US1921700A - Bit - Google Patents

Description

Aug. 8, 1933. REED 1,92L700 1933- E. A. REED l,92l,700

Filed May 26', 1927 2 Sheets-Sheet 2 l E'. eed

Wud

A ORNE Patented Aug. 8, 1933 UNITED STATES PATENT OFFlCE.

15 Claims.

The invention relates to improvements in roller boring drills and has reference more particularly to an improved manner of mounting frustoconical cutters on the bit head.

It is a further object of the invention to provide a single piece bit head which receives and supports'a pair of frusto-conical roller cutters, and at the same time is of sufiicient strength to hold said cutters rigidly in position and to prevent them from springing toward the Vertical axis of a hole in operation.

More specifically the invention comprehends an improved manner of mounting a pair of frusto-conical cutters to projecting legs of a single piece bit head so that' said cutters can be readily removed when it is necessary to substitute new cutters, which frequently happens in the use of tools of this type.

I have discovered that a pair of conical cutters can be mounted on a one piece bit head of the type disclosed in the drawings so that they are closely adjacent to or abut each other and their cutting surfaces substantially extend over the entire end of the bit head. This is accomplished by forming a frusto-conical spindle on the projecting legs of the bit head whose surface elements are approximately right angles to each other, and whose interior line of element is approximately parallel with the Vertical axis of y the bit head, and by forming the interior of the bushing and cutter to register therewith.

Referring now more particularly to the drawings, Figure 1 designates a bit head with a pair of rollers cutters, said head being in part in section. r

Figure 2 is'a detail view of a bushing.

Figure 3 is a sectional viewthrough the bit head. r

Figures 4 and 5 are detail views of the sectional bushing; and,

Figure 6 is a detail view of the cutter mounted on the bushing. x

Figure 7 represents a sectional detailed vie of a modified form of the invention.

Referring now more particularly to the drawings wherein like reference characters indicate corresponding parts, the numeral 1 designates a bit head havinga pair of spaced legs 2 providing a cutter receiving opening 3 therebetween. It will be noted that the lower portions of the legs 2 are formed into integral frusto-conical spindles, shown clearly in Figures 1 and 3, and that the opposed elements of the spindles are disposed at approximately right angles to each other. Also as shown in Figure l all portions of said spindles are positioned in a direction axially of said drill head, with respect to the base areas of the spindles, which areas are defined by the intersection of said spindles with the legs 2 of the drill head as shown in Figure 3. The

head has the usual threaded coupling end 4 with' a water conducting port 5 extending therethrough.

It will be observed that the drill receives a pair of frusto-conical cutters 6 and '7, and that these cutters are frequently held in position by reason of the strength of the legs 2 of the bit head. Each cutter is composed of a single piece of metal having a frusto-conical interior 8 of dimensions sufficient to form fianges 9 which are integral with the cutters and serve toilock them on their bushing to be hereinafter described. The frusto-conical interior portion 8 of .each cutter 'fits around and receives a bushing" 10, which bushing is formed of sections 11, 12 and 13, and with a pair of recesses 15 and 16 providing means by which each bushing may be locked in position. ,It will be observed that the flanges 9 of each cutterfit around the surfacesl of the'frusto-conical bushing, and in this way the cutters are retained against either Vertical or lateral movement on the bit head while at the same time the cutters are free to rotate on the bushing.

Asecond bushing or wear-plate '17 is also pro-` vided, ,this wear-plate being interposed between the bit head and the bushing 8. The wear-plate is of the general configuration of the bushing,

having a pair of openings 19 aligning with the openings in a bushing for receiving locking elements that will be hereinafter described. De-,- pendin'g from each of the legs 2 and 3 of the'bit head is a projection 20 which passes through the i lower opening in the wear-plate 17 and into the opening 15 of one of thesections of the bushing 8. Extending laterally through each of the legs of the bit head ,is a locking plug 20 which plug penetrates the upper opening of each wearplate and enters the socket or opening 16 of one of the sections of the bushing 8.

This plug is retained in position by a threaded locking element 21 which cooperates with threads in the walls of the lateral opening receiving the plug. 4

It will also be seen that the head has a suitable oil duct 22 which extends down to suitable oil openings 23 and 24 passing through the wear plate 17 andthe sections of the bushing 8. This is to provide adequate means for lubricating the rotary cutterscarried by the head. It will furthermore be appreciated that the bushingev is composed of sections in order that it may be in-` serted in the frusto conical opening formed in each of the cutters 6 and 7. It will be apparent that the displacement of the cutters is prevented by the depending looking pin 20 and the looking plug 20 and thatit is only necessary to remove the plug 20 in order to remove from the bit head any one of the cutters. n

It will be apparent also that the depending looking pin is equivalent to and may be readily substituted by a projection or step cut formation fromthe interior of the lower section of bushing 10 into a recess to register therewith formed in the lower part of the spindle on the projecting leg of the bit head.

In Figure '7 I have disclosed a modified form of my invention in which the cutter 6 seats directly on a bushing 2d and on the ends of depending pin and removable plug 27. In this construction a continuous groove is formed in the interior of the cutter to register with the ends of depending pin 25 and removable plug 27 to permit the cutter to rotate thereupon. The object of this construction is to provide a relatively large spindle on small size bits. To hold such cutter rotatably in position but at the same tine to provide a detachable mounting each leg of the bit head carries a depending pin 25 passing through the bushing 24 and entering the groove 26 in the interiorof the cutter While a removable locking plug 27 penetrates each leg of the bit head laterally and bushing 24 and its interior end enters the groove 26 in the cutter,

thus holding the roller cutter rotatably in position although readily detachable from the drill head. To operate the plug a threaded .member 28 enters a threaded socket 29 of the plug, this member being in turn connected to a threaded operating head 30 coacting with suitable threads in thewalls of the bit head, the rotation of which operating member moves the plug 27 toward or away from the cutten Having thus described my invention, what I claim is:

1. In a drill of the character described, the

combination with a bit head, of. a roller cutter of frusto-conical formation and having a substantially frusto-conical interior, and having an integral interior fiange near its base projecting to'- Ward its axis, a sectional removahle frusto-coni cal bushing entering said frusto-conical interior 'ofthe' cutter under its flange, and means for detachably mounting said bushing nonrotatably and its roller cutter rotatably to the bit head. '2. -In a drill ofthe character described, the combination with a bit' head, of a roller cutter 'of frusto-conical formation and having a substantially frusto-conical interior, and having an integral interior flange near its base projecting toward its axis, a section removable bushing entering said frusto-conical interior of the cutter under its hange, and means for detachably mcunting said bushing nonrotatably and its 'cutter rotatably to the bit head, said means including a detachahle fastening device carried by 'the bit 'head and entering said bashing, substantially as described.

3. `The combination with a roller boring drill head, of a of integral downwardly projecting legs diametrically oppositeeach other, a right -angular frusto conical spindle formed on each leg and whose axis of rotation inclines downwardly and inwardly, a unitary, perforated, right angular, frusto-conical bushing surrounding 'eachspindle, 'a single unit roller cutterhaving a frusto-ccni'cal interior, fianged socket therein carriedby each leg, a sectional bushing disposed within said flanged under said ange and'surrounded by the roller cutter, and means for detachably looking said unitary bushing 'and said sectional pushing unmovably to one of the legs of the drill head, and said sectional bush-ing permitting free rotation of said roller 1,921,7oov

cutter relative thereto and to said unitary bush-' ing while serving in conjunction with' said flange to prevent axial separation of the roller cutter from said sectional bushing.

4. A roller boring drill head composed of a single piece including two integral downwardly projecting legs diametrically opposite each other, frusto conical spindles formed on said projecting legs whose axes are inclined downwardly and inwardly and whose surface opposed elements are approximately at right angles to each other and are formed so that the lowermost portion thereof 'forms a line approximately horizontal to the Vertical axis of the bit head while the innermost portion thereof forms a line approximately parallel with the Vertical axis of the bit head, a locking element projecting downwardly from the sur face of each of said spindles, and each of said spindles provided with a lateral aperture, a removable looking device carried in said aperture, one end of which projects beyond the surface of said spindle when in' operative position, means provided to detachably secure the removable looking device in the aperture in each spindle, a roller cutter associated with said spindle and looking device and a bushing positioned between each cutter and spindle and cooperating with said looking elements. V

5. A roller boring drill head composed of a single piece including; downwardly projecting legs, frusto conical spindles formed on said projecting legs whose aXes are inclined downwardly and inwardly and whose opposed surface elements are approximately at right angles to each other and so formed that the lowermost portion thereof forms an approximately horizontal line while the innermost portion thereof forms an approximately Vertical line, a looking element projecting from the surface of each of said spindles, and each of said spindles provided with a lateral aperture, a removable locking device carried in said apertre, the inner end of which projects beyond the surface of said spindle when in operative position, and' threads provided on the removable looking device which cooperate with threads provided in the wall of the aperture in each spindle, a socket provided in the outer end of each lockingdevioe for the reception of an operating tool and roller cutters and bushings cooperating with each; spindle and With the looking elements.

6. In a drill of the character described, the combination with a drillhead having a downwardly extending frusto-conical cutter supporting spindle, of a roller cutter assembly adapted to be associated with and supported by -said spindle, said cutter assembly comprising relatively rotatable cutter and bushing elements, the latter having an interior frusto-conical surface substantially matching the frusto-conical surface of said spindle, a looking element secured to said EIU spindle and' extending at right ,angles to the' latter having an interior frusto-conical surface substantially matching the frusto-conical surface of the spindle and a looking element secured to said spindle and extending at right angles to the frusto-conical surface thereof, said bushing element having a recess adapted to receive said locking element, and a second looking element removably associated with said spindle and adapted to engage a second recess in said bushing element. v i

8. In a drill of the character described, the combination with a drill head having a downwardly extending frusto-conical cutter supporting spindle, of a roller cutter assembly adapted to be associated with and supported by, said spindle, said cutter assembly com'prising relatively rotatable cutter and bushing elements, the latter having an interior frusto-conical surface substantially matching the frusto-conical surface of said spindle, means for preventing axial separation of said cutter and bushing elements, while permitting their free relative rotation, a plurality of looking elements secured to said spindle and projecting outwardly from the frusto-conical surface thereof, said bushing element having recesses for the reception f said locking elements whereby said cutter assembly may be secured to said spindle.

9. In a drill of the character described, the combination with a drill head having a downwardly extending frusto-conical cutter supporting spindle, of a pair of right angularly related looking pins associated with said spindle and each extending at right angles to the frusto conical surface thereof and a cutter assembly including a bushing element having an interior frusto-conical surface matching that of said spindle and provided with reoesses for the reception of said looking pins, one of said pins" being removable to permit the assembly and disassembly of said spindle and cutter assembly.

10. In a drill of the character described, the combination with a drill head, of a roller cutter assembly comprising a roller cutter having internal and external frusto-conioal surfaces "and an inwardy directed base fiange, a bushing having a frusto-conioal exterior adapted :to seat within the interior of said cutter and be retained therein by said base fiange, said bushing being composed of a plurality of segments whereby the same may be appliedto and removed from the interior of said cutter and means for securing said bushing to said drill head.

11. In a drill, the combination with each of a pair of downwardly projecting, frusto-conioal spindles diametrically opposite each other on a drill head, of a roller cutter of frusto-conical exterior and interior formation and having an integral interior fiange near its base projecting toward'its axis; a segmental bushing for frustoconical exterior `and interior formation disposed within and substantially matching said frustoconical interior of the roller cutter under its flange, and containing recesses for the reception of looking elements, and a perforation through its truncated area for the passage of lubricant; a unitary, frusto-conioal wear plate disposed within and substantially matching the frustoconical interior of said segmental bushing and' the frusto-conioal interior of said flange, said wear plate being perforated through its walls for the passage of looking elements and perforated through its truncated area for the passage of lubrioant, and means provided for attachment of said wear plate to said segmental bushing, and means substantially as shown or described for mounting said wear plate and bushing nonrotatably together in operative assembly with said roller cutter rotatably, all against axial separation, to each spindle.

12. In a device of the charaoterdescribed, the

combination with a supporting spindle having an external frusto-conical surface, of a member having an internal frusto-conical surface, a member associated with said spindle and disposed at right angles to the 'frusto-conical surface thereof and adapted to engage a recess formed on the inner surface of the first said member, thev frusto-conical surfaces of each so l member having opposed surface elements disfrusto-conical surface, the opposed elements of which are right angularly disposed, an intermediate member having frusto-conical internal and external surfaces corresponding to the frusto-conioal surfaces ofthe aforesad members whereby all said frusto-conical surfaoes can be placedin complete engagement by relative movement thereof along a line at an anglo to their aXes.

14. In a device of the character described, the combination with a supporting member having a frusto-conical surface which in axial section presents right angularly disposed surface elements, of a member to be supported having a correspondingly formed frusto-conical 'surface, one of said surfaces being external and the other internal and the two said surfaces being adapted for engagement, and means associated with said members for preventing axial separation thereof, said means comprising elements projeoting at right angles 'to the frusto-conical surface of one of said members and engaging reoesses in the frustoconical surface of the other member.

15. In a drill of the character described, the

combination with a drill head, of a plurality of integral downwardly extending spindles having substantially frusto-oonical vcutter supporting surfaoes, roller cutter assemblies adapted to be carried by said spindles and each comprising a wear plate, a bushing and a roller cutter, said wear plate and said bushing having mating f'usto-oonical surfaces and said bushing and said cutter having mating frusto-conical surfaces, said wear plate, bushing and cutter adapted to be positioned in the order named upon said frusto-conical spindles, means for preventing axial separation of 'said cutter and bushing, and lockingdevices associated with the l EARL A. REED.

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