US3325923A - Hydraulic controls for spud - Google Patents

Description

J1me 1967 N. H. CARGILE, JR 3,325,923

HYDRAULIC CONTROLS FOR SPUD Filed June 24, 1964 5 Sheets-Sheet l z I NVENTOR: 9. 125/; 1% (fir/(Wu; J6

June 20, 1967 N. H. CARGILE, JR

HYDRAULIC CONTROLS FOR SPUD Z5 Sheets-Sheet 2 Filed June 24, 1964 INVENTOR: 17 04 26! awe/45,47?

BY 3%, zsn d. @2257 ATTORNEY J1me 1967 N. H. CARGILE, JR 3,325,923

HYDRAULIC CONTROLS FOR SPUD Filed June 24, 1964 C: Sheets-Sheet 3 70 2a 71 51 ii- 1 I 52 2f 4 I Z3 62 50 I 57 1' 57 I [Z ZZZ I 58 I g 5 5Z INVENTOR: Ads/4 2% (keg/15,473

40 4X RESERVOIR BY p 4 ATTORNEY United States Patent 3,325,923 HYDRAULIC 0NTROL FUR SPUD Neii H. Car ile, Jr., American Marine and Machinery Co., Hutu, 201 Woodycrest, Nashville, Tenn. 37211 Filed June 24, 1964, Ser. No. 377,743 Claims. (Cl. 37-73) This invention relates to hydraulic controls for a spud, and more particularly to hydraulic controls on a dredge for elevating and rapidly lowering a spud.

In the art of dredging, a pair of spuds are carried for vertical reciprocable movement at opposite sides of the stern of the dredge. Means are provided for controlling the spuds so that one spud may be dropped into the bottom of the pond or stream, while the other spud is maintained at an elevated position, in order to form a pivot point about which the dredge swings during the dredging operation. When desired, the anchored spud may be elevated and the dredge moved to another dredging location, or the elevated spud may be dropped to shift the pivot point about which the dredge swings.

Each spud is independently controlled and is usually lifted by a cable connected to the spud and passing upward over an elevated sheave and downwardly to a winch. By driving the winch to wind up the cable, the spud is raised. The cable then holds the spud in its elevated position by a brake means or ratchet and pawl mechanism or any other type of locking means. Then, when it is desired to lower the spud, the braking or locking means is released to permit the spud to fall freely by gravity until it strikes the bottom, unwinding the cable as it moves.

In more recent models of dredges where hydraulic control systems are employed, including hydraulic controls for the spuds, a hydraulic piston or ram is employed in connection with a train of sheaves and a cable to obtain the desired mechanical advantage, so that when the ram or piston is elevated by hydraulic pressure to a predetermined piston stroke, then the spud is elevated a multiple distance of the piston stroke, depending upon the mechanical advantage obtained by the number of sheaves or pulleys employed. However, when it is desired to lower the spud, by reversing the circulation of the hydraulic fluid in the ram, the spud can only fall at a rate substantially less than a free fall because of the volume of fluid that has to be expelled from the cylinder in advance of the piston during its reverse or down stroke.

It is therefore, an object of this invention to provide a hydraulic control system for a spud in which the hydraulic fluid in advance of the ram or piston on its down stroke may be rapidly expelled in order to increase the falling rate of the spud.

Another object of this invention is to provide a hydraulic system for a spud in which the return line from the hydraulic ram for the spud is short-circuited to more rapidly exhaust the ram cylinder during the descent of the spud.

Another object of this invention is to provide a hydraulic control system for a spud in which the hydraulic fluid in advance of the ram is short-circuited to the cylinder space behind the ram during the descent of the spud.

Another object of this invention is to provide a hydraulic control system for a spud ram having a doubleacting cylinder, which is provided with a dumping valve adapted to be automatically actuated to rapidly bleed the cylinder in advance of the piston during the descent of the spud.

A further object of this invention is to provide a hydraulic control for a spud including a double-acting cylinder, a pressure sensitive unloading valve adapted to be actuated by a predetermined pressure from the input cir- Patented June 20, 1967 cuit to the cylinder to rapidly bleed the output circuit of the cylinder during the movement of the piston to lower the spud.

Another object of this invention is to provide a hydraulic control for a spud in which the normal return line in the control circuit is bypassed and rapidly unloaded when the controls are actuated to lower the spud.

Further objects and advantages of the invention will be apparent from the description taken in conjunction with the drawings, wherein:

FIG. 1 is a port-side elevation of the stern portion of a dredge, with parts broken away to better illustrate the spud controls;

FIG. 2 is a fragmentary rear elevation of the portside of the stern section of a dredge, with the spud broken away;

FIG. 3 is an enlarged perspective view of the invention as applied to the port spud, shown partly in section;

FIG. 4 is a schematic fluid circuit diagram of the invention in operative position to raise the spud;

FIG. 5 is a view similar to FIG. 4, but operative to lower the spud; and

FIG. 6 is a sectional elevation of one form of the unloading valve employed in this invention.

Referring now to the drawings in more detail, FIGS. 1 and 2 disclose a fragment of the stern portion of a dredge 10 having a hull 11, a deck housing 12 and pontoons, only the port pontoon 13 being disclosed. A gantry 15 is fixedly supported to extend upright in a substantially vertical position from the stern of the hull 11. Mounted on top of the gantry 15 is a freely rotatable sheave or pulley 16. A pair of hinged spud wells 18 are mounted in vertical alignment on the stern of the hull 11 for guiding the port spud 20 in a reciprocable vertical path.

It will be understood that a dredge it) normally incorporates two spuds, a port spud 20, and a starboard spud, not shown, which occupies the same relative position on the opposite side of the stern hull 11. However, in order to avoid unnecessary duplication, only the port spud 29 and its corresponding controls incorporating this invention will be described, since a duplicate form of the invention will be incorporated in the controls for the starboard spud and will function in the same manner.

A hydraulic ram 22, including a double-acting cylinder 23, a reciprocable piston 24 and piston rod 25, is mounted in an upright position on a platform 26 spaced above the deck of the hull 11. The piston rod 25 which extends through the upper end of the double-acting cylinder 23 supports a transverse cylindrical bearing 28 through which is freely journaled the pulley shaft 29 supporting pulleys or sheaves 30 and 31. Thus, the pulleys 30 and 31 are not only journaled to freely rotate within the bearing 28, but are also adapted to reciprocate longitudinally of the ram 22 with the piston rod 25.

Another pulley or sheave 32 is journaled to freely rotate on the starboard side of the platform 26, and a similar pulley 33 is journaled to freely rotate on the port side of platform 26. The pulleys 32 and 33 are adapted to rotate in parallel planes, but in planes perpendicular to the planes of rotation of the pulleys 30 and 31.

A cable 35 is fixed to one end of collar 36 fixedly secured around the port spud 20. The cable 35 is then threaded over the upper sheave 16 thence downwardly around the port sheave 33, then upwardly around the stern piston sheave 31, then downwardly around and under the starboard sheave 32, then upwardly and over the bow piston sheave 30. The opposite end of the cable 35 is then stationarily fixed about a pin 37 secured to the platform 26.

With this cable and sheave arrangement connecting the spud 20 to the ram 22, it will readily be seen that when the ram 22 is actuated to thrust the piston 24 upward, the spud 20 will also be elevated, and when the piston 24- is lowered, the spud 20 will also be lowered. Because of this particular arrangement of the pulleys 30, 31, 32 and 33, and the cable 35, the vertical travel of the spud 20 will be approximately four times the axial movement of the piston rod 25, and in the same direction.

The fluid control system for the hydraulic ram 22 is best disclosed in FIGS. 4 and 5. The fluid pressure, or hydraulic supply circuit 49 includes in series, fluid reservoir 41, pump 42 and a control or reversing valve 43. The control valve 43 communicates with the bottom of the cylinder 23 below the piston 24 through the lower circuit or conduit 45. The other side of control valve 43 communicates with the upper end of cylinder 23 on the opposite side of piston 24 through the upper circuit or conduit 46.

Control valve 43 may be a conventional spool valve, such as spool valve Model TBO7, disclosed in Catalog B012, 1960, of the Commercial Shearing and Stamping Company. Control valve 43 has three operative positions identified in FIGS. 4 and 5 by the letters U for the up position, Which is the operative position for raising the spud 20; N for the neutral position, when the movement of the spud 20 is stopped; and D for the down position, which is the operative position for lowering the spud 20. When the control valve 43 is in the neutral position (N), fluid under pressure is merely circulated through the valve 43, reservoir 41 and pump 42 in the supply circuit 40, and no fluid enters the circuits 45 or 46, so that the ram 22 is not actuated and the spud 20 is not moved. When the handle, not shown, on control valve 43 is moved to the up position (U), fluid under pressure is supplied from the supply circuit 40 through the valve 43 and lower circuit 45 into the bottom of cylinder 23 to thrust the piston 24 and piston rod 25 upward, thus raising the spud 20. The hydraulic fluid in advance or on the upper side of the piston 24 is discharged from the upper end of the cylinder 23 through the upper circuit 46, which functions as the return line to valve 43 and thence into the return side 40' of the supply circuit 40 and into the reservoir 41, illustrated by the direction of the arrows in FIG. 4.

When the handle is moved to D on control valve 43, as illustrated in FIG. 5, fluid under pressure from the supply circuit 40 passes through the control valve 43 and into the upper circuit 46 to enter the upper end of the cylinder 23 and force the piston 24 downward to lower the spud 20. The hydraulic fluid in advance of or below the piston 24 is then discharged from the cylinder 23 through the lower circuit 45, which now functions as the return line to the valve 43, and is then discharged into the return side 40 of the supply circuit and back to the reservoir 41.

The parts thus far described are conventional in the art of dredging, and the invention constitutes improvements of this system for rapid dumping or unloading of the hydraulic fluids in advance of the piston 23, when it is descending to lower the spud 20 more rapidly.

In order to accomplish this rapid unloading, a branch circuit 50 is connected at one end to the lower circuit 45 proximate to the ram 22, and at the other end to the inlet of a dump or unloading valve 51, such as the Vickers Hydro-cushion type pressure control unloading valve, type 4, some of the details of which are illustrated in FIG. 6. The discharge outlet of the valve 51 is connected to the discharge conduit or line 52, Which is connected to the reservoir 41. A small pilot conduit 55 connects the pressure responsive pilot opening in the valve 51 with the upper circuit 46, proximate to the ram 22, as illustrated in FIGS. 3, 4 and 5.

A variable check valve 57, including a ball valve 58 and an adjustable stop 59, is located in the circuit 46 between the pilot line 55 and the upper end of the cylinder 23. By noting the position of the ball valve 58 it will be observed that in -FIG. 4, as long as the circuit 46 acts as the return line from the cylinder 23, the flow through the check valve 57 will be unobstructed and the normal operating pressure will be maintained throughout the circuit 46. On the other hand, when the flow in circuit 46 is reversed, as disclosed in FIG. 5, the ball valve 58 will be forced against the stop 59 and will obstruct the flow of fluid through the check valve 57 to the extent of the adjustment of the stop 59, and will build up a corresponding amount of pressure on the side of the check valve 57 communicating with the pilot line 55. As long as there is normal operating pressure in the line 46, as is illustrated in FIG. 4, no fluid will be discharged or bled from the circuit 45 because the discharge port in the unloading valve 51 will be closed, as illustrated in dashed lines in FIG. 6.

If desired, as disclosed in FIGS. 4-6, the optional inlet of valve 51 may be connected to a second branch line 62 communicating with a second port in the bottom of the cylinder 23 below the piston 24. Thus,,wheu the hydraulic system is disopsed in the spud lifting position, fluid will flow through the circuit 45 into the bow port of the bottom portion of cylinder 23 and also into the stern port of the cylinder 23 through circuit 50, valve 51 and circuit 62.

However, when the flow in circuit 46 is reversed as disclosed in FIG. 5 and the additional predetermined pressure is developed in the pilot line 55, the unloading valve 51 will be actuated to the solid line position'of FIG. 6 to bleed fluid from the bottom part of cylinder 23 through the line 45 and branch line 50 to valve 51,

and from the opposite side of the cylinder 23 through I the line 62 to the valve 51. With the unloading valve 51 open, the fluid is forced through the discharge line 52 into the reservoir 41, because of the weight of the spud being transmitted through the cable 35 to the piston sheaves 30 and 31 and piston 24. Of course, some fluid will continue to flow through the circuit 45 to the control valve 43 to further relieve the cylinder 23. These additional outlets, the shorter circuit provided for the fluid from the cylinder 23 to the reservoir 41, and also larger diameter conduits 50, 62 and 52 than conduit 45, greatly increase the speed of discharge. of hydraulic fluid from the cylinder 23 to decrease the resistance to the piston 24 and permit the spud 20 to fall more rapidly, so that the spud may penetrate the,

bottom of the pond or stream with greater force, and therefore establish a more secure anchorage and pivot point. Although some degree of vacuum will be created in circuit 46 and the upper portion of cylinder 23 be-- tween the check valve 57 and piston 24, such vacuum.

has not been found to create a material drag on the piston 24.

A modification of the invention is discolsed by the phantom discharge circuit 65 in FIG. 5, which may be connected directly to the discharge line 52 or the outlet of the unloading valve 51 at one end, to carry the discharged fluid to an optional stern port in the upper end of the cylinder 23 in order to short-circuit the fluid from the bottom of the cylinder 23 into the upper portion of the cylinder ,23. The circuit 65 may also be used in addition to the discharge circuit 52 in order to further increase the speed of exhausting cylinder 23. Fluid from the unloading valve 51 would then be discharged both through the discharge line 52 into the reservoir 41 and also through the return line 65 to the upper portion of the cylinder 23. The discharge line 65 not only assists in eliminating more rapidly the fluid beneath the piston 24, but also introduces this same fluid into the top of the cylinder to eliminate any possible vacuum on the top of the piston 24, and thus serves a double function in driving the piston 24 downwardly. If desired, the check valve 66 may be incorporated in circuit 65 to prevent circuit 65 from functioning as a return line for the discharge from cylinder 23 on the upstroke of piston 24.

In this invention, the reservoir 41 in the supply circuit 40 is located in the after part of dredge within the deck housing 12, as illustrated in FIG. 1, proximate to the ram 22, while the control valve 43 is located in the console in the pilot house or operators compartment in the forward portion of the dredge. The circuits 50 and 52 provide a considerably shorter route for the return of fluid from the bottom end of the cylinder 23 to the supply circuit 40 then the conventional route through the circuit 45 to the valve 43.

It will thus be observed that an improved hydraulic system has been developed for more rapidly actuating the ram, by providing not only additional outlets but a shorter circuit and a completely automatic means for actuating the circuits in order to quickly dump or unload the fluid from the bottom of the cylinder 23, causing a more rapid descent of the spud and a superior anchorage for the dredge 10.

It will, of course, be understood that a system identical to the devices and circuits disclosed in the drawings will be applied to the hydraulic ram for controlling the starboard, spud, not shown, and an additional control valve would be installed in the same supply circuit 40 to function in the same manner as the control valve 43.

It will be apparent to those skilled in the art that various changes may be made in the invention, without departing from the spirit and scope thereof, and therefore the invention is not limited by that which is shown in the drawings and described in the specification, but only as inidcated in the appended claims.

What is claimed is:

1. A device for controlling a spud comprising:

(a) a spud,

(b) means supporting said spud for substantially vertical reciprocable movement,

(0) a ram including a cylinder having one end and an opposite end and a piston adapted to be reciprocated in said cylinder by fluid pressure between said ends,

(d) means connecting said ram to said spud so that movement of said piston toward said one end will raise said spud, and movement of said piston toward said opposite end will lower said spud,

(e) a control valve,

(f) means supplying fluid under pressure to said control valve,

(g) a first fluid circuit communicating said control valve with said opposite end,

(h) a second fluid circuit communicating said control valve with said one end,

(i) means for actuating said control valve to selectively communicate said fluid supply means with said first circuit or said second circuit, the unsupplied circuit functioning as a return line from said cylinder,

(j) a branch circuit connected to said first circuit,

(k) an unloading valve in said branch circuit, and

(1) means responsive to pressure above a predetermined value in said second circuit for actuating said unloading valve to open said branch circuit, in order to rapidly lower said spud.

2. The invention according to claim 1 in which said means for actuating and unloading valve comprises a fluid pilot line which connects said unloading valve with said second circuit.

3. The invention according to claim 2 further comprising a restricting valve in said second circuit between said pilot line and said one end to increase the pressure of said fluid supplied to said second circuit from said control valve above said predetermined value.

4. The invention according to claim 3 in which said restricting valve comprises a variable check valve permitting free flow in said second circuit when functioning as a return line, and permitting limited flow of fluid in said second circuit toward said one end.

5. The invention according to claim 1 in which said branch circuit bypasses said control valve and connects said first circuit directly with said fluid supply means in order to rapidly discharge fluid from said first circuit through said branch line to said fluid supply means when said unloading valve is open.

References Cited UNITED STATES PATENTS 549,658 11/1895 Pless 37-73 2,267,284 12/1941 Livers 91-451 X 3,005,273 10/1961 Milne 3773 X 3,049,101 8/1962 Ruhl 9l-420 3,050,880 8/1962 Cushing 3773 ABRAHAM G. STONE, Primary Examiner. R. L. HOLLISTER, Assistant Examiner.

Claims (1)

1. A DEVICE FOR CONTROLLING A SPUD COMPRISING: (A) A SPUD, (B) MEANS SUPPORTING SAID SPUD FOR SUBSTANTIALLY VERTICAL RECIPROCABLE MOVEMENT, (C) A RAM INCLUDING A CYLINDER HAVING ONE END AND AND OPPOSITE END AND A PISTON ADAPTED TO BE RECIPROCATED IN SAID CYLINDER BY FLUID PRESSURE BETWEEN SAID ENDS, (D) MEANS CONNECTING SAID RAM TO SAID SPUD SO THAT MOVEMENT OF SAID PISTON TOWARD SAID ONE END WILL RAISE SAID SPUD, AND MOVEMENT OF SAID PISTON TOWARD SAID OPPOSITE END WILL LOWER SAID SPUD, (E) A CONTROL VALVE, (F) MEANS SUPPLYING FLUID UNDER PRESSURE TO SAID CONTROL VALVE, (G) A FIRST FLUID, CIRCUIT COMMUNICATING SAID CONTROL VALVE WITH SAID OPPOSITE END, (H) A SECOND FLUID CIRCUIT COMMUNICATING SAID CONTROL VALVE WITH SAID ONE END,

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