US3794369A

US3794369A - Lifting tool

Info

Publication number: US3794369A
Application number: US00294492A
Authority: US
Inventors: K Hnatko
Original assignee: TACONITE ENG AND Mfg CO
Current assignee: TACONITE ENG AND Mfg CO
Priority date: 1972-10-02
Filing date: 1972-10-02
Publication date: 1974-02-26
Anticipated expiration: 1991-02-26

Abstract

A tool for lifting objects having an opening into which the tool may be inserted and its jaws expanded to grip the article. Although especially adapted to facilitate moving liner segments of rod and ball mills, the tool is adapted to lifting other articles having holes or other openings into which the tool may be inserted, such as pipe, drill rod, etc. The tool is characterized by an easily insertable tip associated with manual squeeze operated positive jaw contraction for ease of insertion in openings, spring assistance to expand the jaws into gripping position and eye means for crank hook-up to permit the load to actuate the jaws for positive gripping as the article is lifted. While the article being lifted is in transit, the lifter operating handle is inoperative and cannot release.

Description

- United States Patent 81 Hnatko LIFTlNG TOOL [75] Inventor: Karl J. Hnatko, Hibbing, Minn.

[73] Assignee: Taconite Engineering &

' Manufacturing Co., Hibbing, Minn.

[22] Filed: Oct. 2, 1972 [21] Appl. No.: 294,492

[56] References Cited UNITED STATES PATENTS 3,124,385 3/1964 Neptune 294/86 R X 3,485,388 12/1969 Bohne 294/96 X 2,642,768 6/1953 Ogburn 294/95 X FOREIGN PATENTS OR APPLICATIONS 40,053 7/1965 Germany 294/95 Feb. 26, 1974 Primary ExaminerRichard E Aegerter Assistant ExaminerJames l... Rowland [57] ABSTRACT A tool for lifting objects having an opening into which the tool may be inserted and its jaws expanded to grip the article. Although especially adapted to facilitate moving liner segments of rod and ball mills, the tool is adapted to lifting other articles having holes or other openings into which the tool may be inserted, such as pipe, drill rod, etc. The tool is characterized by an easily insertable tip associated with manual squeeze operated positive jaw contraction for ease of insertion in openings, spring assistance to expand the jaws into gripping position and eye means for crank hook-up to permit the load to actuate the jaws for positive gripping as the article is lifted. While the article being lifted is in transit, the lifter operating handle is inoperative and cannot release.

12 Claims, 7 Drawing Figures lar hoisting means, the weight of the load actuates the jaws for positive gripping for safe lifting. Although designed primarily for facilitating moving of replaceable.

liner segments in ball and rod mills, the tool may be used to lift other articles having openings into which the tool may be inserted, such as pipe, etc. The tool is of rugged failsafe lightweight construction. It permits handling of heavy articles with maximum safety easily and quickly by unskilled operators.

The invention is illustrated in the accompanying drawings in which:

FIG. 1 is an elevation showing the tool in at-rest position with the jaws at their maximum expansion;

FIG. 2 is a fragmentary elevation on an enlarged scale, partly broken away and in section, showing details of construction of the tool head;

FIG. 3 is a view similar to FIG. 2 but showing the jaws I contracted for insertion in an opening in the article to be lifted;

FIG. 4 is an end elevation of the tool FIG. 3;

FIG. 5' is a transverse section on the line 5-5 of FIG. 3 and in the direction of thearrows;

head shown in FIG'. 6 is a transverse section on the line 6-6 of FIG. 7

3 and in the direction of the arrows; and

FIG. 7 is anelevation, partly broken away and in section, showing a modified form of lifting tool.

Referring now to the drawings, and particularly to FIGS. l'through 6, the lifting tool according to the present invention comprises generally a hollow tubular body 10 secured to alinear lifting. member, such as a length of flexible steel wire rope or cable 11, which extends through the body and is provided with a generally conical insertion tip or load button 12.at one end and a one-piece eye or. loop functioning as a lift sling 13 at the other end. Body 10 is in the form of a hollow tube enclosing a chamber. 14 open at one end and closed at the opposite end'by means of end wall 15. The body 10 is securedto cable 11 and oriented relative thereto by a plurality of reference. screws 16 set in internally threaded radial holes 17 in thebody end Wall.

A reciprocable jaw carrier sleeve. 18 is positioned in the open end of body 10 for movement within chamber 14 so as to extend partially from the body and be retracted within the body. A pair of opposedshort stub shafts 19 are. positioned extending inwardly from the inside walls of sleeve 18 adjacent to the downstream or tip end. Stub shafts 19 function as pivots for a pair of jaws, each indicated generally at 20.

Each jaw is ofgenerally-semi-circular cross section and includes a shank 21 and an enlarged head 22. The inner channel 23.of.the.jaws isof a radius-such that the two jaws when together encloseand embrace cable 11. Theouter end 24 0f channel 23 flares outwardly to embrace the enlarged load button 12. The opposite side walls of jaws 20 adjacent the upstream end are each provided with a transverse semi-circular notch of diameter corresponding to. the diameter of stub shafts 19 such that the notches embrace the stub shafts to permit the jaws to pivot thereon.

surfaces of jaws 20 adjacent the upstream or sling end are tapered outwardly at 26. A jaw closing sleeve 27 extends around cable 11 within sleeve 18. The downstream end of sleeve 27 is tapered around its outside edge 28 and engages the inner tapered surfaces 26 of jaws 20.

Sleeve 18 is reciprocated within the body 10 as follows: An actuating pin 29 extending radially outwardly from carrier sleeve 18 extends through a longitudinal slot 30 in the wall of body 10 and projects beyond the outer periphery of the body. A handle 31 disposed longitudinally relative tothe body extends from the center of a clevis-like yoke 32 having a pair of legs extending on opposite sides of the outside of body 10. The yoke and handle are pivotally mounted by virtue of a pin 33 extending through the free ends of the arms of the yokeand through a tubular mount 34 welded or otherwise rigidly secured to the outside of the body opposite from slot 30. The free end of actuating pin 29 extends into and is loosely engaged by a hole 35 in the center of yoke 32-at the base of handle 31. A heavy coil actuating spring 36 in chamber'1 4 of body 10 extends around cable 11 bearing against the inside surface of body end wall 15 and against closing sleeve 27.

Contraction of the jaws is initiated by the operator squeezing the handle 31 toward the body 10. This clockwise motion of the handle around pivot pin 33- transmitted through yoke 32 imparts a longitudinal upstream motion to the actuating pin 29 causing the jaw carrier sleeve 18 to be retracted/As sleeve 18 is retracted, force transmitted through stub shafts 19 to jaws 20 causes the jaws to be retracted and contracted. The tool tip or load button -12 and body 10 are in fixed relative positions as determined by reference screws 16. Hence, as the jaw carrier sleeve l8"and jaws 20 retract into the body, the jaws retract from the load button. Using the left hand jaw, as seen in the drawings, as an example, the clockwise torque created by contact with the load button becomes zero as the jaw retracts.

The counter-clockwise torque created by the tapered end 28 of closing sleeve 27 being forced bythe actuating spring 36 against the tapered'ends 26 of the jaws functions as a cam to cause each jaw to rotate counterclockwise around its pivot point on stub shaft 19 and lie parallel to the axis of the cable. Thus retraction is positive and complete.

With the jaws thus retracted, the tool may be inserted into any opening whose dimensions are only slightly greater than the maximum diameter of the head 22- of the jaws. The tool 'is inserted into such an opening and permitted to expand by releasing the squeezing force. The sling is then engaged by a crane or other hoisting means. Again, using the lefthand jaw as an example, expansion is caused by the clockwise torque on the jaw around its pivot point on stub shaft 19. Thistorque is created by the relative motion of the load button 12, as the carrier sleeve and jaws extend from the body, and is greater than the counter-clockwise torque created by the closing sleeve 27 under pressure of actuating spring 36 by virtue of the greater lever arm at the load button end. The rounded butt end edge 38 of load button 12 engaging the inner tapered channel surface 24 functions as a cam to expand the free ends of the jaws. The relative motion between the jaws and the load button creates a wedging action that grips the article to be lifted in proportion to its weight. The handle 31 and actuating pin 29 are purposely designed to be relatively light such that if an attempt is made to actuate handle 31 while 'under load, the handle and pin will deform rather than to release the article being lifted.

Desirably the article to be lifted has an internal shoulsigned without departing from the scope of this invention, depending upon need. For this exemplary use, the tool desirably has an overall length of about 45 inches and can safely handle working loads of 2,500 pounds. The jaws are desirably constructed of heat-treated steel. The load button 12 and ferrule 37 are swaged onto the wire rope.

In FIG. 7 there is shown a slightly modified form of lifting tool according to the present invention. In this form of tool the elongated linear lifting member is a rigid rod 11A. Tip or load button 12 is secured to one end of rod 11A. Desirably the opposite end of rod 11A which extends through the body end wall 15 is threaded. Then a first nut 39 within body 10 may function to fix the relative positions of load button 12 and the body. A second nut 40 then functions to secure a swivel eye or shackle 41 to the end of rod 11A outside of the body for attachment of the tool to a crane hook or similar hoisting means. The modified form of lifting tool is operated in the same manner already described.

It is apparent that many modifications and variations of this invention as hereinbefore set forth may be made without departing from the spirit and scope thereof. The specific embodiments described are given by way of'example only and the invention is limited only by the terms of the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A tool for lifting articles having an opening into which the tool may be inserted and expanded, said tool comprising:

A. an elongated linear lifting member,

B. an insertion tip at one end of said lifting member,

C. hoist engaging means at the opposite end of the lifting member secured directly thereto and fixed longitudinally relative to the lifting member,

D. a tubular body extending around and fixedly secured to said lifting member, the end of the body adjacent the tip end of the lifting member being open,

E. a tubular jaw carrier disposed within the body at the open tip end for reciprocal movement relative thereto,

F. a plurality of longitudinally extending jaws disposed around said lifting member, and pivotal support means connecting one end of each of the jaws in said jaw carrier, and

G. means for reciprocating said jaw carrier relative to said tubular body and said lifting member, whereby when the jaw carrier is retracted within the body the jaws are contracted and when the jaw carrier is partially extended from the body the jaws are expanded.

2. A tool according to claim 1 further characterized in that said lifting member is a wire rope.

3. A tool according to claim 2 further characterized in that said insertion tip is a conical load button swaged to said wire rope.

4. A tool according to claim 2 further characterized in that said hoist engaging means is a closed loop at the end of said wire rope.

5. A tool according to claim 1 further characterized in that said lifting member is a rod.

6. A tool according to claim 5 further characterized in that said hoist engaging means is a swivel eye.

7. A tool according to claim 1 further characterized in that said pivotal support means for the jaws comprises:

A. a plurality of short stub shafts extending radially inwardly from the inner walls of the jaw carrier, and

B. a pair of semi-circular notches adjacent one end of each of the jaws in engagement with a pair of said stub shafts.

8. A tool according to claim 1 further characterized in that: A. said jaws extend between the body and insertion tip,

B. each jaw is of generally semi-circular cross section and includes an elongated shank and an enlarged head, and

C. the inner semi-circular surface of each jaw adjacent said enlarged head is tapered outwardly.

9. A tool for lifting articles having an opening into which the tool may be inserted and expanded, said tool comprising:

A. an elongated linear lifting member,

B. an insertion tip at one end of said lifting member,

C. hoist engaging means at the opposite end of the lifting member, I

D. a tubular body extending around and secured to said lifting member, the end of the body adjacent the tip end of the lifting member being open,

E. a tubular jaw carrier disposed'within the body at the open tip end for reciprocal movement relative thereto,

F. a plurality of longitudinally extending jaws disposed around said liftingmember, and pivotal support means connecting one end of each of the jaws in said jaw carrier, and

G. means for reciprocating said jaw carrier, whereby when the jaw carrier is retracted within the body the jaws are contracted and when the jaw carrier'is partially extended from the body the jaws are expanded, said means including a spring biased jaw closing sleeve disposed around said lifting member within the jaw carrier in engagement with the ends of the jaws.

10. A tool according to claim 9 further characterized in that the outer surface of the end of the jaw closing sleeve engaging the ends of the jaws is tapered inwardly and the inner surfaces of the ends of the jaws are tapered outwardly.

11. A tool for lifting articles having an opening into which the tool may be inserted and expanded, said tool comprising: i

A. an elongated linear lifting member,

B. an insertion tip at one end of said lifting member,

C. hoist engaging means at the opposite end of the lifting member,

E. a tubular jaw carrier dispposed within the body at the open tip end for reciprocal movement relative thereto,

F. a plurality of longitudinally extending jaws disposed around said lifting member, and pivotal support means connecting one end of each of the jaws in said jaw carrier, and I G. means for reciprocating said jaw carrier, whereby when the jaw carrier is retracted within the body the jaws are contracted, said means comprising: 1. a longitudinal slot insaid body adjacent the open end,

2. an actuating pin extending outwardly from the outer surface of the jaw carrier sleeve through said slot, and

3. handle means in engagement with said actuating pin to move the pin longitudinally relative to the body. v

12. A tool according to claim 11 further characterized in that: V

A. said handle is disposed longitudinally relative to the body and extends from the center of a yoke having a pair of legs extending on opposite sides of the outside of the body,

B. said yoke is pivotally mounted on said body on the side opposite from said slot, and

C. one end of the actuating pin is loosely engaged by the yoke at the base of the handle, whereby, when squeezing force is applied to the handleQthe actuating pin and jaw carrier are retracted.

UNITED STATES PATENT OFFICE (5/59) CERTIFICATE OF CORRECTION Patent No. 3,794,369 Dated February 26. 1974 lm lentofls) Kari J. Hnatko It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the abstract line 11, "crank" should be "crane".

Signed and sealed this 9th day of July 1971;

(SEAL) Attest:

McCOY M. GIBSON, JR. Attesting Officer -C. MARSHALL DANN Commissioner of Patents

Claims

1. A tool for lifting articles having an opening into which the tool may be inserted and expanded, said tool comprising: A. an elongated linear lifting member, B. an insertion tip at one end of said lifting member, C. hoist engaging means at the opposite end of the lifting member secured directly thereto and fixed longitudinally relative to the lifting member, D. a tubular body extending around and fixedly secured to said lifting member, the end of the body adjacent the tip end of the lifting member being open, E. a tubular jaw carrier disposed within the body at the open tip end for reciprocal movement relative thereto, F. a plurality of longitudinally extending jaws disposed around said lifting member, and pivotal support means connecting one end of each of the jaws in said jaw carrier, and G. means for reciprocating said jaw carrier relative to said tubular body and said lifting member, whereby when the jaw carrier is retracted within the body the jaws are contracted and when the jaw carrier is partially extended from the body the jaws are expanded.

4. A tool according to claim 2 further characterized in that said hoist eng the handle, the actuating pin and jaw carrier are retracted.