US2143448A - Core former for making ducts - Google Patents

Description

Jan 10, 1939. OROURKE.

CORE FORMER FOR'MAKING DUCTS Filed Aug. 1, i936 lNVENTOR V g Y 0 IR\ a g 1. ATTOR Patented Jan. 10, 1939 UNITED STATES PATENT OFFICE 11 Claims.

This l invention relates :to H apparatus for forming hollow molded-:bodiesssuch as concrete ducts. This invention relatesparticularlyitoa core former adapted ,to form-the vcore of iarhollow molded body 'suchuas a duct made of concrete.

:Heretoforeihollow bodies such as Iducts, pipes andvthe likei'have been produced usingrapparatus whichcomprises a vertical mold adapted to form .tthe rexternal surface of abodysuoh as a duct and La core former for compacting andtroweling moldable imaterial such :35 concrete within ,the 'mold .so as tolproduce az'hollow core. The: core former in apparatus of "this character has'been mounted oniarotatabIe shaft and has included a cylindri- .;s "cal ihead havingaapproximately the diameter of thecore which isvttmbeformedin thecompleted duct. Means have:.been;provided forrotating the shaftandzheadn an'dzfor elevatingthe head from thelbottom ofthe molditortheitop while the shaft is being. rotated.

Intapparatus heretoforemanufactured, the core formerrhas1taken-tmany different forms. Generally; the core "former includesone. or more cam shaped. members .zattached to: the r. shaft above the cylindrical head, .the cam surface presented-by the: cam shaped member v havingnits radius from i the axis of the: shaft become increased until the maximum radius corresponds tozthe radius from the axis-of :theshaftiroftthe peripherylof cylinzi-J drical head. Likewise, agitators 'have-beenat- 'tached to the shaft-aboveithe core formerso as to distribute moldable vmaterial such as wet concrete above the cam shaped troweling member. The present invention is 1 especially applicable to the: manufacture-of :ductsv having a cylindrical -hollowcore and external. surfaces disposed at an anglewith respect to each other as is the casefor example whenthe cross section of :the external surfaces forms a square (such ducts being .re- "ferred to herein as square ducts). Prior to this invention I encountered serious-difficulties in the manufacture ofsquare ducts. In using apparatus heretofore employed, I foundthat the concrete at the corners of the molds was compacted more i 45 looselyrthan in the thin layer of concrete between the central hollowcoreand the mid portionofthe walls of the "duct. This was verydisadvantageous as the corners of the ducts crumbled and theiducts were not acceptable. Many.,different typesofv core 50 formers including cam .shaped v troweling members, agitators-and the like, weretried bymebut the percentage of unsatisfactory iducts remained as high as 50%. Forlsome time it appeared that the manufacture of square ducts using machinery 1155 of the general character hereinabove referred a to r. tionejdi that; the mixtureof cementitious material randjfiller which is used in making concrete ducts 15 is quite dryeandithatfiit must be very highly com- ;pactedin:vorderqtmset properly to form a duct which ;;has the requisite structural strength a throughoutqall portions thereof.

vi Featuresaofpthis invention relate to the manner inawhichqagspiral ;blade-has; been combined with acam shapedqcompactor and .with other elements of thecore; former. :Fromonepoint of view, it is aifeatureqof this inventionthat a. spiral blade ifixedptoa rotatable-shaftis-carrieddown so as to ibesinvenfdwise juxtaposition withthe end of the icamicompactor. :Qther-features'of this inven- :tion rrelatezt-o; the .relative positions of r the spiral ;b1ade; and :the cam -compactor and to the form characteristics;ofithese parts. :Fromanother point of view, other features1of thisrinvention relate llOzthe distribution of the sp ral blade between a vblade part and vea'xwinglmember (to be defined therein below). LStill potherifeaturesof this inwventionrelate toithexmanner in which' the blade parmand' wing are mounted, relative: to each other saHdMt-OitheiCYJiHdI'iCfllTfOl-IOWGI' so as to permit :adjustment ofs some-relationships while retaining other relationships. Thusyfor example, the relationship of the blade portion of the wing mem- 40 her to--the blade of 'the blade part can be maintained while the ,cam -surfacepresented by the wing member can be adjustedlaterally relative to the shaft according tothis invention.

Further features, purposesand advantages of 4 this invention will be apparent inconnection with the illustrative embodiment ,of .this invention shown in ,theiaccompanying. drawing, vwherein- Fig.1 1 is a-side view'partly in section showing a 5 core: tormenzembodying this invention and a por- --tion ;,of ammoldif or moldinga hollowtbody such was arconcrete duct.

Fig. 3 is a view similar to that shown in Fig. 2 but taken on the line 33 of Fig. 1.

Fig. 4 is a View similar to Fig. 1 with the core former in a different position from that shown in Fig. 1.

Fig. 5 is a View similar to Figs. 1 and 4 with the core former in a still different position.

Fig. 6 is a detail perspective View of the core former with the spiral blade part separated from the wing member, and

Fig. '7 is a detail side View of a portion of the wing member and illustrates the different radii from the shaft of the difierent portions of the cam compactor portion thereof.

While a core former embodying this invention may be used in connection withv any type of mold for forming the external surface of a molded article such as a concrete duct, it is shown in Figs, 1, 2, 3, 4 and 5 for purposes of illustration in connection with a mold for forming a square duct and is peculiarly suited for use with a mold of this character. The mold is indicated generallyby the reference character I0. It is preferred that the mold be of the type disclosed in my application Ser. No. 93,786, filed August 1, 1936, for Apparatus and method for making ducts (executed on even date herewith). In such case the mold It) comprises two portions, one portion of which is a master section II and the other portion of which is a pallet I2. The master section and pallet of the mold may be maintained in assembled relation by means of any suitable clamping means such as a device comprising the V-shaped member [3 which carries at one end the link I4 hinged thereto by hinge l5. At the other end of the member 13 is a-hooked member l6. Parallel bar members I! are hinged by hinge IE to both sides of the end of link member 14 and hinge pin means !9 carries block 20 between the bar members I! so that the block 20 can be rotated about the axis of the hinge pin means I 9' relatively to the bar members I1. In screw threaded engagement with the block 20 is threaded rod 2| having an end 22 which is adapted to rest in hooked end 23 of hook member l6. Projecting from hook member [6 is a lug 24. By the means above described, the master mold and pallet mold may be clamped together firmly and disassembled when desired as is more fully described in my said application Ser. No. 93,786.

In use the mold l0 can be rested on a suitable support 25 and can be maintained in proper position by suitable means (not shown) such as the means shown and described in my said application Ser. No. 93,786. If the hollow molded form is to be a duct having male and female ends, a die 26 may be used for forming the female end of the duct. This die may be stationary but is, preferably operatively connected to suitable means (not shown) for raising and lowering the die and for rotating the die. The

die 26 fits within an appropriate opening in the support 25. It is to be understoodthat any other suitable die may be used or that a die may be omitted altogether.

The device for shaping the other end of the duct is not shown herein but may comprise apparatus of the character described in my application Ser. No. 93,787, filed August 1, 1936, for Apparatus for making ducts (executed on even date herewith). It is to be understood that any other suitable die for shaping the top of the duct formed in the mold l0 may also be used or can be omitted. a .1

The core former to which this invention is particularly directed is mounted on shaft 30. It is to be understood that suitable means (not shown) are employed for rotating the shaft and for elevating and lowering the shaft. Moreover, it is to be understood that the shaft is adapted to be rotated by suitable means while the shaft is being raised or lowered or while it is maintained at a constant level. Many types of means for imparting the motion to shaft 30 which has been referred to above are well known and for this reason require no description herein.

. Secured to the lower end of the shaft 30 in coaxial relation thereto is a cylindrical head or follower 3!. The radius of the follower normally corresponds to the radius of the core which it is desired to produce in the interior of the finished duct. The block 32 is also secured to the shaft 30. The follower 3| and the block 32 may be formed in one piece with shaft 30 L or may be made separately and assembled in secured relation thereto by suitable means (not shown) as may be desired.

'Above the former head and mounted on the block 32 are wings or wing members indicated generally by the reference character 33. In the embodiment here shown, two wings 33 are employed. Each wing 33 has an inclined blade portion 34, a cam compactor portion positioned with reference to the shaft so as to have a troweling surface 36 that is at a maximum radius from the shaft 33 (which radius preferably is substantially the same as the radius of the periphery of the follower 3|). The cam surface presented by the cam compactor portion also includes portions of lesser radius afiording a valley 35 immediately adjacent and alongside the blade portion 34 and between the blade portion 34 and the follower 3|. This part of the wing is referred to as a cam compactor portion as it has a cam action on material in sliding contact therewith, namely on the moldable material in the mold urging it outwardly away from the axis of the shaft and against the mold parts which form the external surfaces of the duct when the shaft is turned. The wing likewise has an upwardly tapering portion 3'! which serves a purpose referred to below. The wing also includes the base portion 38 which overlies the follower 3| and has a radius corresponding substantially to the radius of the follower 3|. The valley 35 is deepest and widest adjacent the widest end of the wing 33 and becomes gradually of decreased depth and width progressing toward the troweling surface 36. Moreover, the upper end of the wing (and of the cam compactor portion thereof) is inclined as shown so that the cam compactor portion is immediately adjacent the inclined blade throughout a substantial peripheral distance of the blade and of the cam compactor portion.

Each of the wings 33 is mounted for adjustment to vary the radial distance of the troweling surface of the wing (the portion thereof at the greatest radial distance from the shaft) from the axis of the shaft. To this end the wing 33 has a recess 39 in the base portion 38, in the bottom of which is slot 40. A bolt 4i has its head in the recess 39 and extends through the slot 40 into an internally threaded part of the block 32.

' By loosening the bolt 4!, the wing 33 can be slid into position and the slot 40 permits a substantial amount of adjustment of the wing laterally of the shaft. When the wing member 33 is in .what is normally the desired position, i. e., with the blade portion '34 or said '45 is not subjected to anitiate the troweling, surface 36 in alignment 'with the periphery of follower, the bolt can be tightened down so as to fix the cam member in the selected position. The wing and particularly the trowelhead 3|. As wear takes place on the troweling surface 36 so as to reduce its radius from the shaft, the wing can have its position adjustedby loosening the bolt 40 and moving the wing 33 so that the troweling surface36'thereof again comes into alignment with the cylindrical surface of the follower 3!.

A spiral blade part 45 is fixed to a sleeve 46 which is slidable longitudinally with respect to the shaft 30. The sleeve 46 can be maintained in any desired fixed position on a shaft 30 by tightening the set screw 51 one or more of which is carried by the sleeve 46 and is adapted to have its end forced into contact with the shaft 33. The end 4'5 of the blade part 45 is adapted to abut the end 48 of the blade portion 34 of one of the wings 33. In this manner the spiral blade part 45 is made substantially continuous with I wing 33; 'and'the blade part45 and inclined blade portion 34in effectare'parts of one continuous spiral blade. Normally it is preferable to have the pitch of the blade portion 34 the same as that of the blade part 45 as shown'or at least approximately the same.

Theno mal working positions of the partsof the core former are shown in Figs. 1, 4 and 5. In Fig. 6 for purposes'of claritythe blade part 45 is shown moved upwardly on the shaft 33 so ,as to indicate how the spiral blade part '45can be moved into position with reference to wing 33 so that the'end 4'Iof the bladepart"45 and the end 48 of the blade portion 34 will be in abutting relation with respect to each other. It is also to be noted that the 'end 48 of'the blade portion'3 l of the wing33is in a plane corresponding to the plane of lateral movement afforded the wing 33"on block 32. blade part 45 is in butting relationtothe'end 48 of 'blade portion 34, the end4l will likewise be'in this plane. This arrangement enables the wing 33 to be adjusted with reference to follower 3i (and withreference to theshaft so) inthe manner above described while still maintaining the ends M'and 48in abutting" relation with reference to each other. I

The radius ofthe outside edgeof the spiral blade 45 is preferably substantially the same as the radius of the follower 3| and likewise the longitudinal extent of blade 45 is preferably at least as great as the diameter thereof.

Apparatus made according to this invention can be used with only one wing'33. However, two wings 33 'are preferably employed as illustrated herein. In the device herein shown, the spiral blade part 45 can only be made substantially continuous with the blade portion 34 of one of the wings 33. However, the second wing serves a purpose as it compacting and troweling action moldable material such as concrete which has been acted upon by the other wing 33. Moreover; theseco ndwing 33 which does' not have its blade portion 34 abutting the end of the spiralbladepart as severe wear as the other or first wing. After the first wing 33"has*become When the end 4130f the serves to subject to a secondbadly worn, the blade part 45 can be loosened on the shaft 30 and readjusted so that the end 41 thereof willcome'into abutting relation with the end of the blade portion of the second wing 33. This adjustment enables the apparatus to be used for substantially twice as long without renewing the wings 33. While only one spiral blade part 45 is ordinarily contemplated it would be possible in carrying out this invention to use 'one spiral blade part 45 in connection with one wing 33 and a second spiral blade part similar to spiral blade part 45 in connection with the other wing.

'In operation the core former can be used in any desired way. For example, the mold I0 can be assembled, clamped together and placed in position in the support 25. The die 26, if used, is

placed in position at the bottom of the mold.

The core former on shaft 30 is then lowered to position adjacent the :bottom of the mold and is partially inserted in the hollow interior portion of the die 26. C oncretelifl is then poured into the mold in a moist condition and the core former is caused to rotate and to be elevated through the concrete. Preferably the core former is elevated somewhat more slowly while it is adjacent the bottom of the moldto insure compacting of the material intoall parts of the female end to the duct being formed and the speed of rotation is controlled as desired. In Figs. 1, 4 and 5 the l core former is shown in different stages of rotation and elevation, the follower 3|, in Fig. 5,

having been removed from the die 26, leaving a formed core 5| in the concrete '60 (or other moldable material) in mold 10. The core former may be eventually lifted out of the mold iii and the duct, having the core 5 I ,can then be removed from the mold.

Compacting of the material in the mold is produced when the core former is rotated in a coun 4 ter-clockwise direction in the apparatus shown in the drawing and is: due to' the combined action of the spiral blade'and of the cam Compactor.

Of course, the parts can beinreverse direction so as to produce a like effect when the parts are rotated in a clockwise'direction. Moreover, as the core former moves'upw'ardlywithin the mold, the tapered portion 31 has a" still further compacting effect on materiahwithin the mold. During rotation of the core-former the moldable material 1 may be forced by the spiral-blade into the valley 35 in the cam compactor portion of the wing 33 'at a time when the valley hasthe depth indicated at I in Fig. '7. Upon rotation of the core former,

the material will slide inreference to the core former and will be forced to docupy the valley 35 when the depthhas decreased to that shown by line 2 in Fig. '7. Upon further "rotation of the core former, the depth of the valley, which a particular portion of the material occupies, is

decreased as indicated by lines 3 and 4 in Fig. '7 and eventually becomes eliminated. At the same time the widthof the valley decreases as the dotted linesl, 2, 3 and 4 also indicate which imparts a further compacting effect on the material. The material is then troweled by the troweling surface presented by wing 33 and by the periphery of follower 3!.

In connection with a core former'constructed in the manner herein illustrated and described,

it is significant thatthe spiral blade and cam compactor portions are in endwise juxtaposition. The moldable material, e. g.'concrete, is in sliding contact with the'spiral blade and material on a surface thereof toward the cam compactor is' urged toward the cam compactor upon rotation of the shaft in a given direction. Without interruption of the compacting force the material is brought into sliding contact with the cam compactor which then urges the material outwardly from the shaft and toward the wall of the mold. This results in the building up of high pressures on the concrete so that even the remote parts in the angles of square molds are filled and furthermore the compacting is at all times uniform so that there are not portions of concrete 0f varying consolidations within the mold. In previous devices neither the degree of pressure nor the uniformity thereof in different parts of the mold was sufficient to avoid a large percentage of rejectable ducts. In connection with this aspect of this invention, it may be said that if a spiral blade is used which is independent of and is substantially separated from a cam compactor, the results obtainable are very much inferior both in degree of compacting and in uniformity of compacting. With the core former embodying this invention rejections of ducts because of poor consolidation has been substantially eliminated and ducts of substantially higher strength as a whole and uniformity throughout and of substantially improved structure are obtainable.

It may also be noted that the spiral blade including blade portion 34 of wing 33 is so positioned in endwise juxtaposition to the cam compactor portion of the wing 33 that it terminates in that part of the wing having greatest radius from the shaft, namely, above troweling surface 36 of the wing 33. This causes the portions of different radius from the shaft of the cam surface presented by the wing 33 to be immediately alongside the blade portion 34 so as to augment the combined downward and outward compressive forces acting in the material in the mold. Likewise the cam compactor portion is not only decreased in depth but also is decreased in width progressing downward the portion of the wing having greatest radius from the shaft so as to further augment the wedging and compacting of the material in the mold, before it is finally troweled and smoothed by the follower 3|.

The foregoing desirable effects, can, according to this invention, be secured in a core former in which the parts can be readily adjusted and in which the more rapidly wearing parts can be readily renewed. In this connection the adjustability of the wing 33 with reference to the follower 3! while maintaining desired relation between the wing 33 and the blade part 45 is to be observed. The construction of the spiral blade so as to be partly on a blade part and partly on an adjustable wing contributes to this feature. Other desirable features relate to the facility with which the wings 33 and the spiral blade part 45 cannot only'be adjusted but completely removed and be replaced when desired.

It is to be understood that the embodiment of this invention which has been shown and described hereinabove is illustrative merely and that apparatus embodying this invention may take various forms. Accordingly the scope of this invention is to be limited only by the language of the, following claims.

I claim:

1. In apparatus of the character described, a core former adapted to form the core of a concrete duct, which comprises a. shaft, a cam compactor in secured relation to said shaft presenting a cam surface adapted to urge material in sliding contact therewith outwardly away from said shaft pactor in secured relation to said shaft presenting a cam surface adapted to urge material in sliding contact therewith outwardly away from said shaft upon rotation of said shaft in a given direction, and a spiral blade disposed about said shaft in secured relation thereto adapted to urge material in sliding contact with a surface thereof facing said cam compactor toward said cam compactor upon rotation of said shaft in said direction, said spiral blade and cam compactor being in substantially immediate endwise abutment on said shaft, the radial distance of the end of the outer edge of said blade being substantially the same as the greatest radial dimension of said cam compactor.

3. In apparatus of the character described, a core former adapted to form the core of a concrete duct, which comprises a shaft, a cam compactor in secured relation to said shaft presenting a cam surface adapted to urge material in sliding contact therewith outwardly away from said shaft upon rotation of said shaft in a given direction, a spiral blade disposed in endwise juxtaposition to said cam compactor about said shaft in secured relation thereto and adapted to urge material in sliding contact with a surface thereof facing said cam compactor toward said cam compactor upon rotation of said shaft in said direction, said cam compactor having the end portion toward said spiral blade inclined to. correspond at least approximately to the pitch of said spiral blade so that the said cam surface throughout a substantial peripheral extent thereof about said shaft is immediately adjacent said spiral blade throughout a substantial portion of the length of said blade.

4. In apparatus of the character described, a

core former adapted to form the core of a concrete duct which comprises a shaft, a cam compactor in secured relation to said shaft presenting a cam surface adapted to urge material in sliding contact therewith outwardly away from said shaft upon rotation of said shaft about its axis in a given direction, a spiral blade disposed in endwise juxtaposition to said cam compactor about said shaft in secured relation thereto and adapted to urge material in sliding contact with a surface thereof facing said cam compactor toward said cam compactor upon rotation of said shaft about its axis in said direction, a cylindrical follower in coaxial secured relation with said shaft and in endwise juxtaposition with the end of said cam compactor remote from said spiral blade, said cam surface having its maximum distance radially from said shaft about the same as the radial distance from the axis of said shaft of the periphery of said follower and affording throughout at least a part of the peripheral length thereof a valley between said blade and said follower which diminishes in depth and in width progressing toward the portion of said cam sursaid shaft.

5. In apparatus of'the character described, a core former adapted toform the core of a concrete duct which comprises a shaft, a cylindrical follower in coaxial secured relation to said shaft, a spiral blade part disposed about said shaft in secured relation thereto adapted to urge material in sliding contact with a surface thereof facing said follower toward'saidfollower upon rotation of said shaft about its axis in a given direction, and a wing member interposed in endwise juxtaposed position between said follower and said spiral blade part, said wing member having a blade portion at the end thereof adjacent said spiral blade part which has a pitch corresponding at least approximately to the pitch of said spiral blade part and having a cam compactor portion between said blade portion and said follower which is adapted to urge material in sliding contact therewith outwardly away from the axis of said shaft upon rotation of said shaft about its axis in said direction.

6. In apparatus of the character described, a core former adapted to form the core of a concrete duct which comprises a shaft, a cylindrical follower in coaxial secure-d relation to said shaft, a spiral blade part disposed about said shaft in secured relation thereto and adapted to urge material in sliding contact with a surface thereof facing said follower toward said follower when said shaft is rotated about its axis in a given direction, and a wing member interposed in endwise juxtaposed relation between said follower and said spiral blade part, said wing member having a blade portion with its end adjacent said spiral blade part in abutting relation with respect to the end of the said spiral blade part and with a pitch corresponding at least approximately to the pitch of said spiral blade part and having a cam compactor portion between said follower and said blade portion presenting a cam surface adapted to urge material in sliding contact therewith outwardly from said shaft upon rotation of said shaft in said direction about its axis and a troweling surface adapted to smooth the outwardly urged material, means affording said wing member movement laterally of said shaft while maintaining the end of said blade portion thereof in substantially abutting relation with respect to the end of said blade part to vary the radial distance from said shaft of said troweling surface, and means for maintaining said wing member in secured relation with respect to said shaft in a plurality of different positions afforded by said movement.

7. In apparatus of the character described, a core former adapted to form the core of a concrete duct which comprises a shaft, a sleeve about said shaft in slidable relation therewith, means for fastening said sleeve to said shaft, a spiral blade part disposed about and secured to said sleeve, a cylindrical follower in coaxial secured relation to said shaft, a block in secured relation to said shaft between said follower and said sleeve, and a wing member presenting a cam surface adapted to urge material in sliding contact therewith outwardly away from the axis of said shaft when said shaft is rotated about its axis in a given direction, said wing member being mounted for adjustment laterally of said shaft on said block to vary the maximum radial distance of said cam surface from said. shaft, and said spiral blade part being adapted to urge material in sliding contact with a surface thereof facing said wing member toward said wing member.

8. In apparatus of the character described, a core former adapted to form the core of a concrete duct which comprises ashaft, a sleeve about said shaft in -secured relation thereto,a spiral blade part disposed about and secured to said sleeve, a cylindricalfollower in coaxial secured relation to said shaft, a block in secured relation to said shaft between said follower and said sleeve, a wing member includinga blade portion having" a pitch corresponding at least approximately to the pitchofsaid spiral blade part and a cam compactor portion presenting a cam surface adapted to urge material in sliding contact therewith outwardly from the axis of said shaft when said shaft is rotated about its axis in a given direction and means for mounting said wing member on said block with the end of said blade portion thereof abutting the end of said spiral blade for adjustment of the alignment of the portion of said cam surface at maximum radial distance from the axis of said shaft with reference to the peripheral surface of said follower, said spiral blade part being adapted to urge material in sliding contact with a surface thereof facing said wing member toward said wing member upon rotation of said shaft about its axis in said direction.

9. In apparatus of the character described a core former adapted to form the core of a concrete duct, which comprises a shaft, a cam compactor presenting a cam surface adapted to urge material in sliding contact therewith outwardly away from said shaft upon rotation of said shaft about its axis in a given direction and a troweling surface adapted to smooth the outwardly urged material, a spiral blade part disposed about said shaft detachably and adapted to urge material in sliding contact with a surface thereof facing said cam compactor toward said cam compactor upon rotation of said shaft in said direction about its axis, means for mounting said cam compactor for adjustment to vary the radial distance from said shaft of said troweling surface, and means for mounting said spiral blade on said shaft for adjustment to vary the longitudinal position of said spiral blade on said shaft.

10. In combination with a core former mounted on a shaft and adapted to form the core of a concrete duct, compacting means comprising an inclined blade part and a cam compactor part, I

said inclined blade part upon rotation of said core former about its axis in a given direction being adapted to urge material in sliding contact with a surface thereof facing said cam compactor part longitudinally of said shaft toward said cam compactor part, and said cam compactor part presenting a cam surface immediately alongside said inclined blade part throughout a substantial portion of the length of said blade part.

adapted to urge material in sliding contacttherewith outwardly away from said shaft upon rotation of said shaft about its axis in said direction so that said material is urged outwardly by said cam surface simultaneously with being urged longitudinally by said spiral blade part upon rotation of said shaft.

11. In apparatus of the character described a core former adapted to form the core of a concrete duct which comprises a shaft, a wing member including a cam compactor portion presenting a cam surface adapted to urge material in sliding contact therewith outwardly from said shaft upon rotation of said shaft about its axis in a given direction and an inclined blade portion adjacent an end thereof adapted to urge its axis in said direction, and said wing member being mounted on said shaft with the end of said blade portion carried by said wing member abutting said end of said blade part, and means for adjusting said wing member to vary the 5 maximum radial distance of said cam surface from said shaft while maintaining said end of said spiral blade part abutting said end of said blade part carried by said wing. member.

HINIS OROURKE.

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