US3273721A

US3273721A - Hydraulically powered portable lifting apparatus

Info

Publication number: US3273721A
Authority: US
Publication date: 1966-09-20
Anticipated expiration: 1983-09-20

Description

p 20, 1966 J. L. BRUNTON 3,273,721

HYDRAULIGALLY POWERED PORTABLE LIFTING APPARATUS Filed Jan. 15, 1965 ITTR/VE/if United States Patent Ofiice 3,273,721 Patented Sept. 20, 1966 3,273,721 HYDRAULICALLY POWERED PORTABLE LlFTlNG AP?ARATUS James L. Brunton, 20924 Avis Ave, Torrance, Calif. Filed Jan. 15, 1965, Ser. No. 425,816

1 Claim. (Cl. 212-35) This invention relates generally to lifting apparatus and more particularly to such apparatus which is portable and which is powered by fluid under pressure.

In the prior art, portable lifting apparatus such as portable cranes, have been designed and are used in many different applications. However, such prior art portable cranes have for the most part included a static or dead line and have accomplished manipulation of the load through moving the boom of the cane. In some instances, however, where a live line, that is, where the line moves with respect to the boom, has been required, a manually operated boat type winch has been used both for the storage of cable and at the same time for the power to move the line. In each instance the portable crane has been exeessively heavy and the load which can be lifted by the portable crane is extremely limited, and thus the utility of the crane is restricted.

Accordingly, it is an object of the present invention to pnovide a portable lifting apparatus such as a hydraulically powered portable crane which utilizes a live line, which is relatively light in weight, and which has a substantially greater lifting capacity than presently known prior art portable cranes.

It is another object of the present invention to provide a portable lifting apparatus which is substantially selfcontained, is rugged, exceedingly compact, and relatively inexpensive as compared to prior art portable cranes.

Other and more specific objects and advantages of the present invention both as to its construction and method of operation, will become apparent from a consideration of the following description taken in conjunction with the accompanying drawing which is presented by way of example only, and is not intended as a limitation upon the scope of the invention as defined in the appended claims, and in which:

FIG. 1 is a side elevational view of a portable lifting apparatus in accordance with the present invention;

FIG. 2 is a partial view of the boom of a portable lifting apparatus in accordance with the present invention, having one side thereof removed;

FIG. 3 is a top elevati-onal view taken along the lines 3-3 of FIG. 1; and

FIG. 4 is a partial end view of the apparatus illustrated in FIG. 1 taken along the lines 44 thereof.

A portable lifting apparatus in accordance with the present invention includes a boom carrying a cable and having a fluid pressure actuator aflixed thereto. First pulley means is secured to the boom and second pulley means is secured to the fluid pressure actuator, and is movable with respect to the first pulley means. The cable engages the pulley means and has one free end which can be used to engage loads and which moves as the actuator moves when fluid under pressure is applied thereto.

In accordance with a more specific aspect of the present invention, the hydraulically powered portable lifting apparatus in accordance with the present invention, has a boom carrying a cable and includes a hydraulic actuator which is aflixed to the boom. The hydraulic actuator in turn includes a cylinder and a movable piston which has a shaft secured thereto and extending through one end of the cylinder. A pair of pulleys is afiixed at one end of the boom, and another pair of pulleys is affixed at the terminal end of the shaft and is movable therewith. The cable engages the pulleys and has one end fixed and the other end free and extending from the boom for engaging loads. Means is pnovided for maintaining the pairs of pulleys is a predetermined aligned relationship with the boom. Upon application of fluid under pressure to the actuator, the pulleys aflixed to the shaft move, thus causing the free end of the cable to move permitting lifting or other manipulation of the load.

Referring now to the drawing and more particularly to FIGS. 1 through 4 thereof, the portable lifting appara tus or crane is illustrated generally at 10, and includes a post member .11 and a boom member 12. The boom member 12 is pivotally secured to the post 11 as by means of a pivot pin '13. A boom lift hydraulic actuator 14 includes a cylinder 15, and a movable shaft or ram 16, operatively associated with the cylinder 15. The cylinder 15 is pivotally aflixed as by the pin 17 at one end thereof, to a collar 18 rigidly attached to the post 11. The ram 16 is pivotally aflixed as by pin 19, to a plate 21 having a lug 22 extending outwardly therefrom. The plate 21 is permanently afiixed to the boom 12.

As hydraulic fluid under pressure is applied to the hydraulic actuator 14, a piston housed internally of the cylinder 15 is moved and the ram '16 aflixed thereto also moves. As a result of the interconnection between the

pivot pins

17 and 19, the boom 12 is caused to pivot about the pin 13 and raise or lower depending upon the manner in which the fluid under pressure is applied to the actuator 14. Such movement is indicated by the dashed line representations of the boom and the arrow 20.

As shown by the base line 9 the post 11 of the portable crane 10 may be anchored in any manner desired. For example, provision may be made on a desired vehicle or in a loading platform for reception of the post .11. Preferably such receiving provisions are designed to permit the post 11 to rotate and thus the boom 12 to swing to the desired position.

The boom -12 in accordance with the presently preferred embodiment of the present invention, is constructed of two

channel members

23 and 24. A boom line hydraulic actuator illustrated generally at 25 includes a cylinder 26 and a ram or shaft 27. The shaft 27 is affixed to a piston 28 which is movably disposed internally of the cylinder 26, and moves in response to pressure under fluid being applied to the hydraulic actuator 25. The cylinder 26 is affixed by way of pin 29 between the

boom channel members

23 and 24. The pin 29 passes through a block 31 which is rigidly secured to the end of the cylinder 26. A conduit 37 is interconnected between the cylinder 26 and a source of fluid under pressure (not shown) which is housed within the post 11.

First pulley means including

pulleys

32 and 33 are pivotally affixed about a common axis, such as the pivot pin 34, at the terminal end of the boom 12. As is shown particularly in FIG. 3, spacers 35 hold the

pulleys

32 and 33 apart, and also hold them spaced from the inner surfaces of the

channel members

23 and 24, so that the

pulleys

32 and 33 are free to rotate without obstruction at all times.

Second pulley means including

pulleys

40 and 41 are pivotally aflixed about a common axis to the terminal end of the shaft 27, as for example, about the pivot 42. Typical shims or spacers 43 are used to space the pulleys from the shaft 27 thus causing them to be freely rotatable.

Guide means such as U shaped

brackets

44 and 45 are carried by the shaft 27 and in the presently preferred embodiment of the present invention, upon the pin 42, which secures the

pulleys

40 and 41 to the shaft 27. The arms of the U shaped

brackets

44 and 45 engage the flanges on the

channel members

23 and 24. By thus cooperatively engaging the channels, the

guide brackets

44 and 45 maintain the two sets of pulleys in a predetermined alignment with respect to the boom 12. A cable engages the o)

pulleys

32, 33, 40 and 41 and is secured at one end 51, preferably to the channel 24 of the boom 12, thus maintaining one end of the cable or line 50 in a fixed relationship with respect to the boom -12. The opposite end 52 of the cable 50 is free to move and for example, has a hook 53 attached thereto, which is particularly adapted for engaging loads.

A remote control switch 61 may be connected by means of line 62 to the apparatus housed within the post 11, which for example, would include a motor, a hydraulic pump, and a reservoir of hydraulic fluid. A pressure gauge 63 may be provided if such is desired, to determine the pressure appearing within the hydraulic system. Appropriate selector valves and bypass valves along with a relief valve would be interconnected with the hydraulic circuit as is well known in the art.

In operation, with no fluid under pressure applied to the system, the selector valve is placed in the desired position, an appropriate bypass valve opened, and pressure then applied to the hook 53 in a downward direction. This pressure on the hook 53 is transmitted through the cable 50 to the shaft 27 causing it to be pushed into the cylinder 26. Such movement of the shaft 27 carries the

pulleys

40 and 41 toward the

pulleys

32 and 33 as the end 52 of the cable 50 is withdrawn from the boom 12. The hook 53 is then engaged with the desired load and after appropriate manipulation of the selector and bypass valves, fluid under pressure is applied to the system by starting the hydraulic pump and motor, and pumping the fluid under pressure through the conduit 37 to the cylinder 26. As the fluid under pressure enters the cylinder 26 the piston 28 and the shaft 27 move away from the

pulleys

32 and 33 and in so doing carry the

pulleys

40 and 41. As this movement is accomplished, the end 52 of the cable 50 along with the hook 53 move in an upward direction as viewed in FIG. 1, and carries the load with it. The height of the end of the boom 12 carrying the

pulleys

32 and 33 is varied as desired by applying fluid under pressure to the cylinder 15, causing the shaft 16 to move in or out as desired to lower or raise the end of the boom as above referred to.

As the

pulleys

40 and 41 move toward or away from the

pulleys

32 and 33, as a result of application of fluid under pressure to the cylinder 26 or the removal thereof as above described, the

guide brackets

44 and 45 engage and slide along the

channel members

23 and 24, thus at all times maintaining the

pulleys

40 and 41 in a fixed relationship laterally with respect to the

channel members

23 and 24, but permit longitudinal movement of the

pulleys

40 and 41 with respect to the

channel members

23 and 24.

It should be noted that the utilization of the

pulleys

32, 33, 40 and 41 do not in any way ofifer a mechanical advantage in lifting any load that may be applied to the hook 53. The purpose of utilizing the pulley means and hydraulic actuator as disclosed is to accomplish the desired result of having a live line or cable that is engageable with loads for the purpose of lifting or otherwise manipulating the same, and at the same time having the capability of storing sufiicient cable within the system to readily enable such lifting and manipulation from a de- 60 sired distance. By utilizing the pulley means as disclosed wherein one of the pulley means is fixed and the other movable with respect thereto, such storage capacity is provided while at the same time permitting the load to be lifted or otherwise manipulated directly with the free end of the live cable housed upon the boom.

There has thus been disclosed a portable lifting apparatus which is rugged, inexpensive, compact and light in weight and which overcomes the prior art disadvantages of portable lifting apparatus.

What is claimed is:

A hydraulically powered portable lifting apparatus comprising:

(a) a rigid post member adapted at one end thereof to be pivotally mounted upon a support means for receiving the same;

(b) a rigid boom member attached at the opposite end of said post and adapted to be moved pivotally about said point of attachment with said post;

(c) boom lift means including a hydraulic actuator having one end thereof pivotally aflixed to said post and the opposite end thereof pivotally affixed to said rigid boom member intermediate the ends thereof,

( 1) said boom means being raised and lowered by actuation of said hydraulic actuator;

(d) a first pair of pulleys pivotally mounted on a common axis adjacent the opposite end of said boom in a fixed relationship with respect to said boom;

(e) a second hydraulic actuator, including a cylinder housing a movable piston having a shaft aflixed thereto and extending through one end of said cylinder;

(f) attaching means securing the other end of said cylinder to said boom;

(g) a second pair of pulleys pivotally mounted on a common axis and secured to the terminal end of said shaft and being movable with respect to said boom as said shaft moves upon application of fluid under pressure thereto;

(h) said cable being passed over said pulleys and having one end fixed with respect to said boom and the other end free and extending from said first pair of pulleys for lifting loads;

(i) means for applying fluid under pressure to said hydraulic actuator thereby to cause said second pair of pulleys to move away from said first pair of pulleys and said cable to move in a lifting direction in response to application of fluid under pressure to said actuator; and

(j) a pair of U shaped guide brackets atfixed to said terminal end of said shaft and movable therewith,

( l) the arms of said brackets engaging said boom to retain said pairs of pulleys in aligned relationship with said boom.

References Cited by the Examiner UNITED STATES PATENTS 3,082,889 3/1963 Bopp 212 X 3,129,821 4/1964 Graham et a1. 212- FOREIGN PATENTS 1,014,666 6/1952 France.

149,326 12/ 1952 Sweden.

EVON C. BLUNK, Primary Examiner.

SAMUEL F. COLEMAN, Examiner.

A. L. LEVINE, Assistant Examiner.