US3220195A

US3220195A - Expandable mandrel for hollow piles

Info

Publication number: US3220195A
Application number: US292052A
Authority: US
Inventors: Lawrence G Barcus; William R Barcus
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-07-01
Filing date: 1963-07-01
Publication date: 1965-11-30
Anticipated expiration: 1982-11-30

Description

Nov. 30, 1965 G. BARcus ETAL 3,220,195

- EXPANDABLE MANDREL FOR HOLLOW PILES Filed July 1, 1963 2 Sheets-Sheet 1 Lawrence G. Barcus QQW w w 6 William R. Barcus 7 36 IN VEN TORS Mm W 72 I BY wfi zsm Nov. 30, 1965 BARCUS ETAL 3,220,195

EXPANDABLE MANDREL FOR HOLLOW FILES Filed July 1, 1963 2 Sheets-Sheet 2 Lawrence 6. Barcus William R. Barcus IN VENTORS M40162. wqfim United States Patent 3,220,195 EXPANDABLE MANDREL FOR HOLLOW FILES Lawrence G. Barcus and William R. Barcus, both of 1430 State Ave., Kansas City, Kaus. Filed July 1, 1963, Ser. No. 292,052 6 Claims. '(Cl. 6153.72)

This invention relates to the driving of tubular piles or shafts into the ground and more particularly to an expandable type of device inserted in such piles by means of which driving force is transmitted thereto in an axial direction. The device of the present invention therefore involves certain improvements over the expandable type of pile driving mandrel disclosed in prior copending application Serial No. 799,278, filed March 13, 1959, now Patent No. 3,167,924, dated Feb. 2, 1955.

A primary object of the present invention therefore, is to provide an expandable type of pile driving mandrel which is simple in construction, assembly and reliable in operation.

A further object of the present invention is to provide an expandable type of pile driving mandrel consisting of an assembly of two semi-cylindrical elongated members one of which is axially displaceable with respect to the other and held in assembled relation thereto so that upon such axial displacement, the semi-cylindrical members are displaced apart into engagement with the walls of a tubular pile into which the mandrel is inserted so that driving force may then be transmitted through the mandrel to the tubular pile member for driving thereof into the ground.

In accordance with the foregoing objects, the expandable mandrel of the present invention features the provision of a plurality of axially spaced guide pins slidably extending between the active and passive semi-cylindrical members which form the mandrel, the guide pins being disposed at an angle to the longitudinal axis of the mandrel so that driving force applied to the active member for axial displacement thereof, will force the members apart in a direction perpendicular to the longitudinal axis for engagement with the hollow pile.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a side sectional view taken through the expandable mandrel disposed within a hollow pile in a collapsed condition.

FIGURE 2 is a side sectional view of the expandable mandrel in an expanded condition.

FIGURE 3 is a top plan view of the expandable mandrel.

FIGURE 4 is a transverse sectional view taken substantially through a plane indicated by a section line 44 in FIGURE 1.

FIGURE 5 is a perspective view illustrating various disassembled parts of the expandable mandrel.

FIGURE 6 is an enlarged partial sectional view of a portion of the expandable mandrel.

' FIGURE 7 is a partial sectional view taken substantially through a plane indicated by section line 77 in FIGURE 6.

Referring now to the drawings in detail, it will be observed from FIGURES 1 and 2, that the expandable mandrel generally referred to by reference numeral 10, is adapted to be inserted within a hollow or tubular pile 12 having an upper open end 14 through which the mandrel is inserted and a lower closed end 16. The mandrel is therefore adapted to be inserted into the hollow pile and 32 of said members abut each other.

12 in its collapsed condition as shown in FIGURE 1 after which a driving mechanism (not shown) applies force to the upper end of the mandrel as a result of which the mandrel is expanded into engagement with the internal surfaces of the cylindrical wall 18 of the hollow pile as shown in FIGURE 2. The continued application of force to the upper end of the mandrel in its expanded condition will therefore drive the hollow pile 12 into the ground 20.

The expandable mandrel 10 is made up of two elongated members one of which is the passive member 22 adapted to be disposed in an axially fixed position within the hollow pile when inserted thereinto while the other elongated member is the active member 24 adapted to be axially displaced from the position illustrated in FIG- URE 1 to the position illustrated in FIGURE 2 as a result of which the mandrel is expanded into engagement with the walls of the pile. Accordingly, the passive and active members are provided with pile-

engaging surfaces

26 and 28 respectively substantially parallel to the internal surfaces of the hollow pile into which the mandrel is inserted. It will therefore be apparent, that in the illustrated embodiment, the

surfaces

26 and 28 will substan-' tially form a cylinder when the confronting flat faces 30 Each of the

elongated members

22 and 24 is also provided with lower

tapered portions

34 and 36 so as to facilitate insertion of the mandrel into the hollow pile. When inserted however, the elongated members will be axially displaced with respect to each other so that the upper driving end portion 38 of the active member 24 will be above the driving end portion 40 of the passive member. The driving mechanism will therefore initially displace the active member 24 before its driving force is transmitted through the expanded mandrel to the hollow pile. I

The passive and active members are held in assembled relation to each other whether in the collapsed or expanded condition by means of a plurality of axially spaced guide pin elements 42 slidably mounted within both of the elongated members. In this manner, the

elongated members

22 and 24 are maintained in parallel and laterally fixed relation to each other so that the driving force applied to the upper end portion of the mandrel will be effective to expand the

semi-cylindrical surfaces

26 and 28 of the mandrel into uniformly distributed engagement with the internal surfaces of the hollow pile. Each of the guide pins 42 is therefore slidably mounted within axially

alined bores

44 and 46 disposed respectively within the passive member 22 and the active member 24. The bores 46 within the active member 24 extend completely through the active member from the pile-engaging surface 28 thereof to the confronting face 32. It will also be observed, that the bores 46 are disposed at an angle to the confronting faces or the longitudinal axis of the mandrel so that the guide pin 42 slidably mounted therewithin, will cam the elongated members apart when driving force is applied to the upper driving end 38 of the member 24. In order to hold the guide pin 42 assembled Within the axially alined bores, a semi-cylindrical stop disk element 48 is welded within the bore 46 adjacent the end 54) thereof as more clearly seen in FIGURES 6 and 7. The bore 44 disposed within the passive member 22 in axial alinement with the bore 46, extends from the confronting face 30 of the member 22 but terminates Within the member spaced from the pile-engaging surface 26 thereof. A vent passage 52 connects the end of the bore 44 with the pile-engaging surface so as to prevent pressure lock-up of the mandrel inits expanded condition when the ends of the guide pins 42 are spaced from the terminal ends of the bores 44 as illustrated in FIGURE 2. It will therefore be apparent,

that the guide pins 42 are of a length slightly smaller than the total length of the

alined bores

44 and 46. It will also be appreciated, that the number of guide pins and associated bores utilized will depend upon the length of the mandrel and the loads to be sustained. It is also es sential that the axis of the guide pins 42 intersect the longitudinal axis of the mandrel at an angle so that the guide pins extend upwardly from the pile-engaging surface 28 of the active member 24. A downwardly applied force to the driving end portion 38 of the active member will therefore cam the members apart.

In order to collapse the mandrel from its expanded condition, a lift element 54 is provided. A bevelled groove 56 is therefore formed in spaced adjacency to the driving end portion 38 of the active member so that the lift element 54 may be inserted therein and held in the groove by pins 58 which extend into the active member as more clearly seen in FIGURE 5. The lift element which is in the form of a semi-cylindrical disk having an inner semicircular cut-out portion 60, may thereby be located in non-interfering relation to the passive member 22 after which the lift element is welded in place. An upward displacing force may therefore be applied to the active member 24 through the lift element 54 in order to collapse the mandrel.

From the foregoing description, the construction, operation and utility of the expandable mandrel will be apparent. It should therefore be appreciated, that the assembly of the present invention will provide an effective method for transmitting driving force to a hollow pile and avoids the use of costly, complicated and fragile expanding devices heretofore associated with expandable types of mandrels. Also, the arrangement of the present invention whereby the mandrel may be expanded, involves substantially little weakening of the mandrel members or sections necessary to accommodate the expanding guide pins that not only effect expansion of the members but also maintain parallelism between the mandrel-engaging surfaces and the pile so as to obtain effective engagement therewith.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a tubular pile having a longitudinal axis, an expandable mandrel adapted to drive said pile into the ground comprising, an elongated passive member and an elongated active member, said members having confronting faces and pile engaging surfaces, said passive member being disposed in axially fixed position within the tubular pile and having a lower end portion axially engaging the pile, said active member being axially displaceable within the pile and having a lower end portion and an upper driving end portion, and means mounted within both of said elongated members and extending between the confronting faces thereof for maintaining said confronting faces in parallel and laterally fixed relation to each other when displaced in response to axial displacement of said active member by a driving force at the driving end portion thereof, said last-mentioned means including, an elongated pin slidably mounted in axially aligned bores formed in said elongated members, the bore in said active member extending at an angle to said longitudinal axis from the pile-engaging surface through the confronting face, a stop element fixed in the bore of the active member adjacent the pile-engaging surface to limit movement of the elongated pin within said axially aligned bores, the bore in said passive member extending at an angle to the longitudinal axis from the confronting face terminating within the passive member spaced from the pileengaging surface thereof, said passive member being formed with a vent passage between the bore therein and the pile-engaging surface thereof.

2. The combination of claim 1 wherein the lower end portions of said elongated members are tapered for insertion thereof in the tubular pile, and including a lift element secured to the active member adjacent the driving end portion thereof.

3. In combination with a tubular pile, an expandable mandrel adapted to drive said pile into the ground comprising, an elongated passive member and an elongated active member, said members having confronting faces and pile-engaging surfaces, said passive member being disposed in axially fixed position within the tubular pile having a lower end portion axially engaging the pile, said active member being axially displaceable within the pile having a lower end portion axially spaced from the lower end portion of the passive member and an upper driving end portion, and at least two axially spaced guide pins slidably mounted within both of the elongated members and extending between the confronting faces thereof at an angle, whereby said elongated members are maintained in parallel and laterally fixed relation to each other when the active member is axially displaced by a driving force at the driving end portion thereof to expand the pileengaging surfaces into engagement with the pile as the axial spacing between the lower end portions of the elongated members is reduced.

4. The combination of claim 3 wherein said pileengaging surfaces of the passive and active members form a continuous external periphery in cross-section substantially parallel to the tubular pile in cross-section.

5. In combination with a tubular pile having a longitudinal axis, an expandable mandrel for driving said pile in a direction parallel to said axis comprising a pair of axially elongated members received within the pile in axially spaced relation to each other, each of said elongated members having a pile engaging surface, a plurality of axially spaced guide elements, means mounting said guide elements within the elongated members for relative slidable displacement at an angle to the longitudinal axis in response to axial displacement of one of said elongated members, confronting face means on said elongated members engageable to limit said displacement of the guide elements in one direction withdrawing said pile engaging surfaces from the pile and force applying means connected to said one of the elongated members for said axial displacement thereof parallel to the longitudinal axis to engage the pile with said pile engaging surfaces and withdraw the same from engagement.

6. The combination of claim 5 wherein each of said elongated'members is substantially solid in cross-section, said means slidably mounting the guide elements being formed by axially aligned bores extending through the elongated member along axes intersecting the confronting face means at said angle to the longitudinal axis, the pile engaging surfaces and the confronting face means defining the cross-sections of the elongated members.

References Cited by the Examiner UNITED STATES PATENTS 589,026 8/1897 Raymond 6l53.72 X 2,818,618 1/1958 Winship et al. 24272.l X 2,928,252 3/1960 McKee 6l53.72

CHARLES E. OCONNELL, Primary Examiner.

JACOB SHAPIRO, Examiner.

Claims

3. IN COMBINATION WITH A TUBULAR PILE, AN EXPANDABLE MANDREL ADAPTED TO DRIVE SAID PILE INTO THE GROUND COMPRISING, AN ELONGATED PASSIVE MEMBER AND AN ELONGATED ACTIVE MEMBER, SAID MEMBERS HAVING CONFRONTING FACES AND PILE-ENGAGING SURFACES, SAID PASSIVE MEMBER BEING DISPOSED IN AXIALLY FIXED POSITION WITHIN THE TUBULAR PILE HAVING A LOWER END PORTION AXIALLY ENGAGING THE PILE, SAID ACTIVE MEMBER BEING AXIALLY DISPLACEABLE WITHIN THE PILE HAVING A LOWER END PORTION AXIALLY SPACED FROM THE LOWER END PORTION OF THE PASSIVE MEMBER AND AN UPPER DRIVING END PORTION, AND AT LEAST TWO AXIALLY SPACED GUIDE PINS SLIDABLY MOUNTED WITHIN BOTH OF THE ELONGATED MEMBERS AND EXTENDING BETWEEN THE CONFRONTING FACES THEREOF AT