US3700046A

US3700046A - Two-stage drop hammer for driving large diameter piling

Info

Publication number: US3700046A
Application number: US121663A
Authority: US
Inventors: Robert G Evans
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-03-08
Filing date: 1971-03-08
Publication date: 1972-10-24
Anticipated expiration: 1989-10-24

Abstract

A two-stage or multi-stage drop hammer for driving large diameter piling having a backing plate welded onto the upper terminal end of a cylinder to be driven to form a pile, a hammer guide secured onto the backing plate, said hammer guide containing an annular, contoured first hammer for impacting upon a large peripheral portion of the bottom member of the hammer guide, and a second hammer for impacting upon a large central area of the bottom member of the hammer guide, and a flanged extension on the second hammer for lifting the first hammer to a distance above the bottom member of the hammer guide, whereupon dropping of the hammers provides and allows the first hammer to impact upon the bottom member of the hammer guide in timed sequence ahead of the second hammer impacting upon the bottom member of the hammer guide.

Description

United States Patent Evans Oct. 24, 1972 [54] TWO-STAGE DROP HAMMER FOR DRIVING LARGE DIAMETER PILING [72] Inventor: Robert G. Evans, P.O. Drawer 68, Harvey, La. 70058 [22] Filed: March 8,1971 [21] Appl. No.: 121,663

[52] US. Cl ..173/l03 Primary Examiner-James A. Leppink Attorney-Misegades & Douglas [57] ABSTRACT A two-stage or multi-stage drop hammer for driving large diameter piling havinga backing plate welded onto the upper terminal end of a cylinder to be driven to form a pile, a hammer guide secured onto the backing plate, said hammer guide containing an annular, contoured first hammer for impacting upon a large peripheral portion of the bottom member of the hammer guide, and a second hammer for impacting upon a large central area of the bottom member of the hammer guide, and a flanged extension on the second hammer for lifting the first hammer to a distance above the bottom member of the hammer guide, whereupon dropping of the hammers provides and allows the first hammer to impact upon the bottom member of the hammer guide in timed sequence ahead of the second hammer impacting upon the bottom member of the hammer guide.

6 Claims, 2 Drawing Figures mmenomwm 0.700.046

v k v ROBERT 0. EVANS r 7 0 W'd fidfl ggg ATTORNEYS I4 I I I4 TWO-STAGE DROP HAMMER FOR DRIVING LARGE DIAMETER PILING BACKGROUND OF THE INVENTION The present invention relates to drop hammers for driving unusually large diameter piling, and more particularly relates to the arrangement of hammers for driving metal cylindrical piling having up to eight feet diameter or more, and being essentially unique in that there are twoor multi-stage hammers which impact or strike the piling initially with a reduced amount of energy, then following almost instantaneously in time with an increased amount of energy in the form of mechanical forces.

Generally speaking, there are at least two types of hammers in existence for driving pilings into river bottoms, and the like, one of which is a drop hammer which functions and operates on the principle of a weight being lifted and then dropped onto the piling, driving it into the ground; and the other type being mechanical in which the hammer is actuated at an essentially faster rate of impact such as by air, steam, or by mechanical vibrations or rapid rates. While the drop hammer is a simpler form, it is generally slower and if it is made sufficiently massive to acquire additional speed by driving the piling further with each blow, there is a risk of fracturing the piling.

BRIEF SUMMARY OF THE INVENTION lt is an object of the present invention, therefore, to provide means for reducing and eliminating all risk of fracturing the piling, and to provide improved piling as well as attaining the result of more quickly installing the pile driving into river beds and other ground, and the like.

A further object and advantage of the present invention is to provide a two-stage or multi-stage drop hammer, it having a number of advantages and improvements over conventional single-stage drop hammers, such as the following 1. The lifting mechanism lifts the second stage which is lighter first, and gets it moving before the second stage is engaged, reducing the shock on the lifting mechanism;

2. The chance of fracturing the piling is reduced since the first stage hammer engages the piling with less energy momentarily before the second stage is engaged. Since the first stage starts the piling moving, it is able to absorb more energy when the second stage hammer engages it, due to a reduction in inertia, which is occasioned by the piling being in motion when struck by the second stage hammer;

3. The cost of the drop hammer is considerably less than a mechanical hammer producing the same amount of energy;

4. Maintenance and operating skill would be considerably less; and

5. The design lends itself particularly well to driving large diameter cylinders.

It is a further object and advantage of the present invention to apply a lighter force to initiate the movement of the piling, followed almost instantaneously in time by a greater impact force. Where more than two stages are designed into the multi-stage unit, these forces would increase progressively at each additional stage of impact. However, it is not found at present to be practical to visualize a hammer of this invention having more than five stages.

The above and other objects and advantages of the invention will become apparent upon full consideration of the following detailed description and accompanying drawings in which:

FIG. 1 shows a side elevation view shown in part cross-section of a twoor multi-stage hammer according to a preferred embodiment of the present invention for driving large diameter piling and the like; and

FIG. 2 shows a detailed enlarged view of the cable connection for the lever means for lifting the first stage hammer by a flanged extension of the second stage hammer.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, there is shown a cylinder 10 of essentially large diameter, the cylinder forming the piling to be driven, and which may be filled with concrete or other material filling, if desired. The upper end of the cylinder 10 terminates in a back member or impact member such as a backing plate 12 that is welded to the top edge of the cylinder 10.

There is secured upon the top surface of the backing plate 12 a bottom member 16 of a hammer guide 18, the hammer guide having a generally cylindrical configuration with said bottom member 16. On a large peripheral area of the bottom member is an annular plate 22 disposed for receiving the application of a large mechanical force, and centrally disposed thereof on the bottom member 16 is a central means 24 forming a large central area for receiving also the application of a large mechanical force.

Within the hammer guide 18, there is a first'hamm er 26 having a hollow central portion and which traverses a portion of the entire length of the hammer guide. When the first hammer 26 is dropped upon the plate member 22, a large impact applies a mechanical force to the large peripheral area of the bottom member which is transferred to the cylinder 10 for driving it downwardly.

A second hammer 28 central of the first hammer 26 traverses the entire length of the hammer guide 18 and upon impact it applies a large mechanical force to the large central member 24, which is transferred also to the cylinder 10. The hammer guide has a top member 30 which extends upwardly from the cylindrical element of the hammer guide and the top member includes a cable guide 34 extending upwardly therefrom. On the top of the second hammer 28, there is a cable coupling 32 and cable means 33, 33 passes through the cable guide 34 and is coupled to the upper terminal end of the first hammer 26 at a coupling means 36. The slack in the cabling means is adjustable in length so that, as described below, the first hammer may be lifted by the cable means prior to it being lifted by a flanged extension 40.

The second hammer 28 is provided with the flanged extension 40 throughout the entire peripheral element at the impact end of the second hammer. The second hammer 28 is provided with an internal tubular guide 42 for allowing passage of the second hammer together with its flanged extension 40. The upper end of the first hammer 26 and the tubular guide 42 is provided with a plurality of pivotally mounted, radially disposed

levers

46, 46 having their outer ends engaging a

spring

48, 48, respectively, which spring biases the other end of the lever generally upwardly and thus the air ends are prone to be biased downwardly as a result of the force due to the spring 48. The lever is pivotally supported by means 50, as shown.

When the second hammer 28 with its flanged extension 40 reaches the upper position within the tubular guide, it engages the inner ends of the radially disposed

levers

46, 46 and together with the tautness of the cabling means 38, the first hammer 26 and the second hammer 28 are then lifted until the first hammer reaches the upper end of the hammer guide 18.

The first hammer 26 may be of a weight such as 36,000 pounds, dropped through a distance of 3 feet, and provides a force of 108,000 pounds. The second hammer 28 may be of a weight, for example, of 17,000 pounds and if dropped through a distance of, for example, feet, provides a force equal to 170,000 foot pounds. This force is applied to the cylinder 10 to be driven in forming a piling according to the present invention.

When the terminal coupling 60 at the upper end of the second hammer 28 is raised, such as by a cable connected to a crane or the like, the second stage is lifted the entire length of the hammer guide 18 and the flanged extension 40 at the impact end of the second hammer engages with the inner lever ends 50 of

levers

46, 46, any abruptness of such force being absorbed by the spring means 48, 48, so that the first hammer 26 is raised until the

levers

46, 46 reach or engage with the top hammer 30. The first hammer is supported by the flanged extension 40 of the second hammer 28 when the flanged extension travels the full distance to pivot support means 50. When the first and second hammers are brought into engagement with plate members 22, 24, respectively, the cabling (not shown) connected to the coupling 60 is momentarily released so that each of the second (or first) hammer drops. The first hammer 26 drops only, for example, three feet through the hammer guide which may be generally 10 feet in height and engages the peripheral member 22, the impact being first transferred to the cylinder 10. This is a lighter force than the force of the second hammer and starts the piling moving. There is followed almost instantaneously the greater force of the second hammer which falls through the distance of 10 feet, that is, the entire distance, for example, of the hammer guide, and its force is applied to the plate 24, which force is trans ferred to the backing plate 12 similarly to the force of the first hammer to the cylinder 10. The sequential applicationof these forces in increased progressively ranges of magnitude of forces at each additional stage provide greater longitudinal movement of the piling formed by cylinder 10 than is accomplished by separate applications of the hammer, according to prior art means and methods.

The plate 24 within the hammer guide 18 may be coupled by

bolts

70, 72 to the backing plate 12, which are as shown in FIG. 1. By means therefore, the present invention provides a multi-stage hammer to drive metal cylindrical piling which may be up to eight feet in diameter by improved methods into river bottoms, ground, and other areas, so that the staged hammer application of forces for driving the pilings with a reduced amount of energy, then followed almost instantaneously with an increased amount of energy, provides faster, more efficient and improved installation of pilings. In FIG. 2, there is shown the manner by which cabling means is provided to a coupling 76 and a bolt 78 for lifting the first hammer 26 by coupling the bolt 78 to a upper end of the tube 42. There is also shown the manner in which the lever 46 is pivotally coupled by a pivot means 50 to the first hammer 26.

When a shorter interval between the impacts of the first and second hammers is desired, adjustment of the length of the cabling means 33 is made and calculated so that the second hammer falls and impacts at a shortened predetermined time after the fall and impact of the first hammer. Thus, the cabling means 33, 33 is used only when second hammer 28 is less than full drop on capacity. This allows and permits the second hammer 28 to start lifting the first hammer 26 at any selected predetermined point in time that is less than the point of engagement.

Additional embodiments of the invention in this specification will occur to others and, therefore, it is intended that the true spirit of the invention be limited only by the appended claims and not by the embodiments described hereinabove. Accordingly, reference should be made to the following claims in determining the true spirit of the invention.

What is claimed is:

1. A twoor multi-stage drop hammer for driving large diameter piling and the like comprising:

a large diameter cylinder to be driven to form a pile, having its upper end terminating in a backing plate welded onto the cylinder,

a hammer guide having a bottom member secured by means onto the backing plate having a large peripheral area for' receiving the application of a mechanical force and a large central area for receiving also the application of mechanical force,

said hammer guide having a generally cylindrical configuration with said bottom member,

a first hammer for traversing a portion of the entire length of the hammer guide and upon impact applying a mechanical force to said large peripheral area of said bottom member,

a second hammer for traversing the entire length of the hammer guide and upon impact applying said mechanical force to said large central area of said bottom member, and

said hammer guide having a top member and including a cable guide extending upwardly thereof.

2. The invention according to claim 1 wherein said cabling means passes through said cable guide coupled at each end, one to the upper terminal end portion of the first hammer and the other to the upper terminal end portion of the first hammer.

3. The invention according to claim 1 wherein said first mentioned means in the hammer guide are bolts securing it to the backing plate.

4. The invention according to claim 1 where the cabling means is adjustable in length so that the first hammer is lifted up by the cabling means prior to the lower end of the second hammer traverses the entire vertical length of the hammer guide.

5. The invention according to claim 1 wherein a tubular guide is disposed within the first hammer for the outer ends spring-biased upwardly and the inner ends acting against the spring-biased action when the second hammer reaches the upper position on the said hammer guide by engaging said levers with said flanged extension of said second hammer.

Claims

1. A two- or multi-stage drop hammer for driving large diameter piling and the like comprising: a large diameter cylinder to be driven to form a pile, having its upper end terminating in a backing plate welded onto the cylinder, a hammer guide having a bottom member secured by means onto the backing plate having a large peripheral area for receiving the application of a mechanical force and a large central area for receiving also the application of mechanical force, said hammer guide having a generally cylindrical configuration with said bottom member, a first hammer for traversing a portion of the entire length of the hammer guide and upon impact applying a mechanical force to said large peripheral area of said bottom member, a second hammer for traversing the entire length of the hammer guide and upon impact applying said mechanical force to said large central area of said bottom member, and said hammer guide having a top member and including a cable guide extending upwardly thereof.

5. The invention according to claim 1 wherein a tubular guide is disposed within the first hammer for passage therethrough of the second hammer, and said second hammer has a flanged extension at the impact end thereof.

6. The invention according to claim 4 wherein said tubular guide at the upper end terminates in a plurality of pivotally mounted, radially disposed levers having the outer ends spring-biased upwardly and the inner ends acting against the spring-biased action when the second hammer reaches the upper position on the said hammer guide by engaging said levers with said flanged extension of said second hammer.