US3500940A

US3500940A - Free fall hammer apparatus

Info

Publication number: US3500940A
Application number: US752909A
Authority: US
Inventors: George W Guest
Original assignee: Sprague and Henwood Inc
Current assignee: Sprague and Henwood Inc
Priority date: 1968-08-15
Filing date: 1968-08-15
Publication date: 1970-03-17
Anticipated expiration: 1987-03-17

Description

March 17, 1970 Filed Aug. 15, 1968 G. W. GUEST FREE FALL HAMMER APPARATUS 3 Sheets-Sheet 1 INVENTOI? GEORGE 144 61/557 ATTORNEY March 17, 1970 G. W. GUEST 0,500,940

FREE FALL HAMMER APPARATUS Filed Aug. 15, 1968 3 Sheets-Sheet 2 INVENTOR 650965 (4. GUEST ATTORNEY March 17, 1970 G. w. GUEST FREE FALL HAMMER APPARATUS 3 Sheets-Sheet 5 Filed Aug. 15, 1968 5 2/ i H n B 4 w Q 0 W M @X @X J 9 L 0 Mm 0 U M a 0 Y W 1 2 a Q i1| l/Vl/f/VTOI? GEORGE PV. GUEST ATTORNEY United States Patent US. 'Cl. 173-124 8 Claims ABSTRACT OF THE DISCLOSURE Free fall hammer apparatus for use in driving pipes or casing through overburden and in driving soil samplers into soil which is composed of a multi-part hammer, a long assembly and a hydraulically operated lifting assembly.

CROSS-REFERENCE This application is a continuation-in-part of my prior application filed June 17, 1968, Ser. No. 737,443, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention Free fall hammer apparatus for driving pipe or casing and soil samplers into soil and for other purposes which apparatus is hydraulically operated and automatically grips, lifts, and releases the drive hammer.

DESCRIPTION OF THE PRIOR ART The apparatus now generally in use for driving pipe or casing through overburden, and soil samplers into soil ahead of each length of pipe, employs a manually operated cathead hoist or a wire rope hoist. The rope travels over a derrick sheave wheel and is attached to a sling fastened to a drive hammer. Various weights of drive hammers are used, depending on the size of pipe, casing and sampler to be driven and also the type of overburden to be penetrated. Usually a 300 pound drive hammer is used for driving pipe or casing and a 140 pound drive hammer is used for driving soil samplers.

The drive hammer has a center hole made with a loose fit to enable it to slide easily over a guide or jar length. The jar length threads into a drive head, that, in turn, threads into the pipe coupling or casing. The drive head has an internal thread for drill rod or small diameter pipe, providing a connector for use with soil samplers. The drive hammer is picked up by the sling and manually lifted up the jar length until the operator determines it has traveled the necessary distance i.e., or more inches. The operator releases the rope, allowing the drive hammer to fall and strike the drive head driving the pipe or casing and soil sampler into the soil.

The number of blows per inch or foot of penetration of the pipe or casing and the samplersinto the overburden are tabulated and then correlated to determine foundation bearing values.

In order to obtain accurate and meaningful figures it is necessary for the drive hammer to rise and fall freely without any rope or other drag. The apparatus now in use does not permit free fall but resists free fall as a result of the friction between the rope and sheave wheel.

The force required being variable depending on the casing or sampler to be driven and the overburden to be penetrated may require frequent changing of the drive hammer weight which operation is a diflicult and time consuming one.

The present invention eliminates any rope drag or 3,500,940 Patented Mar. 17, 1970 ice restriction to free fall, eliminates the hard physical effort required in lifting the hammer, provides a controlled and constant lift of the drive hammer, and permits of easily varying the weight of the drive hammer.

SUMMARY OF THE INVENTION The present invention relates to a free fall hammer apparatus which has a hydraulically operated lifter assembly, a tong assembly, a free fall two piece hammer and a guiding portion, and fluid controls therefor.

The principal object of the present invention is to provide a free fall hammer apparatus which raises a free fall hammer a predetermined distance and automatically releases it to fall and strike a drive head.

A further object of the present invention is to provide a free fall hammer apparatus which operates with only slight manual labor being required.

A further object of the present invention is to provide a free fall hammer apparatus which permits of easy variation of the drive hammer weight.

A further object of the present invention is to provide a free fall hammer apparatus that is simple and easy to operate and requires little maintenance.

A further object of the present invention is to provide a free fall hammer apparatus that is fast and positive in operation.

Other objects and advantageous features of the invention will be apparent from the description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS The nature and characteristic features of the invention will be more readily understood from the following description taken in connection with the accompanying drawings forming part thereof, in which:

FIGURE 1 is a front elevational view partly in phantom illustrating the free fall hammer apparatus of the present invention;

FIGURE 2 is a partial vertical sectional view, enlarged, taken at the upper part of FIG. 1;

FIGURE 3 is a horizontal sectional view, enlarged, taken approximately on the line 33 of FIG. 1;

FIG. 4 is an enlarged sectional view of the driving hammer and tong assembly of the present invention taken approximately on the line 44 of FIG. 3; and

FIG. 5 is a diagrammatic view of a suitable hydraulic circuit for controlling the tong and hammer operation.

It should, of course, be understood that the description and drawings herein are illustrative merely, and that various modifications and changes can be made in the structure disclosed without departing from the spirit of the invention.

Like numerals refer to like parts throughout the several views.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to the drawings, and FIGS. 1 and 2 thereof, the free fall hammer apparatus includes a lifting assembly 10, a tong assembly 11, a hammer 12 and a driving head 14. The lifting assembly is particularly illustrated in FIG. 2 and includes an upper outer housing 15.

The housing 15 is provided with an inner bore 16 which is closed at its upper end by a bushing 17 and a packing ring 18 with the bushing 17 held in housing 15 by a plurality of cap screws 20. The packing ring 18 is restrained from downward movement in the bore 16 by a shoulder 21 inwardly of the bore 16. A piston stop sleeve 22 is provided below the shoulder 21, which sleeve 22 extends vertically downwardly in bore 16.

On the housing 15, at the right as seen in FIG. 2 a nipple 24 is attached which connects a hydraulic line 25 3 to the bore 16 through an opening 26 in the housing 15. The line 25 is connected as hereinafter explained with respect to FIG. to control the flow of fluid therethrough.

The housing 15 at its lower end is provided with an exterior flange 27, has internal threads 28 and has a hollow cylindrical portion 29 with its outer diameter less than the outside diameter of housing 15.

A lower outer housing 30 has an upper annular exterior flange 31 with a packing 33, such as an O-ring, in a groove 34 bearing against flange 27, and with cap screws 35 engaged in flange 27 and flange 31 holding them together.

The cylindrical portion 29 is provided with a packing 38, such as an inner O-ring, and is connected to an inner tube 39 in threaded engagement in the threads 28.

The outer housing 30 is closed at its lower end by a closure plug 41 in threaded engagement therewith. The plug 41 has a packing 42, such as an O-ring in an outer groove 43 hearing against the inside of housing 30, and a packing 40, such as an O-ring in an inner groove 40a, bearing against the inner tube 39 which is in threaded engagement in the plug 41. The tube 39 has holes 44 therethrough to permit of fluid flow into the interior 49 thereof above the plug 41.

An outer flange 45 is provided attached to housing 30 and with a hydraulic line 46 connected thereto and to a source of fluid (not shown) and communicating with bore 47 through a hole 48 in the housing 30. The line 46 iS connected as hereinafter explained with respect to FIG. 5 to control the flow of fluid therethrough.

A swivel mounting collar 50 is provided with an upper flanged extension 50a with which a split ring 50b is held in engagement by screws 51 to permit swiveling of the cylinder assembly.

The collar 50 has a hollow cylindrical jar length or guide 53 secured thereto in any desired manner such as by threads 53a, with an opening 52 at the bottom end. A set screw 70 may be employed to hold the collar 50 and jar'53 against separation by rotation.

The plug 41 inside tube 39 is provided with a stop assembly 54 which consists of a bufier 55, and a screw 57, engaged in the buffer 55 and plug 41.

A piston assembly 58 is provided comprised of an upper arm 58a with a pair of horizontally extending eyes 58b in engagement therewith, and a central rod or shaft 58c extending through the arm 58a and held thereto by a nut 60 with its washer 61.

The shaft 58c on a lower end portion 63 thereof of reduced diameter has spaced collars 62 and 66 with a piston 64 therebetween engaging piston packing cups 65. The cups 65 and piston 64 are slidable in the tube 39. Nuts 58d on a threaded terminal of the end portion 63 hold the piston 64, washers 62 and 66 and cups 65 in place.

A packing 68, such as an O-ring, may be provided inside piston 64 and bearing piston portion 63 to prevent leakage of fluid thereby.

A pair of cables 71 are attached to the eyes 5812 by pins 72 and U-shaped connectors 73 integral with cables 71. At the lower end the cables 71 have another set of connectors 73 connected thereto which are attached to an arm 74 by pins 75. The arm 74 has an inner bore 76 which is slidably engaged with the guide 53.

A pair of tongs 80 are provided rotatably attached to the arm 74 by pins 81 engaged in upper angularly related arms 82 of the tongs 80.

The arms 82 are joined to upper horizontal rims 83 which have vertical downwardly extending concave fingers 84 integral therewith. A pair of flanges 86 extend vertically from each of the rims 83 and have a pair of double acting hydraulic cylinders 90 attached thereto by pins 91, the cylinders 90 connecting the opposed tongs 80 together.

The cylinders 90 have connecting pipes 92 and pipes 93 as hereinafter explained with respect to FIG. 5 for control of the cylinders 90.

Inside of the tongs 80, and as illustrated in FIG. 4, the

two piece free fall hammer 12 is provided, with an upper weight portion 101 and a lower Weight portion 102, secured by a pair of eye bolts 103 swingably engaged with the lower portion 102 and with collar nuts 104, the bolts 103 being movable in slots 106 in the upper portion 101. The guide 53 extends through the hammer 12 which is free to slide up and down thereon.

The driving head 14 is shown in FIG. 1 below the ham' mer 12 which has a pipe or casing 111 to be driven into the soil engaged therewith. The pipe 111 is provided with a threaded sleeve 112 Which permits of other pipe 11 being joined thereto.

Referring now to FIG. 5 a suitable hydraulic circuit is there shown which includes a tank with a fluid supply connection 121 extending therefrom through a filter 122 and pump 123. While any desired hydraulic power circuit of adequate pressure and fluid flow may be employed for some embodiments it is advantageous to utilize a core drill circuit. The circuit illustrated includes a connection 121 which may provide a core drill circuit supply line in a well known manner and preferably has a manually operable shut off valve V3 therein which is closed for hammer operation. A fluid return line 125 also extends to the tank 120 and provides a return line to the tank 120. A manually operable bypass control valve V4 can be connected by a bypass connection 127 between the fluid connections 121 and 125 and is closed for hammer operation. The bypass connection can have a pressure gage 126 connected thereto on the supply side.

The fluid connection 121 has a fluid connection 129 connected thereto through a manually operable shut off valve V1 to an adjustable pressure relief valve 130 to provide the required pressures to accommodate the system to various weight sizes of hammers 12 and to a four way pilot valve 132, preferably of the slidable spool type. The valve 132 is connected by fluid connections 133 and 134 to a four way valve 135, also preferably of the slidable spool type.

The valve 135 has a fluid supply connection 136 connected to the supply connection 129. The valve 135 has fluid connections 137 and 138 connected respectively to the

pipes

26 and 25 of the cylinder 39 and to the

pipes

93 and 92 of the cylinders 90.

In order to control the pilot valve 132 which in turn controls the valve 135,

sequence valves

140 and 141 are connected respectively by

fluid connections

143 and 144 to the fluid connections 137 and 138 and by fluid connections 145 and 146 tovthe pilot valve 132. The

sequence valves

140 and 141 are of well known adjustable type operated by the pressure build up at the ends of the stroke in the cylinder 37 to cause a reverse of the flow and in turn reverse the flow through the valve 135.

The

valves

140, 141, 132, 135 and 130 have return connections connected to the return connection 148 which is connected through a manually operable shut off return valve V2 to the fluid connection 125. The valve V2 is open during hammer operation.

The mode of operation will now be pointed out.

Assume the hammer 12 is resting on the driving head 14 and the tongs 80 are engaged with the hammer 12. 'Fluid under pressure is supplied through valve 135, fluid connection 137 and line 46 to bore 47 and enters casing 30 and tube 39 through hole 44. Fluid in bore 16 is exhausted through line 25, fluid connection 138, valve 135 and fluid connection 148.

The piston assembly 58 is moved upwardly and lifts the hammer 12 upwardly on guide 53. When the predetermined height is reached the supply of fluid effective against piston assembly 58 is cut off by reversal of flow by sequence valve 141 acting through valve 132 to change the position of valve 135, in pipe 46. Fluid is supplied to cylinders 90 through

pipes

92 and 93 spreading tongs 80 apart releasing the hammer 12 so that hammer 12 is free to fall and strike driving head 14. The piston assembly 58 then moves downwardly carrying tongs 80 down until they are adjacent hammer 12 when pressure supplied to cylinders 90 is reversed and tongs '80 grip hammer 12. The valve 140 initiates the reversal through

valves

132 and 135 and the operation will continue. After the

valves

140 and 141 have been adjusted to the desired settings, operating control for starting and stopping is available at valve V4 and speed control is obtained by variation of the speed of the pump 123.

The hammer weight portion 102 can be changed by loosening nuts 105 and sliding bolts 103 out slots 106 so that lower weight portion 102 is no longer lifted by tongs 80 and can be used as a driving head as desired.

Various weight sizes of hammers can be utilized, the valve 130 permitting of pressure adjustment as required to lift different weight sizes.

It will be noted that the unit operates free standing by being assembled to the casing, pipe or the like to be driven. The swivel joint assembly of the cylinder 39 to the guide 53 provides for ease of assembly and disassembly to the structure to be driven so that additional lengths of easing or pipe can be added as desired.

The hammer is lifted an exact distance prior to the free fall and any desired type of hammer may be employed including the hammer illustrated as well as hammers now in use.

The free fall hammer apparatus of the present invention can be employed for core drilling, soil sampling and for other purposes and with a proper head adapter or locator can be used to drive pilings.

It will thus be seen that apparatus has been described for attaining the objects of the invention.

I claim:

1. Free fall hammer apparatus which comprises a driving head,

a free hammer for intermittent engagement with said driving head,

a tong assembly for engagement with the exterior of said hammer,

hydraulically actuated members controlling the engagement of said tong assembly with said hammer,

a hydraulic lifting assembly controlling the positioning of said tong assembly,

guiding means cooperatively related to said hammer and to said tong assembly controlling the direction of the lifting and falling of said hammer and said tong assembly, and

hydraulic circuit means controlling the activation of the lifting assembly and the tong assembly.

2. Free fall hammer apparatus as defined in claim 1 in which said tong assembly comprises a horizontal arm,

a pair of opposed tongs pivotally mounted on said arm,

and

fluid actuated cylinder means pivotally connected to said tongs controlling the positioning of said tongs.

3. Free fall hammer apparatus as defined in claim 2 in which said lifting assembly has an arm connected thereto,

and flexible supporting members are provided connecting said lifting assembly arm to said horizontal arm in supporting relation. 4. Free fall hammer apparatus as defined in claim 2 in which said lifting assembly comprises a hydraulically operated cylinder. 5. Free fall hammer apparatus as defined in claim 4 in which said last cylinder has an arm connected thereto, and cables are provided connecting said arm and said tong assembly. 6. Free fall hammer apparatus as defined in claim 4 in which said guiding means is a jar length which is detachably engaged with said lifting assembly. 7. Free fall hammer apparatus as defined in claim 1 in which said hammer comprises an upper weight engaged by said tong assembly, a lower separable weight portion, and detachable connecting members connecting said loWer Weight portion to said upper weight portion. 8. Free fall hammer apparatus as defined in claim 1 in which said hydraulic circuit means comprises a source of fluid under pressure, a pilot valve connected to said fluid source, a control valve connected to said pilot valve, fluid connections connecting said control valve to said lifting cylinder and to said tong cylinder means, and sequence valves connected to said pilot valve and to said lifting cylinder and controlling the fluid flow to said control valve and therefrom to said lifting cylinder and to said tong cylinder dependent upon the pressure in the lifting cylinder.

References Cited UNITED STATES PATENTS 368,949 8/1887 Hunter 173124 X 841,032 1/1907 Mellgren 173-124 X 2,659,584 11/1953 Dorkins 173-124 X 2,897,907 8/1959 Blount 94-49 X 3,039,546 6/1962 Janson 173l24 3,166,351 1/1965 Baudrillard 173124 X NILE C. BYERS, JR., Primary Examiner US. Cl. X.R. 94-49