Title:
LIQUID SUPPORTING FURNITURE
United States Patent 3867731
Abstract:
Improved liquid supporting furniture for humans comprising a liquid-filled bladder within a rigid circumscribing framework and bottom support wherein an adjustable head tank in communication with the bladder controls the firmness and response of the bladder to an applied load.
US Patent References:
Physio-therapy apparatus
Whitesell - April 1963 - 3085568
/3585660.html
Gottfried et al. - June 1971 - 3585660
/3585661.html
Gottfried et al. - June 1971 - 3585661
Physio-therapy apparatus
Whitesell - April 1963 - 3085568
/3585660.html
Gottfried et al. - June 1971 - 3585660
/3585661.html
Gottfried et al. - June 1971 - 3585661
Application Number:
05/262112
Publication Date:
02/25/1975
Filing Date:
06/12/1972
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
5/665
International Classes:
A47C27/08; A47C27/08
Field of Search:
5/60,348R,348WB
Primary Examiner:
Nunberg, Casmir A.
Assistant Examiner:
Calvert, Andrew M.
Claims:
I claim
1. In a support for floatingly supporting at least one human body;
1. In a support for floatingly supporting at least one human body;
Description:
This invention relates generally to liquid supporting articles of furniture and more particularly to furniture for supporting humans upon a liquid-filled bladder in which the liquid pressure is adjustable for developing a wide range of bladder firmness.
The principal object of this invention is an improved liquid-filled furniture structure in which the firmness and response to load is easily adjustable.
Another object of the invention is an improved liquid supporting furniture structure having a constrained bladder that readily conforms to body contours and reduces the sloshy and free vibration of an unconstrained bladder.
A further object of the invention is to provide a constrained bladder for liquid supporting furniture which develops minimal side pressure against the circumscribing framework.
Other objects and advantages of the invention will become apparent upon consideration of the following description of a specific embodiment and the accompanying drawings wherein
FIG. 1 is a perspective view of a bed having the structural features of this invention;
FIG. 2 is a cross-sectional view of the bed of FIG. 1 taken along line 2--2; and
FIG. 3 is a perspective view partially in section of the bladder employed in the bed of FIGS. 1 and 2.
The drawings illustrate the improved liquid supporting structure of this invention in the form of a bed; however, the general principles which that structure employs and which are described herein are equally applicable to other furniture structures such as sofas, chairs, etc.
The bed of FIGS. 1 - 3 is designed to floatingly support one or more human bodies. It includes a bladder 1 made from flexible substantially inelastic material such as, for example, polyvinyl chloride plastic sheeting frequently used in air mattresses and the like. The bladder defines a load supporting chamber 2 having an upper wall of sufficient size to support one or more adult human bodies. The load supporting chamber 2 of the bladder encloses and is filled with a body of liquid, such as water referred to generally as 4, so that there is substantially no air in the chamber. That portion of the bladder which defines load supporting chamber 2 is constrained in the vertical direction in the illustrated embodiment by a plurality of baffles 5 welded between the upper wall 3 and the lower wall 6 of the bladder to generally define a corrugated mattress structure.
Other constraints are equally applicable such as a plurality of single filaments button welded to the same walls or welded seams joining them. However, regardless of the particular constraint design used, the load supporting chamber 2 is a single closed cavity with free communication of liquid within it from one part to the other, as for example, by channel 7 at the foot end of the bladder 1 and at the other end of baffles 5 at a heat tank 10 defined by an unconstrained generally tubular portion 11 of the bladder 1. The liquid 4 within the bladder extends upwardly into the head tank 10 to develop a head that determines the liquid pressure within load supporting chamber 2. The constraints reduce the sloshy feel and vibration of an unconstrained bladder under a moving load.
A rigid framework 15 circumscribes the bladder 1. It is separable from the bladder and helps prevent lateral distotion of it. The constraints 5 minimize the side pressure of the bladder against this framework. The framework includes a pair of sideboards 16, a footboard 17, an inclined headboard 18 supported from sideboards 16, and back plate 19 mounted upon horizontal brackets 20 extending from backboard 21 along the inside of the sideboards. Bottom board 22 supports the bottom of the bladder and confines it within framework 15.
As appears in FIGS. 2 and 3 one extreme end of the bladder has a plurality of grommets 23 through which fastening means 25 secure the tubular portion 11 of the bladder in an upward orientation with respect to load supporting chamber 2 upon vertical back plate 19 and headboard 18 to form head tank 10. Back plate 19 is adjustably positioned horizontally upon the brackets 20. Movement of the back plate 19 along brackets 20 with respect to inclined headboard 18 varies the cross-sectional area of the head tank 10 which is confined between them. If the back plate 19 is moved to the left in FIG. 2, for example, the cross-sectional area of the head tank 10 becomes smaller forcing the water contained in it upwardly to increase the liquid head upon the fluid in chamber 2. If back plate 19 is moved to the right in FIG. 2, the head tank cross-sectional area increases, the liquid level in it goes down, and the resulting liquid pressure in chamber 2 is reduced. The firmness of the bladder and its response to load is a function of the pressure in chamber 2.
The head tank 10 is useful for accommodating an immersible heater 26 in FIG. 2 to control the water temperature in the bladder to the desired temperature. Access to the heater 26 and to position the back plate 19 is through cover 27 hinged at 28 from backboard 21. The head tank 10 also may carry a transparent open-ended stand pipe 29 so that one can directly observe the water level in the tank. This stand pipe can be provided with a petcock as at 30 to drain the bladder. A foam pad 31 may be provided over the upper wall 3 of chamber 2 for insulation or further comfort.
A bladder in the order of 31/2 to 4 inches in depth at chamber 2 with constraints 6 inches on centers has been found to be sufficient to floatingly support an adult human body on the upper wall 3 of chamber 2 with the wall conforming to body contours without any part touching bottom board 22.
The principal advantage of liquid supporting furniture with a head tank and constrained load supporting chamber 2 is that the structure behaves as if it contains a high density fluid when filled with water. Really dense fluids are expensive and usually poisonous so that the described structure achieves with water the effect of a more dense liquid at low cost. The bed described is capable of adjusting to a wide range of initial firmness and response to load.
If the liquid density is D
D × S = W/A (1)
for a static condition where S is the depth of liquid displaced by applied weight W over an area A upon upper wall 3 of the bladder. The pressure W/A supporting the weight is produced by the column of liquid in the head tank
D(H + L + S) = W/A (2)
where H is the height of the liquid level in head tank 10 with no load applied and L is the increase in level when weight W is applied to upper wall 3. Since the separating upper wall 3 is constrained
C × L = S × A (3) L = S (4) D(H + S × A/C (5) ) = W/A
D(H + S (A+C)/C = W/A (6)
where C is the cross-sectional area of the head tank at the liquid level in it. Comparing (1) and (6) it is apparent that the liquid pressure has two variable components, H and C. H can be controlled by the initial amount of water. Eight inches of depth for H is typical. C can be controlled by varying the cross-section area of the head tank. Water is not dense enough for very comfortable flotation. But if one chooses H to be very small one can choose C small enough so that (A+C)/C is equal to say 5 and can develop a very comfortable pressure in chamber 2.
The same principle is extendable to chairs, or sofas or other pieces of furniture. In such application the back of the chair or sofa is replaced by a hollow wooden structure which contains the head tank portion of the bladder with the constrained portion as the seat. A sofa, for example, can use a series of independent envelopes and back plates to create variations in seating performance. The equivalent headboard can be padded or provided with back pillows.
The specific embodiment described above is for illustrative purposes only. It will be apparent to those skilled in this art that modifications to it may be made and equivalents substituted which are within the scope of the invention defined in the following claims.
The principal object of this invention is an improved liquid-filled furniture structure in which the firmness and response to load is easily adjustable.
Another object of the invention is an improved liquid supporting furniture structure having a constrained bladder that readily conforms to body contours and reduces the sloshy and free vibration of an unconstrained bladder.
A further object of the invention is to provide a constrained bladder for liquid supporting furniture which develops minimal side pressure against the circumscribing framework.
Other objects and advantages of the invention will become apparent upon consideration of the following description of a specific embodiment and the accompanying drawings wherein
FIG. 1 is a perspective view of a bed having the structural features of this invention;
FIG. 2 is a cross-sectional view of the bed of FIG. 1 taken along line 2--2; and
FIG. 3 is a perspective view partially in section of the bladder employed in the bed of FIGS. 1 and 2.
The drawings illustrate the improved liquid supporting structure of this invention in the form of a bed; however, the general principles which that structure employs and which are described herein are equally applicable to other furniture structures such as sofas, chairs, etc.
The bed of FIGS. 1 - 3 is designed to floatingly support one or more human bodies. It includes a bladder 1 made from flexible substantially inelastic material such as, for example, polyvinyl chloride plastic sheeting frequently used in air mattresses and the like. The bladder defines a load supporting chamber 2 having an upper wall of sufficient size to support one or more adult human bodies. The load supporting chamber 2 of the bladder encloses and is filled with a body of liquid, such as water referred to generally as 4, so that there is substantially no air in the chamber. That portion of the bladder which defines load supporting chamber 2 is constrained in the vertical direction in the illustrated embodiment by a plurality of baffles 5 welded between the upper wall 3 and the lower wall 6 of the bladder to generally define a corrugated mattress structure.
Other constraints are equally applicable such as a plurality of single filaments button welded to the same walls or welded seams joining them. However, regardless of the particular constraint design used, the load supporting chamber 2 is a single closed cavity with free communication of liquid within it from one part to the other, as for example, by channel 7 at the foot end of the bladder 1 and at the other end of baffles 5 at a heat tank 10 defined by an unconstrained generally tubular portion 11 of the bladder 1. The liquid 4 within the bladder extends upwardly into the head tank 10 to develop a head that determines the liquid pressure within load supporting chamber 2. The constraints reduce the sloshy feel and vibration of an unconstrained bladder under a moving load.
A rigid framework 15 circumscribes the bladder 1. It is separable from the bladder and helps prevent lateral distotion of it. The constraints 5 minimize the side pressure of the bladder against this framework. The framework includes a pair of sideboards 16, a footboard 17, an inclined headboard 18 supported from sideboards 16, and back plate 19 mounted upon horizontal brackets 20 extending from backboard 21 along the inside of the sideboards. Bottom board 22 supports the bottom of the bladder and confines it within framework 15.
As appears in FIGS. 2 and 3 one extreme end of the bladder has a plurality of grommets 23 through which fastening means 25 secure the tubular portion 11 of the bladder in an upward orientation with respect to load supporting chamber 2 upon vertical back plate 19 and headboard 18 to form head tank 10. Back plate 19 is adjustably positioned horizontally upon the brackets 20. Movement of the back plate 19 along brackets 20 with respect to inclined headboard 18 varies the cross-sectional area of the head tank 10 which is confined between them. If the back plate 19 is moved to the left in FIG. 2, for example, the cross-sectional area of the head tank 10 becomes smaller forcing the water contained in it upwardly to increase the liquid head upon the fluid in chamber 2. If back plate 19 is moved to the right in FIG. 2, the head tank cross-sectional area increases, the liquid level in it goes down, and the resulting liquid pressure in chamber 2 is reduced. The firmness of the bladder and its response to load is a function of the pressure in chamber 2.
The head tank 10 is useful for accommodating an immersible heater 26 in FIG. 2 to control the water temperature in the bladder to the desired temperature. Access to the heater 26 and to position the back plate 19 is through cover 27 hinged at 28 from backboard 21. The head tank 10 also may carry a transparent open-ended stand pipe 29 so that one can directly observe the water level in the tank. This stand pipe can be provided with a petcock as at 30 to drain the bladder. A foam pad 31 may be provided over the upper wall 3 of chamber 2 for insulation or further comfort.
A bladder in the order of 31/2 to 4 inches in depth at chamber 2 with constraints 6 inches on centers has been found to be sufficient to floatingly support an adult human body on the upper wall 3 of chamber 2 with the wall conforming to body contours without any part touching bottom board 22.
The principal advantage of liquid supporting furniture with a head tank and constrained load supporting chamber 2 is that the structure behaves as if it contains a high density fluid when filled with water. Really dense fluids are expensive and usually poisonous so that the described structure achieves with water the effect of a more dense liquid at low cost. The bed described is capable of adjusting to a wide range of initial firmness and response to load.
If the liquid density is D
D × S = W/A (1)
for a static condition where S is the depth of liquid displaced by applied weight W over an area A upon upper wall 3 of the bladder. The pressure W/A supporting the weight is produced by the column of liquid in the head tank
D(H + L + S) = W/A (2)
where H is the height of the liquid level in head tank 10 with no load applied and L is the increase in level when weight W is applied to upper wall 3. Since the separating upper wall 3 is constrained
C × L = S × A (3) L = S (4) D(H + S × A/C (5) ) = W/A
D(H + S (A+C)/C = W/A (6)
where C is the cross-sectional area of the head tank at the liquid level in it. Comparing (1) and (6) it is apparent that the liquid pressure has two variable components, H and C. H can be controlled by the initial amount of water. Eight inches of depth for H is typical. C can be controlled by varying the cross-section area of the head tank. Water is not dense enough for very comfortable flotation. But if one chooses H to be very small one can choose C small enough so that (A+C)/C is equal to say 5 and can develop a very comfortable pressure in chamber 2.
The same principle is extendable to chairs, or sofas or other pieces of furniture. In such application the back of the chair or sofa is replaced by a hollow wooden structure which contains the head tank portion of the bladder with the constrained portion as the seat. A sofa, for example, can use a series of independent envelopes and back plates to create variations in seating performance. The equivalent headboard can be padded or provided with back pillows.
The specific embodiment described above is for illustrative purposes only. It will be apparent to those skilled in this art that modifications to it may be made and equivalents substituted which are within the scope of the invention defined in the following claims.