METHOD FOR FABRICATING A THREADED TAP BY STAMPING

• US 3,857,349 A
• Filed: 07/19/1973
• Issued: 12/31/1974
• Est. Priority Date: 07/19/1973
• Status: Expired due to Term

• Current Assignee: James Pritulsky
• Original Assignee: James Pritulsky
• Inventors: Pritulsky, James
• Primary Examiner(s): Herbst, Richard J.
• Application Number:
  US05/380,921
• Time in Patent Office: 530 Days
• Field of Search: 113/119 339/263,268,232 85/32V,1L,85
• US Class Current: 29/874
• CPC Class Codes: B21D 53/24 nuts or like thread-engaging members
• CPC Class Codes: F16B 35/00 Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws F16B33/008 takes precedence; joining sheets or plates using screws with two separate threads F16B5/0275; using screws with adjustment sleeves F16B5/0283; thread cutting screws F16B25/00
• CPC Class Codes: F16B 37/02 made of thin sheet material fastening to surfaces F16B37/04 ; used as lock-nuts F16B39/14
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing

Abstract

A method for fabricating a threaded tap from a continuous supply of flat stock material comprising the steps of feeding a portion of the flat stock to a work station, stamp cutting a blank having two appendages thereon with a rectangular tab on each appendage, cold working each of the two tabs into half cylindrical configurations, cold working threads into each of the two half cylindrical elements, and then folding said appendages about fold lines selected to cause said threaded half cylindrical elements to come together to form one commplete, cylindrical element, with the threads properly aligned to receive a bolt or screw.

Claims

1. A method for forming an electrical terminal having a cylindrically shaped element with internal and external threads thereon from a continuously fed supply of flat stock material and comprising the steps of:

feeding a predetermined section of said flat stock material into at least one given work area containing cutting and forming dies;

cutting the predetermined section of flat stock into a shape having thereon first and second rectangularly shaped tabs of equal shape and positioned such that corresponding lines of each rectangularly shaped tab are symmetrical mirrored about a centerline lying therebetween;

forming corresponding portions of each tab into curved surfaces which are mirrored images of each other about said centerline to define a pair of truncated, half cylinders, with a first end of each half cylinder being integrally secured to the remainder of said section of flat stock and the second end thereof terminating in a plane substantially normal to the longitudinal axis of said half cylinder;

cold working the half cylinders to form threads thereon; and

folding said half cylinders towards each other through a predetermined arc and about folding lines located in said remainder of said section and bisecting those portions of said remainder of said section of said flat stock lying between said centerline and the junctions of said tabs and said section so that the concave surfaces of each of said half cylinders approach each other and the corresponding longitudinal edges of each half cylinder are spatially poSitioned substantially coincident with each other to form a complete, truncated, threaded cylinder.

2. A method for making threaded, cylindrically shaped elements from a sheet of flat stock material and comprising the steps of:

feeding successive portions of said flat stock into at least one work area;

stamp cutting the portion of said flat stock which is in said work area to form at least one pair of appendages thereon and an aperture positioned between said two appendages;

cold working a section of each appendage into a half cylinder configuration which is truncated in a plane normal to the rotational axis of the half cylinder at the first end thereof, and having the second end thereof secured to the remainder of said portion of flat stock;

folding each of said appendages about predetermined folding lines and through a portion of an arcuate path of a given arcuate length selected to eventually bring said half cylinder configurations together to form a complete cylindrical section when said appendages are folded completely through said given arcuate length;

said folding lines bisecting straight lines which join the midpoints of said appendages where they in turn join said remainder of said portion of said flat stock and the center of said aperture;

said straight lines having a length more than twice that of the diameter of said aperture;

cold working said half cylindrical configurations at an intermediate point in their arcuate paths to form threads thereon;

folding said appendages along said folding lines through the remainder of said given arcuate length to bring said half cylindrical configurations together to form a complete cylindrical section positioned over said aperture and with the threads formed thereon being properly aligned to receive a mating threaded element.

3. A method for fabricating cylindrically shaped elements, threaded both internally and externally, from a sheet of flat stock and comprising the steps of:

feeding successive portions of said flat stock into at least one work area;

stamp cutting the portion of said flat stock which is in said work area to form two appendages thereon and an aperture positioned between said two appendages;

cold working a section of each of said two appendages into a half cylinder configuration which is truncated at one end thereof, and having the other end thereof secured to the remainder of said portion of flat stock;

cold working said half cylindrical configurations to form threads thereon both internally and externally;

folding said appendages along selected folding lines through a given arcuate path to bring said half cylindrical configurations together to form a complete cylindrical section positioned over said aperture and with the threads formed thereon being properly aligned to receive a mating threaded element;

said folding lines bisecting straight lines which join the midpoints of said appendages where they in turn join said remainder of said portion of said flat stock and the center of said aperture;

said straight lines having a length more than twice that of the diameter of said aperture.

4. A method for fabricating cylindrically shaped elements, threaded internally and externally, from a sheet of flat stock and comprising the steps of:

feeding successive portions of said flat stock into at least one work area;

stamp cutting said portion of said flat stock in said work area to form an element comprising a main body having at least one pair of appendages, with each appendage having a tab thereon and also to form an aperture between said pair of appendages;

shaping each of said tabs into a half cylindrical configuration truncated at one end thereof in a plane normal to the rotational axis of the half cylindrical configuration and having the other end thereof secured to the main body of said element;

cold working said half cylindrical configurations to form threads thereon; and

folding said threaded half cylInder shaped configuration about predetermined folding lines along an arcuate path selected to bring said half cylinder sections together to form a complete cylindrical section over said aperture and having continuous threading;

said folding lines bisecting straight lines which join the midpoints of said appendages where they in turn join said main body of said element and the center of said aperture;

said straight lines having a length more than twice that of the diameter of said aperture.

5. A method for fabricating threaded cylindrically shaped elements from a sheet of flat stock and comprising the steps of:

feeding successive portions of said flat stock into at least one work area;

cutting and stamping said portion of said flat stock in said work area to form an element having at least two appendages each of which is shaped into a half cylinder configuration truncated at one end and having the other end secured to the main body of said element;

cold working said half cylinder configurations to form threads thereon; and

folding said element about predetermined folding lines along an arcuate path selected to bring together two of said half cylinder configurations to form a complete cylindrically shaped element with continuous threading thereon;

said folding lines bisecting straight lines which join the midpoints of said appendages where they in turn join said remaining portion of said flat stock and the center of said aperture;

said straight lines having a length more than twice that of the diameter of said aperture.

6. A method for fabricating threaded cylindrically shaped elements, from a sheet of flat stock and comprising the steps of:

feeding successive portions of said flat stock into at least one work area;

stamp cutting said portion of said flat stock in said work area to form an element having at least two pairs of appendages, with each appendage having a tab formed thereon;

cold working each tab into a half cylinder configuration which is truncated at one end thereof in a plane normal to the rotational axis of the half cylinder configuration, and having the other end thereof secured to the main body of said element;

cold working said half cylinder configurations to form threads thereon;

folding each appendage of each of said pairs of appendages about predetermined folding lines and along a portion of an arcuate path selected to bring the half cylindrical configurations on each pair of appendages together to form two complete cylindrically shaped elements, each with continuous threading thereon.