US3779026A

US3779026A - Expansible mandrel employing leaf springs to bias its sections into its pile entering relationship

Info

Publication number: US3779026A
Application number: US00240381A
Authority: US
Inventors: C Guild; W Goodman
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-04-03
Filing date: 1972-04-03
Publication date: 1973-12-18
Anticipated expiration: 1990-12-18

Abstract

An expansible mandrel is disclosed of the type provided with power operated means by which the mandrel sections are forced into their pile-gripping relationship and with means resiliently biasing the sections towards their pile-entering relationship, each in the form of a leaf spring extending lengthwise of the mandrel and connected at its ends to one mandrel section with the other mandrel section having a member so engaged with the central part of the leaf spring as to tension it as the the mandrel sections are forced apart into their pile-entering relationship.

Description

United States Patent [191 Guild et al.

[451 Dec. 18, 1973 EXPANSIBLE MANDREL EMPLOYING 3,064,439 1l/l962 Cobi (SI/53.72 LEAF SPRINGS T0 BIAS ITS SECTlONS FOREIGN PATENTS OR APPLICATIONS INTO ITS FILE ENTERING RELATIONSHIP 1 I09 412 4/1968 Great Britain 242/72 [76] Inventors: Charles L. Guild, 7 Stone Tower 'Ln., Barrmgton, R1. 02806; Willard Primary Examine, ]acob Shapiro B. Goodman, R0. BOX NO. 62, An0rney Abbott Spear Newport oreg. 97365 [22 Filed: Apr. 3, 1972 [57] ABSTRACT PP ,381 An expansible mandrel is disclosed of the type provided with power operated means by which the man- 52 us. Cl (El/53.72, 242/72, 279/2 i 2" faced l? their P?' 51 Int. Cl E02d 7/30 tmshp and means reshemly basmg the seams [58] Field of Search 61/53.?2; 242/72; Wards their P- each in 279/2 form of a leaf spring extending lengthwise of the mandrel and connected at its ends to one mandrel section [561 232;: 3:22;:21111 32229222; $22 52; i8 UNITED STATES PATENTS tension it as the the mandrel sections are forced apart 3,264,834 into their pile entering relationship 777,780 l2/l904 Easton 242/72 3,000,337 9/1961 Schpatz 242/72 12 Claims, 6 Drawing Figures f; y, X I H B 7 5 gr s N E14 Q I" z \c 5 id 1 2 a a t2. 2' g 49 48 49 $42 L 6: 6'9 238 41; 5/ 4g 48 45 9 7/ 7 12:7 7 1 *"r 'i 125 I *7'T"""7""/"'7' 7' 1 f""" j 'f/T/"Wi' r -r L 66 17 I 9 I V v. 2; l .2 j 7 W I H \TV W I l i 1 4B 3? 3 35 PATENTEU use 1 8 ms SHEUZBFZ FIG 5 BACKGROUND OF THE INVENTION umandrel sections into their pile-gripping relationship;

inflatable means, mechanically operated linkage, and also, the various means disclosed in our co-pending ap plication Ser.No. l l,786, filed June I0, 1971, a continuation-impart of our application Ser. No. 824,631, filed May 14, 1969, and now abandoned. The means disclosed in said co-pending application utilize a plurality of members within and spaced lengthwise of the .mandrel with flexible means in trained engagement therewith and operable on a pull thereon in a predetermined direction then to move the members to exert opposite forces on the mandrel sections, in the case of the present invention, to effect their pile-gripping relationship.

Means resiliently biasing the sections into their pileentering relationship that have proved effective required that the mandrel sections be interconnected at spaced intervals along their sides by rods extending through oppositely opening, aligned pairs of sockets with nuts threaded thereon confining compression springs against the bottoms of the sockets. This construction requires bores through the main arcuate portions of the mandrel sections and these, even when the sockets at opposite sides are not transversely aligned, result in troublesome stress rises.

THE PRESENT INVENTION The objective of the present invention is the provision of expansible mandrels in which the means biasing the mandrel sections into their pile-entering relationship are more effective and at the same time avoid the creation of previously mentioned stress problems that were previously encountered.

In accordance with the invention this objective is attained with a mandrel for use in driving or withdrawing tubular piles and the like, the mandrel having longitudinal sections interconnected by a head. A plurality of axially spaced means within the mandrel are operable to force the sections into their pile-gripping relationship and the mandrel includes at least one and typically a plurality of means resiliently biasing the sections into their pile-entering relationship in yieldable opposition thereto and located in an intermediate space or spaces within the mandrel. Each resilient means is wholly within ithe mandrel and in preferred embodiments includes a leaf spring extending lengthwise of the mandrel with its ends connected to one mandrel section and with means connected to the other mandrel section and so engaging the central part of the leaf spring as to exert a tensioning pull thereon as the sections are forced into their pile-gripping relationship.

Resilient means biasing the mandrel sections into theirpile-entering relationship not only eliminate the previously encountered troublesome stress rises but also result in a more effective force distribution centered lengthwise of the mandrel.

THE PREFERRED EMBODIMENT OF THE INVENTION The preferred embodiment of the invention is disclosed in the accompanying drawings in which FIG. I is a somewhat schematic view of ,a mandrel taken lengthwise of its sections;

FIG. 2 is a section, on an increase in scale, taken approximately along the indicated line 2-2 of FIG. 1;

FIG. 3 is a fragmentary and partly sectioned view, with the mandrel turned from its FIG. 1 position, showing the connection between the fluid pressure operated means and the actuating cable;

FIG. 4 is a view on a further increase in scale, taken approximately along the indicated line 4-4 of FIG. 1;

FIG. 5 is a section taken approximately along the indicated line 5-5 of FIG. 1; and

FIG. 6 is a section taken along the indicated line 66 of FIG. 1.

In FIG. 1, an expansible mandrel is shown that has a .pair of arcuate sections 10, each of substantial length a drive head, generally indicated at 11 and provided.

with an outwardly disposed flange 12, but otherwise not detailed as it may be of any conventional type. The upper end of each section 10 has a reinforcement 13, shown as an internal reinforcement, and also has an end plate 14 welded thereto providing an outwardly disposed flange portion l5 securely clamped to the head flange 12 by means of boltsl6 which also secure an interposed, inwardly tapered shim or wedge sections 17. The thus attached ends of the mandrel section 10 are spaced apart but the shims l7 bias them inwardly towards each other a short distance below the head.

The end plates 14, when the mandrel sections 10 are secured to the head 11, establish abutting portions defining an axial passageway 18, see FIG. 3, and supporting a concave seat member 19 receiving a complemental, spherical washer 20. A bolt2l extends freely down wardly through the passageway 18 and has a locked nut 22 on its upper end seated against the washer 20. Links 23 are connected by a pivot 24 to the other end of the bolt 21 and by a pivot 25 to the hanger 26 of a fluid pressure operated ram 27 with the hanger 26 extending between the mandrel sections 10 thereby to prevent the supported ram 27 from turning.

The stem 28 of the ram 27 has a fork 29 to which a hanger 30 is secured by apivot 31. Links 32 are connected to the hanger 30 by a pivot 33 disposed at right angles to the pivot 31 and rotatably support a sprocket 34. A chain 35 is trained about the sprocket 34 and each end thereof with its ends attached to the appropriate one of a pair of yokes 26, each rotatably supporting a sheave 37. i

The other ends of the mandrel sections 10 are closed by boot portions 38 and one has an intermediate key -3 member 39 welded thereto slidably entrant ofa keyway 40 in an intermediate member 41 welded to the other mandrel section thereby to prevent misalignment of the boot ends of the section as the sections are moved between their pile-entering and their pile-gripping relationships.

The mandrel sections 10, in order to effect the pilegripping relationship thereof, are connected by operating means spaced lengthwise of the mandrel and including, as the flexible means, a pair of cables 42 and a plurality of

sheaves

43 and 44 arranged in groups. The

sheaves

43 and 44 are alternately disposed in each group with the sheaves 43 connected to one mandrel section and the sheaves 44 connected to the other mandrel section. The number of sheaves in each group may vary as may the distance between them, preferably with the largest number of sheaves in the lower end of the mandrel and with the space between the groups increasing towards the upper end thereof to ensure the application of maximum force in the lower portion of the mandrel as the resistance of the earth to its penetration increases with its depth.

Each mandrel section has internal reinforcements 45 extending lengthwise thereof throughout most of the length of the mandrel and of a right angular section welded in positions to define a central channel 46 for the sheaves and the cables. The reinforcements 45 of each section have transversely aligned pairs of bars defining seats 47.

Each of the

sheaves

43 and 44 has four grooves and is rotatably supported in a U-shaped mount 48 shaped and dimensioned for slidable entry into an appropriate one of the seats 47 and to bear against the mandrel section that forms the bottom of that seat with each sheave dimensioned to extend into the opposite channel 46 with clearance between it and the bottom thereof when the mandrel sections are in their pile-gripping relationship. The mounts 48 have guide rollers 49 arranged to hold the cable courses in the appropriate sheave channels, the end mounts having but one such guide roller and the intermediate mount or mounts having both infeed and outfeed guide rollers.

A bottom sheave 50, having four grooves, is supported in a mount 51 welded to the key member 30 and to the section 10 of which it is a part. Above the uppermost group of sheaves there is a mount 52 welded to one section 10 provided with anchors 53 for both ends of both cables 42. The mount 52 is also provided with a four groove sheave 54 and a guide roller 55 adjacent a four groove sheave 56 whose mount 57 is welded to the other section 10 and also having a guide roller 58. The cables 42 have both of their ends connected to the anchors 53 and both ends of both cables 42 are trained in the same manner about the sheaves of the several groups in succession and about the sheave 50. It will be seen that the cable courses are sinuous as alternately they pass part way around the sheave 43 and then part way around a sheave 44 with the engaged portion of each sheave being that which is within the channel 46 of the section 10 to which it is not attached so that a pull on the cables tends to straighten them and, in so doing, forces the mandrel sections 10 into their pilegripping relationship. The intermediate course of each cable 42 extends from the bottom end of the mandrel upwardly between the sheaves 54 and 56 and is trained about the appropriate sheave 37 and then between the sheaves 54 and 56 to the bottom of the mandrel.

With this arrangement, when the fluid pressure controls (not shown) are operated to effect the retraction of the ram stem 28, an upward pull is exerted that effects a straightening pull on the portion of the cables in trained engagement with the groups of

sheaves

43 and 44 thereby forcing the mandrel sections 10 apart from their pile-entering relationship into their pile-gripping relationship.

The mandrel sections 10 are resiliently biased into their pile-entering position when the ram controls are again actuated to advance the ram 28 thus relaxing the cables 43. At the bottom end of the mandrel, the means for urging the free ends of the mandrel sections together are of the type previously used throughout the length of the mandrel. As may best be seen in FIG. 2, the member has outwardly opening sockets 59 adjacent its sides each aligned with a corresponding one of the outwardly opening sockets 60 with which the member 41 is provided. Rods 61 slidably interconnect the members 39 and 41 through the aligned sockets and nuts 62 threaded thereon hold compression springs 63 against the bottoms of said sockets.

In accordance with the invention, the means spaced lengthwise of the mandrel to resiliently urge its sections 10 into their pile-entering relationship are generally indicated at 64 and each is located in a selected space between groups of

sheaves

43 and 44. v

Each of the resilient means 64 has a leaf spring 65 shown as having one end closed upon itself to provide an eye 66 and the other end doubled to establish a slot 67. U-shaped anchoring mounts 68 are provided, one for each end of the leaf springs 65 and welded to the reinforcements 45 of one section 10. Each mount 68 has a pin 69 with the pin 69 of one mount extending through the eye 66 and the pin 69 of the other mount extending through the slot 67. As will be apparent from FIG. 6, the base of each mount 68 serves as a spacer for the intermediate courses of the cables 42. A transverse pin' 70, carried by plates 71 welded to the reinforcements 45 of the other mandrel section 10, underlies the central part of each leaf spring 65 with its engagement therewith tensioning it as the mandrel sections are forced apart into their pile-gripping relationship. The central part of each spring 65 is of a width fitting between the plates 71 and its width is shown, see FlG. 5, as tapering inwardly towards its ends.

As the resilient means 64 do not require that holes be bored through the mandrel sections 10, previously experienced stress rises do not occur. It should be here noted that troublesome stress problems do not occur with the spring arrangement at the bottom end of the mandrel as the sockets are in the members 39 and 41 and not in the main arcuate portion of the mandrel section 10. It will also be appreciated that the resilient means are of a simple rugged construction and that the forces applied by each spring 65 are in zones spaced lengthwise from each other in an axial plane centrally of the sections.

We claim:

1. An expansible mandrel for use in driving or withdrawing tubular piles and the like, said mandrel comprising longitudinal sections, a head connecting the upper ends of the sections, a plurality of axially spaced means within the mandrel and operable to force the sections from their pile-entering relationship into their pile-gripping relationships, and at least one means resiliently biasing the sections into their pile-entering relationship and located in a space between the first named means and including a leaf spring extending lengthwise of the mandrel. connections between each end of the leaf spring and one of the mandrel sections, and an intermediate member connected to the other of said mandrel sections and so engaged with the central part of said leaf spring as to hold said central part against independent movement toward one mandrel section thereby to exert a tensioning pull thereon as the sections are forced into their pile-gripping relationship.

2. The expansible mandrel of claim 1 in which the connections include transverse pins, the leaf spring has an eye at one end through which one pin extends and a slot at the other end through which the other pin ex tends.

3. The expansible mandrel of claim 2 in which the intermediate member is.a transverse pin underlying said central part.

4. The expansible mandrel of claim 1 in which the width of the leaf spring decreases from the central part towards both of its ends.

5. The expansible mandrel of claim 1 in which the mandrel sections include lengthwise reinforcements and the connections and the intermediate member are secured to the reinforcements of the appropriate one of the mandrel sections.

6. The expansible mandrel of claim 5 in which each mandrel section includes a reinforcement extending lengthwise of each side and defines a central channel, the connections extend into one channel and are welded to the reinforcements that define it, and the intermediate member includes supports entrant of the other channel and welded to the reinforcements that define it.

7. The expansible mandrel of claim 6 in which the spaced means that are operable to force the sections into their pile-gripping relationship are all operated by at least one flexible member common to all of them and including one course connected to them in series and another course extending parallel thereto, both courses within said one channel and the connections are U- shaped with their closed ends within said one channel and separating the courses.

8. The expansible mandrel of claim 1 in which there is one resilient means between each two of the axially spaced means.

9. An expansible mandrel for use in driving or withdrawing tubular piles and the like, said mandrel comprising longitudinal sections, a head connecting the upper ends of the sections; a reinforcement extending lengthwise of the interior of each section, a plurality of axially spaced means within the mandrel and operable to force the sections into their pile-gripping relationship, and at least one means resiliently biasing the sections into their pile-entering relationship and located between the first named means and wholly within the mandrel sections and connected to the reinforcements resiliently biasing means is centrally of the mandrel sections.

11. The expansible mandrel of claim H) in which the resiliently biasing means is arranged to apply retractingforces in longitudinally spaced zones.

12. The expansible mandrel ofclaim 9 in which the reinforcements extend along each side of each section. =k. =l=

Claims

1. An expansible mandrel for use in driving or withdrawing tubular piles and the like, said mandrel comprising longitudinal sections, a head connecting the upper ends of the sections, a plurality of axially spaced means within the mandrel and operable to force the sections from their pile-entering relationship into their pile-gripping relationships, and at least one means resiliently biasing the sections into their pile-entering relationship and located in a space between the first named means and including a leaf spring extending lengthwise of the mandrel, connections between each end of the leaf spring and one of the mandrel sections, and an intermediate member connected to the other of said mandrel sections and so engaged with the central part of said leaf spring as to hold said central part against independent movement toward one mandrel section thereby to exert a tensioning pull thereon as the sections are forced into their pile-gripping relationship.

2. The expansible mandrel of claim 1 in which the connections include transverse pins, the leaf spring has an eye at one end through which one pin extends and a slot at the other end through which the other pin extends.

3. The expansible mandrel of claim 2 in which the intermediate member is a transverse pin underlying said central part.

7. The expansible mandrel of claim 6 in which the spaced means that are operable to force the sections into their pile-gripping relationship are all operated by at least one flexible member common to all of them and including one course connected to them in series and another course extending parallel thereto, both courses within said one channel and the connections are U-shaped with their closed ends within said one channel and separating the courses.

9. An expansible mandrel for use in driving or withdrawing tubular piles and the like, said mandrel comprising longitudinal sections, a head connecting the upper ends of the sections, a reinforcement extending lengthwise of the interior of each section, a plurality of axially spaced means within the mandrel and operable to force the sections into their pile-gripping relationship, and at least one means resiliently biasing the sections into their pile-entering relationship and located between the first named means and wholly within the mandrel sections and connected to the reinforcements thereof.

10. The expansible mandrel of claim 9 in which the resiliently biasing means is centrally of the mandrel sections.

11. The expansible mandrel of claim 10 in which the resiliently biasing means is arranged to apply retracting forces in longitudinally spaced zones.

12. The expansible mandrel of claim 9 in which the reinforcements extend along each side of each section.