US3925868A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Clamping assembly for cutter bits
Assignee: Mccrosky Tool Corp
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Filing: 1974-06-21
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Granted: 1975-12-16
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Expires: 1994-06-21
Abstract
Abstract A clamping assembly for an apertured indexable cutter bit within a recessed seat therefor on a tool holder, comprised of a fastening bolt having a threaded portion at its inner end and a tapered head at its outer end. A resilient split collet or sleeve, of a height comparable to the height of the cutter bit and of increasing thickness from the outer end to the inner end thereof, surrounds the tapered head and fits closely within the space between the tapered head of the bolt and the aperture in the cutting bit. The rotation of the fastening bolt and its advance into a threaded opening in the tool holder, effects a spreading of the resilient collet so that the outer lateral surface of the collet grasps tightly the cutter bit and fixes it within the seat of the tool holder for all cutting operations. No parts of the clamping components project beyond the contours of the tool assembly to cause any interference with the chip flow. Furthermore, the clamping action may be released easily by rotation of the fastening bolt in the reverse direction which causes the resilient split collet to release the cutting tool from the tool holder for indexing or removal. Since none of the parts undergo any permanent distortion, the newly positioned cutter bit may be fixed quickly in its new position by again advancing the fastening bolt into the threaded opening in the tool holder.
Inventors
- 👤 Kanwar J Singh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:35
CPC Classifications
B; B23; B23B; B23B27/00; B23B27/14; B23B27/16; B23B27/1662; B23B2205/00; B23B2205/04; B23B2260/00; B23B2260/136; Y; Y10; Y10T; Y10T407/00; Y10T407/22; Y10T407/2272; Y10T407/2274; Y10T407/2276
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
371 words
A tool clamping assembly for detachably fastening an indexable cutting bit on a tool holder, comprising a. a tool holder having a recessed seat therein for receiving a regular polygonal cutting bit provided with a plurality of cutting edges, b. said recessed seat having a base portion and at least one shoulder portion extending upwardly therefrom, c. said base portion having a threaded bore at the interior portion thereof extending inwardly of the tool holder, d. said indexable cutting bit having a cylindrical opening of larger diameter than said threaded bore, said opening extending between the opposite faces of said bit and centrally of the lateral edges thereof, e. a clamping bolt for fastening said cutting bit onto said seat, said bolt having a threaded portion at the one end thereof and an external tapered lateral surface at the opposite end thereof, f. a radially expansible sleeve surrounding said tapered lateral surface of said bolt provided with a narrow slot in the lateral wall thereof extending from the opposite ends thereof, g. said sleeve having an external substantially cylindrical surface normally fitting closely within said cylindrical opening of said cutting bit, and an internal frusto-conical surface having a conicity corresponding to the tapered lateral surface of said bolt to effect substantially complete surface contact between said internal frusto-conical surface and the tapered lateral surface of said bolt around its entire circumferential area except for the small area adjacent to said narrow slot, and h. means at the end of said bolt for imparting rotary movement thereto, whereby the advancing movement of the threaded portion of said bolt into said threaded bore of said tool holder imparts only radial expansive movement to said sleeve to the exclusion of any translational movement thereto, which effects tightly engaging contact between substantially the entire periphery of said tapered lateral surface of said bolt and the correspondingly tapered internal surface of said sleeve as well as between substantially the entire external cylindrical surface of said sleeve and the internal periphery of said cylindrical opening in said indexable cutting bit, whereby a rigid and tight clamping interconnection is effected between said tool holder and cutting bit at both said base portion and shoulder portion of said seat.
Claim 2
Dependent Claim
371 words
A tool clamping assembly for detachably fastening an indexable cutting bit on a tool holder, comprising a. a tool holder having a recessed seat therein for receiving a regular polygonal cutting bit provided with a plurality of cutting edges, b. said recessed seat having a base portion and at least one shoulder portion extending upwardly therefrom, c. said base portion having a threaded bore at the interior portion thereof extending inwardly of the tool holder, d. said indexable cutting bit having a cylindrical opening of larger diameter than said threaded bore, said opening extending between the opposite faces of said bit and centrally of the lateral edges thereof, e. a clamping bolt for fastening said cutting bit onto said seat, said bolt having a threaded portion at the one end thereof and an external tapered lateral surface at the opposite end thereof, f. a radially expansible sleeve surrounding said tapered lateral surface of said bolt provided with a narrow slot in the lateral wall thereof extending from the opposite ends thereof, g. said sleeve having an external substantially cylindrical surface normally fitting closely within said cylindrical opening of said cutting bit, and an internal frusto-conical surface having a conicity corresponding to the tapered lateral surface of said bolt to effect substantially complete surface contact between said internal frusto-conical surface and the tapered lateral surface of said bolt around its entire circumferential area except for the small area adjacent to said narrow slot, and h. means at the end of said bolt for imparting rotary movement thereto, whereby the advancing movement of the threaded portion of said bolt into said threaded bore of said tool holder imparts only radial expansive movement to said sleeve to the exclusion of any translational movement thereto, which effects tightly engaging contact between substantially the entire periphery of said tapered lateral surface of said bolt and the correspondingly tapered internal surface of said sleeve as well as between substantially the entire external cylindrical surface of said sleeve and the internal periphery of said cylindrical opening in said indexable cutting bit, whereby a rigid and tight clamping interconnection is effected between said tool holder and cutting bit at both said base portion and shoulder portion of said seat.
Claim 3
Dependent Claim
23 words
An assembly as set forth in claim 1, wherein said shoulder portion is comprised of two intersecting surfaces extending upwardly from said base.
Claim 4
Dependent Claim
32 words
An assembly as set forth in claim 2, wherein a free gap is provided between the two intersecting surfaces extending upwardly from said base for accommodating a corner of said cutting bit.
Claim 5
Dependent Claim
32 words
An assembly as set forth in claim 2, wherein said cutting bit is of rectangular outline and the surfaces of said shoulder portions of said seat are arranged perpendicularly to each other.
Claim 6
Dependent Claim
32 words
An assembly as set forth in claim 2, wherein said cutting bit is of square outline and the surfaces of said shoulder portions of said seat are arranged perpendicularly to each other.
Claim 7
Dependent Claim
27 words
An assembly as set forth in claim 1, wherein the bottom of said expansible sleeve rests upon the base portion of the seat in said tool holder.
Claim 8
Dependent Claim
24 words
An assembly as set forth in claim 1, wherein said last-mentioned means comprises an opening of hexagonal cross-section for accommodating an Allen wrench therein.
Claim 9
Dependent Claim
39 words
An assembly as set forth in claim 1, wherein the axis of said threaded bore and that of said cylindrical opening are parallel to each other, with the former being slightly closer than the latter to said shoulder portion.
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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |