US1510962A - Cutter head - Google Patents

Description

Get. 7 1924. 1510,92

G. W. RUSSELL I CUTTER HEAD Filed July 9, 1923 2 Sheets-Shee't l O27 3/ I7 for:

Oct 7 a G. W. RUSSELL CUTTER HEAD Filed July 9, 1923 2 Sheets-Sheet 2 Patented Oct. 7, 1924.

UNITED STATES PATENT OFFICE.

GEORGE w. RUSSELL, or COMPANY, OF

CLEVELAND, OHIO, ASSIGNOB TO THE ACME MACHINERY CLEVELAND, OHIO, A CORPORATION OF OHIO.

CUTTER HEAD.

Application filed July 9, 1928. Ser1al No. 850,815.

To all whom it may concern:

Be itknown that I, GEORGE W.

RUssELL,

a citizen of the United States, residing at Cleveland, in the county State of Ohio,

of Ouyahoga and have invented a new and useful Cutter Head, of which the following is a specification.

This invention relates to improvements in cutter-heads for cutting pipes, bolts, etc., and ly to a cutter-head of the screw-threads on pertains more especialtype in which the body of the cutter-head has a central bore and substantially radial and each engaged by a held in either in carrying a c of hard metal such, for steel, and has parallel guidew ays which instance, as hard ridges formed on its face and extending endwise of the chaser,

and is kept sharp by grinding at its workengageable or cutting end and arranged tangenti ally to a circle the axis of which is coincident with the axis of the cutterhead.

One ob'ect of a cutteread of the which is simpler and more this invention is to produce character indicated durable in construction than cutter-heads heretofore devised,'and to facilitate the manufacture and assemblage of the component members of my improved cutter-head.

provide improved Another object is to ing slides.

Another object is to provide a simple and highly practical operative connection between each chaser-carrying slide and a sleeve which is mounted on and shiftable endwise of and rotatable with the body of the cutterhead and adapted to be either position of held in place in the chaser-carrying slides.

Another object is to have each chasercarrying slide provided, portion of the guideway at the outer end for said slide, with a member which projects forwardly through a slot parallel with said guideway and extending to formed in a face-plate which is of the cutter-head and secured to the body forms the forward wall portion of said guldeway,

the outer circumference of and removably of the inner end so as to. permit the .struction, and combinations and relativearran ements of parts, hereinafter described in t 's specification, pointed out in the claims, and illustrated in the accompanying drawings.

In said drawings, Figure 1 is a front elevation of a cutter-head embodying my invention. Fig. 2 is a section taken along the broken bent line 2-2 in Fig. 1. Figs. 3, 4 and 5 are sections, in detail, taken along the line 3-3, line 4-4 and line 5-5, respectively, in Fig. 2. Fi 6 is a front view of one of the chaser-hol ers of my improved cutterhead. Figs. 7, 8, 9 and 10 are sections, in detail, taken along the line 77, line 8-8, line 9-9, and line 10-10, respectively, in Fig. 6. Fig. 11 is a front view of the cutterhead-body detached. Figs. 6, 7,8, 9 and 10 are drawn on a larger scale than Figs. 1, 2, 3, 4, 5 and 11.

Referring to Figs. 2 and 4 of said drawings, 15 indicates the horizontal body of my improved cutter-head. Said body is circular in end elevation as shown in Fig. 11. In its rear portion said body has a central horizontal screw-threaded bore 16 extending to the rearward end face of the body as shown in Fig. 2. Said body is therefore adapted to be threaded at said bore onto a support such, for instance, as a shaft (not shown) for rotating the cutter-head.

The body 15 (see Figs. 2 and 11) is pro vided, centrally of its forward portion, with a horizontal bore 17 arranged in line endwise with and diametrically smaller than the bore 16 and extending from said bore 16 to the forward end face of said body.

The body 15 (see Figs. 2, 4 and 11) has four slots 18 spaced equidistantly circumferentially of the bore 17 and extending from said bore to the outer circumference of said body and from a point s aced a short distance forwardly from the re 16 to the forward end face of said body. The bore 17 (see Figs. 2 and 1 1) smaller diametrically at a point rearward of the slots 18 than between said point and the forward end face of the body 15 so as to effect the formation, on and internally of said body, of a forwardly facing annular shoulder 20 rearward of said slots and forward of the bore 16.

' A substantially horizontal metal tube 21 (see Fig. 2) engages the diametrically larger and main portion of the bore 17 and abuts at its rear end against the shoulder 20 and extends from said shoulder forwardly not only to the forward extremity of said bore but forward of the body 15 and measures less in external diameter from its-forward extremity to the forward end face of said body than between said face and the rearward extremity of the tube so as to efi'ect the formation, on and externally of said tube, of a forwardly facing external annular shoulder 22 which is flush with said face and overlapped by an annular faceplate 23 which is concentric in relation to said tube and mounted, next forward of said shoulder 22, on said tube. Said plate 23 is preferably flush at its outer circumference with the outer circumference of the body 15 and secured removably by screws 24 to said body.

Arranged within each slot 18 (see Figs. 2 and 4) is a U-shaped member 25 disposed to form the-rear wall 26 and opposite side walls 27 respectively of a substantially radial guideway 28 extending inwardly from the outer circumference of the body 15, and said U-shaped member is preferably connected, at its portion which forms said rear wall 26, to said body by a pin 29 extendin- 1 rearwardly into said body from within sai portion of said U-sha ed member.' The side walls 27 of said gui eway are parallel and extend to the forward end face of the body 15, and the rear wall 26 of said guideway is at a right angle to said side walls. The inner end portion of said guideway has a forward wall formed by the central portion of the face-plate 23, and the outer portion of said plate (see Figs. 2 and 3) has aradial sl0t30. which registers with the outer end portion of and is parallel with said guideway and extends to the outer circumference of said plate.

Each guidewa 28 (see Figs. 2 and 4) is engaged by a side 31 which is shiftable endwise of the guideway and therefore radially of the body 15, and in Fig. 2 a slide 31 is shown in its inner position.

By the hereinbefore described construction it will be observed that the forward portion of my improved cutter-head has as many guideways 28 as there are slots 18 formed in the body 15, and it would here remark that simple, efiicient and reliable means whereby the slides engaging said guideways may be simultaneously actuated comprise a sleeve 32 which (see Fig. 2) is slidably mounted on and shiftable endneronee wis of the body 15 and has an external annular recess 33 for receiving a lever or member (not shown) for actuating the sleeve. Means for actuating a sleeve on a cutter-head-body without interferin with the rotation of'said sleevewith sai body and for holding said sleeve in either position thereof are too well known in the art to require description and illustration in this specification.

The sleeve 32 (see Figs. 2 and 3) is internally provided, opposite the outer end of each guideway 28, with. a recess 35 extending to the forward end face of said sleeve from a point spaced rearwardly from said guideway, and said recess 35 is gradually enlarged in depth toward the forward extremity of the sleeve so as to efiect the formation, internally of the sleeve and opposite said outer end of said guideway, of a wall 36 extending endwise and to the forward end face of the sleeve and arranged at an angle to the path of the sleeve and facing forwardly and toward the axis of the cutter-head. Said sleeve is provided, at the forward end of said recess 35, with a forwardly projecting lug 37 formed between the forward extremity of said recess and the outer circumference of the sleeve and having a forwardly and inwardly facing inclined surface 38 which is flush with and forms a forward extension of the wall 36 of said recess. Said recess 35 is enlarged at said wall 36 laterally and in opposite directions, as shown at 39 in Fig. 3, and abutting against and extending endwise of said wall is an inclined channel-shaped member 40 which on ages the enlargements 39 of said recess and is parallel with said wall and disposed with its flanges 41 projecting toward the body 15, and said channel-shaped member conforms externally to and tightly fits the walls of said enlargements of said recess and extends opposite the surface 38 of the adjacent lug 37 of the sleeve 32 and is preferably connected to the sleeve by a pin 42 extending into the sleeve from within the web of said channel-shaped member.

Each slide 31 (see Figs. 2, 3 and 5) has a member 43 arran ed externally of the guideway 28 for said slide, and said member 43 extends radially outwardly from said guideway and to and internally of the adacent channel-shaped member 40, and said member 43 also projects or extends through and forwardly of the slot 30 which registers with said guideway. Said member 43 therefore extends opposite and forwardly across and beyond the inner end wall .45 of said slot 30 and forwardly of the faceplate 23. .Said member 43 of said slide has the portion thereof which extends through said slot 30 spaced, as shown in Figs. 2 and lllll 3, in any position of the slide, from said m wall 45 so as not to interfere with the actuation of said slide from one to the other of its positions.

The member 43 of each slide 31 (see Figs. 2 and 3) has its sleeve-facing edge 46 parallel with the adjacent internal wall 36 of the sleeve 32, and said member 43 is provided, at each side thereof internally of the adjacent channelhaped member 40, with a laterally and outwardly projecting flange 47 which. is parallel with said channelchaser.

shaped member and arranged to widen said edge of said member 43, and each flange 41 of said channel-shaped member has a member 48 overlapping the inner side of the adjacent flange 47 of said member 43 of the slide. It will be observed, therefore, that the channel-shaped member adjacent each slide 31 (see Fig. 3) straddles the member 43 of said slide and is loose in relation to said member 43, and that said channelshaped member and the flanges 47 of said member 43 of said slide form an operative connection between the slide and the sleeve 32 without interfering with the endwise shiftability of said sleeve on the cutterhead-body' 15.

Associated with each slide 31 is a chaser 50-supported from said slide as will hereinafter appear and, as shown more clearly in the upper half of Fig. 2, spaced at its cutting end inwardly from the inner edge of the forwardly projecting member 43 of said slide and arranged, as shown in Fig. 1, at

an acute angle of preferably sixty degrees to the path of the slide and tangentially to a circle having its axis coincident with the axis of the cutter-head. Said chaser isof the well known type comprising a rigi strip which is composed of hard metal such, for instance, as hard steel, and (see Figs. 2, 8 and 10) has parallel ridges 51 formed on the face andextending endwise of the chaser and kept sharp by grinding the inner and work-engageable or cutting end of the chaser.

Said chaser (see Figs. 2, 9 and 10) has beveled forward and rearward longitudinal edges diverging toward the back of the The cutter-head is adapted to be rotated in the direction indicated by the arrow 52 in Fig. 1, and said chaser is carried by a holder comprising a plate 53 abutting against the forward end face of and secured to the member 43 of the slide with which said chaser is associated and extending laterally of said member-of the slide, as at 54 in Fig. 1, in a direction opposite to the di rection in which the cutter-head is adapted to be rotated. Said plate 53 has a portion 55 thereof projecting rearwardly into proximity to the forward side of the faceplate 23 and arranged opposite the inner edge of the member 43 0f the associate slide 31, as shown in Fig. 1. The portion 55 of theplate 53 (see d suitabl 2, 6, 8, and 10) has a flan e 56 arranged to serve as an abutment or the rear longitudinal edge of the chaser, and the holder carrying said chaser and comprising said 'plate 53 also comprises a clamping member 57 which is held in clamping engagement with the forward longitudinal edge of the chaser. Said plate 53 also has a beveled external surface 58 formed at the forward side of the plate and facing forwardly and in the direction of the outer circumference of the cutterhead, and is provided with a forwardly facing shoulder 59 at and extending alon the rear longitudinal edge of said beveled surface, and the aforesaid clamping member overlaps said beveled surface and extends endwise of and abuts against said shoulder. A screw 60 (see Figs, 6, 7, 8 and 9) for adjusting said chaser endwise, when the chaser has been rendered free to be readjusted or removed for regrinding or replacement, has its axis substantially coincident with the rear longitudinal edge of the back of said chaser and abuts, at its inner end, against the outer end surface of the chaser and engages a segmental screw-threaded hole 61 which is formed in said plate 53 at said edge and opposite adjacent portions of the rear longitudinal edge and back of the chaser and extends longitudinally of said edge. The application and operation of a screw 60 of the character indicated are too well known in theart to require further description in this specification.

The hereinbefore mentioned clamping member 57 (see Figs. 6 and 8) is preferably secured to the associated plate 53 by applied screws 62 spaced endwise of sai clamping member, and said plate 53 (see Fig. 2) is preferably removably secured to the member 43 of the slide associated with said plate by two suitably applied Vertically spaced bolts 63, and preferably a. horizontal pin 65, arranged centrally between said bolts, extends from within said plate into said member of said slide, and said plate (see Fig. 6) has a hole 66 for said pin and holes 67 for said bolts. Also, said plate 53 is preferably provided, centrally between the side edges of the forward end face of the member 43 of said slide, (see Fig. 5) with a recess 68 extending endwise of said face and engaged by a tongue 69 projecting from said member of said slide, and obviously said tongue and the side Walls of said recess and the hereinbefore mentioned pin 65 prevent strain upon the bolts 63 during the operation of the cutter-head. Also, the member 43 of said slide preferably extends, as at 70 in Fig. 2, toward the axis of the cutter-head and opposite the forward side of the faceplate 23 from the slot 30 through which said member 43 extends, so as to enlarge the support adorded by said member 43 to the associated plate 53. lit will also beobserved (see Figs. 1 and 2) that the sleeve 32 is provided internally, at each of several points spaced circumferentially of the "body 15 of the cutter-head, with a recess 72 extendin endwise of and through the sleeve, that sai recess is occupied by a metal wearing strip 73, and that said strip is connected to said sleeve by pins 7% spaced longitudinally of the strip and extending from within said strip into the sleeve. The cutter-head-body 15 is provided at its outer circumference, opposite each wearing strip 73 of the sleeve 32, with a wearing strip 75 which (see Fig. 2) extends from the forward end face of said body rearwardl to an end wall 76 of'a recess 77 occupied by said wearing strip 75 of said body and formedin said body at the outer circumference of the body and extending to the forward end face and endwise of said body. Said wearin strip 75 of the cutter-headbody has its forward end face overlapped by the face-plate 23 and is connected to said body by pins 78 spaced longitudinally of said strip and extending from within said strip into said body. Fig. 11 shows the wearing-strip-receiving recesses 77 in the cutter-head-body.

lln placing my improved cutter-head in condition for operation upon a piece of work, each clamping member 57 is loosened,

if not already loosened, in relation to the associated chaser 50 by the required manipulation of the screws 62 for said clamping member, so as to permit independent readjustment of said chaser endwise, and the screw 60 associated with said chaser is manipulated as required, if necessary, to permit said readjustment of said chaser,.and also manipulated as required, when necessary, to move said chaser inwardly endwise. When the chasers have been independently adjusted as required to space them equidistantly from the axis of the cutter-head, each chaser is secured in the desired adjustment by tightening the screws 62 associated with the clamping member 57 for said chaser so as to again bring said clamping member into clamping relation to said chaser. Thereupon the sleeve 32 is adjusted or shifted endwise of the body 15 of the cutter-head as required. Obviously, durin forward movement of the sleeve, the we of each channel-shaped member 40 exerts pressure against the sleeve-facing edge 46 of the member 43 of the slide associated with said chan nel-shaped member, so as to result in inward movement of said slide. Obviously, during rearward movement of the sleeve, the members 48 of the flanges 1-1 of each channel shaped member 40 exert pressure against the inner sides of the flanges 47 of the slide associated with said channel-shaped member,

the sleeve, upon the completion of the operation by thechasers on theworlr, results in outward movement of said slides as required to withdraw the chasers from the work.

What ll claim is-- 1. A cutter-head of the character indicated comprising a body which has a central bore extending rearwardly from the forward end face'of the body and at each of a plurality of points spaced circumferentially of said bore has a guideway extending inwardly from the outer circumference of the body and having a forward wall spaced from the outer end of the guideway, a sleeve slidably mounted on said body a slide engaging said guideway and having a member which extends from said'guideway forwardly and opposite and beyond the outer end face of said wall and has the portion thereof which is opposite said face spaced from said face in the inner position of the slide, means whereby said slide is actuated by and during endwise movement of the sleeve, and a chaser associated with said slide and arranged tangentially to a circle the axis of which is coincident with the axis of the cutter-head, said chaser being supported from the aforesaid forwardly extending member of said slide and spaced, at its inner or cutting end, inwardly from the inner edge of said member of said slide.

2. A cutter-head comprising a body having a substantially radial guideway at each of a plurality of points spaced circumferentially of the axis of the cutter-head, a slide engaging said guideway and having a mem ber extending forwardly of the guideway, a sleeve slidably mounted on the aforesaid uody and internally provided adjacent said slide with a recess which extends endwise of the sleeve and has a wall extending endwise of and arranged at an angle to the path of the sleeve, a channel-shaped member arranged in said recess and parallel with and connected to said wall and disposed with its flanges projecting toward said body, and a chaser supported from the aforesaid forwardly extending member of the aforesaid slide, said memberof said slide also extending to and internally of the aforesaid channel-shaped member and provided, at each side thereof internally of said channelshaped member, with a laterally and outwardly projecting flange which is parallel with said channel-shaped member, and each lUJ ill;

flange of said channel-shaped member having a member overlapping the inner side of 31% adjacent flange of said member of said 3. A cutter-head comprisingl a body having a substantially radial gui eway at each of a plurality of points spaced circumferentially of the axis of the cutter-head, a slide engaging said guideway and having a member extending forwardly from the guideway, a sleeve slidably mounted on said body and internally rovided adjacent said slide with a recess which extends endwise and to the forward end face of the sleeve and has a forwardly facing sloping wall extending endwise and to the forward extremity of said recess, an inclined member arranged opposite and parallel with and connected to said wall, and a chaser supported from the aforesaid forwardly extending member of the aforesaid slide, said member of said slide also extending to the aforesaid inclined member and havin a laterally and outwardly projecting ange arranged at and parallel with said inclined member, the sleeve being provided between the said inclined member and the outer circumference of the sleeve with a forwardly projecting lug having an inwardly facing surface flus with the aforesaid wall, and said inclined member extending opposite said surface and having a portion thereof overlapping the inner side of the aforesaid flange.

4. V A cutter-head comprising a bod which has a central bore extendin to the orward end face of, the body an also has slots spaced circumferentially of said bore and extending to said face and to the outer circumference of the body, a sleeve slidably mounted on said body, a U-shaped member arranged in each slot and connected to said body and disposed to form the rearward wall and opposite side tially radial guideway, an annular facelate secured to said body and arranged to orm a forward wall for said guideway, a slide engaging said guidewa and having a member projecting forwar 1y of the face-plate, means whereby said slide is actuated by and during endwise movement of the aforesaid sleeve, and a chaser supported from aforesaid forwardly projecting member of said slide and arranged forward of the aforesaid face-plate.

5. A cutter-head comprising a body having substantially radial slots which are spaced circumferentially of the axis of the cutter-head and extend to the forward end face and to the outer circumference of said body, a sleeve slidably mounted on said body, a U-shaped member arranged in each slot and connected to said body. and disposed to form the'rearward wall and op 0- site side. walls of a substantially ra a1 guideway, an annular face-plate secured to walls of a substansaid body and having. a substantially radial slot which registers with said guideway and extends to the outer circumference 0 said plate, a slide engaging said guideway and having a member projectin forwardly through and beyond said slot 1n said plate; means whereby said slide is actuated by and during endwise movement of the aforesaid slceve,'and a chaser supported from said forwardly projecting member of said slide and arranged forwar of the face-plate.

6. cutter-head comprising a body which has a central bore extending end face of the body and at each of a lurality of points spaced circumferentia ly of said bore has a guideway extending endwise between said bore and the outer circumference of the body, a tube arranged in said bore and extending from a point forward of said body to a oint rearward of said guidewa and provi ed externally of its forward en portion with a forwardly facing shoulder, a member overlapping said shoulder and secured to said body, a slide engaging the aforesaid guideway and having a mem- .ber extending forwardly from said guideway and forwardly of the aforesaid tube means whereby said slide is actuated by and during endwise movement of the aforesaid sleeve, and a chaser supported from said forwardly extending member of said slide and arranged forward of the aforesaid tube, the aforesaid body having an internal shoulder arranged to form anabutment for the rear end of said tube.

7. A cutter-head comprising a body which has a central bore extending to the forward end face ofthe body and at each of a plurality of points spaced circumferentially of said bore has a substantially radial guideway, a tube arranged in said bore and extending from a pomt forward of said body to a point rearward of said guideway and held against rearward displacement and provided externall of its forward end portion with a forwardl the forward end face of said body, a faceto the forward facing shoulder flush with plate mounted on said tube and abutting against said shoulder and removably se cured to said bod and having a slot which registers with sai guideway and extends to the outer cinglmfe'ence of plate, a slide engaging sai gu1 ewa an avmg a member extending forwar ly through said slot and forward of said plate, means whereby said slide is actuated by and during endwise movement of the aforesaid sleeve, and a tangential chaser arranged aforesaid plate and su ported from the aforesaid forwardly pro ecting member of said slide and having its cutting end spaced inwardly from the inner edge of said member of said slide. I

8. A cutter-head comprising a bod which has a central bore extending to the f brward forward of the CJI end face of the body and also has slots spaced circumferentially of said bore and extending to said face and to the outer circumferenceof the body, a tube arranged in said bore and extending from a point forward of said body to a point rearward of said slots, a-sleeve' slidably mounted on said body, a U-shaped member arranged in each slot and connected to said body and disposed to form the rearward wall and opposite side walls of a substantially radial guideway, a face plate secured to said body and mounted on the aforesaid tube and arranged to form a forward wall for said guideway, a slide engaging said guideway and having a member projecting forwardly of said plate, means whereby said slide is actuated by and during endwise movement .of the aforesaid sleeve, and a chaser supported from the aforesaid forwardly projecting member of said slide and arranged forward of the face-plate, the forward end portion of the aforesaid tube having a forwardly facing shoulder overlapped by said plate, and the aforesaid body halying an abutment for the rear end of said tu e.

9. A cutter-head comprising a body which at each of a plurality of points spaced circumferentially of the axis of the cutter-head has a substantially radial guideway having a forward wall spaced inwardly from the outer end of said guideway, a sleeve slidably mounted on said body, a slide engaging said guideway and having a member which extends forwardly and opposite and beyond the outer end face of said wall, means whereby said slide is actuated by and during the actuation of the aforesaid sleeve, a tangential chaser associated with said slide and spaced at its cutting end inwardly from the inner edge of the aforesaid forwardly extending member of the slide and arranged at an acute angle to the path of the slide, a holder for said chaser, said holder abutting against the forward end face of and being secured to the aforesaid member of the aforesaid slide.

10. A cutter-head comprising a body having a substantially radial guideway at each of a plurality of points spaced circumferentially of the cutter-head, a sleeve slidably mounted on said body, a faceplate arranged at the forward end face of and secured to said body and having a slot which registers with said guideway, a slide engaging said guideway and having a member which extends through said slot and forwardly of said face-plate, means whereby said slide is actuated by and during the actuation of the aforesaid sleeve, said slide and spaced at its cutting end inwardly from the inner edge of the aforesaid forwardly extending member of said slide and arranged at an acute angle to the path of the shde, and a chaser-holding plate abuta chaser associated with ting against the JEorvvard end face of and secured to said member of said slide and having a portion thereof extending rearwardly opposite the inner edge of said member of said slide and into roximity of the forward side of the aforesald face-plate, the chaser being clamped to said rearwardly extending portion of the chaser-holding plate.

ll. A cutter-head comprising a body which has a substantially radial guideway 'ateach of several points spaced circumferentially of the axis of the cutter-head, a slide engaging said guideway and having a member extending forwardly from the outer end portion of said ideway, a tangential chaser associated wlth said slide and spaced at its cutting end inwardly from the inner edge of said member of the slide and disposed with the opposite longitudinal edges thereof facing forwardly and rearwardly respectively, and a chaser-holder comprising a plate which is secured to said member of said slide and has a surface forming an abutment for the back of the chaser-and also has a flange overlapping the rear longitudinal edge of the chaser, said chaser-holder also comprising a clamping member held in clamping engagement with and extending endwise of the forward longitudinal ed 'e of the chaser and secured to the aforesaid plate.

12. A cutter-head comprising a body having a substantially radial guideway at each of a plurality of points spaced circumferentially of the axis of the cutter-head, a slide engaging said guideway and having a member extending forwardly from the outer end portion of said guideway, a tangential chaser associated with said slide and having beveled forward and rearward longitudinal edges diverging toward the back of the chaser, and a chaser-holder comprising a plate which is secured to said member of said slide and has a surface arranged to form an abutment for said back and also has a flange arranged to serve as an abutment for the rear longitudinal edge of said chaser, said chaser-holder also comprising a clamping member held in clamping engagement with the forward longitudinal edge of the chaser, the aforesaid plate having a beveled external surface which is formed at the forward side of said plate and faces forwardly and toward the outer circumference of the cutter-head and also having a forwardly facing shoulder at and extending along the rear longitudinal edge of said beveled surface, and the aforesaid clamping member overlapping said beveled surface and ex tending endwise of and abutting against said shoulder.

13. A cutter-head comprising a body having a substantially radial guideway at each of a plurality of points spaced circumferential y of the axis of the cutter-head, a

slide engaging said guideway and having a member extending forwardly from the outer end portion of said guideway, a tangential chaser associated with said slide and having beveled forward and rearward longitudinal edges diverging toward the back of the chaser, and a chaser-holder comprising a plate which abuts against the forward end face and extends opposite the inner edge of and is secured to the aforesaid forwardly extending member of said slide and has a surface arranged to form an abutment for said back and also has a flange which overlaps the rear longitudinal edge of said chaser, said chaser-holder; also comprising a clamping member which is held in clamping engagement with the forward longitudinal edge of said chaser, the aforesaid member of said slide and the aforesaid plate being provided centrally between the side edges of the forward end face of said member of said slide, the one with a tongue arranged radially of the cutter-head, and the other with a recess engaged by said tongue.

14. A cutter-head comprising a body having a substantially radial guideway at each of several points spaced circumferentially of the axis of the cutter-head, a sleeve slidably mounted on said body, a slide engaging said guideway and having a member which extends forwardly from said guideway, means whereby said slide is actuated by and during the actuation of the aforesaid sleeve, a chaser associated with said slide and spaced at its cutting end inwardly from the inner edge of the aforesaid forwardly extending member of said slide and arranged at an acute angle to the path of the slide, a chaserholding plate secured to said member of said slide and extending laterally of said member of the slide in a direction 0 posite to the direction in which the cutteread is adapted to be rotated and having a ortion thereof extending rearwardly opposlte the inner edge of said member of said slide, and means whereby the aforesaid chaser is firmly secured to said portion of said plate.

15. A cutter-head comprising a body provided at its outer circumference with recesses extending rearwardly from the forward end face of said body, wearing strips engaging and extending from end to end of said recesses and held against rearward displace ment, a substantially radially movable slide at each of several points spaced circumferentially of the axis of the cutter-head, a sleeve slidably mounted on and rotatable with said body and internally provided with recesses extending endwise of the sleeve and spaced circumferentially of said body, wearing strips occupying the last-mentioned recesses and held against endwise displacement, means whereby the aforesaid slide is actuated by and during endwise movement of said sleeve, an annular face-plate arranged at and opposite the forward end face of and secured to the aforesaid body, and a chaser arranged forward of said face-plate and supported from the aforesaid slide, said face-plate overlapping the forward end faces of the first-mentioned wearing strips, and each of said first-mentioned wearing strips being opposite one of the second-mentioned wearing strips.

In testimony whereof, I sign the foregoing specification.

Images