US2702059A

US2702059A - Cylindrical cutter head with slotted blade seat

Info

Publication number: US2702059A
Application number: US93701A
Authority: US
Inventors: James S Ballantine
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-05-17
Filing date: 1949-05-17
Publication date: 1955-02-15
Anticipated expiration: 1972-02-15

Description

1955 J. 5. BALLANTINE CYLINDRICAL CUTTER HEAD WITH SLOTTED BLADE SEAT Filed May 17, 1.949

2 Sheets-Sheet l Feb. 15, 1955 J, 5. BALLANTINE 2,702,059

CYLINDRICAL CUTTER HEAD WITH SLOTTED BLADE SEAT Filed May 17, 1949 2 Sheets-Sheet 2 United States Patent CYLINDRICAL CUTTER HEAD WITH SLOTTED BLADE SEAT James S. Ballantine, Absecon, N. J. Application May 17, 1949, Serial No. 93,701 2 Claims. (Cl. 144230) This invention relates to rotary cutter heads of the type employed in jointers, planers and similar woodworking tools and more particularly to improved mounting and holding devices for the bits or cutter blades of rotary cutter heads.

A primary object of the invention is the provision of improved adjusting and holding devices for the bits or cutter blades of a rotary cutter head wherein the bits or blades may be adjusted to a desired cutting position and then quickly and easily secured in such position by a simple manipulative procedure.

' Another object ofthe invention is the provision of improved holding devices for the cutter blades of rotary cutter heads which may be quickly and easily released from locking position.

A further object of the invention is to secure a cutter blade in a recess of converging cross-section in a rotary cutter head by a locking bar through wedging or clamping engagement of one side of the bar with a side wall of the recess limited to substantially line engagement lengthwise of such sides. A related object of the invention is to differentially shape the coacting sides of the recess and bar and through such shaping limit their engagement to substantially line engagement.

Other objects and advantages of the invention will become more apparent in connection with the following description of preferred embodiments of the invention illustrated in the accompanying drawings.

In the drawings:

Fig. l is a view in side elevation of a rotary cutter head embodying one form of the invention;

Fig. 2 is an enlarged view in side elevation of a portion of the cutter head shown in Fig. 1;

Fig. 3 is an enlarged view similar to Fig. 2 with the cutter blade, locking bar, and adjusting screw omitted from the lower slot;

7 Fig. 4 is a cross-sectional view taken on the line 4-4 of Fig. 2;

Fig. 5 is a perspective view of the locking bar;

5 Fig. 6 is a vertical cross-sectional view of the locking Fig. 7 is a vertical cross-sectional view of a modified form of locking bar; and, I

Fig. 8 is a vertical cross-sectional view of a further modified form of locking bar.

In general the present invention is directed to novel means for removably securing the cutter blades of a cutter head in place. The securing means includes a locking bar. The locking bar together with the cutter blade is fitted in a recess of outwardly converging crosssectionin the cutter head.

' Thecutter blade will be disposed with one side against oneside, of the recess. The locking bar will be removably located between the blade and the opposite side of the recess. The bar should be of a cross-section to be loose'in the inner wider portion of the outwardly converging recess but movable outwardly as a Wedge into bearing engagement at its opposite sides with the cutter blade and one side of the recess.

- The coacting sides of the recess and locking bar are limited to substantially line bearing engagement lengthwise thereof at an intermediate area of the bar when the bar is in wedging position. .To this end such sides aredifferentially shaped so as to be spaced from each other above and below their line of engagement. One or the other of such sides must be contoured vertically, and both may be. I prefer. to contour one only of the coacting sidesandtomake the other flat. I further prefer to contour the side of the locking bar and to make the coacting side of the recess fiat and I have chosen various embodiments of such form of the invention for illustration in the drawings;

T IThe' opposite side 'Ofthe" locking bar is preferably flat so as to make extended surface contact with the side of the cutter blade and wedge it securely against the second wall of the cutter head recess.

The shaping of the cutter head recess and locking bar as above explained to limit their sides to substantially line engagement insures increased wedging action and permits easier manipulation of the bar to and from wedging position than would be the case if the coacting sides of the recess and bar were both flat and in bearing engagement over an extended surface area.

While operation tests have shown that centrifugal force developed by rotation of the cutter is suilicient to maintain the wedging action of the locking bar it is desirable to provide means for positively holding the bar in wedging position and which also serves to adjust the bar from released to wedging position. Such means preferably will comprise a series of set screws threaded vertically in the locking bar which will bear at their inner ends against the bottom of the cutter blade recess and which upon turning will move the bar outwardly in the recess until it reaches wedging position.

Contouring to obtain the desired line contact between the sides of the locking bar and cutter blade recess may take a number of forms. According to one type of construction the side of the locking bar which engages a flat-formed side of the recess is formed with two angularly related upper and lower surfaces or faces which meet along a longitudinal line substantially midway between the top and bottom of the locking bar. The sur face below the line may desirably be flat and is preferably substantially parallel to the opposite blade-engaging side so as to be downwardly divergent at a small acute angle with respect to the adjacent coacting side of the recess when the bar occupies its wedging position therein. The surafce or face above the line is inclined inwardly toward the opposite side of the locking bar with a curved contour so that when occupying its normal position in the recess it will form a gradually increasing small acute angle with the adjacent side of the recess from the line of intersection With the lower surface.

In another but similar type of construction the recess coacting side of the locking bar is contoured to provide upper and lower surfaces or faces which are both flat and angularly related so as to meet along a longitudinal line and form small acute angles with the adjacent side, again flat, of the recess. In still another type of construction the side of the locking bar may continuously be curved for all or a substantial intermediate part of its height so that an intermediate curved portion is tangent to the adjacent side of the fiat form of the recess and adapted to bearing engagement therewith substantially along a longitudinal line and the portions of'the side above and below the tangent portion curve away from v the adjacent face of the recess to form gradually increasing acute angles.

These and similar types of construction resulting in substantially line contact between the locking bar and the adjacent wall of the recess may be utilized in accorddance with the present invention. The expression line contact? as used herein is intended to mean contact along a line or area of very narrow width longitudinally of the locking bar as contrasted to extended surface contactl between substantially parallel flat faces as hitherto use Referring now to the drawings and particularly to Figs. 1-4 the numeral 9 designates a cutter head of iron, steel, or the like, comprising a body member 10 which may be substantially cylindrical in shape and formed with a plurality of longitudinal recesses or channels 11 for the reception of cutting blades 12 and locking bars 13. Any suitable number of recesses may be used, four being shown for the purpose of exemplifying the invention.

Each of the recesses 11 has a mouth 14 opening toward the periphery of the cutter head, opposite side walls 15 and 16 and a bottom wall 17. The side wall 15 forms a backing-face against which the impact of the blow exerted on the blade 12 in the cutting operation is received. The bottom wall 17 preferably extends at an acute angle with relation to the side wall 15 and is provided at one edge thereof with a groove 18 for the reception of the inner edge of blade 12. The side wall leisarranged. in. outwardly .convergingrelationship. .with.

the side wall to form a.-recess which is of tapering form in cross-section, wider at its bottom area than at its mouths. V p

Each'of the? locking barsr13.has. a side: face 21). adapted to be urged toward theblade 'an opposite: side-face 21-, atop -face .22, and a bottom face 23. In. operative position the'side face is substantially parallel to thebacking-faee 15 of the recess 11 and. isdesigned'towedge the blade in. adjusted position aswill be'apparentfrom FiguA. The bottom face; 23 :iskpreferably, thou gh. not necessarily, arrangedsubstantially at'right angles to the side face 20and at an acute angle to. the bottom wall 17 of the recess 11. The-top face 22 is preferably concavely curved or grooved as shown at 37 to provide a chip clearance and thereby increase the. depth 0f; cut of the machine; V

The side-face 21 of thelockingybar'is' shaped'so: that the locking; barwill have a wedge-action within the walled :recess :11. In-accordance with the. present invention this;wedge action is. along-a single line of icontact-atdthemeeting of .two angularly relatedupper and lowersurfaces'of the side face-21'. This construction facilitates and increases the wedging:actionzof1the1ockingrbar and additionally facilitatespremoval of 'the locking, bar from its wedging. position.

In the form of the invention .shown int-Figs. 1-6' the sideface 21 is formed with two:angularlyrelatedxsurfaces 24 and '25 which meet or intersect along a line 26 extending longitudinallyiof the bar. The. surface 24'is preferably flat and may desirably be substantially parallel with the opposite side facer20.. The surface is preferably curved convexly inwardlyjtoward the face 20. in'such' a: manner that no portion of' the curved surface-above. the line 261 is incontact with the side wall 16 of the recess 11 .When the locking bar 13' is in wedging'position. This construction provides an improved wedge action along a relatively narrow line of contact and simultaneously minimizes thepossibility of particleswof wood and the like working around the-locking bar to disturb the wedging action. In-the:modification of the invention shown-in-Fig. 7 the side face 21 is preferably formed with two intersecting'flat faces 27 and 281wh-ich'meet in a line 29extendingvlon'gitudinally of the locking bar. The faces. 27 and 28 f are preferably arranged so that they form small acute angles withthe side wall 16 of the recess-11 thus giving the desired'line contact and minimizing the collection :of foreign matter.

A further modification of the locking bar is shown inFig. .8 wherein the line contact'is-obtained by a curved face 30 whichv is shaped sothat a-portion thereof is tangent to the wall 16 along a line longitudinally thereof; The curve of the face30 maybe variedas-desired but'isipreferably arrangedso as to recede gradually and to axrelatively limited extent away from the face 16 above and below the line of contact.

In accordance with the present invention the line-of contact ofthe locking bar withithe adjacent wall of the recess is preferably located approximately midway between. th'eupper and lower edges of the face 21. in order to obtain best allaround results. Quite satisfactory re= sults may be obtained, however, when the line, of contact is' above or below this location ZS'IOIlgi as thev resultant of the forces acting on the-blade througlr'the line contact are sufficient to. exert thedesired'clamping action.

The locking bars 13are moved to and released from locking position by set-screws 31; Set-screws 31'. are screw-threadedlymountedrin openings 32in. the'locking bars 13- and are'preferably'disposed substantially at right an'glesto the lower wall 17 0f the recesses. The topsof the set-screws may be provided with suitable slots or the like for engagementby' a screw driver; wrench or other suitable tool to rotate them. When it is desired to move the locking bars .to locking-position the set-screws 31 are rotated until they contact thebottom walls=17 of the: recesses 11. Furtherrotation of' the set-screws urges the. locking bars upwardly in the tapering recesses-11 s01 thatith'e line contact between-the side faces-21 of the locking bars andthe adjacent walls1'6 ofthe recesses urges-"the-faccs 20*of thelo'cking-ibarsinto tightengage mentwitli-the cutting:blades123 The blades'1'2 areithus clamped between'the'walls 15 of'the' recesses 11 an'dthe faces. 20.. of. the.1ocking. bars, 13.. andusecurely, held..in. position for the cutting operation.

Prior to being clamped in position as above described the cutting blades 12 are adjustably positioned for a desired cutting operation by nuts 33 screw-threadedly engaged with-set-screws; 34. Set-screws-34 are'rotatably mounted in openings 35 in the cutter head 10 with the bottoms thereof resting in contact withv the bottoms of the openings. The tops of the set-screws 34 may be provided with slots or the like whereby they may berotated by a suitable tool to raiseor lower thenuts 33. The nuts 33 are provided with extensions 33a which underlie the lower edges of the cutting blades 12 so as'to support-and move them 'upwardly or downwardly iii responseto ro tation of the set-screws 34. The-extensions 33iz-move upwardly and downwardly in-openings-36:-whiehare par allel to and communicate with openings 35. lift-W111? be apparent that *when the-set-screws 34 arexrotated' with' the bottomsthereof in contact with-the bottomsof the openings 35 the nuts 33 being screw-threadedly-engaged there= with and held against rotation: thereon" are moved-upwardly or downwardly to adjustably positionthewutter blades 12. When the blades aeethus adjusted' to-a desir'ed 'cuttingposition the locking bars may then be moved to locking position asabove described-Eta securely 'h'old the cutter blades in position.

It will thus be seen thatthe. present invention pro vides an improved cutter head 'wherein' the cutter-"blades may be easily, quickly; and accurately adjusted-to-a desired cutting position andthen'quickly'and' positively cladmped -in such-position-by a: simple 'manipulative=pro= ce ure.

Although I have illustrated-z and'dcscribed: preferred embodiments of the invention-'Ido not'intend' to be limitedto the'precise details thereofas the scope of the invention is best defined in the appended claims.

I claim;

1. A rotary cutter comprising a body member having alongitudinal slot therein provided with outwardly goon: verging walls, a cutter blade in the slot. a locking barin the slot, means for adjustably positioning saidlocking bar outwardly 'of the. slot so that one face thereofisin pressure contact with the cutter blade andthe opposite face thereof is in pressure contact with. anaadjacentiwall of .the slot, said opposite face of the locking banirlcl'ud mg a longitudinally straight and" vertically convexly rounded surface in contact with said adjacent .wall along, a. line extending longitudinally thereof, and spacedlffom said'wall above and below this line, saidloc-kingt-bal: being narrower at its. top than at its bottom-.andithe surfaceofsaid opposite faceadj'acentthe. top converging in an upward direction towards said one face.

2. .A rotary cut-tercomprisinga body member having a longitudinal slot therein providediwithoutwardly' con-1 verging walls, a cutterblade inthe'slot, a. locking bar; in the slot, means for adjustably positioning.saidrlocking baroutwardly of the slot so that one. face thereof isz-in pressure contact with thecutter blade and the. opposite face th'ereofis in .pressurecontact withan adjacentjwall of the slot, said opposite face .ofthe: lockingbar having a, convexly. curved. surface portion andwaaffl'at surface portionwhich'meet along a lineextending longitudinally thereof, .saidsurfaceportions being: in contact with-said adjacent wall along theircommon meeting-lineandsbeing spacedi therefrom above andbelow said meeting; line, said locking bar being-narrower'at itstop thanat its bottom and the surface of said-opposite face. adjacent the top, converging in an upward directiontowardssaid one face.

References Cited in the file ofthis patent-- UNITED STATES PATENTS 874,871 Shimer' Dec; 24, 1907 995,024 Mitchell June13; 1911: 1,032,636 Watkins July 1:6, 1912- 1,039,054 Hartzell Sept. 17, 1912 1,320,482 Lenker Novmi'; 1919 -1,780;846.- Shimerzret al Nov. 4," 1930 FOREIGN PATENTS.

93,153" Sweden 1938: 550,077 Great Britain ....D'ec.'l 22,. 1942 890,658 France Feb. 14, 1944