pin on the housing of the gauge 44 by means of a spring 53.
The wire 50 runs inside its corresponding arm 20, through an opening 52 in the lower front of the arm 20 and a further opening 54 in the seat base to be secured to a bolt 56 threaded into the seat base 11. By this bolt 56 the tension in the wire 50 is adjusted. To alter the length of the path of the wire 50, when the arm 20 is rotated about the coil springs 22, and thus move the pointer 48 of the gauge 44, a rigid tongue 60, extending from the opening 52 in the arm 20 into the opening 54 in the seat base 11, catches the wire and pulls it out of its path as force is exerted on the arm 20. This movement causes the spring 53 to extend to accommodate the change in length, thus rotating the spindle 46. A similar wire 62 extends backwardly to be anchored to a bolt 64 through openings 66 and 68 in the rear of the arm 20 and seat base 11 respectively.The wire 62 restrains the action of the wire 50 and vice versa. Movement of the arm 20 due to pressure applied on the front pads 42 is substantially reflected in movement of the wire 50 and the pressure applied to the rear pads 40 is substantially reflected in the movement of the wire 62. Slackening in the tension in one wire due to a pull on the other wire is accommodated by the corresponding spring.
In order to ensure that the arms 20 are able to withstand the normal forces imposed on them in the course of normal use as armrests the coil springs 22 are of sufficient stiffness to make any movement thereby substantially imperceptible.
With this in mind, it is necessary to use a gauge that is able to measure changes in the length of a wire of no more than a few millimetres. In an alternative embodiment, the gauge is replaced by a digital voltmeter which registers the change in electrical resistance of a strain gauge 70, as used in theWheatstone Bridge circuit of Figure 5. The voltmeter display 72 or other voltmeter is balanced to read zero in the unused state by a trimming resistor 74. A switch 76 is inserted in the circuit to conserve the battery 78 when not in use.