JOINT MECHANISM

• US 20130340608A1
• Filed: 03/11/2011
• Published: 12/26/2013
• Est. Priority Date: 03/11/2011
• Status: Active Grant

• Current Assignee: Sugan Co. Ltd. (Sheen Man Co. Ltd.)
• Original Assignee: Sugan Co. Ltd. (Sheen Man Co. Ltd.)
• Inventors: Yamamoto, Tetsuya
• Granted Patent: US 9,694,146 B2
• Time in Patent Office: Days
• US Class Current: 92/140
• CPC Class Codes: A61M 2005/14553 comprising a pressure jacket
• CPC Class Codes: A61M 5/14546 Front-loading type injectors
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod
• CPC Class Codes: A61M 5/5066 Means for preventing re-use by disconnection of piston and piston-rod
• CPC Class Codes: F04B 1/00 Multi-cylinder machines or pumps characterised by number or arrangement of cylinders machines or pumps with pistons coacting within one cylinder F04B3/00
• CPC Class Codes: F04B 13/00 Pumps specially modified to deliver fixed or variable measured quantities
• CPC Class Codes: F04B 53/14 Pistons, piston-rods or piston-rod connections

Abstract

In the joint mechanism, when connecting a plunger to a piston, after engaging members of a plunger-side engaging region in a retracted state pass through a first engaging wall region of a piston-side engaging region, the engaging members of the plunger-side engaging region come into a projected state in a second engaging wall region and the projected state of the engaging members is fastened by a fast block, and thereby, the plunger-side engaging region engages with the piston-side engaging region.

Claims

1. A joint mechanism for a slidable plunger disposed in an injector head and a piston which is disposed inside a syringe mounted on said injector head,

a plunger-side engaging region which engages with said piston being disposed at a front end of said plunger,

a piston-side engaging region which engages with said plunger-side engaging region being disposed inside said piston,

said piston-side engaging region including

a first engaging wall region having a first inner diameter, and

a second engaging wall region located inside relative to said first engaging wall region and having a second inner diameter larger than said first inner diameter,

said plunger-side engaging region including

a cylindrical portion having an outer diameter smaller than said first inner diameter,

an engaging member disposed inside said cylindrical portion in a way of being switchable between a projected state of projecting from an outer surface of said cylindrical portion and a retracted state without projecting from the outer surface of said cylindrical portion, and

a fast block for fastening said engaging member in said projected state,

said fast block being disposed inside said cylindrical portion and closer to a center side thereof than said engaging member,

in the case where said plunger and said piston are in a connected state, said fast block preventing said engaging member from moving toward a center side in a radial direction so as to fasten said engaging member in said projected state, and

in the case where said plunger and said piston are in a disconnected state, the prevention by said fast block of the movement of said engaging member toward the center side in the radial direction being released.

2. The joint mechanism according to claim 1, wherein

said fast block is formed into a shape of a substantially equilateral triangle,

said engaging member is disposed on a peripheral surface of said cylindrical portion at three locations with a pitch of 120°

, and is configured to be rotatable around said fast block together with said cylindrical portion,

said projected state of said engaging member is fastened at a position where three vertices of the triangle of said fast block come into contact with an inner side of said engaging member, and

the fastening of said projected state of said engaging member is released at a position where said engaging member is rotated by 60°

to disengage said three vertices of the triangle of said fast block from the inner side of said engaging member.

3. The joint mechanism according to claim 2, wherein said engaging member includes

a projected portion projectable from an outer surface of said cylindrical portion,

an extended portion extending from said projected portion in an axial direction of said cylindrical portion, and

a base portion disposed at a side of said extended portion which is opposite to said projected portion,

three said base portions are formed into a circular shape by combining three said base portions of three said engaging members together and having a fast ring disposed around outer peripheral surfaces of said base portions.

4. The joint mechanism according to claim 1, wherein

said fast block, as a whole, is formed into a shape of a race track having a curved surface portion and a linear portion which is configured to include a pair of D-cut surfaces each having a flat face on a part of the peripheral surface of a circular block,

said engaging member is disposed on a peripheral surface of said cylindrical portion at two locations with a pitch of 180°

and is configured to be rotatable around said fast block together with said cylindrical portion,

said projected state of said engaging member is fastened at a position where two vertices of said curved surface portions of said fast block come into contact with an inner side of said engaging member, and

the fastening of said projected state of said engaging member is released at a position where said engaging member is rotated by 90°

to disengage said two vertices of said fast block from the inner side of said engaging member.

5. The joint mechanism according to claim 4, wherein said engaging member includes

a projected portion projectable from an outer surface of said cylindrical portion,

an extended portion extending from said projected portion in an axial direction of said cylindrical portion, and

a base portion disposed at a side of said extended portion which is opposite to said projected portion,

two said base portions are formed into a circular shape by combining two said base portions of two said engaging members together and having a fast ring disposed around outer peripheral surfaces of said base portions.

6. The joint mechanism according to claim 1, wherein

said engaging member is normally retained in said projected state, and

as said engaging member passes through said first engaging wall region of said piston-side engaging region, said retracted state without projecting from the outer surface of said cylindrical portion is selected.