Bed having load detection function and load detector for bed

Abstract

An object of the invention is to provide a bed to which a load detection function is added with a simple structure, while suppressing an increase in the number of parts. The invention also provide a bed with a load detection function in which a load cell of a load detector is incorporated into a caster mechanism of a leg section in a bed body. Additionally, a load detector suitable for the bed is provided.

1 . A bed with a load detection function that detects a change in a load applied to a bed surface of a bed body, using a load detector attached to the bed body, and detects a state of a user on the bed surface of the bed body,
 wherein the bed body has a plurality of leg sections that have contact with a surface on which the bed body is to be installed,   wherein the leg sections are provided with caster mechanisms, respectively, and   wherein the load detector has load cells that are incorporated into the caster mechanisms of one or more leg sections among the leg sections, and measure a strain caused by loads applied from the bed surface to the caster mechanisms.   
     
     
         2 . The bed with a load detection function according to  claim 1 ,
 wherein the bed body has a bottom frame supported via the leg sections on an installation surface,   wherein the caster mechanism has a wheel that rotates around a horizontal axis, and a turning portion that turns the wheel around a vertical axis, and has a structure in which an upper end opening portion of a tube portion is closed by a top portion in a state where a shaft portion protruding from an upper portion of the turning portion is inserted into the tube portion provided at the bottom frame so as to be movable in an axis direction, and   wherein the load cell is arranged in a state where the load cell is sandwiched between the shaft portion and the top portion inside the tube portion.   
     
     
         3 . The bed with a load detection function according to  claim 2 ,
 wherein the load cell is arranged above a position where the tube portion is connected to the bottom frame.   
     
     
         4 . The bed with a load detection function according to  claim 2 ,
 wherein any one of a lower end surface of the load cell and an upper end surface of the shaft portion has a flat surface, and the other has a convex surface, and the flat surface and the convex surface are brought into contact with each other on a central axis.   
     
     
         5 . The bed with a load detection function according to  claim 2 ,
 wherein a bush that guides the shaft portion so as to be movable in the axis direction is arranged between an inner peripheral surface of the tube portion and an outer peripheral surface of the shaft portion.   
     
     
         6 . The bed with a load detection function according to  claim 1 ,
 wherein four load cells are provided as the load cells, and   wherein the load cells are respectively incorporated into caster mechanisms of four leg sections arranged at four corners of the bed body that are in a mutually symmetrical positional relationship.   
     
     
         7 . A load detector for a bed that is attached to a bed body having a plurality of leg sections, thereby measuring a change in a load applied to a bed surface of the bed body, and detecting a state of a user on the bed surface of the bed body, comprising:
 a load cell that measures strain caused by the load applied thereto,   wherein the load cells are configured so as to be capable of being incorporated into caster mechanisms provided at the leg sections.   
     
     
         8 . The load detector for a bed according to  claim 7 ,
 wherein the caster mechanism has a wheel that rotates around a horizontal axis, and a turning portion that turns the wheel around a vertical axis, and has a structure in which an upper end opening portion of a tube portion is closed by a top portion, in a state that is a shaft portion protruding from an upper portion of the turning portion, is inserted into the tube portion provided at a bottom frame of the bed body so as to be movable in an axis direction, and   wherein the load cell is arranged in a state that is the load cell is sandwiched between the shaft portion and the top portion inside the tube portion.   
     
     
         9 . The load detector for a bed according to  claim 8 ,
 wherein the load detecting part is arranged above a position where the tube portion is connected to the bottom frame.   
     
     
         10 . The load detector for a bed according to  claim 8 ,
 wherein any one of a lower end surface of the load detecting part and an upper end surface of the shaft portion has a flat surface, and the other has a convex surface, and the lower end surface of the load detecting part has a flat surface or a convex surface so that the flat surface and the convex surface are brought into contact with each other on a central axis.   
     
     
         11 . The load detector for a bed according to  claim 8 ,
 wherein the caster mechanism includes a bush that is arranged between an inner peripheral surface of the tube portion and an outer peripheral surface of the shaft portion to guide the shaft portion so as to be movable in the axis direction.   
     
     
         12 . The load detector for a bed according to  claim 7 ,
 wherein four load cells are provided as the load cells, and   wherein the load cells are configured so as to be respectively arranged at caster mechanisms of four leg sections arranged at four corners of the bed body that are in a mutually symmetrical positional relationship.