US2794232A

US2794232A - Mechanism for finishing the ends of clay pipes

Info

Publication number: US2794232A
Application number: US512801A
Authority: US
Inventors: Cecil E Webb
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-07-21
Filing date: 1955-05-20
Publication date: 1957-06-04
Anticipated expiration: 1974-06-04

Description

June 4, 1957 c. E. WEBB 2,794,232

MECHANISM FOR FINISHING THE ENDS OF CLAY PIPEs Original Filed July 21, 1951 2 Sheets-Sheet l 9, L-zao /zas IN VEN TOR.

A T TOENE ys.

June 4, 1957 c. E. WEBB MECHANISM FOR FINISHING THE ENDS OF CLAY PIPES Original Filed July 21. 1951 2 Sheets-Sheet 2 JNVENTOR.

ATTU/QNE ys.

I l atented June 4, 1957 MECHANISM FQR FINISHING THE ENDS OF CLAY PIPES Cecil E. Webb, Cincinnati, Ohio, assignor to M. S. Bowne, Clearfield, Ky., trustee Original application July 21, now Patent No. 2,713,189, vided and this application May 20, 1955, 512,801

Serial No.

4 Claims. (Cl. 25-1419) This invention pertains to the manufacture of ceramic pipe such as sewer pipe sections, drainage tiles and the like which are formed of plastic clay and hardened by firing. The invention is directed in particular to a mechanism for trimming and finishing one or both ends of the pipe sections while the clay is in a plastic state.

This application is divided from the copending application of Cecil E. Webb, Serial No. 237,920, entitled Automatic Apparatus For Finishing the Ends of Tile Sections, now Patent No. 2,713,189. e

A primary object of the invention has been to provide a simple, automatic finishing mechanism for finishing one end or concurrently finishing both ends of a plastic clay tile pipe at a rapid production rate and in an accurate reliable manner.

In its preferred form, the finishing mechanism is provided with a pair of axially spaced finishing heads which trim both ends of the pipe accurately to length, and at the same time, form an internal peripheral groove in the socket end and an external peripheral groove in the opposite or spigot end of the pipe.

A typical sewer pipe section consists of a cylindrical column having at one end an enlarged coupling hub adapted to establish a telescopic connection with the column end of an adjoining pipe section when the sections are connected to one another to make up drainage or waste lines. The tile pipe sections are usually fabricated by extending the cylindrical column, then expanding one end of it to form the coupling hub or socket. The socket is formed by suitable dies either in conjunction with the extrusion process or with a separate op eration. The inside diameter of the hub is made sufiiciently larger than the column to provide an annular space between two sections when they are telescoped together, and upon installation, this space is packed with wet cement or equivalent material to provide a seal between the connected pipe sections. which is formed at the juncture of the inside diameters of the hub and column, forms an abutment for the column end upon insertion into the hub.

The present finishing mechanism is disclosed in connection with this type of tile pipe as a preferred formof the invention and is adapted to finish both the hub and spigot ends concurrently. derstood that the invention is not tion to this particular type but can be used in finishing one or both ends of tile sections having plain ends or in finishing others having special formations at one orv both ends. It will also be understood that the operating principles disclosed herein in relation to plastic clay can be applied to the production of tubes formed of other plastic materials having similar characteristics.

In the sewer pipe industry,

by the extrusion and-forming dies" but the length ofthe 1951, Serial No. 237,920, dated July 19, 1955.. Di--v An internal shoulder,

However, it will be un limited in its applica-' the forming operations;

spigot and hub cannot be controlled precisely during therefore, it has been the practice in the industry to extrude the sections in lengths greater than the desired finished length of the product and while the extruded sections are still in plastic condition, to trim and finish them to their final dimensions.

Along with the final trimming operation, annular grooves are formed upon the outside diameter of the spigotend and corresponding annular grooves are formed in the inside diameter of the coupling hub'to key the coupled sections permanently together when the wet ceformerly were executed by hand.

hand in the machine,

ment hardens in the annular space. In addition to the gr'oovirigoperation, it is customary to, chamfer the corner of the internal shoulder which is formed at the juncture between the, inside diameter of the hub and spigot. The purpose of the chamfer is to remove isusually present at this point. inmost of the extruded tiles, being formed by leakage of plastic clay under pressure between the interfaces of the dies during the forming of the hub.

The trimming, grooving and chamfering operations More recently, the present inventor developed an apparatus and method for performing these operations mechanically as disclosed in the copending application of Cecil E. Webb, Serial No. 111,182 filed August 19, 1949, now Patent No. 2,630,613. This prior machine is presently in successful operation as a hand fed machine and includes a pair of finishing'heads which are generally similar to those of the present machine. Individual tiles are placed by the machine being provided with It '7 means for guiding and sustaining the tiles in finishing ally similar to v in a simple manner with in the manufacture of clay pipe,

position. Upon placement of the tiles, the finishing heads move axially into the opposite ends of the tile and rotate in opposite directions to perform operation.

The finishing heads of the present invention are generthose of the prior Webb patent; however, the present structure utilizes fluid pressure, preferably compressed air, for feeding the heads axially into the pipe and for extending the finishing tools laterally or radially to operating position after the heads are inserted. The use of compressed air adapts the mechanism to hand operation if desired, utilizing a simple hand valve for control purposes. On the other hand, air operation makes it possible to combine the present finishing mechanism other automatic machines used thus providing automatic trimming and finishing.

The automatic finishing machine of the original Webb Patent No. 2,713,189 includes a revolving turret having pipe clamping jaws for advancing unfinished pipes to the finishing heads.

When the turret is indexed to transfer an unfinished pipe into alignment with the finishing heads, the heads are in retracted position. The heads, which rotate continuously, then move axially into the opposite ends of the pipe, execute the finishing operation and remain within the pipe until the turret jaws advance the next pipe.

the cylindrical columnis' usually designated as the spigot end and the tile. sewer At this time, the finishing heads retract to allow the jaws to discharge the finished pipe while another set of jaws transfers the unfinished pipe to the finishing heads.

The present mechanism is disclosed in relation to a machine'having clamping jaws of this nature. However, it will be apparent from the detailed description, that the finishing'heads can be utilized without pipe jaws if desired.

A- further object of the invention has been to provide a simple, pressure actuated cylinder arrangement which, in a positive sequence, first shifts the finishing head axially into the end of the pipe and then shifts the finishing tool laterally toward the periphery of the pipe, thereby to introduce the head into the plastic pipe without marring itssurfarie:

the flashing which This flashing is found- After the rotating heads are fully inserted by operation of a first set of cylinders, but before the toolsactually con tact the surface of the pipe, back pressure from the cylin-, ders is transmitted to a second set of cylinders having tool actuating pistons. These pistons gradually present the tools to the pipe surface while in motion to impress a smooth clean groove. During this operation, cutting tools on the heads trim ofif the opposite ends of the pipe while the chamfering tool trims the internal shoulder of the socket. After the finishing operation is completed, the air pressure is relieved from the cylinders. The arrangement is such that the tool actuating pistons first retract the tools, then at a lower pressure, the first set of cylinders retract the heads axially.

Various features and advantages will be more fully apparent from the following detailed description in conjunction with the drawings.

In the drawings:

Figure 1 is a diagrammatic view illustrating the finishing heads of this invention jaw means for clamping the pipe. shown in broken lines.-

Figure 2 is an enlarged fragmentary sectional view i1- lustrating the lower finishing head assembly of Figure 1.

Figure 3 is a sectional view taken on line 33, Figure 2, detailing the gear drive for rotating the finishing tools.

Figure 4 is an enlarged fragmentary sectional view taken from Figure 2, detailing the air valve and associated parts.

Figure 5 is an enlarged top plan view along line 5-5,. Figure 2, showing the arrangement of the pedestal, trimming knives and scoring roller of the lower head.

Figure 6 is a fragmentary sectional view' taken on line 6'6', Figure 5, further detailing the lower finishing head.

Figure 7 is an enlarged fragmentary sectional view detailing a portion of the upper finishing head.

Figure 8 is a plan View taken along line 8-8, Figure 7, detailing the upper finishing head.

Figure 9' is a fragmentary sectional view, taken on line 9-9, Figure 8, detailing the mandrel and trimming knives of the upper finishing head.

The relationship of the finishing heads, as applied to an automatic finishing apparatus of the original Patent No. 2,713,189 is illustrated diagrammatically in Figure 1 to demonstrate the principles of the invention. As indicated, the machine includes a basev 8 and a column 9 which supports a rotatable turret 10 including pipe clamps 11. A typical clay tile pipe 14, shown in broken lines, consists of the spigot portion and socket or hub 16. Theupper finishing head, indicated generally at 12, is arranged to finish the spigot'end and the lower finishing head, indicated at 13, is arranged to finish the socket end of the pipe. The

finishing heads rotate continuously while the machine. is

in operation.

As indicated above, the pipe is indexed by the turretjaws from. a feed conveyor (not shown)v to a position in axial alignment. with the rotating finishing heads. The heads. normally reside in. advanced position as shown in broken lines in Figure 1. When the pipe is advanced to the jawsit trips a starting switch (not shown) causing the finishing; heads to'be retracted (as shown in full lines), the clamping jaws to. grip the pipe, and the turret. to be indexed. to trans.- fer the. pipe to the finishing heads. The rotating. heads are then shifted axially into the ends of the pipe, to perform the finishing operation. This sequence is initiated each time the starting switch is tripped by an unfinished pipe, the turret having multiple jaws to advance the unfinished pipe to the heads while the finished one'is transferred to a discharge conveyor (not shown).

The finishing heads trim the end of hub 16 and spigot end 15 of' the tile to predetermined length and also perform a. grooving; or. scoring. operation upon the outside diameter of the spigot end and a similar grooving. operation upon the inside diameter of the hub end. The. shoulder 16a at the hub also receives applied to a machine. having a chamfer along .with the.-

trimming and grooving operation to remove any flashing which may be present.

As noted above, the finishing heads may be arranged to finish the tiles in inverted position, that is, with the tiles resting upon their spigots as they are advanced to the turret. This is necessary in finishing the large diameter tiles. In the following disclosure, the hub finishing head is located at the bottom in onder to finish tiles advancing in the position they assume as they leave the forming machine. It will be understood the mounting apparatus is in duplicate for both heads so that they may be interchanged conveniently. When operating on the large tiles, the invertor may be arranged to deliver the tiles in inverted position directly upon the feed conveyor.

The finishing heads each include a mandrel which enters respectively the hub and spigot ends of the tile, the respective mandrels being approximately of the same diameter as the inside diameters of the hub andspigot. The turret in its indexed position is fixed and the mandrels are accurately aligned with the axis of the indexed tile. The arrangement is'such that the mandrels, upon being extended into the plastic tile, will bring the tile into axial alignment even though itmay have been bent slightly in handling.

The finishing. heads are shifted axially into and out of working'engagement with respect to the tile by the air cylinders 18-18, air being valved. to the respective cylinders from the air pressure supply system. The air cylinder assembly is identical for the upper and lower finishing heads; therefore, the following description of the lower finishing head assembly applies to both.

The inside and outside grooving operations are executed by grooving rollers which are rotatably mounted upon thefinishing" heads. These rollers each include a fiat tracking surface adapted to contact the surface of the tile on the inside and outside to control the groove depth, the tracking surface having a circumferential head or ring which is shaped in cross section to the configuration of the groove. The flat tracking surfaces control the depth of the groove While the bead penetrates the plastic material as the roller is rotated in tracking engagement upon it.

Since the grooving rollers must move into facial engagement against the respective surfaces of the tile, they normally assume a retracted positionv out of contact with the surface of the tile and are extended gradually during rotation of the finishing heads so as to progressively deepen the groove as the roller is rotated around the tile. This mode of operationprevents marring of the tile surfaces as the rollers are brought into operating position; in addition,,it has beenfound in practice that the progressive formation of the groove produces a cleaner and more accurate groove contour.

' A simplified arrangement has been developed for causing the upper and lower grooving, or scoring rollers to move progressively into the tile surface after the cutting heads assume their final operatingv position. This arrangement in both instances consists of a piston and cylinder assembly connected by suitable linkage to the groovingroller and supplied with air pressure which is metered from the' main operating cylinder 18 of each finishing head. The arrangement is such that when air pressure is valved into the main actuating cylinders, the finishing heads are moved concurrently into the opposite ends of the tile. A metering aperture, communicating with the interior of the main actuatingcylinder,allows a controlled quantityofair pressureto pass from the main cylinder 18 to the" roller actuating cylinder and piston assembly.

The grooving roller piston of each finishing head is springloaded in its retracting direction so that the metered isinsufi'icientto move the roller into operating position while thecutting head assembly is being moved toward operating: position. However, when the finishingv head reaches final position,.with its piston engaged against'the eniofthe, cylindenasufficient backpressure is developed in the main actuating cylinder 18 to overcome the bias effect of the spring, thereby causing the roller piston to move the roller progressively into tracking engagement against the tile surface. The metering aperture restricts the fiow of air to such an extent that the grooving roller penetrates gradually into the surface of the plastic tile during several revolutions to produce a smooth, uninterrupted groove during the several passes of the grooving roller around the circumference of the tile.

As above noted, the operating cylinder assemblies for both finishing heads are duplicated and the following detailed description in conjunction with Figures 2 to 6 will apply to both assemblies. As shown in Figures 1 and.2, the cylinder assembly for the lower finishing head, is secured by means of a bracket'212 to the base of the machine. The upper finishing head assembly is secured by an identical bracket 212 to the cross arm 28 in a similar manner. As shown in Figure 2 the lower finishing head assembly constitutes two sections, the lower section 213 including the air cylinder 18 and an upper section 214 including a bearing bracket for a combined drive shaft and piston rod 215 upon which is mounted the finishing head.

At the juncture between the cylinder and bearing bracket there is provided a gear box 216, see also Figure 3, which encloses a worm wheel 217 in-mesh with a worm 218 for rotating the combined piston rod and drive shaft 215. The worm is journalled in bearings 220-229 fitted in a sleeve 221 forming a part of the gear box and is driven by the drive shaft system 20 which extends from the finishing head. According to the original patent, the drive shaft system 20 is driven by a motor which is energized continuously while the machine is in operation. The system is common to both heads and is arranged to drive them in opposite directions so as to neutralize the turning force acting upon the clay pipe.

Again referring to Figure 2, it will be observed that the combined piston rod and drive shaft 215 is rotatably mounted in the bearing bracket 214 by the upper and lower ball bearings 222-222, the shaft being slidably confined in a driving sleeve 223 which is rotatably supported by the bearings 222. The lower end of the driving sleeve 223 is keyed as at 224 to the worm wheel 217 and the worm wheel is locked against axial movement by means of the nut 225. The drive shaft and piston rod 215 is splined as at 226 to the lower portion 227 of the sleeve, being splined to provide the driving connection (Figure 3).

The splined connection so provided, transmits the drive from the worm wheel 217 to the shaft 215 and also provides a slidable connection so that the rotating shaft can be shifted axially by operation of the actuating cylinder 18. The piston rod section 228 extends through a packing gland 230 formed in the gear box to prevent escape of air from the cylinder and the end portion of the piston rod is connected to the piston 231.

The connection between the piston and the combined piston rod and drive shaft allows rotation of the piston rod with respect to the piston, the rotatable connection being provided by the ball bearings 232. These ball bearings are confined in a complementary race formed in the piston and in the piston rod.

For this purpose, the piston rod includes a semicircular groove and the piston includes a corresponding semi-circular groove formed in two half sections to permit insertion of the balls. The piston includes an end plate 233 secured by screws 234, the raceway being formed between these two parts. The end plate is of course removed to permit insertion of the balls and is then fastened in position by the screws to provide a rotatable connection with the rod. The skirt 235 of the piston is grooved and flexible sealing rings 236 are installed in these grooves in the customary fashion.

The piston includes

ports

237 and 238 at opposite endsin communication with -the flexible air conduits 249 and 241rto. cause piston reciprocation by air pres- 6 sure in either direction. The conduits extend to the cylinders 18 of the upper and lower finishing heads as indicated in Figure 1, air being supplied by way of the conduits through a reversing valve to either end of the cylinders to advance or retract the finishing heads in unison. The air supply may be controlled by the electrically operated valves of the original patent or it may be controlled by a manually operated valve (not shown), as noted earlier.

In order to supply air pressure to the scoring roll cylinder, a bore 244 is formed through the piston rod 228 and drive shaft section 215 leading to a lateral port 245 formed at the upper end of the shaft section. The upper end of the shaft section is screw threaded as at 246 to provide a detachable connection for the hub 247 of casting 248 in which is formed the scoring roll cylinder 250. A groove 251 is machined in the shaft to provide communication from the port 245 to a passageway 252 leading to the scoring roll cylinder. A second groove is also machined in the shaft to provide a seat for a sealing ring 253 which prevents air leakage from the hub.

Air is admitted to bore 244 by way of the metering orifice'254 drilled through the lower end of the piston rod. The lower end'of the bore 244 is closed off by a ball checkvalve 255 held in closed position by a compression spring 256 seated within a thimble 257 (Figure 4). It will be apparent, that air under pressure beneath the piston is in communication with the scoring roll cylinder by way of the metering orifice 254, bore 244, lateral port 245, and from port 245 by way of passageway 252 to the cylinder.

It is also to be noted that the piston 258 of the scoring roll cylinder is biased by the compression spring 260 seated between the end of the cylinder and piston forcing the piston normally in roll retracting position as shown in Figures 2 and 5. The area of piston 258 is proportionately smaller than the main actuating piston 231, and due to the bias effect of spring 260, the scoring roll piston is inoperative during advancement of the finishing head. However, when the finishing head reaches the end of its stroke with the piston seated against the end of the cylinder as indicated in broken lines in Figure 2, the back pressure developed behind the main piston is sufficient to overcome the resistance of spring 260, causing the scoring roll to move into its scoring position. The metering action restricts the admission of air sufficiently to cause the scoring roll to move slowly into the scoring position and only after the head is fully extended.

When the finishing head is retracted from the tile airv pressure is applied to the opposite end of cylinder 18 by way of conduit 240 and is exhausted by way of the opposite conduit 241 by'operation of the reversing valve. Upon release of air pressure trapped behind the main piston 231, air pressure trapped within the scoring roll cylinder 250 is discharged rapidly through the ball check valve 255 due to the pressure exerted by the compression spring 260. This allows the scoring roller to be retracted quickly out of engagement with the surface of the tile section before the finishing head begins its axial motion in the retracting direction and thereby prevents damage to the finished surface of the tile section.

As best disclosed in Figure 5, the scoring roller 261 is mounted upon the swinging end of a lever 262 which is pivotally mounted as at 263 to a lug 264 forming a part of the casting 248. The scoring roller is pivotally mounted upon a stub shaft 265 extending from the swing ing end of the lever. The lever 262 is pivotally connected as at 266 to the piston rod 267 extending outwardly from the scoring roll cylinder. The pivot points 263, 266 and 265 preferably consist of shoulder screws, each being provided with a nut 268.

The mandrel of the lower finishing head assembly is in the form of a pedestal 270 which enters the hub" end of the tile section, as-shown in broken lines'in' Figure 2,

a es aduringzthe finishingw per t u As in icat d, :th insi diameter of the hell i tap r d a d th p es a move upwardly :until it engages .the shoulder 1 6a such that the pedestal properlyrrelates thefinishing toolsiwith reference totheplaue of this shoulder. In ,setting'up the machine, thefinishingheads arebrought-to accurate alignment with the .axis of tthestile section in indexed position but it has beenfouud impractiee that theplastic clay sections sometimes are bent slightly in handling and thepedestal is found ,to straighten the bent sections as ;it enters -the taperedrboreat the.;,hu b endofithe section. This is true also of'the upper finisher, the upper-mandrelheing 1ta- Pered to .facilitatedtsen ry and tors r ighten out z nyirregular.- condition.

Th p des al 7270 includes ahub 127.11 and ;is rotatably jOlllflldllfidgllROllZiliSllllb haft; 273 3by;mea-ns of ball bearings 327.4. This permits :t-he pedestal-to rotate with-respect to 111 2 2 11) :shaft dlponxwhich .it is mounted.

.The:. zhamferiug knife 227.5 is mounted-and rotates with he drivesshaft relative to the-pedestal and .is arranged toflformiheeehamferiat the shoulder .1611. The purpose of ;the phamferingoperation is ;to remove the flashing which usually XiStS,at'fl1lS;POi1Htcby reason of the extrading operation. .The .chamfering iknife .is mounted by;means ;of rfa.:SC1eWT27.6 (Figure 5) .upon a disk 277 which resides within :the :pedestal "27.0. .The shank of the ;knife.is;slotted..as at t278 toprovide radial adjustment. The disk 277is clampedagainst the inner race of 'thei'upperball :bearing :274by-means of -.a nut 279 threaded upon the upper end of the stub shaft 1273-to provide the driving connection between the disk and stubs-shaft. Itz-Wl'll'be apparenttherefore, that-the knife andqdisktarerotated relative to the pedestal 270 during the finishing operation.

.As Ibest :shown in Figures 5 and 6, the trimming knives 7-280x280 are mounted upontheouter ends of the; radial arms 281 281 which extend from diametricallyiopposite sides of -the casting 248 below the pedestal 270. hese knives are thus mounted in fixed relationshipwith-the-plane of the pedestal so as to trim'the-hub to .a predetermined length, measured from the shouldere16tz.

Each knife is-moun-ted upon 'a-stub shaft 1282,:loosely journalle'd in-a bushing'283 pressed into a lug 284 formed at the outer ends of the radial arms 281. The outer endsof--the-st-ub shaft'282 include a block285 and as viewed in Figure 6, thetnfmm-ing knife consists of a blade which has itscutting edgeparallel with, but offset from the axis of the stub shaft. The finishing head rotates in the direct-ion indicated by the arrow in Figure '5 such. that the-cutting edge trails behind the axis of the stub shaft; in addition the stub shaft is free to rock to'a limited-extent to provide a feathering action to provideandimprove the cutting action.

As .viewed in Figure 6, thefeathering motion is limited'by means of the cotter pin 286 passing across a flat portion 287 of the stub shaft. Upon encountering the unfinished end of the hub, the rotating knife will naturally featherjslightly to a cutting position and will thereby remove the excess material progressively and without leaving an abrupt -break in the finished end.

The feathering of the bla'de is limited on the hub end because the amount of material to ,be removed is relatively slight as indicated inbroken lines in Figure 1. Thetrimming knives on thespigot end areallowed full feathering -movement as disclosed in.,the above mentioned copending-application' because substantial amount ofmaterial is. removed from the spigot end of the tile section.

As shown inliigure 2, the ,mountingbracket 2 l2;consists of an angulated web 290,,forming a part of the bearing sleev 21 an h ving amount ng pad f m along; i s upper-edge- I e fi Qmb13/ se re to the fiaage'....292. xtending-from 1the-'.- a e: o ..-th :m chi e, t

bracke bein secu e t m -flange .by s reW 9 3-- In ord r to adiu e as mb y ac u at l n isnmeat with t e .ax p th il a dju m ud294 is ro atdbly mountedin a hub 295 formed :in the flange 292. The upper end oftheadjustment stud is squared to provideengagemenpwithe wrench and the lower end ofthe stud is providedwith an eccentric pin 296 which fitsinto abor e formed in the pad. Thescrews 293 are screwthreaded into the .pad 291 .and the flange 292 includes clearance ,holes indicated .at 297 which .allow the finishing head ;assem bly ;to be ,shifted bodily bythe eccentric pin 296 when the'adjustment shaft is rotated with .the screws 293 slightly loosened. When .proper adjustment is niade, the screws are tightened to lock h ssemb y in fi a pes fiq As above, noted, the.finishing head for the spigottend of t t secti n embo e a y d a emb which is identical with that of the ,lowerfinishing head except that it is-mounted in reversed position upon the support 28 vextending from the column. Theend of thearm includes a flange 292 as above described, the y d as m l l einga iu ta m nt w e t to this flangein the-same manner.

As shown in-Eigures 7 to-9, the finishing tools for the upper head are substantially the same as those of the lower head-except thatthe scoring roller is arranged to operate upon theoutside diameter of the spigot end of the; tile. ,Also, in place'of the pedestal 270 of the lower he drth eri pm ide sen e amau r 300 h h fits the;inside; ;dian 1et er of;-t he spigot. The mandrel 300 is provided with; a tapered portion 301 to facilitate entry into the tile and to;l in e up-the end of the tile should it be deformed i;n,- handling. The mandrel 300 is rota ably i urna ledtunonth s ub s a 2 i t s m manner as described with reference to the;lower pedestal exeeptthatin'this case, thedisk 277 ,a nd charnfering knife275 are, omitted.

It willbenoted inFigure 9 that-the tr-immingknives 280 in the present instance are arranged for complete featheringin-the manner disclosed-in the above noted copending, application. *For this purpose the stub shafts 282, which mount the upper. trimming knives, are grooved completely as at 302 to permit complete rotation of the trimming .knives as distinguished from the partial feathering, provided by groove slot 287 (Figure 6) forthe lower trimming knives. Complete featheringis provided for the upper knives because a greater length of material isremoved from the spigot end and this allows them to descend without; interference into :the tile to trimming depth.

.Since the scoring roll operates uponthe outside diameter of the spigot section, the scoring roller must be moved inwardly into engagement with the tile section as shown in Figure 8 instead of outwardly as disclosed in Figure 5. This is accomplished inasimple manner using the identical casting 248 previously described, but in this case the fulcrum point of the lever 262 is reversed so as to reverse the direction of.-movement. .As shown in Figure 8 the lever 262,. which is used on the lower head, is replaced with a lever 303. This lever is slightly longer than the lower lever and isxfulcrumed wat a point intermediate its length as at 304, thepiston rod being .pivotally connected ,as.at 305, with .the scoring roll .306 rotatably mounted on the opposite end as at 307. It will be observed that the scoring roll.306 is cylindrical in shape to'conform to the outside diameter of the tile section whereas the lower scoring roll is. tapered to conform to the taper of the inside diameter of the hub.

The other parts .ofthe cylinder :assembly including the worm andworm wheel-driving system, the air supply system, and the passageways to the piston rod for metering, air pressure to the scoring roll piston, are identiealwith the structure disclosed in Figure-2.

. Accor ng to h ig p tent, the column of -the machine; is utihged; accumulator; for the airsupply for the cylinders." It will be understood that any conventional air supply system may be employed for the head or heads, utilizing reversing valves for controlling the operation of the cylinders as described above.

It will be understood that the finishing heads may be rotated by any suitable source of power, the driving system 20 of the original patent being disclosed in the present application. The driving system of the lower head consists of the shaft 322 including a universal joint 321. The driving system for the upper head consists of shaft 336 including the universal joint 338. As best shown in Figure 3 the universal joint 321 provides a driving connection with the worm shaft 219 of the lower finishing head, the universal joint being slidably keyed to the shaft to allow the lower head to be adjusted laterally with respect to the base of the machine. The upper universal joint 338 likewise provides a telescopic connection which permits the upper finishing head to be adjusted laterally.

From the foregoing, it will be apparent that each finishing head is a self-contained unit which can be utilized either with an automatic handling machine or for manual finishing operations. For example, a single finishing head may be mounted above a pipe conveyor and controlled manually to finish the ends of pipe as they are advanced along the conveyor. It will be understood that when two finishing heads are utilized, then it is preferable to provide gripping mechanism to position and support the pipe relative to the heads.

What is claimed is:

1. In a sewer pipe machine, a finishing device adapted to be extended and retracted relative to the end of a pipe for finishing the same comprising, a primary air motor, said primary motor having a reciprocating element movable longitudinally and including a rotatable, longitudinally movable shaft, means for rotating the shaft, pipe scoring means mounted upon the outer end of the shaft, the scoring means being movable transversely with respect to the axis of the shaft to engage and score the periphery of the pipe, a secondary air motor, said secondary air motor having a reciprocating element movable transversely relative to said shaft, said element connected to the scoring means for moving the same transversely, means for applying air pressure to the primary air motor for extending said rotatable shaft and the scoring means longitudinally to a position for engagement with the pipe, said primary motor including positive stop means engaging the reciprocating element thereof at the limit of said longitudinal motion, thereby stalling the primary motor at said limit and developing back pressure therein, and an air passageway leading from the primary air motor to the secondary motor said passageway conducting said back pressure to the secondary air motor, and yielding means connected to the reciprocating element of the secondary air motor normally biasing said element and scoring means to a retracted position, the primary motor being responsive to lower air pressure than the secondary air motor, whereby the air pressure is ineffective to shift the scoring means transversely as said primary air motor extends the scoring means longitudinally, the said secondary air motor moving the scoring means transversely into engagement with the periphery of the pipe in response to said back pressure after the primary air motor has been stalled and the scoring means have been moved into position for engagement with the end of the pipe.

2. In a sewer pipe machine, a finishing device adapted to be extended and retracted relative to the end of a pipe for finishing the same comprising, a primary air motor having a rotatable, longitudinally movable shaft, power means for rotating the shaft, pipe trimming means extending from the shaft, scoring means mounted upon the shaft, the scoring means being movable transversely with respect to the axis of the shaft, and adapted to engage and score the periphery of the pipe, a secondary air motor mounted on the shaft and connected to the v the pipe in response l0 scoring means, yieldable means connected to ondary air motor,

the motor and scoring means to a retracted position, said secondary air motor adapted to move the scoring means transversely from said retracted to an extended position, means for applying air pressure to the primary motor, said primary motor extending the trimming and scoring means longitudinally to a position for engagement with to said air pressure, said primary motor developing back pressure therein at the limit of the longitudinal motion of said trimming and scoring means, an air passageway leading from the primary air motor to the secondary motor, said secondary motor moving the scoring and trimming means into engagement with the periphery of the pipe in response to said back pressure, the primary air motor being responsive to a lower air pressure than the secondary air motor, whereby the scoring means remains in retracted position until the primary motor moves the scoring and trimming means into extended position and develops said back pressure, whereupon the secondary motor moves the scoring means transversely to said extended position.

3. In a sewer pipe machine, a finishing device adapted to be extended and retracted axially relative to the end of a pipe for finishing the same comprising, a primary air cylinder, a piston in said cylinder having a'rotatable, longitudinally movable piston rod, power means for rotating the piston rod, pipe trimming means extending from the piston rod, scoring means mounted upon the piston rod, the scoring means being movable transversely with respect to the axis of the piston rod and adapted to engage and score the periphery of the pipe, a secondary air cylinder having a piston connected to the scoring means for moving the same transversely from a retracted to an extended position, means for applying and exhausting air pressure to and from the primary air cylinder for extending and retracting the trimming and scoring means longitudinally with respect to the pipe, the piston rod of the primary piston having an air passageway communicating with the primary cylinder and extending to the secondary cylinder, said air passageway including a metering aperture adapted to restrict the flow of air through the passageway, said passageway and metering aperture being arranged to move the scoring means transversely into engagement with the periphery of the pipe after the trimming and scoring means are extended longitudinally into operating engagement with the pipe.

4. In a sewer pipe machine, a finishing device adapted to be extended and retracted axially relative to the end of a pipe for finishing the same comprising, a primary air cylinder, a piston in said cylinder having a rotatable, longitudinally movable piston rod, power means for rotating the piston rod, pipe trimming means extending from the piston rod, scoring means mounted upon the piston rod, the scoring means being movable transversely with respect to the axis of the piston rod and adapted to engage and score the periphery of the pipe, a secondary air cylinder having a piston connected to the scoring means for moving the same transversely from a retracted to an extended position, means for applying and exhausting air pressure to and from the primary air cylinder for extending and retracting the trimming and scoring means longitudinally with respect to the pipe, the piston rod of the primary piston having an air passageway communicating with the primary cylinder and extending to the secondary cylinder, said air passageway including a metering aperture adapted to restrict the flow of air through the passageway, said passageway and metering aperture being arranged to move the scoring means transversely into engagement with the periphery of the pipe after the trimming and scoring means are extended longitudinally into operating engagement with the pipe, and a check valve in said passageway bypassing the said metering aperture, the check valve being arranged to block the flow of air from the primary cylinder to said the see said yieldable means normally urging 11 1,2 pzggs ag qway agd to xhaust ghe air from the passageway EQREIGN PATENTS lld Qw a1 y l d when air is .exhausted f 408,465 GreaLBritain Apr, 12, 1.934 Prim q y indd d thereby vd iz z 11118 sco ng 653,567 Germany Nov. '26 1937 means frpm the pipe before the ;trimmingand scorirgg means are retracted vlongitudinally. 5

Refergncgs Cited in the file of this patgnt UNITED STATES PATENTS 2,291,899 Jones Aug. 4, 1942 10 2586341 Pear-[I e et a]. Oct. '9, 1945