Method of and an apparatus for producing disposable syringes and the disposable syringe produced
AssigneeSORTIMAT Creuz & Co. GmbH
InventorsFriedrich Holzwarth, Gerhard Heinze
Life of this patent
Estimating the term…
Abstract
A metallic syringe tube is fused to a plastic fitting into which the tube is inserted so that the inner end of the tube contacts the fitting, by clamping the tube between a counterelectrode which acts as an abutment for the inner end of the tube and a clamping jaw which engages the free end of the tube, and applying a resistance heating voltage to the tube between the counterelectrode and a location between the fitting and the clamping jaw for heating at least a portion of the syringe tube inner end in contact with the fitting to the melting temperature of the plastic forming the fitting.
Claims29
In a method for fusing a metallic syringe tube having an inner end and a free end into a plastic fitting by pushing the inner end of the syringe tube into the fitting so that the inner end of the syringe tube contacts the fitting, clamping the syringe tube between a counterelectrode which acts as an abutment for the inner end of the syringe tube and a clamping jaw which engages the free end of the syringe tube, and temporarily applying a resistance heating voltage between the counterelectrode and the free end of the syringe tube projecting from the fitting for heating at least a portion of the syringe tube inner end in contact with the fitting to at least the melting temperature of the plastic forming the fitting, while at the same time displacing the clamping jaw and the counterelectrode relatively toward one another, the improvement wherein said step of applying a resistance heating voltage is carried out by applying such voltage between the counterelectrode and a location on the free end of the syringe tube between the fitting and the clamping jaw such that the voltage is applied along a length of the syringe tube which is shorter than the length of the syringe tube between the clamping jaw and the counterelectrode, and said method further comprises maintaining the length of the syringe tube along which the voltage is applied substantially constant during said step of temporarily applying.
A method of producing a disposable syringe component composed of a syringe tube of metal and a fitting of a softenable or meltable material having a central bore, comprising inserting the syringe tube into the bore so that the syringe tube projects out of the fitting, expanding the syringe tube within the bore, and subsequent to expanding the syringe tube, deforming a portion of the fitting material by softening or melting that portion and displacing that portion to a position in front of the inner end of the syringe tube to form a constriction opposite the inner end of the syringe tube, such that in both axial directions of the syringe tube, material of the fitting is located opposite the expanded portion and the tube is connected to the fitting in a sealed, compression- and tension-resistant manner.
In a method for fusing a metallic syringe tube having an inner end and a free end into a plastic fitting by pushing the inner end of the syringe tube into the fitting, clamping the syringe tube between a counterelectrode which acts as an abutment for the inner end of the syringe tube and a clamping jaw which engages the free end of the syringe tube, and temporarily applying a resistance heating voltage between the counterelectrode and the free end of the syringe tube projecting from the fitting, the improvement comprising supporting the syringe tube on the shoulder of a constriction of an axial bore extending through the fitting, and, after said step of supporting, laterally expanding the inner end of the syringe tube within the fitting by passing a mandrel through the constriction for securing the tube to, and establishing a tension-proof and compression-resistant engagement with, the fitting.
In a method for fusing a metallic syringe tube having an inner end and a free end into a plastic fitting by pushing the inner end of the syringe tube into the fitting, clamping the syringe tube between a counterelectrode which acts as an abutment for the inner end of the syringe tube and a clamping jaw which engages the free end of the syringe tube, and temporarily applying a resistance heating voltage between the counterelectrode and the free end of the syringe tube projecting from the fitting, the improvement wherein the fitting is initially provided with a recess adjacent the inner end of the syringe tube, and comprising laterally expanding the inner end of the syringe tube within the fitting for securing the tube to, and establishing a tension-proof and compression-resistant engagement with, the fitting, and, during said step of expanding, filling the recess with material of the fitting.
In a method for fusing a metallic syringe tube having an inner end and a free end into a plastic fitting by pushing the inner end of the syringe tube into the fitting, clamping the syringe tube between a counterelectrode which acts as an abutment for the inner end of the syringe tube and a clamping jaw which engages the free end of the syringe tube, and temporarily applying a resistance heating voltage between the counterelectrode and the free end of the syringe tube projecting from the fitting, the improvement comprising laterally expanding the inner end of the syringe tube within the fitting, by inserting into the syringe tube inner end an expansion mandrel also constituting the counterelectrode, for securing the tube to the fitting.
In a method for fusing a metallic syringe tube having an inner end and a free end into a plastic fitting by pushing the inner end of the syringe tube into the fitting, clamping the syringe tube between a counterelectrode which acts as an abutment for the inner end of the syringe tube and a clamping jaw which engages the free end of the syringe tube, and temporarily applying a resistance heating voltage between the counterelectrode and the free end of the syringe tube projecting from the fitting, the improvement comprising laterally expanding the inner end of the syringe tube within the fitting by inserting an expansion mandrel into the syringe tube inner end for securing the tube to the fitting, wherein said step of inserting comprises rotating the mandrel.
In a method for fusing a metallic syringe tube having an inner end and a free end into a plastic fitting by pushing the inner end of the syringe tube into the fitting, clamping the syringe tube between a counterelectrode which acts as an abutment for the inner end of the syringe tube and a clamping jaw which engages the free end of the syringe tube, and temporarily applying a resistance heating voltage between the counterelectrode and the free end of the syringe tube projecting from the fitting, the improvement comprising laterally expanding the inner end of the syringe tube within the fitting by inserting an expansion mandrel into the syringe tube inner end for securing the tube to the fitting, wherein said step of inserting comprises vibrating the mandrel.
Dependencies are inferred from the claim text.