Abstract A pump spindle has a screw-shaped configuration and is in the form of an elongated hollow tube of small wall thickness, carrying at one end a means through which a drive is transmitted to the pump spindle. The tube is given its required configuration by means of pressing jaws which press inwardly against the tube and which are suitably shaped so as to achieve the desired helical configuration for the hollow pump spindle. These jaws are supported not only for axial movement but also for radial movement toward and away from a given axis along which the tube is advanced and around which the tube is rotated, so that by advancing the tube in steps synchronized with the movement of the shaping jaws there will issue from an apparatus for manufacturing the pump spindle a tube of required configuration from which a section of predetermined length can be cut. Thereafter, a connecting means is fastened to one end of the thus cut tube to be able to transmit a drive to the tube through the connecting means.
A method for manufacturing a tubular screw spindle of a pump from a seamless tube of small wall thickness, comprising the steps of feeding the tube axially while continuously rotating the tube about its axis, radially pressing shaping jaws against the exterior of the tube and then retracting the jaws, advancing the tube, and again pressing the tube with the jaws to provide the tube with a predetermined configuration, cutting from the thusworked tube a selected length thereof, and then fastening to one end of the selected length of tube a means for transmitting a drive thereto.
Claim 2
Independent Claim
97 words
A method for manufacturing a tubular screw spindle of a pump from a seamless tube of small wall thickness, comprising the steps of feeding the tube axially while continuously rotating the tube about its axis, radially pressing shaping jaws against the exterior of the tube and then retracting the jaws, advancing the tube, and again pressing the tube with the jaws to provide the tube with a predetermined configuration, cutting from the thusworked tube a selected length thereof, and then fastening to one end of the selected length of tube a means for transmitting a drive thereto.