CA2087198A1 - Hydraulic rod pusher-puller apparatus - Google Patents

Abstract

A hydraulic rod pusher-puller apparatus is provided for forming a borehole underground. The apparatus combines the concept of simultaneously pushing or pulling and rotating the bore-forming rod using the same hydraulic cylinder system for so doing.
Furthermore, the invention discloses two novel sets of rod gripping jaws units and a novel bearing assembly.

Description

FIELD OF 'rHE INVENTION

2 The present invention relates to a rod p~lsh1ng and 3 pulling apparatus utilized in the formation of an underground bore 4 hole.
BACKGROUND OF THE INVENTION
6 At present, solid rod pusher-pullers are utilized to 7 prepare guided bores for the installation of pipes and cables into 8 the formed borehole. Typically, such pusher-pullers carry on the 9 first rod, an electronic tracking device, which is an off-the shelf item used to ascertain that the desired directional borehole is 11 obt'ained. Such rod pusher-pullers usually comprise a hydraulically 12 actuated rod reciprocating mechanism and ~aws for gripping the rod.
13 In order to obtaln a well directed borehole, it is, however, 14 necessary to combine the pushing or pulling motion with a rotational v~- -nL.
16 To Applicant's best knowledge, there is only one such 17 device whioh inco po,ates the co~cept of simultaneous reciprocatlon 18 with rotation. Thls unit sold as the Ditch Wltch, is manufactured 19 by The Charles Machlne Works, Inc., P. O. Box 66, Perry Ok, 73077 (Undated Brochure).
21 However, dlsadvantageously thls commercially available 22 prlor~art unlt is built wlth the rod belng reclprocated through the 23 cylinder. Consequently, the ~cc~ ted soll on the rod ~ams up '24 the core of the cyllnder. In cold weather the problem ls further compounded because the earth wlll stlck to the rod causlng stlll 26 further bulld up, the cyllnder wlll clog more frequently wlth 27 concomltantly longer equlpment down times. Addltionally, these 28 devices lack stability ln thelr method of rod-gripplng, thus in 29 many lnstances lt is necessary to tle the rod back. Generally, these prior art unlts are e~ ely labour lntenslve, both to 31 render them operational, and durlng use.
32 A search of the prlor art plpe puller or pusher unlts was 33 conducted. Exemplary patents located include U.S. Patent 4,842,248 34 issued to M. H. Shy, U.S Patent 4,502,665 lssued to L.S. Yoder or U. S. Patent 4, 251,058 issued to W.O. Schosek.

1 In light of the patents located, and the existing 2 available commercial units, it is evident that there is a need for 3 an apparatus having the following characteristics:
4 - capability of simultaneous reciprocation and rotation of the rod with avoidance of the nece~s1ty of passing the rod 6 through the cylinder;
7 - need for less accurate requirements in the preparation of 8 the pit:
9 - a unit which is more highly automated, and - a -r.h~ ne having the capability of exertin~ greater force 11 during the pushing or pulling v~ ~nts.

14 It is an objective of the present invention to provide a 15 apparatus which is capable of simultaneously pushing or pulling and 16 rotating the rod but which avoids the necessity of passing the rod 17 through the oylinder.
18 It is a second obJective to provide a more highly 19 automated unit.
It is stlll a further ob~ective to provide an apparatus 21 exerting a greater force during the plJ~hlng or pulling mo~ nts.
22 It is still yet another ob~ectIve to provide a novel rod 23 cleaner Acsoo~ated with the apparatus.
~'24 Flnally, the inventlon seeks to provide an apparatus 25 whioh has greater sensitivity of control and ~ -oved directional 26 borehole formation.
. :
27 In accordance with the present invention there is 28 provided an apparatus for puchl ng or pulllng a rod through the 29 ground to thereby form a borehole. The devioe is functional to form horlzontal, vertical, undulating or direotional boreholes.
31 Preferably, the apparatus is best suited to form horizontally 32 directed boreholes.
33 More specifioally, the apparatus is mounted on a frame, 34 which is placed in a pit. A rod ls pushed or pulled through the ground by the apparatus whereby once the borehole has been defined 1 pipe, cable or the like may be installed therein.
2 The apparatus comprises means for simultaneously pushlng 3 or pulling and rotating the rod together with releasable rod 4 gripping jaw means ( hereinafter termed Jaw gripping means). All of thase means are operated using a single hydraulic cylinder 6 system and are operatively interconnected. Specifically, said 7 means for pushing or pulling and rotating the rod simultaneously, 8 comprises a carriage unit operatively co~nected to a bearing 9 housing and a cylindrical housing, a pair of hydraullc cylinders and rotation means. Said rotation means preferably comprises a 11 spiral track engagable with a roller bearing mounted on said 12 cylindrical housing. The jaw gripping means comprises plvoted 13 linkages which are movable between a gripping position and a 14 release posltion upon actuation of the hydraulic cyllnders.
More specifically, the Jaw gripping means is comprised of two 16 dlstinct sets of ~aw gripping units.
17 The first unit utilizes two pairs of opposed pivotally 18 connected lin~ members which by means of r~-~o~able pins .
19 interconnect the jaw holding - '- s with the carriage means.
~20 The~seaond unit comprises a s$ngle Jaw holding - ~?r having 21 ~spaced apart teeth. A single forward pivot pin and a rearward ~22 travelling pin are utl117e~ in place of the rather more complex 23 linkage SySt? of the first ~ ~o~ ~rt.
24 This second unit is further adapted for use with a novel bearing housing, which employs nylotron blocks in place of 26 conventional thrust bearings.
27 Advantageously, the secon~ Jaw gripping unit is ~ n1cally 28 less complex than the first, and provides a more secure gripping i~
29 movement. Furthermore, the second unit, when used in con~unction . . ~ .
with the novel bearing housing, provides a less expensive unit 31 having a longer wear life and the sheli bec~ ~s self-supporting.
32 Broadly stated the invention comprises a hydraulic rod 33 pusher-puller apparatus for fo. ~ ng an underground borehole which 34 comprises a frame adapted to receive said apparatus: a rotatable cylindrical housing; jaw gripping means for releasably engaging 1 said rod, said means being mounted within said housing; and means 2 for simultaneously pushing or pulling and rotating said rod in a ~;
3 predete~ ined direction of travel.

Figure 1 is a side-sectional view of the pusher puller apparatus 6 positioned in a pit. -7 Figure 2 1S a plan view of the apparatus of figure 1 with the cover 8 removed.
9 Figure 3 is a side-sectional view of the apparatus of figure 1.
Figure 4 is a perspective view of the puller-pusher assembly of 11 figure 1.
12 Figure 5 is cross sectional illustration of the apparatus of 13 figure 1.
14 Figure 6 is a plan view illustrating the ~aw gripping unit of the apparatus of figure 1. ~ ;
16 Figure 7 is a plan view of the ~aw gripping unit with the housing 17 shown only ln cross-section.
18 Flgure 8 1s a more detalled view of the ~aw gripping unit 19 illustrated in figure 7.
, ;:
Figure 9 i8 an exploded view of the bearlng housing and Jaw 21 grlpping - ~rs of the first Jaw gripplng unit.
22 Figure 10 i8 a detailed perspective of the rod cleaner.
23 Figure 11 ls a front view of the rod cleAner mounted on the frame.
'24 Figure 12 1s a plan vlew of the second embodiment of the ~aw grlpplng unit.
26 Figure 13 is a plan view of a third embodiment of the ~aw gripping 27 unit.
28 DESCRIPTION OF THE ~K~ ~*~ EMBODIMENT -29 Having reference to the accompanying drawings, there is shown the pusher-puller apparatus 1. The apparatus comprises a ~
31 frame 2, a carriage unit 24, a Jaw gripping unit 26, and a rod ~-32 cleaner 100.
33 The apparatus 1 is mounted on an upst~n~ng frame 2 which 34 is adapted for pl~r~ - t in a pit 4 in the ground. The apparatus 1 is functional to push or pull a rod 6 underground so as to form -/~
1 a borehole.
2The frame 2 is provided with first and second stabilizing 3 brace plates 8 and 10 respectively at opposed ends thereof. The 4plates 8 and 10 each define cen~lal apertures 9 and 11 respectively.
6A telescoping unit comprising an outer tubular member 12 7 and an inner tubular member 14 is utilized. The inner tubular 8 member 14 is co~nected to the brace plate 8. The outer tubular 9member 12 supports a pair of hydraulic oylinders 16. A pin 18 on -~
the outer tubular member 12 is used to co~nect it to the cylinders 1116. Similarly, a pin 20 on the brace pla~e 8 is used to connect 12 the piston rod of cylinder 16 thereto. The brace plate 8 is forced 13 by the extension of the pistons of cylinders 16 into engagement 14 wlth the plt wall, or by retraction of the pistons of cylinders 16, 15out oP engagement with the pit wall. ;~

17~ Havlng particular refèrence to figures 10 and 11, thereis 18further provlded a rod oleaner 100. The rod cleaner is mounted on 19the~frame 2 ad~acent support plate 10.
, ~
~ 20 ;~ The rod cle~ner lOO comprises a first support plate 102 `-~ 21 with a sliding plate 104 posltloned rearwardly thereof. A pair of . 22 ~ threaded fasteners 108 are posltloned at;the top and bottom of the ~23cleaner 100. The fasteners 108 have a wlng bar 110 and extend ., ~ '24through alignment apertures 106. The plate 102 deflnes an ~
., 25elongate straight slot 112. The rear plate 104 forms an arcuate 26slot 114. Thus, when the rear plate 104 and front plate 102 mate, 27a oircular aperture 116 is provided, whlch aperture ls functlonal ;~
28 to scrape the dlrt from the rod 6 as lt reciprocates therethrough.
29An arcuate, spring lo~e~ tightening lever }24 is -30pivotally mounted at pivot point 122, which lever 124 is functional : ~ .
31to rotate the rear plate 104 into and out of mating engagement with 32the front plate 102. A latch 120 engages the lever 124 into 33 looking engagement therewith.

35AS clearly illustrated in figure 5, a carriage unit 24 is 1provided for reciprocating the jaw gripping assembly 26. ~-2The carriage 24 comprises a base support 44 connected to 3the front and rear circular end plates 46 and 48 respectively. A
4pair of spacer bars 50 are placed between the end plates 46 and 48.
SA pair of sliders 54 are bolted to the base support 44 and are i 6 adapted for longitudinalov- srt along guide channels 28 formed in 7the frame 2. The end plates 46 and 48 respectively further form 8central apertures 60.
9A pair of pushing bars 86 are secured on diametrically 10opposed sides of the housing 62 to the carriage support 44 by means 11of bolts 92. Plastic bushings 90 are provided between pushing bars 1286 and the carriage support 44. The pushing bars 86 are connected ~ ;
13to hydraulic cylinders 30 and secured thereto by means of pins 34.
14At thelr outer ends, the cylinders 30 are connected to the outer .. . . .
15tubular member 12 by means of a pin 32. ~
~ . .

17As mentioned earlier, there is provided a cylindrical 18 houslng 62, whlch has an access openlng 63.
19A pair of inner bearing houslngs 64 are secured at the outer ends of housing 62. More specifically, and having particular 21 reference to Flgure 9, the bearing housings 64 comprise an outer 22body 64a, and an inner body 64b and a thrust bearlng 64d. A
: .
23 retainer rlng 64c extends clrcumferentlaIly ln a formed y-oovæ on 24 the outer body 64a. A threaded fastener 65 secures the bearing 25houslng 64 to the housing 62. The bearlng houslng 64 defines an 26 end face 88 and an inner bore 89.
27A pair of flanged sleeves 56, functionlng as ~aw 28 actuators, extend lnto the lnterior of housing 62. The flanged 29 sleeves 56 form an end surface 57, and further deflne a central axial bore 58.
31Taking particular note of flgures 7 and 8, rectangular 32 bars 66 are mounted on dlametrlcally opposed sides of the houslng 33 62 and secured thereto by means of bolts 78.
34A pair of ~aw holding - h~r$ 68 are pivotally conn4cted to the rectangular bars 66 by means of oval-shaped llnk members 70.

1 Removable pins 72 are utillzed to interco~nect link members 70 to 2 the jaw holding members 68. Pins 74 are used to secure the llnk 3 members 70 to the bars 66. Removable teeth 76 extend outwardly 4 from the side walls of plates 68, said teeth 76 being adapted to grippingly engage the rod 6. It is to be noted that ~ vable pins 6 are employed so that when reversing the orientation of the link 7 members 70, reversal of the direction of travel of the pusher-8 puller assembly 22 is attained.

Mounted on the outer surface 80 of the cylindrical 11 houslng 62, into a hole 84, there is thre~de~ly engaged a roller 12 bearing 82. The roller bearing 82 is adapted to travel in a spiral 13 track 38 which is defined on the inner surface of cover 36. A
14 hinge assembly 40 attaches cover 36 to the outer tubular member 12 and a locking assembly 42 is provided to secure the cover 36 to the 16 member 12.
17 Additionally, four centring rollers 52 are affixed to the 18 outer surfaae 80 of cyllndrical housing 62.

In operation, upon actuatlon of the cylinders 30, the 21 pushing bars 86 move the cylindrical housing 62 longitu~n~lly.
22 ~ As the housing 62 is moved, the plates 66 are moved into 23 abutment wlth the end face 57 of sleeve 56. As the ho~ ng 62 ls '24 moved longituA~n~lly the link 70 are moved from an angled posltion until perp~ clllar to the plate 66. At this point the teeth 76 26 are in grlpplng engagement with the rod 6, and the clearance 27 between the end surface of the flanged sleeve 57 and plate 66 28 reverses to the opposite sleeve end face and corresponding plate 29 edge. The ~aw gripplng unlt 26 and the carriage unit 24, then move as a whole, once the rod 6 is in gripping engagement with the ~aw 31 gripping unit 26. Upon further actuation by the cylinders 30 32 longitudlnal mov~ art of the carriage unit 24 is caused, which is 33 in turn translated to the ~aw gripping unit 26. The direction of 34 v nt is selected so as to be in the desired push or pull mode.
The rotation is effected as follows. As the ~aw gripping unit 26 1and the carriage unit 24 are moved longitudinally, the roller 2bearing 82 and the spiral track 38 coopera~e to effect rotation of 3the jaw gripping unit 26, the unit turning one third of a 4revolution during each stroke of the pistons of cylinder 30.
5Upon retraction of the cylinders 30, plates 66 are moved 6out of engagement with sleeve 56, the llnks 70 are returned to the 7angled position, and teeth 76 move out of engagement with the rod 86. The carriage unit 24 is returned to its initial starting 9position. Meanwhile, the roller bearing 82 returns to the 10c onc~ -nt of the spiral track 38.
11SECOND JAW GRIPPING UNIT EMBODIMENT ...
12Having reference to figure 12, there is lllustrated an 13alternative embodiment of the pusher-puller assembly of the 14invention.
15More speaifically, there ls provided a cylindrical 16housing 62, a carriage unit ( not shown, but which is identical to 17that described earlier herein with the exception that no sleeves 56 18are provided), ~aw gripping means and means for rotatlng the rod 19(again identical to that described for the fir~t embodiment). ~;~
20Partially mounted wlthin the outer ends of the ~
21cylindrical housing are a~pair of circular, bearlng housings 130, ~i , .:
22whlch houslngs define a central bore adapted to recelve tho rod 6 ;
23 exten~ng therethrough. The bearing housing 130 comprises an outer 24body 132 and an inner body 134. A ret~ n~ ng ring 136 secures by 25means of a screw 137 the outer and inner bodies 132 and 134 ~6respeotively of the bearing housing 130. The bearing body 130 27 defines an interior face 138.
28A pair of ring plates 139 secure the connecting bars 140 29to said bearing housings 130. The con~ecting bars 140 extend between opposed bearing housings 130.
31A pair of dlametrically opposed inner underlying plates 32142 are secured to the cylindrical housing 62. Pivot pins 146 33 extend through Jaw gripping - ~ers 144 and through ~l -vable 34 plates 143.
35Each jaw gripping member 144 comprises an integral, :'i 1 generally mushroom-shaped member, which member 144 defines on its 2 circumferential edge a pair of spaced apart teeth members 76 3 adapted to grippingly engage the rod 6.
4Travelling pins 148 are provided adjacent the inner end of the jaw gripping members 144 extendlng through slotted holes 6150. A pair of removable limit$ng pins 154 and 156 are mounted on 7 the cylindrlcal housing 62 and serve to restrict the travel of the 8 Jaw gripping members 144 so as to bring the teeth 76 out of 9gripplng engagement wlth the rod 6 when the faces 160 and 162 of 10the jaw - ~rs 144 abut the travelling pins. Four holes 158 are 11 provided at the forward and rearward ends respectively for the 12llmiting pins 154 and 156. Reinsertion of the pins 154 and 156 in 13 the opposed holes permits of reversal of direction of travel of the 14 rod.
15In operation, as the pl1ch~ng bars 86 are actuated by the 16 hydraulic oylinder ~y&L~ , the bearing housing 130 pushes on the 17pivot pin 148 rotating the jaw gripping member 144 until it is in 18 gripping engagement with the rod 6. The small bearings (not shown) 19 on the outslde of the cylindrical housing 62 function to restrict 20movement thereof. Il0:l3~er, the bearing housing 130 are functlonal 21 to slide in and out of sald cylindrioal hous~ng a small distance.
22Again, the frame, stab~l171ng means and rod cleaner are 23substantially ldentical to those of the first embodiment.
'24THIRD JAW GRIPPING EMBODIMENT OF THE INVENTION
25ThiS version of the pipe puller pusher --hlne resides in the 26substitution of the thrust bearings for nylotron friction bearing 27members in the above-described second Jaw gripping unit.
28More speclflcally, having reference to figure 13, there is 29provlded a Jaw grlpping unit sl ~l ~r to that shown in figure 12 30with the following changes and substitutions. The conventional 31thrust bearing 64d is replaced by a bearing - ~er 160. The member 32160, which is interposed between the outer body 132 and the inner 33body 134, is preferably formed of a nylotron material which is a 34plastic exhibiting exceptional load-bearing and wear 35characteristics. A plurality of seals 162 are positioned between 1 the housing 62 and a sleeve 56 as illustrated ln the drawlng. It 2 is to be noted that no flange 58 is provided on said sleeve 56.In 3 this instance, the sleeve 56 functions as a support for the bearing 4 housings.
It can be seen, furthermore, that stops 164 are mounted at the 6 outer ends of the housing 62 to limit longitudinal travel thereof.
7 The stops 164 are also made of nylotron.
8 Advanageously, the four centring rollers 52 affixed to the 9 housing 62 are not required with this arrangement.
Again, a carriage unit, means for rotating the rod, a frame, 11 stabllizing means and rod cleaner~ identical to both first and 12 second embodiments of the invention descr~bed earlier herein are 13 provided.
14 ` It is to be understood that the scope of the invention is defined by the claims which now follow and that it is not limited 16 to the specific best modes that has been described herein.

- . . 23 '24

Claims (24)

1. A hydraulic rod pusher-puller assembly for forming an underground borehole which comprises:
a frame adapted to receive said apparatus:
a rotatable cylindrical housing defining an aperture:
jaw gripping means for releasably engaging said rod, said jaw gripping means belng mounted within said housing; and means for simultaneously pushing or pulling, and rotating, said rod and said cylindrical housing.

2. The assembly as set forth in claim 1 further comprising means for reversing the direction of travel of said rod.

3. The assembly as set forth in claim 2 wherein said means for reversing the direction of travel comprises pivoted links associated with said jaw gripping means wherein said links have removable pins assoaiated therewith whereby when said pins are removed, said links may be reversed in orientation, and said pins reinserted, thereby permitting the direation of travel of said rod to be reversed.

4. The assembly as set forth in claim 1 wherein said means for simultaneously pushing or pulling and rotating comprises, an inner pair of bearing housings mounted into the outer ends of said cylindrical housing, said bearing housings each defining a central circular bore;
carriage means associated with said cylindrical housing;
a pair of diametrically opposed pushing bar members secured to said bearing housing and said carriage;
a spiral track positioned externally of said cylindrical housing, said track being adapted to engage a cooperating member mounted on the outer surface of said cylindrical housing whereby longitudinal displacement of the latter imparts rotation thereto;
and hydraulic cylinder means, operatively connected to said pushing bar members, whereby, upon actuation of said cylinders, the carriage means associated with said cylindrical housing, pushing bar members, and jaw gripping means are functional to first bring said jaw gripping means into releasable engagement with said rod, and then to push or pull said rod into the ground, with simultaneous rotation thereof.

5. The assembly as set forth in claim 4 , further comprising means for reversing the direction of travel of said rod.

6. The assembly as set forth in claim 4 wherein said bearing housings further contain a flanged sleeve member, said member being functional to actuate said jaw gripping means and being positioned in the central bore of said bearing housings.

7. The assembly as set forth in claim 6 further comprising means for reversing the direction of travel of said rod.

8. The assembly as set forth in claim 4 wherein said carriage means comprises a carriage support, a pair of circular end plates each defining a central circular aperture and being positioned at each end of said carriage support, a pair of spacer bars mounted between said end plates, slider means connected to said carriage support, a pair of pushing bars operatively connected to said carriage support, bushings mounted between said bars and said carriage support, and hydraulic cylinders adapted to actuate said pushing bars.

9. The assembly as set forth in claim 6 wherein said carriage means comprises a carriage support, a pair of circular end plates each defining a central circular aperture and being positioned at each end of said support, a pair of spacer bars mounted between said end plates, slider means connected to said support, a pair of pushing bars operatively connected to said support, bushings mounted between said bars and said support, and hydraulic cylinders adapted to actuate said pushing bars.

10. The apparatus as set forth in claim 4 wherein said jaw gripping means comprises a pair of opposed single jaw members pivotally mounted between a pair of chordal plates, each single jaw member forming circumferential teeth members thereon.

11. The assembly as set forth in claim 8 wherein said jaw gripping means comprises a pair of opposed single jaw members pivotally mounted on said bar members, each single jaw member forming a pair of spaced apart circumferential teeth members.

12. The assembly as set forth in claim 9 wherein said jaw gripping means comprises a pair of opposed single jaw members pivotally mounted on said bar members, each single jaw member forming a pair of spaced apart circumferential teeth members.

13. The assembly as set forth in claim 4 wherein said jaw gripping means comprises a pair of opposed jaw members, each member comprising two spaced pivotally mounted links, each link being, at its outer end pivotally mounted onto a plate member, and at its inner end being mounted on a tooth-bearing member and jaw actuator means associated with said bearing housing and said carriage means.

14. The assembly as set forth in claim 6 wherein said jaw gripping means comprises a pair of opposed jaw members, each member comprising two spaced pivotally mounted links, each link being, at its outer end pivotally mounted onto a plate member, and at its inner end being mounted on a tooth-bearing member and jaw actuator means associated with said bearing housing and carriage means.

15. The assembly as set forth in claim 4 further comprising rod cleaning means associated therewith.

16. The assembly as set forth in claim 6 further comprising rod cleaning means associated therewith.

17. The apparatus as set forth in claim 15 wherein said rod cleaning means comprises a pair of plates which when mating define a circular aperture which may be expanded out of engagement with the periphery of the rod and contracted into engagement therewith whereby as the rod is slid through the aperture earth is scraped therefrom.

18. A rod cleaner which comprises, a first support plate defining a radial, elongate slot; a second sliding plate pivotally mounted rearwardly of said first plate, said second plate defining an arcuate slot, lever means for rotating said second plate relative to said first plate whereby a central circular aperture is formed, and means for releasably locking said plates in fixed relationship one to another.

19. A bearing housing which comprises a circular outer body, and a circular inner body, inner and outer bodies both define central bores therethrough, a circular race defined on the outer body and a corresponding inner circular flange defined upon the inside face of the inner body, a ring of friction bearing material positioned in the race, and means for retaining the bearing material in position and for securing said inner and outer bodies one to another.

20. A bearing housing as set forth in claim 19 wherein said bearing material comoprises nylotron.

21. A pushing and pulling apparatus for inserting or retracting rods within the ground which comprises:
a frame adapted to receive said assembly;

a cylindrical housing;
jaw gripping means for releasably engaging said rod, said means being mounted within said housing;
means for simultaneously pushing or pulling and rotating said rod in a predetermined direction of travel, means for reversing the direction of travel of said rod, rod cleaner means; and means for stabilizing said assembly when within the ground.

22. The apparatus as set forth in claim 20 wherein said stabilizing means comprises a plate associated with said frame, said plate being actuated by a pair of hydraulic cylinders into and out of engagement with the ground.

23. The apparatus as set forth in claim 20 wherein said means for pushing or pulling and rotating comprises in combination carriage means which comprises a carriage support, a pair of circular end plates each defining a central circular aperture and being positioned at each end of said support, a pair of spacer bars mounted between said end plates, slider means connected to said support, a pair of pushing bars operatively connected to said support, bushings mounted between said bars and said support, and hydraulic cylinders adapted to actuate said pushing bars and rotation means comprising a spiral track positioned externally of said cylindrical housing, said track being adapted to engage a bearing mounted on the outer surface of said cylindrical housing whereby longitudinal displacement of the latter imparts rotation thereto.

24. The apparatus as set forth in claim 22 wherein said jaw gripping means comprises a pair of opposed single jaw members pivotally mounted on said bar members, each single jaw member forming a pair of spaced apart circumferential teeth members.

26. The apparatus as set forth in claim 22 wherein said jaw gripping means comprises a pair of opposed jaw members, each member comprising two spaced pivotally mounted links, each link being, at its outer end pivotally mounted onto a plate member, and at its inner end being mounted on a tooth-bearing member and jaw actuator means associated with said bearing housing and carriage means.

27. The apparatus as set forth in claim 23 further comprising a rod cleaner which comprises, a first support plate defining a radial, elongate slot; a second sliding plate pivotally mounted rearwardly of said first plate, said second plate defining an arcuate slot, lever means for rotating said second plate relative to said first plate whereby a central circular aperture is formed;
and means for releasably locking said plates in fixed relationship one to another.

26. The apparatus as set forth in claim 24 further comprising a rod cleaner which comprises, a first support plate defining a radial, elongate slot; a second sliding plate pivotally mounted rearwardly of said first plate, said second plate defining an arcuate slot, lever means for rotating said second plate relative to said first plate whereby a central circular aperture is formed, and means for releasably locking said plates in fixed relationship one to another.