SLIP RING ASSEMBLY AND METHOD OF MAKING SAME

• US 3,785,049 A
• Filed: 05/10/1971
• Issued: 01/15/1974
• Est. Priority Date: 05/15/1970
• Status: Expired due to Term

• Current Assignee: Hideo Tatsumi, Hisanobu Kanamaru, Yasushi Ohuchi
• Original Assignee: Hideo Tatsumi, Hisanobu Kanamaru, Yasushi Ohuchi
• Inventors: Kanamaru, Hisanobu, Ohuchi, Yasushi, Tatsumi, Hideo
• Primary Examiner(s): Lanham, Charles W.
• Assistant Examiner(s): Duzan, James R.
• Application Number:
  US05/141,923
• Time in Patent Office: 981 Days
• Field of Search: 310/232 339/5,8,190,198E,218 29/628,629,63B,627
• US Class Current: 29/597
• CPC Class Codes: H01R 39/08 Slip-rings
• CPC Class Codes: H01R 43/10 Manufacture of slip-rings
• CPC Class Codes: Y10T 29/49011 Commutator or slip ring assembly

Abstract

A slip ring assembly in which principal components, a molded cylindrical base, conductive rings and terminals are separately manufactured and assembled together. In assembling, the terminals are fitted in diametrically spaced grooves formed on the cylindrical base and the conductive rings are press-fitted on the cylindrical base thereby to bring the conductive rings into pressure contact with the respective terminals and to ensure satisfactory engagement of the conductive rings with the cylindrical base.

Claims

1. A method of making a slip ring assembly comprising the steps of separately preparing a base of electrical insulating material having a cylindrical base part, a plurality of conductive rings and a plurality of wire terminals of the same number as that of said conductive rings, the step of preparing said cylindrical insulating base part including forming a plurality of grooves of the same number as that of said conductive rings for receiving said wire terminals therein, axially extending each of said grooves through the overall length of said cylindrical base part, and forming each groove with a shallow portion having a depth substantially smaller than the thickness of said wire terminals at a predetermined position of the cylindrical base part where a corresponding conductive ring is to be press-fitted and with a deep portion having a depth substantially larger than the thickness of said wire terminals at the remaining portion of the groove excepting said shallow portion, disposing one of said wire terminals in each of said respective grooves, and press-fitting said conductive rings onto the respective predetermined positions of said cylindrical base part such that each of said wire terminals is pressed by the corresponding one of said conductive rings to be firmly held between the bottom surface of the shallow portion of the corresponding one of said grooves and the inner peripheral surface of said corresponding conductive ring to thereby electrically connect said wire terminals to said corresponding conductive rings and insulate said conductive rings from each other.

2. A method of a making a slip ring assembly as claimed in claim 1, in which a generally U-shaped wire of electrical conductor is disposed in said terminal receiving grooves, and after press-fitting said conductive rings to engage the outer peripheral surface of said wire, unnecessary wire portions are cut off and removed to provide said wire terminals.

3. A method according to claim 1, further comprising positioning wire insulation in surrounding engagement over a predetermined portion of the length of at least one of said wire terminals prior to disposing said at least one wire terminal in one of said respective grooves, wherein said disposing of said wire terminals includes positioning said one of said wire terminals with the wire insulation extending along the deep portion of the corresponding groove.

4. A method according to claim 1, wherein said base includes an end part adjacent said cylindrical base part which has a greater cross-sectional area than said cylindrical base part, wherein openings are provided in said end part which Are aligned with respective ones of said grooves, and wherein said disposing of said wire terminals includes extending portions of said wire terminals through said openings.

5. A method according to claim 4, further comprising bending the extreme ends of said wire terminals extending through said openings to form attachment points for electrical circuitry after said press-fitting.

6. A method according to claim 4, wherein said disposing of said wire terminals includes positioning the legs of a U-shaped piece of wire in two respective grooves, and further comprising cutting off unnecessary portions of said U-shaped piece of wire after said press-fitting.

7. A method according to claim 6, wherein said U-shaped piece of wire is positioned with said legs extending through said openings in the end part of the base.

8. A method according to claim 7, wherein the bridge part of said U-shaped piece of wire is positioned adjacent the cylindrical part of said base, and wherein said cutting includes cutting said wire immediately adjacent the respective press-fitted ring in press-fitting contact with said wire portion being cut.

9. A method according to claim 1, including preparing said cylindrical part with a constant diameter along its length and preparing each of said conductive rings similar inner diameters.

10. A method of making a slip ring assembly comprising the steps of separately preparing a base of electrical insulating material having a first part with constant cross-section along its length, a plurality of conductive rings and a plurality of wire terminals of the same number as that of said conductive rings, the step of preparing said first part including forming a plurality of grooves of the same number as that of said conductive rings for receiving said wire terminals therein, axially extending each of said grooves through the overall length of said first part, and forming each groove with a shallow portion having a depth substantially smaller than the thickness of said wire terminals at a predetermined position of the first part where a corresponding conductive ring is to be press-fitted and with a deep portion having a depth substantially larger than the thickness of said wire terminals at the remaining portion of the groove accepting said shallow portion, disposing one of said wire terminals in each of said respective grooves, and press-fitting said conductive rings onto the respective predetermined positions of said first part such that each of said wire terminals is pressed by the corresponding one of said conductive rings to be firmly held between the bottom surface of the shallow portion of the corresponding one of said grooves and the inner peripheral surface of said corresponding conductive ring to thereby electrically connect said wire terminals to said corresponding conductive rings and insulate said conductive rings from each other.

11. A method according to claim 10, further comprising positioning wire insulation in surrounding engagement over a predetermined portion of the length of at least one of said wire terminals prior to disposing said at least one wire terminal in one of said respective grooves, wherein said disposing of said wire terminals includes positioning said one of said wire terminals with the wire insulation extending along the deep portion of the corresponding groove.

12. A method according to claim 10, wherein said base includes an end part adjacent said first part which has a greater cross-sectional area than said first part, wherein openings are provided in said end part which are aligned with respective ones of said grooves, and wherein said disposing of said wire terminals includes extending portions of said wire terminals through said openings.

13. A method according to claim 12, further comprising bending the extreme ends of said wire terminals extending through said openings to form attachment points for electrical circuitry after said press-fitting.