US3055090A - Apparatus for bridge construction - Google Patents

Description

Sept. 25, 1962 J. P. MURPHY APPARATUS FOR BRIDGE CONSTRUCTION Original Filed Jan. 23, 1956 5 Sheets-Shet 1 IN V EN TOR. Joy/v PM IP MWqP/IY Sept. 25, 1962 J. P. MURPHY APPARATUS FOR BRIDGE CONSTRUCTION Original Filed Jan. 2a, 1956 5 Sheets-Sheet 2 INVENTOR. ./OHA/ Pun/p MURPHY Sept. 25, 1962 J. P. MURPHY APPARATUS FOR BRIDGE CONSTRUCTION Original Filed Jan. 23, 1956 5 Sheets-Sheet 4 1 v mm m \k m mw w ATZWKNEYS Sept. 25, 1962 J. P. MURPHY 3,055,090

APPARATUS FOR BRIDGE CONSTRUCTION Original Filed Jan. 23, 1956 s Sheets-Sheet s AMI Q t x g United States Patent ()fiice 3,055,090 Patented Sept. 25, 1962 3,055,090 APPARATUS FOR BRIDGE CONSTRUCTION John Philip Murphy, Piedmont, Caiif., assignor, by mesne assignments, to Yuba Consolidated Industries, Inc.,

Emeryville, Califl, a corporation of Delaware Original application .Ian. 23, 1956, Ser. No. 560,678, now

Patent No. 2,958,940, dated Nov. 8, 1960. Divided and this application Dec. 31, 1959, Ser. No. 3,223

4 Claims. (Cl. 29-200) This invention relates generally to a method. and ap paratus for bridge construction and more particularly to a method and apparatus for assembling and erecting eyebar assemblies in bridges of the cantilever type.

The present application is a division of my Patent No. 2,958,940, issued November 8, 1960.

In cantilever bridges or spans it is often common practice for upper chord members that are in tension to be made up of a plurality of laterally spaced eyebars to form a laminated type of construction. Heretofore, the eyebars have been put in place one by one. This method of assembling the eyebars has been found to be particularly diflicult because of the great length and extreme flexibility of the individual eyebars. The weight of the individual eyebars also makes them difiicult to handle. It also has been found that the eyes in the eyebars are frequently out of alignment making it difiicult to force the pins through the eyebars. This is particularly disadvantageous because the pin connections must be made at a considerable distance above the water within a limited working area, and with a minimum of equipment.

In general, it is an object of the present invention to provide a method and apparatus for bridge construction in which the eyebars are readily assembled into eyebar assemblies prior to field erection and the completed eyebar assemblies placed in position in the cantilever span to eliminate the aforementioned difficulties.

Another object of the invention is to provide a method and apparatus for bridge construction of the above character in which individual eyebars are spaced laterally from each other as they are assembled into clusters to form eyebar assemblies for the cantilever span and then aligned vertically and longitudinally by the use of expanding mandrels.

Another object of the present invention is to provide a method and apparatus for bridge construction of the above character in which the assembled eyebars are bound together to form a unitary assembly after they have been aligned.

Another object of the invention is to provide a method and apparatus for bridge construction of the above character in which the eyebar assembly is lifted into position and the pins driven by the use of a jack.

Another object of the invention is to provide a method and apparatus for bridge construction of the above character in which the free end of the eyebar asembly is supported by tying it to the erected portion of the bridge span to permit erection of the other truss members adjacent the free end of the eyebar assembly.

Another object of the invention is to provide apparatus for bridge construction of the type in which means is provided for assembling the eyebars into eyebar assemblies to provide tension members for cantilever spans.

Another object of the invention is to provide apparatus for bridge construction of the above character in which means is provided for spacing the eyebars in each eyebar assembly and roughly aligning the eyebars.

Another object of the invention is to provide apparatus for bridge construction of the above character in which an expanding mandrel is used for accurately aligning the eyebars vertically and longitudinally.

A further object of the invention is to provide apparatus for bridge construction of the above character in which a platform is provided for supporting men, apparatus and the connecting pin while it is being driven into place by jacking.

A still further object of the invention is to provide apparatus for bridge construction of the above character in which a cable assembly is provided for supporting the free end of the eyebar assembly after one end of the eyebar assembly has been connected to the cantilever span to permit the erection of subsequent members in the cantilever span preparatory to fastening the free end of the eyebar assembly.

Additional objects and features of the invention will appear from the following description in which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

FIGURE 1 is an elevational view of a typical cantilever span after it has been completed.

FIGURE 2 is an enlarged side elevational view showing the progressive erection of the anchor arm and the cantilever arm of the cantilever span from one of the bridge piers by the balanced cantilever erection method.

FIGURE 3 is a plan view of the cantilever span shown in FIGURE 2.

FIGURE 4 is an enlarged cross sectional view taken along the line 4-4 of FIGURE 2.

FIGURE 5 is a cross sectional view taken along the line 5-5 of FIGURE 4.

FIGURE 6 is a reduced partial plan view of the pin connection shown in FIGURE 5 but showing the pin in its final position.

FIGURE 7 is an enlarged cross sectional view taken along the line 7-7 of FIGURE 5.

FIGURE 8 is a partial view of the pin with a permanent cap.

FIGURE 9 is a side elevational view of a typical eyebar assembly in the assembly yard or ear.

FIGURE 10 is a plan view of the eyebar assembly shown in FIGURE 9.

FIGURE 11 is an enlarged fragmentary side elevational view of the eyebar supports.

FIGURE 12 is an enlarged cross sectional view taken along the line 12-12 of FIGURE 9 and shows the eyebar supports.

FIGURE 13 is an enlarged cross sectional view taken along the line 13-13 of FIGURE 9 and shows the mandrel in place but before it has been expanded.

FIGURE 14 is a partial cross sectional view similar to FIGURE 13 but showing the mandrel in a fully expanded position.

FIGURE 15 is a side elevational view taken along the line 15-15 of FIGURE 13.

FIGURE 16 is a cross sectional view taken along the line 16-16 of FIGURE 13.

FIGURE 17 is a cross sectional view line 17-17 of FIGURE 9 and shows spacing assembly.

FIGURE 18 is a cross sectional view taken along the line 18-18 of FIGURE 9 and shows the lifting assembly.

The method and apparatus I have used for theplacement of eyebars in contilever bridge spans can best be understood by first giving a typical erection sequence for a cantilever span. One method commonly used for erecting a cantilever span and often referred to as the Balanced Cantilever Erection Method is shown in FIG- URES 1, 2 and 3 of the drawing. By this method an inclined shoring strut 11 is erected adjacent the tower portion 12 of a pier 13. The initial bottom floor and chord system including a plumb post 14 is then erected. Stilf leg travelers 16 and 17 are mounted in the completed portion and are used for completing the anchor arm 18 and taken along the a tightening and cantilever arm 19 by balancing one arm against the other as is well known to those skilled in the art. The same procedure is used for erecting anchor and cantilever arms from the next pier. Both cantilever arms are then completed to close the span. Temporary shoring bents 21 may be used to support the anchor arms when the span between piers is great.

The aforementioned method of erection of cantilever spans is substantially conventional and hence is not given in detail. My invention is concerned primarily with the method and apparatus for assembling and erecting the eyebar assemblies 23 which form the upper chord members in the anchor and the cantilever arms. Even though the general method of erecting the cantilever span is changed the installation of the eyebar assemblies will remain the same. In accordance with'my invention, I mount a plurality of elongate eyebars 27 having eyes 28 at each end upon a suitable framework 29 such as shown in FIGURE 10. The framework consists of a pair of I-beams 30 resting upon a relatively flat surface 31 as in an assembly yard or area. A pair of shorter I- beams 32 and 33 are mounted at right angles to and near the ends of I-beams 30 and serve to carry a plurality of eyebar supports 34.

Each of the eyebar supports 34 consists of a pair of flat plate-like members 36 fixed to a pair of right angle members 37 to form a substantially U-shaped assembly. Each of the right angle members is provided with suitable clampingmeanssuch as a bolt 38 and a pair of nuts 39 for locking the eyebar supports 34 in position on the flanges 41 of the I- beams 32 or 33.

The right angle members 37 are fastened to the plate like members 36 in such a manner that the toe portions 42 are level and in alignment when the eyebar supports 34 are mounted upon the I-bearns 32 and 33..

The eyebar supports 34 are mounted upon the I- beams 32 and 33 in a predetermined space relationship and the eyebars 27 are laid side by side in the eyebar supports 34 in a manner shown in FIGURE 10. One end of each of the eyebars is mounted flush against a backstop 43 which is fixed to one end of the channel members 29. This serves to roughly align the eyebars in a longitudinal direction.

After the eyebars have been mounted in the eyebar supports 34 as hereinbefore described, a plurality of tightening and spacing assemblies 46 are spaced longitudinally along'the length of the assembled eyebars 27. However, the tightening and spacing assemblies are not tightened at this time. A typical tightening and spacing assembly 46 is shown in FIGURE 18 and consists of a plurality of spacing plates 47 of different Widths and a plurality of spacing members 48 mounted upon a pair of elongate bolts 49 and -1.

Each of the spacing members 48 consists of a pair of vertical plate like members 52 and 53 and a pair of horizontal bracing members 54 and 56 connecting the opposite ends of the plate like members. A U-shaped rod 57 is connected to the upper ends of the plate like members 52 and 53 for a purpose hereinafter described.

In placing the tightening and spacing assemblies 46 upon the eyebar asembly, the spacing plates 47 and the spacing members 48 are first mounted upon the upper elongate bolt 49 after which the spacing plates 47 and the spacing members 48 are dropped down into the spaces between the eyebars and then the lower bolt 51 is inserted. .By utilizing different widths of spacing plates 47 it is possible to properly space the eyebars.

Suitable means is provided for lifting the eyebar assembly and consists of a lifting beam assembly 59 mounted midway between the ends of the eyebar assembly. Such a lifting beam asembly consists of a pair of horizontal channel members 61 and 62 which are connected to a pair of vertical lifting members 63 and 64. The upper ends of the members 63 and 64 are provided with openings 66 for the reception of hooks or the like. A pair of bolts 67 and 68 serve to secure the vertical lifting members 63 and 64 to the eyebar assembly by urging the spacing plates 47 into frictional engagement with the vertical lifting members 63 and 64. The members 63 and 64 are provided with holes (not shown) which receive the bolts 67 and 68. A plurality of spacing plates 47 of various widths are mounted upon the bolts 67 and 68 and serve as spacing means in a manner similar to that in the tightening and spacing assemblies 46.

A plurality of angular members 71 are spaced longitudinally of the eyebar assembly 23 and are fastened to the eyebars by clamps 72. The angular members 71 form a permanent part of the cantilever span and serve as a support for a handrail (not shown).

After the tightening and spacing assemblies 46 and the lifting beam assembly 59 are in place, the eyes 28 in the eyebar assembly are ready for alignment.

It is well known to those skilled in the art of bridge building that in making eyebars it is practically impossible to maintain exact tolerances. If the eyes 28 in the eyebars are out of alignment it will be difficult to make the pin connection for connecting the eyebar assembly to the other bridge members. Therefore, I have found it desirable to align the eyes in each eyebar assembly before the assembly is lifted into place. To accomplish this I have provided expanding mandrels or pilot pin assemblies 77 which are adapted to be inserted in the eyes 28 of the eyebar assembly.

Each pilot pin assembly 77 consists of a suitable number of segments such as the four segments 78 shown in FIGURES 15 and 16. Each segment comprises an arcuate portion 79 and a pair of plate like portions 81 and 82. The plate like portions 81 and 82 are fixed to the arcuate portion 79 and extend radially therefrom to subtend an arc of degrees. A plurality of reinforcing portions 83 are fixed to the arcuate portion 79 and are spaced longitudinally along the length thereof. A beveled end portion 84 is fixed to the reinforcing portions 83 adjacent the opposite ends of the arcuate portion 79. Additional arcuate reinforcing portions 86 serve to connect the outer ends of theplate like portions 81 and 82 and are also fixed to the outer periphery of the arcuate reinforcing portions 83.

The segments 78 are connected into a cylindrical expanding-type mandrel by a plurality of bolts 87 mounted .in holes 88 in the plate like portions 81 and 82. The inner surfaces of the arcuate portions 79 are provided with a pair of abutments members or shoulders 89. A U-bolt 91 is mounted in each end of each of the segments 78. The U-bolts are used for facilitating withdrawal of the pilot pin assembly 77 from the eyes 28.

A hollow pipe-like member 93 is loosely mounted within the opening 94 formed by the arcuate portions 79. It is provided with a pair of enlarged tapered portions 96 and 97 for a purpose hereinafter described. A draw bar 98 is slidably mounted within the hollow pipe-like member 93 and is provided with a plurality of annular grooves 99 spaced longitudinally thereof. The draw bar 98 is of a length that it extends substantially beyond both ends of the pipe-like member 93. A clamp or yoke 101 is mounted in one of the grooves 99 at one end of the draw bar. Suitable shimming means such as a pipe section '102 is mounted on the draw bar and takes up substantially all of the play between the yoke 101 and the adjacent end of the hollow pipe-like member 93.

Suitable means is mounted on the other end of the draw bar 98 for applying a pulling force to the draw bar. One means found to be satisfactory consists of hydraulic ram 104 such as R6010 ram manufactured by Templeton, Kenley & Company of 16th and Gardner Road, Broadview, Illinois. The ram 104 is connected to a suitable fluid pump (not shown) by means of hydraulic lines 106 and 107. A yoke 108 similar to that shown in FIGURE 13 is mounted in oneof the grooves 99 in the other end of the draw bar 98 adjacent the upper end of the ram 104.

A drive washer 109 is mounted on the draw bar 98 between the ram 104 and the pilot pin assembly 77.

Assuming that the bolts 87 are so adjusted that the segments 78 can be expanded, the ram 104 may be operated to apply pulling force to the draw bar 98. This will cause movement of the draw bar to the right as shown in FIGURE 14 to cause the enlarged tapered portions 97 of the hollow pipe-like member to move into engagement with the abutment members or shoulders 89 on the segment 78. This will cause the segments 78 to be expanded symmetrically in a radial direction to cause alignment of the eyes 28 in the eyebars by movement of the eyebars vertically and longitudinally. Movement of the draw bar is continued until the largest portion of the enlarged tapered portion 97 engages the shoulders 89 as shown in FIGURE 15. Both of the pilot pin assemblies 77 are operated simultaneously so that the eyes on both ends of the eyebar assembly are aligned.

As soon as the pilot pin assemblies 77 have been moved to the fully expanded position, the tightening and spacing assemblies 46 are secured to maintain the eyebars in alignment. If desired, the pilot pin assembly 77 may be removed by operating the ram 104 to cause it to continue to pull the hollow pipe-like member towards the ram until the enlarged tapered portions 97 no longer engage the shoulders 89. The pilot pin assemblies may then be readily removed by grasping the U-bolts 91 and drawing the assemblies from the eyes 28.

Normally, however only one of the pilot pin assemblies is removed in the yard and the other pilot pin assembly is not removed until a pin is driven in the other end as hereinafter described.

After the eyebars 27 have been assembled into eyebar assemblies 23 and aligned as hereinbefore described they are loaded on suitable means such as a barge 111 and moved to the erection site.

Let it be assumed that the erection of the cantilever span has progressed to the point shown in FIGURE 3 and that the vertical truss member 112 and the last erected eyebar assembly 23, which will be designated as 113, are in the position shown. The following procedure is used for making the pin connection with the next eyebar assembly 23 to be erected, which will be designated as 114, and the vertical truss member 112 and the eyebar assembly 113. A suitable platform 116 is connected to the upper portion of the vertical truss member 112.

The platform 116 consists essentially of a bottom platform member 117 connected to truss member 112. A plurality of vertical members 118 and bracing members 119 are connected to the bottom platform member 117 and to a channel shaped member 121 which serves as a working surface for the pin 122 and the ram 123. A block 124 resting upon the member 121 supports the ram in a position to drive the pin 122. A plurality of rods 125 are mounted along the outer edges of the bottom platform member 117 and form a rectangular enclosure to serve as safety or guide rails for the platform.

The eyebar assembly 114 is lifted from the barge 111 by suitable means such as the stiff leg derrick 16 which is connected to the lifting beam assembly 59. The eyebar assembly 114 is then held in the position shown in FIGURE 2 so that one end is adjacent the upper end of truss member 112 and the free end of eyebar assembly 113.

The upper end of the vertical truss member 112 is provided with an inclined bottom gusset plate 131. A pair of side gusset plates 132 and 133 are fixed to the gusset plate 131 and are provided with a bore 134 which is adapted to receive pin 122.

A pair of temporary erection supports 137 and 138 are mounted upon the bottom gusset plate 131 and serve as temporary supports for the adjacent ends of the eye bar assemblies 113 and 114. The erection supports 137 and 138 consist essentially of a prefabricated beam 139 in which the upper surface 141 is inclined with respect to the other portions of the beam. The beam is connected to a plate 142 which is fastened by means of a hook bolt 143 to a channel member 144 secured to the bottom gusset plate 131. A plurality of wooden wedges 146 (FIGURES 5 and 7) are used for carrying the individual eyebars of the eyebar assembly upon the temporary erection supports 137 and 138.

In making the pin connection between the vertical truss member 112 and the eyebar assemblies 113 and 114, the free end of the eyebar assembly 113 is lowered into place on top of the wedges 146 resting on the temporary erection support 137 and upon wedges 147 immediately below the free end of the eyebar assembly 113. The eyebar assembly 114 is lowered into position so that the eyebars of assemblies 113 and 114 are interleaved as shown in FIGURE 5 and eyebar assembly 114 is resting upon the temporary erection support 138 and wedges 147.

If required, an additional stiffener plate 148 (FIG- URE 7) may be inserted for strengthening the bottom gusset plate 131 to carry the weight of the eyebar assemblies 113 and 114 after they have been set in place but before they have been pinned to the side gusset plates 132 and 133.

The position of the wedges 146 and 147 can be shifted to roughly align the eyes in the eyebar assemblies 113 and 114 with the bore 134 in the side gusset plates 132 and 133. The pin 122 is lifted and placed upon the channel shaped member 121 on the platform 116. The pin 122 is provided with a bore 151 which is adapted to receive the draw bar 152 having a plurality of grooves 153 spaced longitudinally along the length thereof. A pilot nut 154 with rounded corners is threaded on one end of the pin 122 and facilitates initial insertion of the pin 122 into bore 134. The draw bar 152 extends substantially beyond each end of the pin 122 and extends through a member 156. A yoke or keeper 157 engages one of the grooves 153 in the draw bar 152 and serves to prevent the draw bar from being pulled through the member 156. The member 156 is provided with a plurality of legs 158 which serve to space the member 156 from the adjacent eyebar to provide a space which is adapted to receive the pilot nut 154 when the pin 122 is drawn to its final position.

The ram 123 is then mounted upon the draw bar 152 adjacent a drive nut 161 and is held in place by a yoke or keeper 162 engaging a groove 153 in the draw bar, The ram 123 is identical to ram 104 hereinbefore described and is operated by a suitable fluid pump (not shown). Operation of the pump causes movement of the ram plunger 163 to the right to cause the ram 123 to pull against the draw bar 152 to push the pin 122 into the bore 134 and eyes 28. If desired, the pin 122 may be greased to facilitate driving of the pin 122. Since the stroke of the ram plunger is limited, it is necessary to drive the pin 122 in steps, the yoke 162 being moved to engage the next sucessive groove until the pin 122 is driven into place. Because the eyes in the eyebars have been previously aligned as hereinbefore described, the pin 122 is driven into place with little or no difiiculty. After the pin 122 is in place, the ram 123 and the draw bar 152 and the member 156 are removed. The pilot nut 154 is also removed from the pin and a permanent cap 164 (FIGURE 8) is put into place. A similar cap 165 is placed on the other end of the pin (FIGURE 6) to complete the pin connection between the vertical truss member 112 and the eyebar assemblies 113 and 114.

A top gusset plate 166 if such is provided in the design is then riveted in place and the lateral truss members 167 are riveted to gusset extensions 168. The platform 116 may then be removed for use in making the next pin connection.

After the pin connection between the vertical truss member 112 and the eyebar assemblies 113 and 114 has been completed, the free end of'the eyebar assembly 114 is tied to the completed portion of the anchor arm in a manner similar to that shown in the cantilever arm in FIGURE 3 in which a suitable cable assembly 169 has one end connected to the free end of an eyebar assembly 171 and the other end connected to a previously completed pin connection 172.

The free end of the eyebar assembly 114 is maintained in this tied-back position while the additional truss members shown in dotted lines in FIGURE 5 are erected. As soon as the vertical truss member represented by the dotted line 173 is erected, the free end of the eyebar in a manner very similar to that thereinbefore described.

After both ends of the eyebar assembly 114 have been pinned, the tightening and spacing assemblies 46 may be loosened and removed by suitable means. For example, they may be removed by a sling (not shown) connected to the stiff leg derrick 16 and by connecting the ends of the sling to the U-shaped rods 57 connected to the spacing members 48.

It is apparent that the eyebar assemblies for the cantilever arm may be erected in a manner similar to that described for erecting the eyebar assembly 114 in the anchor arm. It is also apparent that the eyebar assemblies 23 previously erected in the anchor and cantilever arms prior to the erection of eyebar assembly 114 are also erected in a similar manner. For example, in commencing the erection of the cantilever span, the

plumb post 14 is erected on the tower 13. After a few of the other truss members have been erected in a mannot well known to those skilled in the art of bridge building, the eyebar assemblies 23 on each side of the plumb post 14 are lifted by the stiff leg derricks 16 and 17, and one of the ends of each of the eyebar assemblies connected to the plumb post 14 in a manner hereinbefore described. 7

It is apparent from the foregoing that I have provided a new method and apparatus for erecting eyebar assemblies used in forming the upper tension chords in the anchor and cantilever arms of a cantilever span. The use of pro-assembled and aligned eyebar assemblies greatly facilitates placement of the eyebar assemblies in the cantilever span and makes possible a substantial saving in the cost of erection.

'I claim:

1. Apparatus for assembling and aligning a plurality of elongate eyebars into a unitary eyebar assembly, the

eyebars being of the type having an eye at each end opening in a direction at right angles to the longitudinal axis of the eyebar, the apparatus com-prising a framework, a plurality of eyebar supports mounted on said framework and being adapted to slidably receive for longitudinal movement a plurality of said eyebars mounted therein, said eyebar supports being spaced laterally on said framework to cause said eyebars to be spaced with respect to each other, an expanding pilot pin assembly adapted to be inserted in the eyes at each end of the assembled eyebars, means for expanding the pilot pin assemblies to cause vertical and longitudinal alignment of the eyebars, and means for clamping said assembled eyebars into a unitary assembly whereby when i said unitary assembly is lifted from said framework said eyebars will be maintained in an aligned space relationship. 1

2. Apparatus for assembling and aligning a plurality 8 of elongate eyebars into a unitary eyebar assembly of the type whereinthe'eyebars have an eye at each end opening in a direction at right angles to the longitudinal axis of the eyebar, the apparatus comprising a horizontal framework, a vertical backstop on one end of said framework, a plurality of U-shaped eyebar supports mounted on said framework and being adapted to slidably receive a plurality of said eyebars mounted therein with one end in engagement with said backstop to roughly align said eyebars, said eyebar supports being spaced laterally on said framework to cause said eyebars to be spaced with respect to each other, an expanding pilot pin assembly adapted to be inserted in the eyes at each end of the assembled eyebars, means for expanding the pilot pin assemblies to cause vertical and longitudinal alignment of the eyebars, and means for clamping said assembled eyebars into a unitary assembly whereby when said unitary assembly is lifted from said framework said eyebarswill be maintained in an aligned space relationship.

3. Apparatus as in claim 1 in which said pilot pin assembly and said means for expanding said pilot pin assembly comprise a plurality of arcuate segments, means for securing said arcuate segments into a substantially cylindrical mandrel having a central bore therethrough, a plurality of abutment members mounted on said arcuate segments, the abutment members extending radially into the vcentral bore, a substantially cylindrical member mounted in said central bore, said member having an enlarged tapered portion adapted to engage said abutment members, and means for urging said cylindrical member longitudinally of the bore to bring the enlarged tapered portion on said cylindrical member into engagement with said abutment members to cause said segments to be expanded symmetrically in radial directions.

4. Apparatus as in claim 1 wherein the pilot pin assembly and said means for expanding said pilot pin assembly comprise a plurality of arcuate segments, means for loosely securing said arcuate segments into a substantially cylindrical mandrel having a central bore therethrough, a plurality of abutment members mounted on said arcuate segments, the abutment members extending radially into the central bore, a hollow pipelike member mounted in said central bore, said pipelike member having enlarged tapered portions spaced longitudinally along the length of the same, said tapered portions being adapted to engage said abutment members, a-draw bar mounted within said pipe-like member and extending beyond the ends of the mandrel, clamping .means mounted on one end of said draw bar, means adapted to enga e one end of said pipe-like member and mounted on said draw bar between said clamping means and said pipe-like member, and means mounted on the other end of said draw bar for applying a pulling force on said draw bar to urge said pipe-like member longitudinally of the central bore to bring the enlarged tapered portions of said pipe-like member into engagement with said abutment members to cause said segments to be expanded symmetrically in radial directions.

References Cited in the file of this patent UNITED STATES PATENTS 591,803 Aylworth Oct. 19, 1897 1,649,809 Campbell Nov. 22, 1927 1,852,683 Sunderland Apr. 5, 1932 1,979,856 Bennett NOV. 6, 1934 2,687,105 Riggs Aug. 24, 1954 2,694,376 Hauser Nov. 16, 1954 2,705,375 Foreman et al. Apr. 5, 1955

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