US2608893A - Jaw design and adjusting means for pipe tongs - Google Patents

Description

P 1952 B. CRANNER 2,608,893

JAW DESIGN AND ADJUSTING MEANS FOR PIPE TONCS Filed July 15, 1949 2' smms-smw "1 Patented Sept. 2, 1952 J AW DESIGNAND ADJUSTING MEANS FOR PIPE TONGS Bjarne Cranner, Holen, Ostfoldbahen. Norway Application July 15, 1949, Serial No. 104,983 In Norway June 27,1949? dCIaimsu (01. 81-80) Tube tongs commonly in use are provided witheccentric jaw members, so that when the handles of the tongs are pressed towards each other, the jawsbite into the tube and the grip isincreased when the tongs are turning the tube. Some tube tongs now in use have a hammer-like shape, the jaw opening being orientated substantially at right'angles to the longitudinal direction of the handles. However, tubes to be manipulated are often situated at places where they are not easily accessiblewith tongs of a hammer-shape, -as=forexample on awall, in a-pit'or at the underside ofan automobile.

This drawbackis remedied. by the present invention; the-main feature of which consists in I that the jaw opening isarranged substantially inparallel to the longitudinaldirection of the' handles so that the device has a: more or less In order-that'such a beak-likeshape shall-be provided it is necessary that abeak -like shape.

usualpivot orcenten'about which thejaw-mem her-turns in usual tube tongs, is dispensed with,

andthatthe jaw member turns-about an -imagi-.- nary-center, in'such manner-that it performs" the-iunctionsof an eccentric member in'relation to a tube.- v i Thismay be effected in several differentm'aneners. That arm to which the eccentric member is 'attached,referredto as the superiorarm or alsoltheeccentric member proper, may be pro- Y vided' with a curved surface or with more than one curved surface having a common center, and at the." same time the eccentric or thatarm to which' itis attached may be provided with a similarnumberof. surfaces so situated and formed thatiwhen the curved surfaces slide on each other theieccentric memberwill move correctly.

Instead of 1 curved surfaces there may also beused surfaces of other arcuate form or sloping planes; In the last case the eccentric member actszas a wedge. V

The distancebetween the twojaws may-beadjustedi by. means of an adjustment device, ior

example-a1 rack that cooperates with teeth on thezotherpart, or an adjustment screw, the. ends of.-which are .provided'with opposite threads that are-threaded into the two jawsrespectively; :The

higher thepitch of such-screw, the more rapidly the. adjustmentmay be eifected; The pitchmay even beso high that adjustment may be effected simplyby. pressingthejaws towards each other oripullin'gthem apart without it being necessary toimanipulatethe adjustment screw proper. This maybe. of advantage where tube tongsare use I imaplacewhich isvery: narrow.

If the adjustment screw forms the' onlyjcon i nection between the arms it is-necessarythat the jawsdo not turn in-relation to each other duringadjustment of the jaw distance. To this end one jaw is provided with-a guide-slot'and theoth'er jaw with a corresponding extension:

It may be suitable to give such guide slot amore or less dovetailed shaped-cross section-yand the sliding part ofthe other jawa corresponding section, so that thisguide'connection is-able'to transfer pulls in a direction forwards to thejaws opening as well as pressures in the opposite direc- Hereby the stress upon the adjustment tion. screw during use of the tongs is relieved.-

A furtherfeature of the invention-consists: m that between the jaws there is-provided a tiltablea' regulator, which is swung more or less towards? the ends of thejaws as the jaws are-moved more" or less towards each other and which so acts that any tube that is grippedbetweenthe-jaws will engage said jaws at substantially the same. distance from the jaws ends, irrespective ofithez diameter of such tube. The free end 'ofthis mem ber may be so disposed and arranged'thatxit" hinders that the jaws turning in relation toi'each other during manipulation of the. tube tongs. By; a resilient device the member .is so COmblnd Withi the jaws that the jaws will alwaysv exert a bending or, flexing stress upon the adjustmentscrew;

in order that the jaws shall not be able, during; use of the tongs, to alter the width of theijawie' opening.

The eccentric member may. consist ofn-(l): simply a single head without arm and without: direct connection with the handle of the tongs (the tongs then will have one handle only) (2) orthe member may be attached to the superior arm througha movable intermediate member;.

(3) or the member may be attached to -a special.

arm, so that in such case the tongs will have;

two armstor handles.

In any of the embodiments the construction-10f the tube tongs must be such that thereis automatically obtained a suflicient pressure between the eccentric jaw surface and the tube as is .neces-:- sary in'order that the eccentric membershall fulfill its p rpose;

The annexed drawingsillustrate by way of ex ample tube tongs according to the invention,.and in which Figure 1 is a side elevational viewof the tongs of this invention shown partly in section;

Figure 2 is an elevational view of an eccentricmember used in the tongs; l

, Figure. 3 is .a partial elevational viewof anfeccentric head of a second embodiment of the invention;

Figure 4 is a partial elevational view of the device of Figure 3, with an eccentric head applied thereto;

Figure 5 is a plan view of the eccentric head of Figure 4;

Figurefi is an elevational view, parts thereof being broken away, of another embodiment of the invention, and

Figure 7 is a partial elevational view, partly in section, of a modification of a handle of the invention.

Figure 1 illustrates a construction havin two arms. A jaw member I3 is attached to or formed unitarily with one arm 2 of the tongs, which arm may be termed a swingable arm. The other arm 3, the superior arm, of the tongs is provided with a curved surface 5 adjacent to the jaw portion thereof and with a curved surface 6 of greater radius than said surface 5. These curved surfaces have a common center line 4. The member I3jis provided (see Fi 2) with a curved surface 5' of equal radius to the surface 5 and adapted tocooperate therewith. The curved surface 5 on arm 3 cooperates with a corresponding surface on the arm 2, or with a pin thereon (not shown).

The intermediate bottom portion l of the jaw on arm 2 is provided with a curved surface 9, the center line of which coincides with the center line 4. Arm 3 carries a pin it which abuts against surface 9 and thus serves as a support for the front part of the jaw.

The other or lower jaw ll may be adjusted in relation to the parts I and 13 by means of an adjusting screw l2 that extends between the superior, arm 3 and the jaw H. When the jaws have been so adjusted that they contact the periphery of atube and then the arms 2 and 3 are pressed towards each other said surface or .pin on the arm 2 will slide. along the surface 6 on arm 3, whereby the surface 5' on the member I3 is forced toslide along the surface 5 on arm 3, and eccentricaction occurs.

1.The'adjusting screw [2 is at its two end portions. provided with threads of opposite directions, and is received in threaded holes in the arm 3 and the jaw ll respectively. Preferably the/middle part of the screw is provided with a knurled flange M. The greater the pitch of the threads, the more rapidly the adjustment may take place. As already mentioned in the preamble to this specification it is possible to use a pitch sufiiciently steep that adjustment may take place only by pressing the jaws towards each other or pulling them from each other, without turning the screw by directly manipulating the same with the fingers. In the embodiment shown on Figure 1 the superior arm 3 is provided with a downward extension 15, which may slide in a corresponding vertical groove at the rear end of the lower jaw .l I. It may be suitable that this groove and the corresponding part of the extension I5 be dovetail shaped in cross section, in order that they may be able to transfer both pulls forwardly towards the opening of the jaw opening and pressure in the opposite direction. Hereby the stress on the adjusting screw during use of the tongs is relieved. This is desirable when only an adjusting screw connects the tongs arms. It is not necessary if the tongs arms have a common pivot point in addition to the adjustment screw.

On a pin 16 on the jaw l I there is pivotally arranged a member ll, which extends between the jaws and by a spring I8 is always maintained as far as possible towards the superior arm 3, viz. so that a curved portion thereof rides against a projection l9 provided on the arm 3. The free end of member I! is in the form of a rounded hook 20, which abuts against the periphery of a tube to be handled. The shapes and dimensions of the parts I! and I9 are so chosen in relation to each other and to the jaws, that any tube which is gripped between the jaws after being inserted as far as permitted by the hook 20, will always contact the jaws at substantially the same distance from the front end of the jaws, irrespective of the diameter of the tube grasped. The free end of the intermediate member I! may be arranged (not shown) to be guided in a groove in the under side of the part I, and will then help to prevent the jaws turnin in relation to each other during use of the tongs. The intermediate member ll is pressed upwards by means of a spring 18.

Arms 2 and 3 are acted on by a helicalspring 2|, the ends of which are attached to a transverse member 22 that rests in grooves provided at the top side of the respective arms. A projection 23 on arm 3 limits the distance which the arms may be moved towards each other, so that the spring 2| cannot be ruptured by too great a pressing of arms 2 and 3 towards each other.

A simple eccentric head, may take a shape as illustrated by 26 in Figs. 3, 4 and 5. This head carries on each side a flap 21. These flaps slide on corresponding surfaces on the beak of the superior arm 3 and guide the eccentric head. In order that said head shall be moved as desired during operation thereof, the beak portion of the superior arm is provided at each side thereof with curved surfaces 24 and 25 and the eccentric head is provided with corresponding curved surfaces 24' and 25' respectively. All of these surfaces have a common center line. The eccentric head is maintained in position by means of a leaf spring 29. The eccentric head is also provided with two tongues 28, the front edges of which are situated at an angle to the jaw surface proper. During operation of the tongs the tube abuts against these edges of tongues 28 and against the jaw surface.

When a tube is so positioned, and the lower jaw has been brought into contact with the tube, and

to roll upwards under the jaw surface and thereby press against the inclined surfaces of 28, which acts to turn the eccentric head counter-clockwise, whereby the jaw surface is pressed downwards against the tube and the desired eccentric action is obtained. Thetongues 28 moreover act to insure that the tube, irrespective of the diameter thereof, will always contact the jaw surface at the most convenient place both as regards the pressure exerted on.the tube and as regards correct work of the eccentric.

In orderto obtain a safe and rapid starting contact between the eccentric and the tubeone may, as shown on Figure 6, :connect the simple eccentric just described with the handle 3|)v by means of a connection plate 3| and a member 32. Parts 3i and 32 aremovably interconnected by part 32 having a lug or pin 33 that enters a hole At :the right end of member 32 there is provided an oblique surface 34 which may in the plate 3!.

slide against the end of for example the superior arm 3. At its left end thememberSi is by means of tongues 35 in movable contact with the eccentric head. When the handle 30 is gripped, part 32 is pressed inwards and, due to the oblique surface 34, part 32 is moved towards right. Thus the member 3| is pulled towards right and the eccentric head is turned counter-clockwise, whereby the pressure between the eccentric jaw and the tube is increased. Part 32 slides in a groove in handle 30 proper.

Figure 7 illustrates an embodiment in which the handle 36 is pivotable in relation to the arm 3, and is in connection with the plate member 3| through a pin 31. If handle 36 is swung upwards, the plate member 3| is pulled towards right, acts upon the eccentric head, and ultimately takes the arm 3 with it due to the projections 38.

In an embodiment of the type illustrated in Figure 1 the eccentric head may also be welded to the arm 2 to form a single member.

I claim:

1. In tube tongs, a movable eccentric jaw and a fixed jaw, means for adjusting the distance between said jaws, a handle carrying said fixed jaw, curved surfaces on said handle, correspondingly curved surfaces on said eccentric movable jaw for coaction with said curved surfaces on said handle, said curved surfaces having a common center line of curvature external of said tube tongs, said eccentric movable jaw being adapted to slide on said curved surfaces on said handle upon applying pressure to and turning said tube tongs when applied to a tube and to be eccentrically displaced with respect to said fixed jaw about said common center line.

2. In tube tongs as claimed in claim 1, a handle carrying said eccentric jaw, said curved surfaces on said eccentric jaw being on said handle, displacement of said eccentric jaw with respect to said fixed jaw being effected by movement of said handles toward one another.

3. In tube tongs as claimed in claim 2, a displacement screw interconnecting said fixed jaw and said movable eccentric jaw and comprising a means for adjusting the distance therebetween, and means comprising a common rotation axis for said handles whereby jaw pressure is transferred to said adjustment screw as tension whereby the diameter of the screw can be diminished.

4. In tube tongs as claimed in claim 1, a hook member pivotally mounted on said fixed jaw and extending into the space between said jaws, biasing means pressing said hook member against said eccentric movable jaw, said hook member ooacting with said movable jaw to limit insertion of a tube between said jaws by contact with said tube, the point of contact of said hook with said tube varying with the distance between said jaw members whereby said jaw members will contact a tube at the same distance from their end points regardless of the diameter of the tube.

5. In tube tongs as claimed in claim 1, an arm supporting said movable eccentric jaw, that portion of said arm carrying said jaw having curved surfaces at each side thereof, said movable eccentric jaw comprising two side portions and an interconnecting central portion adapted for contact with a tube, said sides having curved surfaces thereon corresponding with said curved surfaces on said arms, all said curved surfaces having a common center line of curvature, a leaf spring interposed between said arm and said movable eccentric jaw for maintaining said jaw in proper position and said jaw having two tongues thereon, the front edges of which are situated at an angle to the jaw surface proper whereby during operation of the tongs the tube will abut against the front edges of the tongues and against the jaw surface.

6. In tube tongs as claimed in claim 1, a connection plate slidably mounted on said handle, tongues on said connection plate in contact with a portion of said movable eccentric jaw for rotation thereof whereby pressure between said movable eccentric jaw and a tube can be varied by movement of said connection plate and means associated with said connection plate for movement thereof.

BJARNE CRANNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,064,744 Kindt June 17, 1913 1,105,875 Beyer Aug. 4, 1914 1,454,333 Ochoa May 8, 1923 1,561,681 Barnes Nov. 17, 1925 2,407,990 Lurie Sept. 24, 1946 FOREIGN PATENTS Number Country 7 Date 217,839 Great Britain June 24, 1924

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