Tube pump

Abstract

The tube pump includes a base that holds a drive shaft; a rotor portion that rotates with the driving shaft, the rotor portion having a pair of rollers; a casing having a U-shaped internal surface along which an elastic tube is arranged, the casing being mounted on the base so that the casing can slide with respect to the base in a direction parallel to the linear portions; a cover that is rotatably mounted on the casing; a moving mechanism including a rack that is formed on the base and a pinion that is fixed to the rotation shaft of the cover. The moving mechanism moves the casing to the operating position where the roller deforms the elastic tube when the cover closes, and the moving mechanism moves the casing to the exchange position where the roller comes apart from the elastic tube when the cover opens.

1 . A tube pump comprising: 
 a base that holds a drive shaft that connects with and is driven by a motor;    a rotor portion that rotates with said driving shaft, said rotor portion having a pair of rollers each of which has a rotating shaft decentered from said drive shaft;    a casing having a U-shaped internal surface that includes a semicircular portion and parallel linear portions connected to both ends of said semicircular portion along which an elastic tube is arranged, said casing being mounted on said base so that said casing can slide with respect to said base in a direction parallel to said linear portions;    a cover that is rotatably mounted on said casing at the outside of said semicircular portion, said cover covering the portion surrounded by said internal surface at its closing position;    a moving mechanism including a rack that is formed on said base and a pinion that is fixed to a rotation shaft of said cover and engages with said rack, said moving mechanism moving said casing with respect to said base to an operating position where said roller deforms said elastic tube arranged along said internal surface when said cover closes, and said moving mechanism moving said casing with respect to said base to an exchange position where said roller comes apart from said elastic tube when said cover opens.    
   
   
       2 . The tube pump according to  claim 1 , wherein said internal surface of said casing has a step portion so that the diameter of the semicircular portion at the side of the cover becomes larger than the other side, and said cover has a convex rim, which can insert inside said internal surface, is formed on said cover at the position opposite to said step portion, whereby said step portion and said convex rim function as a means for guiding said elastic tube that is arranged along said internal surface.  
   
   
       3 . The tube pump according to  claim 1  or  2 , further comprising: 
 a pair of clamp arms that is mounted on said base to hold entrance and exit portions of said elastic tube to the pump, respectively, the base end of each of said clamp arm being rotatably attached to a pivot that is vertical to the axis of said drive shaft and is parallel to said linear portions, each of said clamp arm having a tip end that is formed to hold said elastic tube and having a small roller at a middle portion thereof;    a biasing mechanism that applies bias pressure to said clamp arms so that said small rollers move closer and said clamp arms release said elastic tube; and    a connecting projection that is formed on said cover to intrude between said small rollers when said cover closes,    wherein said connecting projection of the cover intrudes between said small rollers and separates them from each other, which rotates the clamp arms against the bias pressure applied by the biasing mechanism when the cover closes.    
   
   
       4 . The tube pump according to one of claims  1  through  3 , further comprising: 
 a permanent magnet mounted on said rotor portion at the position opposite to the casing; and    a magnetic sensor installed on either of said casing and said base for detecting magnetic flux of said permanent magnet to determine the rotation position of said rotor portion.