US 2794661 A
Description (OCR text may contain errors)
June 4, 1957 c. E. SEARS COLLAR FOR DRILL STEELS Filed July 9, 1954 INVENTOR CLARENCE E. SEARS HIDS ATTORN-EY United States Patent 2,794,661 COLLAR FOR DRILL STEELS Clarence E. Sears, Sherbrooke, Quebec, Canada, assignor to Ingersoli-Rand Company, New York, N. 1., a corporation of New Jersey Application July 9, 1954, Serial No. 442,357
3 Claims. (Cl. 287-85) This invention relates to drill steels, and more particularly to a collar that is readily attachable to and detachable from a drill steel.
Drill steels of the type to which the present invention pertains are used in rock drills having retaining devices as adjuncts to cooperate with the collar for preventing ejection of the steel from the rock drill. Heretofore, it has been customary to form collars on drill steels by upsetting a portion thereof at a point chosen as the juncture of the body portion of the steel and its shank. This operation, as may be readily appreciated, requires both a considerable degree of skill and costly machinery for carrying it out. In many instances, moreover, the forging operation develops defects which, when sub jected to the heavy stresses of drilling, cause breakage of the drill steel in the area of the collar.
It is accordingly an object of this invention to obviate the need of disturbing the initial form of a drill steel requiring a collar.
Another object is to enable a drill steel to be expeditiously equipped with a collar without the need of special skill or costly machinery.
Other objects will be in part obvious and in part pointed out hereinafter.
In the drawings accompanying this specification and in which similar reference numerals refer to similar parts,
Figure 1 is a side elevation of the front end portion of a rock drill and a drill steel therein, the latter being equipped with a collar constructed in accordance with the practice of the invention,
Fig. 2 is an elevation, partly in section, of a drill steel and a collar, the parts of the latter being shown in position preparatory to the final step of securing them to the drill steel,
Fig. 3 is a view similar to Fig. 2 showing the parts of the collar in the positions which they occupy when firmly attached to the drill steel, and
Fig. 4 is a transverse view taken through Fig. 3 on the line 4-4.
Referring to the drawings, and at first more particularly to Figure 1, 2t) designates the front end portion of a rock drill, 21 a drill steel actuated by the rock drill and 22 a retainer for preventing ejection of the drill steel from the rock drill.
The casing of the rock drill is provided, as is customary, with trunnions 23 to support the retainer 22, and the yoke 24 of the retainer partly encircles the drill steel 21 at a point a sufiicient distance forwardly of the collar 25 to normally avoid contact between the two.
The collar 25 comprises an elongated member 26 which is preferably in the form of a sleeve that is shaped internally to conform with the contour of the drill steel 21. It is constructed of elastic material, as for example rubber or neoprene which is readily deformable and may, therefore, be constricted and pressed into firm gripping engagement with the drill steel.
mflwc The means serving to thus constrict the member 26 comprises a pair of easing parts 28 and 29 that fully encase the said member and a nut 30 for drawing and securing the casing parts together. Each casing part has a wall or shoulder 31 at its outer end to abut the adjacent ends of the member 26 and in said Walls are apertures 32 for the accommodation of the drill steel 21. The apertures 32 are of the same cross sectional shape as the drill steel and preferably have a sufliciently close fit thereon to prevent the extrusion of the ends of the member at these points.
In order to assure the compactness of the member 26 essential to preclude shifting thereof relativelyto the drill steel said member is initially of somewhat greater length than the space it occupies in the operative pos'itions of the parts. The portion 33 of the member 26.
encased by the part 28, as well as the part 28 itself,
is of frustoconical shape to permit of the free adjustment of all areas of the member 26 when subjected to the pressure of the casing. The inner surface 34 of the casing part 29, on the other hand, is of cylindrical shape as is also the portion 35 of the member 26 lying therein.
Preferably, the parts 28 and 29 have portions in telescopic engagement with each other, the casing part 28 having an annular extension 36 that extends into the part 29. The external surface 37 of the extension 36 is of cylindrical shape for sliding engagement with the inner surface of the part 29, and the free end of the annular extension 36 is in the form of a sharp edge 38 that may readily slide along the surface 34 without snagging on the comparatively soft material of the member 26 when the casing parts are being drawn together.
The nut 36 which serves to impart such movement to the casing parts is threadedly connected to the part 29 and has an introverted flange 39 at one end to overlie and engage an external flange 40 on an intermediate portion of the part 28. The opening 41 defined by the flange 39 is of a size to readily pass all portions of the part 28 other than the flange 40 and the nut 30 has suitable flatted surfaces 42 for the accommodation of a wrench whereby it may be manipulated.
In practice, whenever it is intended to attach a collar to a drill steel the member 26 is first disposed in a desired position on the drill steel. The casing parts 28 and 29 are next disposed about the member 26 and the nut 30 is manipulated to draw them together. Such movement of the casing parts will have the effect of constricting the member 26 and forcing it into firm gripping engagement with the drill steel where it will remain unaffected by any jars imparted thereto when projected against the yoke 24 of the steel retainer or when thrust against the front end of the rock drill.
In the event that the drill steel becomes broken, or otherwise useless, the parts constituting the collar may be conveniently removed for re-use and without the need of tools other than those which are normally available at the drilling site.
1. A detachable collar for a drill steel comprising an inner compressible member having a longitudinal hole of uniform section substantially conforming to the configuration of the steel, said member having an outer surface continuously tapered for the greater part of its length and substantially cylindrical toward one end, a first casing member tapered inside to receive the tapered part of said compressible member, and a second casing member cylindrical to receive the cylindrical end of said compressible member, and means to draw said casing members together in telescoping relation to each other for contracting the compressible member onto the steel.
2. A detachable collar for a drill steel comprising an inner compressible member having a longitudinal hole of uniform section substantially conforming to the configuration of the steel, said member having an outer surface continuously tapered for the greater part of its length and substantially cylindrical toward one end, a first casing member tapered inside to receive the taperedpart of said compressible member, and a second casing member cylindrical to receive the cylindrical end of said. compressible member, and means to draw said casing members together in telescoping relation to each other for contracting the compressible member onto the steel, each of said casing members having an abutment end face closely fitting the steel and held against rotation thereby.
3. A detachable collar for a drill steel comprising an inner compressible member having a longitudinal hole of uniform section substantially conforming to the configuration of the steel, said member having anouter surface continuously tapered for the greater part of its length and substantially cylindrical toward one end,
References Cited in the file of this patent UNlTED STATES PATENTS 2,431,120 Howe Nov. 18, 1947 2,562,359 Iredell July 31, 1951 2,721,084 Weiss Oct. 18, 1955