Blood sedimentation rate test means

Blood sedimentation rate test means, comprising:

• (a) a blood collecting vessel,
• (b) a plunger in said vessel, movable axially thereof,
• (c) a calibrated measuring tube extending into said collecting vessel and connected to said plunger for axial movement therewith, and
• (d) pressure actuated, normally closed valve means in said plunger operative between said collecting vessel and said measuring tube,
• (e) said valve means being adapted to open when the measuring tube is manually moved relative to the collecting vessel to push the plunger against the blood collected therein,
• (f) whereby blood is forced out of the collecting vessel, through the open valve means, and into the measuring tube until it attains a predetermined level therein,
• (g) said valve means being adapted to close and to confine the displaced blood to the measuring tube when said measuring tube and its connected plunger are immobilized relative to the collecting vessel,
• (h) the valve means being adapted to open under negative pressure when the measuring tube and its connected plunger are retracted relative to the collecting vessel,
• (i) whereby, in the event the blood level in the measuring tube is higher than the predetermined level, blood may be returned to the collecting vessel under atmospheric pressure,
• (j) said valve means being adapted to close when the measuring tube and connected plunger are again immobilized.