Patent US2936368A successfully refreshed from Google Patents.
Patent US3826153A successfully refreshed from Google Patents.
US3826153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ball-screw mechanism
Assignee: RH Sheppard Co Inc
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Filing: 1972-09-06
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Granted: 1974-07-30
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Expires: 1992-09-06
Abstract
Abstract An easily machined ball-screw mechanism of compact design and characterized by improved smoothness of operation is disclosed. In the mechanism, a tubular nut is encased by an outer removable enclosing member and is operatively engaged with a screw member having a helical groove. The tubular nut has two helical guideways, one on the inner circumferential surface, in opposed relationship with said helical groove, and one in the return direction on the outer circumferential surface. A first set of bearing members is held captive between the inner helical guideway of the nut and the groove, and a second set is held captive in the outer guideway of said tubular nut by the enclosing member. Separate transfer discs positioned at each end of the tubular nut have an open grooved ramp spiraling from cooperative adjacency with the inner guideway to the outer guideway to transfer bearing members between said first and second sets. A sleeve adapted to mate with the enclosing member and the nut assist in loading the bearing members.
Inventors
- 👤 R Sheppard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:08
CPC Classifications
F; F16; F16H; F16H25/00; F16H25/18; F16H25/20; F16H25/22; F16H25/2204; F16H25/2214; F16H25/2219; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19642; Y10T74/19698; Y10T74/19702; Y10T74/19744; Y10T74/19749; Y10T74/19753
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
170 words
A ball-screw mechanism comprising a screw member having a helical groove, a tubular nut having inner and outer circumferential faces, one of the faces having a first open helical guideway formed therein in opposed relationship to said groove, a first set of bearing members held captive between said groove and said guideway to establish the relative driving relationship between said screw and said nut, a second open guideway formed in the other face of said nut and in the return direction, a second set of bearing members in said return direction guideway, a removable enclosing member contiguous with said other face and in engagement with said second set of bearing members to hold the same captive, separate transfer discs at each end of said nut, each disc having an open grooved ramp spiraling from cooperative adjacency with said first guideway to said second guideway to transfer said bearing members between said first and second sets, whereby the parts are easily machined with open grooves and the assembly thereof is compact.
Claim 2
Dependent Claim
170 words
A ball-screw mechanism comprising a screw member having a helical groove, a tubular nut having inner and outer circumferential faces, one of the faces having a first open helical guideway formed therein in opposed relationship to said groove, a first set of bearing members held captive between said groove and said guideway to establish the relative driving relationship between said screw and said nut, a second open guideway formed in the other face of said nut and in the return direction, a second set of bearing members in said return direction guideway, a removable enclosing member contiguous with said other face and in engagement with said second set of bearing members to hold the same captive, separate transfer discs at each end of said nut, each disc having an open grooved ramp spiraling from cooperative adjacency with said first guideway to said second guideway to transfer said bearing members between said first and second sets, whereby the parts are easily machined with open grooves and the assembly thereof is compact.
Claim 3
Dependent Claim
36 words
The ball-screw mechanism of claim 1 wherein said second guideway is helical with substantially the same pitch as said first guideway whereby the resistance to movement of said bearing members along the entire path is minimized.
Claim 4
Dependent Claim
34 words
The ball-screw mechanism of claim 1 wherein said second guideway is substantially the same depth as the cross section dimension of said bearing member, whereby said enclosing member is ungrooved for ease of assembly.
Claim 5
Dependent Claim
43 words
The ball-screw mechanism of claim 1 wherein said tubular nut and end discs are mounted within a cavity in said enclosing member, and ring means at the open end of said cavity to hold said nut and discs together and in said cavity.
Claim 6
Dependent Claim
86 words
The ball-screw mechanism of claim 4 wherein is provided a loading sleeve for said bearing members, said sleeve fitting into said open end of saiD cavity and the inner surface mating with said other face of said nut and the adjacent disc, and a lateral opening in said sleeve for alignment with any selected portion of said second guideway for loading said bearing members, said sleeve holding said bearing members in place until the nut and end disc assembly is pushed into place in said cavity.
Claim 7
Dependent Claim
31 words
The ball-screw mechanism of claim 1 wherein said end discs are affixed to said nut to form an assembly by pin means fitting into aligned holes by a tight friction fit.
Claim 8
Dependent Claim
28 words
The ball-screw mechanism of claim 6 wherein one of said pin means is received in a locating aperture in said enclosing member to prevent movement of said assembly.
Claim 9
Dependent Claim
28 words
The ball-screw mechanism of claim 1 wherein said spiral ramp extends through 360*, the depth of said ramp gradually varying from minimum to maximum and back to minimum.
Claim 10
Dependent Claim
19 words
The ball-screw mechanism of claim 8 wherein the ramp includes a central maximum depth portion extending through approximately 45*.
Claim 11
Dependent Claim
38 words
The ball-screw mechanism of claim 8 wherein the remainder of the 360* of the ramp is divided into radially inner and outer portions, the inner portion extending through approximately 180* and the outer portion through approximately b 135*.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |