US1717487A - Tube-pulling device - Google Patents

Description

WWW/FEES INVENTOR obwt/lrmsm BY n ATTORNE? R. ARMSTRCNG TUBE PULLING DEVICE Filed Aug. y4, .1927

June 18, 1929.

Patented June 18, 1929.

. UNITED STATES* PATENT o FFlcE. g

normar ARMSTRONG, or mmm-rum, 'New JERSEY. 'Assioma or 01m-'mura rnunnarcx BREITENFELD, or New Yoan, N. Y.

TUBE-MILLING* :envien Application med August 4, 1927i `Serial No. 210,544.

My present invention relates generally to tools, and Ihas particular reference to a tool or devicel for pulling* tubes from a tube sheet.

Although4 I` have ,illustrated and shall hereinafter describe a device which is pri-- marily' designed for the removal of tubes from a vsurface condenser, nevertheless it will be understood that as to certain phases" of my invention a specific application of this character is notessential.

Before proceeding to describe my invention in detail, I will premise that a surface condenser comprises a series of tubes arranged in a parallel group, these tubes bemg supported at. their ends bytwo tube sheets, `each of which forms the inner4 wall of a chamber.' Water isdirected into the bottom of one chamber, thence through certain of the tubes 4to the other chamber,

r tween the Vtwo sheets necessitates the ement of suitable packing.

' plo e tubes corrode ad` become otherwise mim out after a certainperiodof use, andL the, re lacement thereof hereto ore been beset with many great d1tIiy new tubes. has

vculties, principally due to the packing ar- -ranv ed at each end of each tube. This pac ing, generally becomes hardened, it'

o adheres to the tube and to thetwalls ofthe opening through which the tube extends, f audit rendersthe withdrawal ofthe tube --extremely diiicult Where the removal of a-tube has been attempted'lby driving the tuba-)obvious diiculties, have 'arisen be 'cause Aof the burring producedup'on the'tube end by `the drivin This iculty is aggravated'by the act thatf` ern-out' tubes are 4generally of greaty thickness,

5o the 'walls being Vsometimes'extrrnely thin andthe tube end presenting -'n almost ra# providing means for forcibly withdrawing vthe en aged tube and packing, and more zorlike edge. On the other hand, where the withdrawal of a tube has been attempted by a purely pulling or drawing action, difficulties-'have arisen in securely grasping'the tube from the inside, and in efecting ya prompt withdrawal of the-obstinate hardened packing.

The diliiculty last mentioned is perha s thle greatest. Althoughthe tube 'may' e securely'engaged from the inside', it is frequently necessaryto withdraw the tube for a distance of anywhere from six to eighteenfeet before the packin ent1re gang of men is' requently necessary to eifect the withdrawal of a single `tubein this manner, although after the packing has` yleldedl a single workman can draw the entire length of tube (approximately twenf ty-five feet) out with Vgreat ease.

It is an object ofmy present invention to p rovlde a tube-pullmg device which will ,enable a sin le operator to initiate the itself yields. An`

withdrawal o the tubes in rapid succession without encountering any of the diiiiculties heretofore metfwith in practice and illustratlvel'y set forth f'above.' Moreparticularly, 1t is an object of my invention to provide a device which forcibly'and posi` I tively withdraws the obstinate packing in a .simple and ecientmanner accompanied by an initial withdrawingof the tube for a distance as slight as approximately one foot.` O nce this initial withdrawal has been eiiected, a workman following inthe path of the operator may withdraw the tube by hand with relativeease.

Another object of my invention is to provide a device which engages the tube and the packing in the posltive manner mentioned and'which is at the same time easily withdrawable itself from the tube after its circling packing.

Another feature lies in providing means for limiting the initial insertion of thetubeengaging means to a predetermined extent,

thereby rendering it possible to bite through 'successive tubes at exactly thel right points to achieve the desired' result. l

Another feature of my invention lies 1n particu arly, byeii'ecting this forcible withoutwardly through the tube and into the endrawal by means which braces itself` between l the tube sheet itself' andthe tube being pulled. v l A preferred-form of construction provides the tube-engaging means in the form of radiall reciprocable teeth, and it isV afeature ofy my invention to provide exteriorly operable mechanism for positively controlling the Areciprocation, inwardly, of the teeth.

It is a further featureof my invention to provide means foradjusting kthe amount by which the teeth may be made to bite o utwardly through the tube, thereby rendering my device usable with different tubes of differing widths and thicknesses.

Other features of my invention lie' in the particular arrangement and construction' of parts hereinafter more fully described whereby I ant enabled to provide a device which is simple and inexpensive from a manufacturing standpoint, easy and -eiiicient from an operating standpoint, andI highly capable of achieving its contemplated functions in a reliable manner.

For the attainment of the foregoing ob jects and such other objects as may hereinafter appearlor be pointed out, I have illustrated one .embodiment of my invention in the accompanying drawings in which- Fig. 1 is a longitudinal view of a device embodying the features of my invention, portions being shown in cross-section for the sake of clearness;

Fig. 2gis a similar view upon a greatly enlarged scale of the forward or operative portion of my device in actual engagement with a tube to be withdraw-n;

Fig. 3 isa fragmentaryplan view taken substantially along the line 3-3 of Fig- -ure2;

Fig. 4 is a cross-sectionalwiew taken substantially along the line 4-4 of Figure 2; and.

Fig. 5 is across-sectional view .showing the normal' disposition of a tube 'end in a t tube sheet, andindicatiiig the function for whichl my ,device is designed.

Referring for the moment to Figure 5, wherein I have illustrated the normal asseciation between .a tube sheet 10 and asingle tube 11, it will be noted that the tube sheet is Yprovided with a stepped bore, the inner portion 12 thereof being designed vto receive the tube snugly therethrough andithe outer portion 13 thereof being of increased diameter and thereby providing a shoulder 14 against' which suitable packing is der signed to be forced.

The tube is generally made' to extend to a position wherein its outer surface or edge 1 5 is in substantial alignment with the outer surface 16 of the tube sheet 10. The pack-4 ing which isforced against the shoulder 14 when the tube is initially inserted into the both outwardly and respect tb the tube'sheet.

tube sheet may com rise two spaced leather washers 17 or the l' e-and coil packing material 18 between said washers. After said packing has been inserted, a ferrule 19 is applied. The latter is externally threaded and engages with threads provided in the enlarged portions 13` `of the bore. It will vbe noted that the ferrule is bored, having an,l inner bore portion 2O adapted to fit snugly .about the tube end and having a somewhat reduced bore portion 21 arranged to provide a shoulder 22v which does not necessarily bear against the tube end 15 but which prevents any possible withdrawal or accidental displacement of the tube with The ferrule is generally provided with a groove 23 adapted to receive an instrument like a screw driver to facilitate the withdrawal thereof.

The assembly 'illustrated in Figure 5 shows clearly how water passing through the tube 11 (and the other tubes which are arranged in a parallel group-and similarly mounted) may pass outwardlythrough the bore 21 and hence into the water chamber or Water box at the right of the tube sheet 10 of Figure'5. 'Atthe same time, it will be noted that the space surrounding the tube at' the left of the tube sheet 10 is eiiciently sealed from the water by means of the packing which encircles the tube end.

to of the present device.

I have found that frictionally engaging the tube linternally and then drawing thetube outwardly isnot satisfactory for the reason that extreme force must be applied continually until the packing 17-18 yields and comes out. On the other hand, if the packing is withdrawn, the tube may be pulled out by hand.

In Figure 1 I haveillustrated the principal elements of my completely assembled tube-pulling device.V vThe'device comprises an elongated portion 24:, a forward operative or tube-engaging portion 25, and a piston and cylinder arrangement 26 'at the opposite end. These elements will be presently 'described in greater detail, but I will mention at this point that the operative end 25 is designed to be inserted into the -tube end,

the tube-engaging means is then rendered operative, the piston is then forced to move in the cylinder, andthe tube is thereby forcibly withdrawn lby the amount of the piston travel, the packing encircling the tube being at the same time forcibly and positively engaged and withdrawn duringthis slight movement of withdrawal.

Referring now to Figure 2, I provide an elongated axially bored member 27 provided at its forward end with fourvradially disposed recesses or .grooves 28, these recesses eing arranged at substantially 90 to each other and two opposite ones thereof being shown in Fi re 2. These recesses'extend v radially outwardly from the forward portion of the axial bore to points short of the external periphery of the member 27 g Pivotally mounted inv each' recess is a rocker having a reanarm' 29, a forward arm 30, and a medially pivot'ed portion '31. A suitable pivot pin 32 is made to extend transversely across the recess or groove within which the rocker is disposed. f

The yforward portion or arm 30 of the rocker extends outwardly beyond the forward end of the member 27. These forwardly extending portions or arms are clearly disclosed in Figure 1. At the for- Award end of each arm 30, I provide an outwardly .disposed tooth 33 preferably pointed or wedge-shaped so that radially outward movement of the tooth will cause it to bite through whatever it encounters.

The teeth 33 are in this way designed for radial reciprocation, and vI provide externally controllable mechanism for effecting this reciprocation in a..positive manner in either direction. This mechanism comprises a longitudinally reciprocable rod 34 arranged in thebore of the member 27, the forward portion 35 being externally threaded and extending considerably beyond the'teeth 33. Mounted upon this externally threaded portion 35 is an internally'threaded adjustable wedge member 36l whose positional relationship upon the rod 34 is controllable and variable by simply-screwing the member 36 upon the portion 35. A suitable lock nut 37 is provided at the forward end of the portion 35.

The rearwardly disposed surface 38 of the member 36 is substantially conical or, more accurately, pyramidal, it being contemplated that rearward movement of the rod 34 will cause the ,engagement of thesurfaces 38 with the rear surface' of the teeth 33 to move the latter radially outwardly.

.Immediately behind the recesses 28, vthe bore in the member 27 enlarges, and the rod 34 also enlarges, to provide a conical or py rami'd'al surface or wedge portion 39 oppositely disposed with' respect -to the surface 38. It is contemplated that forward movement of the rod 34 will cause the engagement of the surface 39 with the rear surfaces of the arms 29. to pivot the rockers so as to movethe teeth 33 radially inward.

In other words, the exteriorly controlled reciprocation of the rod 34 in either oneor the other direction willcause the teeth 33 to be forcibly and positively moved either outwardlyor inwardly. The positional adjustability' of the wedge surface 38 permits the extent of this radial Areciprocation of the teeth to be controlled. The nearer the vwedge surface 38 is to the' wedge surface i l39 (assuming the reciprocable movement of` the rod 34 is constant), the greater will be thejradial reci rocation of the teeth.

Tocontrol' t is reciprocation of4 the rod 34, I-'provide a rear portion 40 of the rod 34 with a transverse slot 41 within which an actuating eccentric, 42 is mounted. The

longitudinal lengthA of the slot 41 is .sub-

stantially equal tothe diameter of the eccentric. 42. The latter is mounted upon a pivot pin 43 which extends `transversely through the walls of the member 27 and whose rotation will obviously effect areciprocal movement of the rod 34. This rotation is designed to'be effected by manual means, and l provided, and the rear surface 49 -of the,

portion 40 may advantageously be provided with a groove 50 for receiving a screw driver or the like in the initial assembly of the device. v

The tube-engaging means which may be said broadly to include the member 27 and the various elements, associated therewith and heretofore described, is designed to be for- Vcibly withdrawn from the tube sheet 10 after the tube 'and encircling packing has been engaged by the teeth 33. I will now describe the means which I provide for accomplishing the dual purpose of (a) facilitating this withdrawal by cooperation with the tube sheet 10, and (b) rendering the extent of the initial insertion' of the teeth and the tube end adjustably uniform for a given set of tubes.

A sheath or abutment member 51 encircles the entire member 27 and is provided with oppositely disposed longitudinal slots52 for permitting passage therethrough of the pin 43. Reference to Figure 1 will show how the sheath 51 extends rearwardly into connection at 53 with the forward cylinder head l54 of the piston and cylinder arrangement 26. The sheath 5l is made in two longitudinal adjustable sections, the adjacent portions therev of being provided with left and right-band "threads respectively. An internally threaded adjusting collar 55 engages both of these adjacent ends, and it will he obvious that rotation of the Collar 55 will draw the two sections toward each other or away from each other and thereby reduce or extend the total length of the .sheath 51.

The forward end vofthe sheath `5 1 is i adapted to bear against the outer surface 16 of the tube sheet 10 and thereby form an abutment which limits the extent to which the teeth 33 may be initially inserted. By adjusting the totallength of the sheath 51, the extent of insertion of the teeth 33 may be adjusted.

The rear end of the member 27 is suitably connected to a connecting rod or member 5 which exten ds rearwardly through the sheath 51 into connection with the piston 58. A valve 59 is adapted to control the reciprocal movement of the piston 58 in either one or the other direction.

lVhen the device is employed, the wedge 'member 36'is first adjusted so that the out- Ward movement of the teeth 33 will be suiii-y cient to bite through the tube to be Withdrawn, and not only bite completely through the latter but also to engage the encircling packiug. The adjustment of the wedge member 36 is therefore designed to compensate for varying diameters and thicknesses of tubes being withdrawn. With the teeth in ret-ractive position (with the rod 34 posi-` tioned forwardly to its full extent), the forward operative end of the device is inserted into the tube to be withdrawn. The extent of this insertion must be adjusted (by the adjustment of the length of sheath 51) so that the teeth will be substantiallyv aligned with the shoulder 14 in the tube sheet 10. In-

asmuch as these shoulders are uniformly positioned in'any one tube sheet, an initial adjustment of the sheath 51 will render the Vdevice usable without further adjustment in the withdrawal of all the tubes from that particular tube sheet.

The operative end having been inserted to the proper extent, theltool is applied to rotate the pivot pin 43 and thereby force the rod 34 rearwardly. When this occurs, the wedge surface 38 forces the teeth 33 radially outwardly,`and the leverage afforded by the eccentric 42 and the Itool 45 causes the teeth to bite entirely through the tube 11 and into 'the innermost portion of'the encircling packing. If the sheath 51 is carefully adjusted,

`the teeth will bite almost exactly between the shoulder 14 and the adjacent packing therekby engaging the latter in a positive manner..

The valve 59 is then turned to admit compressed air, steam, or other working fluid, to the left-hand side of the piston 58, as the latter is shown in Figure 1. The pressure will force -the kpiston 58 tothe right, and the cylinder head 54 to the left,- thereby forcibly withdrawingthe tube and the engaged pack.- ing outwardly with respect to the tube sheet 10.- In other words, the sheath 51 serves as an abutment member -which braces itself against the tube sheet 10.

The valve 59 is then turned to return thepiston 58 to its initi'alposition, and the tool ure 4 I have illustrated a preferred method of mounting the rockers in the recesses 28. Each pin 32 is provided with van externallythreaded head 60, the latter being engageable with the internal threads 61 of a bore provided at the suitable point in the member 27. Each of the latter bores may be made to extend from the exterior surface of the member 27 to a point short of the opposite surface, each bore obviously extending along a chordal line. The heads 60 areI so designed that they will countersink themv selves within the bores 61 and thereby permit the member'27 to present only a smooth,Y

external surface.

-In Figure 3 I have erable arrangement of a longitudinal slot 62 in the sheath 51, and thev arrangement of a pair of slots 63 in the member 27, the slots 62 and 63 being aligned with the slot 4l and-serving to permit the eccentric 42 to move between two positions shown in Figure 3. rIhe slot 62 is provided in only one side of thesheath 51, and when the eccentric is moved, it is moved in the direction which passes it through the slot 62. The reason for this is that if a simlarslot were provided. in the opposite side of the sheath 51 it would be essential to maintain the eccentric 42 in the exact dead center position, otherwise the force of the piston might tend to dislodge it and thereby cause Va release of the teeth 33. I prefer to swing `and packing 'in extremely rapid succession.

Only. two men are therefore required. to effect an efiicienttotal withdrawal ofa'lltubes. When it is considered that whole gangs of -men where heretofore required to withdraw even one tube, and that the Withdrawal of one tube has frequently necessitated a. wholly unreasonable amount of time, the 'advantages of my device will be obvious.

It will be understoodthat the details herein described and illustrated for the purpose of explaining the nature of my invention may be changed by. those skilled in the art illustrated the preflas - means independent of said tube drawing.

to suit varying requirements without departmg from the spirit and scope` of the invention as expressed in the appended' claims. It is therefore intended that these details be interpreted asillustrative, and not in a limiting sense.

Having thus described my invention and illustrated its use, what I- claim as new and desire to secure by Letters Patent is- 1. In a device for pulling a tube from a tube sheet, tube-engaging means insertable into the tube, said means being arranged and constructed to bite outwardly through they tube and the encircling acking, exteriorly controllable mechanism or rendering said 4engaging means operative, and means for voperatively interposing an expansible me-v means for limiting the insertion of theI engaging means to a predetermined extent, whereby the entire packing may be positively engaged.

3. In a device for pulling a tube from a tube sheet, tube-engagingmeans insertable into the tube, said means being arranged and constructed to bite outwardly through the tube and the encircling packing, exteriorly controllable mechanism' for rendering said engaging means operative, an adjustable member adapted to bear against the tube sheet, means operatively interposed between said member and the engaging means for drawing the latter and hence the tube out with 'respect to the tube sheet, and means independent of said tube drawing means for initially adjusting said member into predetermined relationship with respect to the engaging means, whereby the insertion of thellatter may be predeterminedly limited in extent.

4. In a device for pulling a tube from a tube sheet, tube-engaging means insertable into the tube, said means being arranged and constructed to bite outwardly through the tube and the encircling packing, exteriorly controllable mechanism for rendering said engaging means operative, and means operatively interposed between the tube sheet and the engagingmeans for drawing the latter out with-respect to the tube sheet, said last named means comprising a cylinder and piston, one thereof being braced against the tube 'sheet and the other being connected with the engaging means.

' 5. Ina device for pulling a tube from a' tube' sheet, tube-engaging means'l insertable into the tube, said means bein arranged 1 and constructed tol bite outwar y through thetube and the encircling packing, exte riorly controllable mechanism for rendering' said engaging means operative, and means operatively interposed between the tube sheet and the engaging means fordrawing the latter out with respect to the' tube sheet; said last named means comprising a cylinder and piston, the latter being connected with the engaging means, and an abutment member adapted to bear against the tube sheet and connected witl'ithe cylin- 6. In a devirie for pulling a `tube from a tube sheet,'tubeengaging means insertable into the tube, said means being varranged and constructed to bite outwardly through the tube and the encircling packing, ex-l teriorly controllable mechanism for rendering said engaging means operative, and

means operatively interposedv between the tube sheet and the engaging means for drawing the latter out with respect to the tube sheet; said last named means comprising a cylinder and piston, the latter "-:being connected with the engaging means, `and an adjustable abutment member adapted to bear against the tube sheet and connected with the cylinder; and means for initially adjustin with respect to t e engaging means so as to predeterminedly limit,the insertion of the latter. v

7. In a device for pulling a tube from a tube sheet, tube-engaging means insertable into the tube, saidmeans being arranged and constructed to be radially reciprocable and to bite outwardly through the tube, and exteriorly operable mechanism :for controlling the .reciprocation in both directions of said engaging means.

8.'In a device for pulling a tube from a tube sheet, tube-engaging means insertable into the tube, said means being arranged and constructed to be radially reciprocable and to bite outwardly through the tube, and exteriorly operable mechanism for controlling the reciprocation in both directions of said engaging means, said mechanism including a pair of oppositely arranged substantially conical wedges mounted so as to the abutment member be axially adjustable into and out of conand to bite outwardly through the tube,

and exterior-ly operable mechanism for controllin the reciprocation'in both directions of sai engaging'A means, vsaid mechanism comprising a pair of longitudinally reciprocable substantially ,conical wedges, and

Ameans for reciprocating the latter.

10. In a device for pulling a tube from a tube sheet, tube-engaging means insertable into the tube and comprising a set of radially reciprocable teeth arranged and constructed to bite through the tube and the encircling packing, `and means for positively controlling the reciprocation in eitherdirection of said teeth. y

11. In a device for pulling a tube from a tube sheet, tube-engaging means insertable .into the tube and comprising a se'tof radially reciprocable -teeth 'arranged andconstructed to bite 'through'thetube and the encircling packing, and mechanism for positively controlling the reciprocation of said teeth, said mechanism including a pair of substantiallyconical wedges vmounted 'for longitudinal axial reciproc'ation and engageable withsaid teeth whenreciprocated. 12. In a device for pulling atubefrom a Vtube'sheet, tube-engaging means insertable into the tube and comprisingvfav set'of radially reciprocable teeth arranged and constructed to bite through the tube and the encircling packing, mechanism for positively controlling'the reciprocation of said teeth, said mechanism including a substantially con'ical wedge mounted for longitudinal axial reciprocation and engageable'with said teethl 35 when it is reciprocated, and means for limiting the extent of reciprocation of'said Wedge so as to control the extent of outward movement ofthe teeth. y

13. In a device for pulling a'tube from a tube sheet, an elongated member, a lset of tube sheet, an axially bored elongated memradially reciprocable teeth carried at the e'nd of said member and insertable into the tube, and remotely controlled means for reciprocating said teeth in either direction so as to cause them either to b ite outwardly throughthe tubevor to retract into compact relation withinthe tube.

14. In a device for pulling a tube from a tube sheet, an elongated member, a set of radially reciprocable teeth carried at the end of said member and insertable into the tube, and means for, reciprocating said teeth to r cause them either to bite outwardly through the tube or to retract into compact relation withinLA the tube; said means comprising a" set of rockers pivotally mounted in said. end

' pivoting said rockers.

and carrying said teeth, and mechanism for 15. In a\device for pulling a tubeifrom a tube sheet, an elongated member, a set of radially reciprocable teeth carried at the .Y end of said member and insertable into the tube, and `means for reciprocating said teeth to cause them either to bite outwardly through the tube or`to retract into compact relation within the tube said means comprising a set of rockers pivotally mounted 1n saidlend and carrying said teeth, and mech- 1 "through the tube orto retract into compact lrelation-within the tube; said means comprising a longitudinally reciprocable rod having wedge portions engageable with the teeth when the rod is reciprocated; and means for positionally adjusting said Wedge portions to 'control' -the amountv of tooth reciprocation. i

17.v In a devicefor. pulling a tube from a tube'sheet," an elongated member, a. set of radially reciprocable teeth carried at the 'end of said member and insertable into the tube, and means for reciprocating said teeth to cause them either to bite outwardly A-through the tube or to retract into compact relation within thetube; said means comprising a set of rockers pivotally mounted in said end and carrying said teeth, and mechlanism for pivoting said rockers; said mechanism comprising a longitudinally reciprocable rod;- having wedge portions adapted to encounter said rochers when the rod is reciprocated; and means for positionally adjusting said wedge portions to control the -amountof tooth reciprocation.

18. -In .a device for pulling a tube from a ber, a set of radially Yreciprocable teeth carried at the end thereof and insertable into the tube,'a set of rockers pivotally mounted in said end and carrying said teeth, each rod is reciprocated, one ofsaidwed ev por-l A tions being adjustably mounted on t erod to permit positional adjustment thereof and thereby control the amount of tooth recipr'o cation.` 19. In a device for pulling a tube fro'mga tube sheet, anlaxially bored elongated member, a set of radially reciprocable teeth carv ried at the end thereof and insertable into the tube, a set .of rockers pivotally mounted in said end and carrying saidteeth, eachv rocker being arranged to pivot in a radial plane about 4a'midportion thereof, a longitudinally reciprocable rod in said bore, means carried. y said rod for engaging and `11o rocker being arranged to pivot in a radial gageable with the rod to reciprocate the latter when the eccentric is rotated.l

20. In a device for pulling a tube from a tube sheet, tube-engaging means comfprising an elongated member having a set o longitudinal recesses arranged in the exterior of one end thereof, a setof rockers pivotally mounted i'n said recesses respectively-,each rocker having an end extending beyond the end of said member and provided with an outwardly disposed tooth at said end; and

` means for pivoting said rockers to move the teeth radially outwardly or inwardly.

21. In a device or'pullin'g a tube from a tube sheet, tube-engaging means comprising an airially bored elongated member having a set of longitudinal recesses arranged in the exterior of one end thereof, a set of rockers pivotally mounted in said recesses respectively, each rocker being pivoted at a midportion thereof and provided with an 4outwardly disposed tooth at its outermost end; and meansA for pivoting said rockers so as to movethe teeth` in radial. directions either outwardly or inwardly; sald 'means comprising a rod reciprocably mounted 1n said bore and provided with spaced and oppositely arranged wedge portions which engage op osite ends of said' rockers respectively w en the rod is reciprocated.

22. In a device for pulling a tube from a tube sheet, a tube-engaging means insertable into' the tube and including an axially bored elongated member; and mechanism for controlling the operation' of said means, said mechanism comprising a slotted rod reciprocably. mounted in said bore and arranged to operate said means when reciprocated,

,and exteriorly controllable mechanismengaging said slot for reciprocating said rod.

23. In a device for pulling a tube from a tube sheet, tube-engaging means insertable into the tube and including anaxiall bored elongated member;and mechanism or controlling the operation of said means, said mechanism comprising a slotted rod reciprocably mounted in said bore and arranged to operate said means when reciprocated, a pivot pin mounted in the elongated member at, right angles to thev slot, and, aneccentric on said pin and in said slot and so arranged that rotation of the pin will cause the eccentric to engage the end walls of the slot to reciprocate said rod.

In witness whereof I have signed and sealed this specification this 27th day of July, 1927. V

ROBERT ARMSTRONG.

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