| 摘要 |
A cylinder-piston unit, of a needle-free injector, with at least one cylinder accommodating an injection solution, and with at least one piston. The piston is composed of a drive body and of a sealing body. The sealing body is at least one elastic disc, which bears under a radial clamping action against the inner wall of the cylinder. The drive body is a pot-shaped body with a peripheral elastic skirt. At least one area of the skirt bears under a radial clamping action against the inner wall of the cylinder. The cylinder chamber areas located in front of and behind the drive body communicate with each other via at least one recess. The drive body is arranged behind the sealing body in the cylinder, and the skirt faces towards the sealing body. A piston is developed which, at ambient pressure, can be set down on the liquid level of a filled cylinder in a bubble-free, sterile and gas-tight manner and which nevertheless withstands a high compression pressure without leakage during the targeted emptying of the cylinder-piston unit. |
| 主权项 |
1. Cylinder-piston unit (10) of a needle-free injector, comprising:
a cylinder (20) for accommodating an injection solution, and at least one a piston (80), each of the at least one piston (80) includes a drive body (81) and a sealing body (100), the sealing body (100) for setting down on a liquid level (2) of the injection solution and includes at least one disc comprising a rubber-like or a silicone-like material and for bearing under a radial clamping action against an inner wall (31) of the cylinder (20), the drive body (81) is a pot-shaped body having a peripheral elastic skirt (90), at least one area of the peripheral elastic skirt (90) for bearing under a radial clamping action against the inner wall (31) of the cylinder (20), the cylinder (20) having cylinder chamber areas located in front of and behind the drive body (81) in fluid communication with each other via at least one recess (97) of the drive body (81), either directly or by way of a valve, the drive body (81) is arranged behind the sealing body (100) in the cylinder (20), and the peripheral elastic skirt (90) faces towards the sealing body (100), and the drive body (81), for being forwardly displaceable upon actuation, and for about completely receiving the sealing body (100) during the forward travel of the drive body (81), for causing the combination of the drive body (81) and of the sealing body (100) to function of as the piston (80). |
