US3100625A - Extensible mast derrick - Google Patents

Description

Aug. '13, 1963 c. F. BACK EXTENSIBLE MAST DERRICK Filed April 28, 1961 INVENTOR. CflEL F 5146K HIS ATTORNEYS JIG. 2

Unite States 3', 1 Patented Aug. 13, 1963 This invention relates to a hoist device and more particularly to a hydraulically controlled device for lifting loads from below the surface of the earth; however, this invention is not necessarily so limited.

In the construction of apparatus for pumping water from subterranean wells, it has become conventional prac tice to employ pumps which are either submerged in or supported just above the subterranean well. In such cases, repairs of the pumping apparatus is complicated by the need to lift the pump to the surface of the earth so as to make the pump accessible for repair.

Ordinarily, when the well is initially constructed, the well drilling apparatus is provided with attachments which can be used to lower the pumping apparatus into the well and, if necessary, to raise the pumping apparatus out of the well. However, the well drilling equipment is both massive and expensive and, once a well is completed, it is no longer economically feasible to return the equipment to the well for making incidental repairs to the pumping apparatus. There is a clear need for inexpensive hoist devices which can be easily transported to the site of a Well for making incidental repairs.

An object of the present invention is to provide a light weight hoist device of a type readily transported on light trucks.

Another object of the present invention is to provide an improved hoist device utilizing a telescopic mast and including means for extending the mast, said means having a double function in that it also provides the source of power for operating the hoist.

Another object of the present invention is to provide a hoist device including a telescopic mast and new and improved braces for supporting the mast in an upright position.

Still another object of the present invention is to provide a hoist device having a telescopic mast and hydraulically actuated means for elevating the mast to an upright position.

Still another object of the present invention is to provide a hoist device including a telescopic mast and duofunctional hydraulic actuator means capable of extending the mast and also capable of powering the hoist mechanism.

Still a further object of the present invention is to provide a new and improved tackle mechanism effective to convert a linearly directed force to a rotational torque, said tackle mechanism including torsion means effective to maintain the cable of the tackle mechanism taut at all times.

Other objects and advantages reside in the construction of parts, the combination thereof, the method of manufacture and the mode of operation, as will become more apparent from the following description.

In the drawings:

FIGURE 1 is a side elevational view illustrating the hoist mechanism of the present invention mounted on a truck.

FIGURE 2 is a greatly enlarged fragmentary side elevation view illustrating two positions of the hoist mechanism.

FIGURE 3 is a fragmentary plan view taken in the direction of the arrows 3--3 in FIGURE 2.

FIGURE 4 is an enlarged fragmentary perspective view illustrating block and tackle apparatus employed in the present invention.

FIGURE 5 is an enlarged fragmentary section view taken along the line 5-5 of FIGURE 2.

Referring to the drawings in greater detail, FIGURE 1 illustrates the hoist apparatus of the present invention mounted upon the bed of a truck 10. The supporting frame for the hoist apparatus comprises a pair of spaced upright posts 12 and 14' joined by transverse beam 16 best illustrated in FIGURE 2. Struts 18 and 20 support the posts 12 and 14 in a substantially vertical position.

The support members 12, 14, 16, 18 and 20, which are visibly in the drawings, form only one side of the supporting structure for the mast. The opposite side of the supporting structure substantially duplicates the side which is visible and is spaced behind the visible side from the direction viewed in FIGURES 1 and 2. The two sides of the supporting structure are connected in spaced relation by crossed bars not visible in the drawings to form a rigid framework.

Pivotally mounted adjacent the upright posts 12 between the two sides of the supporting framework is an elongate tubular mast 22 which telescopically receives an extension 24. A hydraulic actuator 26 fixedly attached to the lower portion of the mast 22 actuates a piston 28 for moving the extension 24. Secured to the outer end of the piston 28 is a pulley block 30 adapted to engage an actuator rod 32 which is fixedly attached to a bracket 34 mounted on the upper end of the extension 24. Through operation of the actuator 26, which is bi-directional, the extension 24 may be raised or lowered so as to increase or decrease the effective length of the mast.

The mast 22 is adapted to be pivoted from the upright position shown in solid line detail in FIGURES 1 and 2 to a horizontal position shown in phantom detail in FIG- URE 2 by means of a second hydraulic actuator 36. The lower end of this actuator is secured pivotally be tween the transverse support beams 16 while the piston 38, driven by the actuator, is attached pivotally at 44 to a flange 42 secured to the mast 22.

Braces are provided for supporting the mast in an upright position. The brace structure comprises an elongate brace 46 pivotally secured to the extension 24 and a telescopic brace 48 pivotally connected between the lower end of the brace 46 and the supporting framework between the posts 14. As clearly shown in FIGURES 1 and 2, the two braces 35 and 48 cooperate to support the mast, when upright, in a position slightly deviated from the vertical such that the mast has a tendency to fall away from the truck. This places the braces 46 and 48 in tension. In order to avoid a dead center position as would occur if the braces were aligned in a straight line, a pivot arm 62 holds the pivotal connection between the braces 46 and 48 in spaced relation to the mast 22. This keeps the braces 46 and 48 slightly cocked.

It is evident from inspection of FIGURES 1 and 2 that lowering of the extension 24 into the mast 22 can be accomplished only if one of the braces 46 or 48 can be shortened. For this reason, the brace 48 is constructed in two sections 50 and 52 which may telescope one into the other. As can be observed in FIGURE 3, the section 50 comprises two parallel bars 50a and 50b and the section 52 comprises two parallel bars 52:: and 52b. The bars of section 52 are joined at one end by a clev-is and at the other end by a transverse plate 56. The clevis 60 forms the pivotal connection between the uprights 14 of the supporting frame and the telescopic brace. The plate 56 is provided with apertures which slidably receive the parallel bars 50a and 50b of the section 50. These parallel bars are joined by a plate 54- which is also apertured to slidably receive the parallel bars 52a and 52b of the section 5-2. Through this construction, the section 52 is free to slide telescopically into the section 50. A cross piece 58 mounted fixedly between the bars 52a and 52b limits the maximum extension of the telescopic brace 48, the location of the cross piece 58 determining the deviation of the mast 22 irom the vertical.

As illustrated in FIGURE 3, the brace 46 is constructed from parallel bar elements 4 6a and 46b pivotal- 1y joined to the bars 50a and 50b of the telescopic brace 48. Similarly, the pivot arm 62 is also constructed fnom parallel bar elements 62a and 62b pivotally connected to the bars 50a and 50b of the telescopic brace.

With this brace construction, it is evident that movement of the mast extension 24 into the mast 22 causes the telescopic brace 48 to reduce in size as the brace 46 moves downwardly to a position parallel with the mast 22, the pivot arm 62 pivoting downwardly. In such position, the braces do not interfere with pivotal movement of the mast 22 to the horizontal position illustrated in FIG- URE 2.

In the present invention, the actuator 26, which supplies power to position the mast extension 2 4, is also used to supply power for hoisting loads. In order to free the actuator 26 for performing this function, a latch 66 is pivotally mounted on the upper portion of themast 22 by means of a suitable bracket 68. This latch 66 is permitted to project inwardly of the mast 22 through an aperture'70 formed in the wall of this mast. An elongate rod 72 hangs downwardly from the latch 66 and the weight of this rod functions to bias the latch into the aperture 70. Thus, when the extension 24 is elevated by the actuator 26 to such a position that the lower end of the extension passes above the latch 66, the latch pivots to the interior of the mast 22. Upon subsequent retraction of the actuator 26, the latch 66 engages and supports the lower end of the extension 24 as the pulley block 30 moves out of contact with the actuator rod 32. To assist in this function, the latch is provided with an inclined surface 74 which moves to a substantially horizontal position as the latch pivots downwardly under the weight of the extension 24.

The rod 72 which hangs from the latch 66 extends downwardly to a convenient height where the operator of the hoist mechanism may grasp this rod. When it is desired to lower the extension 24, the actuator 26 is raised sufiioiently to contact the actuator rod 32 and lift the extension off the latch 66; then, by raising the rod 72, the operator may hold the latch upwardly to permit the extension to pass freely into the mast 22 as the actuator 26 is retracted. FIGURE 2 illustrates a hook 76 which may be used to hold the rod 72 loosely adjacent the mast 22. In order to equip the actuator 26 for hoisting a load, the pulley block 30 at the upper end of the piston 23 supports two pulleys 80 and 82. Another pulley 84 is mounted at the base of the mast 22 with a bracket 86-. Journalled for rotation between the two sides of the supporting frame is a drum 88 which supplies a cable 90. Also, journalled between the sides of the supporting frame is a pulley 92. The cable 90 passes from the drum 88 under the pulley 92 over the pulley 82 in the block 30, then downwardly underthe pulley 84, then upwardly over the pulley 80 in the block 30, and then downwardly to a fixed point of attachment 94 which is located at any convenient point on the supporting frame. With this arrangement, four lengths of the cable 90 lead to the pulley block 30. Accordingly, for each foot of upward movement of the pulley block 30, four feet of cable are withdrawn from the 88. w

r In order to permit downward movement of the pulley block 30 without unraveling the cable 90, means are provided for tensioning the cable 90 at all times. This means includes a drum 100' fixedly attached in concentric relation to the drum 8 8, the drum 100- being considerably smaller in diameter than the drum 88. The drum 100 supplies the cable 102 which is attached to a second drum 104. The drum 104 is mounted fixedly on a shaft 106 which is supported for rotation adjacent the strut 18 by journals 108 and 110. Encircling the shaft 106 between these journals is a coil spring 1112. One end of this spring, the right end as viewed in FIGURE 2, is fixedly secured to the journal .110. The other end of this spring is fixedly secured to the shaft 106. With this construction, rotation of the drum 88 to supply cable 90 causes cable 102 to be drawn onto the drum 100 and thereby generates a torsional restoring force in the spring 112. This torsional restoring force maintains cable 90 taut at all times.

Since the drum 100 is considerably smaller than the drum 88, the length of cable 102 required to maintain the restoring torque is only a fraction of the length of the cable 90 associated with the block and tackle mechanism driven by the actuator 26.

From the foregoing description, it will be apparent that upward and downward movement of the piston 28 controlled by the actuator 26 results in clockwise and counterclockwise rotation of the drum 88. This rotational movement of the drum 68 is utilized for hoisting loads by pro- 1 viding a third drum 120' adjacent the drum 88 as shown in FIGURE 4. The drum is mounted for rotation about the same axis as the drum 88 but is free to rotate independently of the drum 88. Thus, when the actuator 26 is employed to raise and lower the mast extension 24, as described previously, the rotational movement of the drum 88 is not necessarily transferred to the drum 120. To transfer rotary movement from the drum 88 to the drum 120, a key 122 is passed through a suitable aperture in the drum 88 and into a suitably located aperture in the drum 120. With the key in place the drums 88 and 120 are caused to rotate in unison.

The drum 120 supplies a hoisting cable 124 which moves upwardly to the top of the mast extension 24 where it passes over a pulley 126 supported in the bracket 34. From the pulley 126, the cable 124 passes downwardly for connection to a load 114. With the block and tackle arrangement illustrated in the drawings, upper movement of the piston 28 causes the drum 120 to wind in the cable 124 thus hoisting the load. With downward movement of the piston 28, any load on the cable 124 cooperates with the spring 112 to maintain tension in the cable 90.

For operation of the actuators 26 and 36, an oil reservoir 132 is provided on the bed of the truck 10 and a pump mechanism is mounted under the bed, this pump mechanism being operated from a power takeoff in the transmission for the truck. FIGURE Z schematically illustartes two operating levers 134 and 136 which regulate suitable reversing valves, not shown, one for each of the actuators 26 and 36.

The hoistingapparatus is ordinarily transported on the truck ldwhen the mast 22 is in the horizontal position illustrated in FIGURE 2. When the hoist apparatus is to be placed into operation, the transmission for the truck is shifted to operate the pump 130*. The lever 134 is then actuated to cause the actuator 36 to pivot the mast to its upright position. Thereafter lever 136 is actuated to cause the actuator 26 to move the extension 24 upwardly above the latch 66. Thereafter the lever 136 is pivoted oppositely to retract the actuator 26 permitting the latch 66 to engage and support the extension 24. Throughout the proceeding operations, the key 122 is removed so that rotaton of the drum 8% is not transferred to the drum 120. After the actuator 26 has been lowered, the key 122 is inserted to lock the drum 120to the drum 38. For easy insertion of the key 122, a number of spaced key engaging apertures may be provided in the drum 120.

After the key '122 has been inserted into place, the actuator 26 may be used as required for hoisting operations.

When the work to done is completed, the key 122 is removed to disengage the drum 120 and the actuator 26 is elevated to raise the extension 24 off the latch 66. Then the rod 72 is pushed upwardly manually to permit free movement of the extension 24 into the mast 22 and the actuator 2.6 is lowered. Finally, the lever 13 i is moved to lower the mast 2 2 to its horizontal position.

From the foregoing, it is apparent that the entire operation of the present hoist mechanism is automatic with the exception of manual manipulation of the key 122 and manual manipulation of the rod 72.

While the present hoist mechanism has been illustrated and described as mounted on a truck for mobility, it is to be understood that the apparatus is fully applicable to stationary mountings. Further, it is to be understood that the hoisting apparatus may be mounted on other types of vehicles.

While the apparatus of the present invention has been described as utilizing hydraulic actuator devices, it is deemed within the purview of the present invention to utilize other types of linear actuator devices. It is also eerned within the purview of the present invention to utilize other types of tension devices for maintaining tenison in the block and tackle mechanism.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

1. A hoist apparatus comprising a telescopic mast having an upper and a lower section, means to support said mast in an upright position, a linear actuator device mounted on said lower section and engageable with said upper section to elevate said upper section, means to latch said upper section in an elevated position, said actuator device being thereby free to operate independently, a pulley supported on said upper section, a cable drum fixedly attached with respect to said support means, cable means Wrapped on said drum and passing over said pulley for engaging a load, and means responsive to said actuator device to rotate said drum.

2. A hoist apparatus comprising, in combination, a cable drum, a pulley, mast means supporting said cable drum and pulley in spaced relation, said drum supplying a cable which passes over said pulley to engage a load, and means to rotate said cable drum to hoist the load, said means comprising a reciprocally operable linear actuator device supported by said :mast means, a second drum secured to said cable drum for unitary movement therewith, block and tackle means responsive to linear movement of said actuator device and including a cable for rotating said second drum to thereby hoist the load, and tensioning means applying a torque to said second drum opposing rotation thereof when said linear actuator device is driven in one direction, said tensioning device 'holding said second cable means taut during operation of said actuator device in the reverse direction.

3. A hoist apparatus comprising a telescopic mast having an upper and a lower section, means to support said mast in an upright position, a linear actuator device mounted on said lower section and engageable with said upper section to elevate said upper section, means to latch said upper section in an elevated position, said actuator device being thereby free to operate independently, a pulley supported on said upper section, a cable drum fixedly mounted with respect to said support means, cable means wrapped on said drum and passing over said pulley for engaging the load, and means responsive to said actuator device to rotate said drum, said last named means including a second drum secured to said cable drum 'for unitary rotation therewith, block and tackle means responsive to upward movement of said linear actuator device for rotating said second drum and thereby rotating said cable drum, and tensioning means supplying a torque to said second drum to maintain said block and tackle means taut.

4. The hoist apparatus according to claim 3 including means to detach said cable drum from said second drum so as to enable operation of said linear actuator device independently of said cable drum.

References Qited in the file of this patent UNITED STATES PATENTS 963,237 Milton July 5, 1910 1,632,935 Turner et a1 June 21, 1927 1,793,381 Vanatta et a1 Feb. 17, 1931 1,975,555 Presley Oct. 2, 1934 2,495,392 Smith Jan. 24, 1950 2,588,037 Orton Mar. 4, 1952 2,670,177 Pearson Feb. 23, 1954 2,706,022 Brown Apr. 12, 1955 2,848,977 Prestrud et al Aug. 26, 1958

Claims (1)

1. A HOIST APPARATUS COMPRISING A TELESCOPIC MAST HAVING AN UPPER AND A LOWER SECTION, MEANS TO SUPPORT SAID MAST IN AN UPRIGHT POSITION, A LINEAR ACTUATOR DEVICE MOUNTED ON SAID LOWER SECTION AND ENGAGEABLE WITH SAID UPPER SECTION TO ELEVATE SAID UPPER SECTION, MEANS TO LATCH SAID UPPER SECTION IN AN ELEVATED POSITION, SAID ACTUATOR DEVICE BEING THEREBY FREE TO OPERATE INDEPENDENTLY, A PULLEY SUPPORTED ON SAID UPPER SECTION, A CABLE DRUM FIXEDLY ATTACHED WITH RESPECT TO SAID SUPPORT MEANS, CABLE MEANS WRAPPED ON SAID DRUM AND PASSING OVER SAID PULLEY FOR ENGAGING A LOAD, AND MEANS RESPONSIVE TO SAID ACTUATOR DEVICE TO ROTATE SAID DRUM.

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