US3602266A

US3602266A - Carriers for shuttleless looms

Info

Publication number: US3602266A
Application number: US852024A
Authority: US
Inventors: Jean Duplessy
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-08-27
Filing date: 1969-08-21
Publication date: 1971-08-31
Anticipated expiration: 1988-08-31
Also published as: GB1258960A; CH496827A; FR1588263A; DE1942865A1; BE737906A; BR6911884D0

Abstract

The present invention refers to giving and taking carriers (sometimes referred to as inserting and withdrawing carriers) for shuttleless looms with two rapiers or tapes to which carriers for the filling insertion are attached. These carriers are adapted to function without adjustment for a wide variety of sizes and types of filling. Each is self-contained and while unlatching of one and latching of the other of the filling clamping elements is accomplished outside the warp shed, the releasing of one and the clamping function of the other are effected by the carriers themselves at the transfer point within the shed.

Description

United States Patent 72] Inventor Jean Duplessy 132. Ave. lllmsan ll, Casablanca, Morocco [211 Appl. No. 852,024 [22] Filed Aug. 21, 1969 [4S] Patented Aug. 31, 1971 [32] Priority Aug, 27, 1968 [33] France [31] 50 331 [54] CARRIERS FOR SHUTTLELESS LOOMS 10 Chlms, 31 Drawing Figs. [52] US. Cl 139/122 [51] Int. Cl. D03d 47/20 [50] FieldolSeau-ch 139/122, 1, 124, 127

E In

Primary Examinerl-lenry S. J audon AttorneyRodney C. Southworth ABSTRACT: The present invention refers to giving and taking carriers (sometimes referred to as inserting and withdrawing carriers) for shuttleless looms with two rapiers or tapes to which carriers for the filling insertion are attached. These carriers are adapted to function without adjustment for a wide variety of sizes and types of filling. Each is self-contained and while unlatching of one and latching of the other of the filling clamping elements is accomplished outside the warp shed, the releasing of one and the clamping function of the other are effected by the carriers themselves at the transfer point within the shed.

PATEHTEH M183] :9?!

SHEET 1 UP 4 INVENTOR ATTORNEY SHEET 2 BF 4 Figs x 24 4 c i 7 LE l 1. U33 25a 25:2: 106 Fig. 25 B A i, A W

C o M J 100 Fig. 28 B A I-/-- 24 -"1 FM M258 o W 25G J 31 'INVENTOR ATTORNEY PATENIEH M831 m;

SHEEI 3 [1F 4 5a Fig. 11 A INVENTOR few/1 Bap/easy BY [xi/4 ATTORNEY CARRIERS FOR SI-IU'I'ILELESS LOOMS BACKGROUND OF THE INVENTION n presently known shuttleless looms it is necessary to adjust the carriers according to the type and thickness of the yarn to be woven. With carriers so far used, it is therefore not possible to weave cloth of yarn with large differences with regard to their counts and material.

It has been proposed to provide the carriers with a clamping device controlled from outside, to enable weaving filling yarn of any type. Such clamping devices are controlled by mechanisms which act on the carriers through the warp ends by means of mechanical levers or the like. However, such mechanisms can damage the warp ends.

The purpose of the present invention is to provide carriers with accurately constrained timing of thread clamping devices, the actuation of which is safely achieved at the moment when the carriers meet in the middle of the shed. Opening and closing of the thread clamping devices must at that time be possible without mechanical influence from outside. The actuation of the clamping devices outside of the shed can be effected by means provided at the return point of the carriers on the loom.

In order to keep the description of this invention simple and clear the carrier that carries the filling to the middle of the shed will be referred to as the giving carrier. The carrier which receives the filling in the middle of the shed and guides it to the opposite side will be referred to as the taking carrier.

SUMMARY OF THE INVENTION The present invention differentiates from the designs of the prior art in that each carrier has a movable jaw which is pivotable around the longitudinal axis of the carrier and which can elastically rest against a fast or fixed jaw, and in that holding and release devices for the movable jaws are provided, the giving carrier being provided with a rod for the actuation of the release device to take over the filling from the giving carrier and hold it fast and in that the movable jaw of the giving carrier can be pivoted from closed to open position to release the filling from the giving carrier.

Torsion springs can be used as means to have the movable jaws rest against'the fast jaws. It is useful if the torsion spring of the taking carrier has a higher torque than the torsion spring of the giving carrier. The movable jaw can consist of a piece with a rotatable shell which is borne in a bore in the longitudinal axis of the carrier body. As an alternative the part that carries the carriers can have the configuration of a telescope and embody a spring which withdraws the carriers to their basic position.

For better understanding of the characteristics and func tions, the drawings show by way of example a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic front view of part of a shuttleless loom with the carriers in basic position for start of the weaving process.

FIG. 2 is a plan view ofthe parts as per FIG. 1.

FIGS. 3 to 6 are views similar to FIG. 1, however, showing consecutive phases of the weaving process.

FIG. 7 is an exploded view of the giving carrier.

FIG. 8 is an exploded view of the taking carrier.

FIGS. 9 and 10 are sections across the giving carrier.

FIG. 1 l is a longitudinal section through both carriers at the moment of mutual penetration.

FIG. 12 is an axial section on a horizontal level of the rear part of the giving carrier in its closed position.

FIG. 13 is a section through FIG. 12 along the line XIII- FIG. 16 is a perspective view-of the rear part of the taking carrier.

FIG. 17 is a view of the parts of FIG. 11 showing the sections IX-IX and X-X of the FIGS. 9 and 10.

FIG. 18 is a section of FIG. 17 along the line XVIII-XVIII.

FIG. 19 shows the parts of FIG. 17 shortly before complete penetration.

FIG. 20 is a section of FIG. 19 along the line XX-XX.

FIG. 21 shows the parts of FIG. 17, the carriers being in end position of mutual penetration.

FIG. 22 is a section of FIG. 21 along the line XII-XII.

FIG. 23 is a view of the opening cam for the taking carrier.

FIG. 24 is a side view of the cam as per FIG. 23.

FIG. 25 is a plan view of the two carriers shortly before the moment of the filling transfer.

FIGS. 26 and 27 are end views of the two carriers in the position of FIG. 25.

FIG. 28 shows the parts of FIG. 25, the carriers being positioned as at the moment of complete penetration.

FIGS. 29 and 30 show the carriers after having reached the position is per FIG. 28.

FIG. 31 is a view of the parts of FIGS. 25 and 28 showing the carriers after the filling transfer.

DESCRIPTION OF THE PREFERRED EMBODIMENT For better understanding of the following description of the invention, some of the function of a shuttleless loom is explained with reference to FIGS. 1 to 6. FIGS. 1 and 2 show the beginning of a filling insertion. The giving carrier A is situated at the right-hand side, the taking carrier B at the left-hand side of the shuttleless loom. Both carriers have their jaws open. The filling thread C which is pulled off the cone D is guided through an eyelet E so that it is positioned in front of the giving carrier A. A shuttle guide or shuttle race board marked F, corresponds with the usual shuttle race board of a fly-shuttle loom. On shuttleless looms this shuttle guide is in certain cases not necessary because, e.g. the carriers are sufficiently guided by the rapiers or tapes. Apart from this the warp shed provides additional guidance.

The two carriers are now moved toward the middle of the shed, (FIG. 3). The carrier A at the right hand side catches the filling thread and closes as the cam G is contacted. The closing process is described further below. In the middle of the shed the carriers A and B meet each other (FIG. 4) and mutually penetrate in such a way that the taking carrier B closes upon the filling C while, or just slightly before, the carrier A opens and thereby releases the filling C. The two carriers return to their basic position (FIGl 5). At the end of the return of the taking carrier, the cam H is touched so that the carrier B opens and releases the filling C. Therewith the insertion of a pick is completed.

On the return of the carrier A its cam G is again touched, however, at this time it has no influence, i.e. the carrier remains open. FIGS. 7 and 8 are perspective views showing the individual parts of the carriers A and B. The giving carrier A consists of a body 1 having at its front end a lateral opening toward the shed. This opening is usually closed by the flat plate 2. The plate 2 is attached to the carrier by means of screws 3 (FIG. 9). The plate 2 has at its front end a horizontal saddle 2a that matches with a recess la in the body 1 (FIG. 10). A rod 4 is provided and fixed in the angle formed by the plate 2 and the saddle 2a, thereby forming a fast jaw. This fast jaw which is shown as one piece in the figure for reasons of simplicity, can preferably also be composed by welding of corresponding parts. The front end of the fast jaw 4 is shaped in such a way as to ease the penetration of the two carriers. The plate 2 is provided with a rib 2b for mutual guidance of the two carriers.

The body 1 is provided with a shell 5, the front end of which engages the back of the fast jaw 4. The front part of the shell is provided with an axial extension 5a which runs parallel with the fast jaw and thereby forms a movable jaw which can act together with the fast jaw 4. A tooth b is designed to open the giving carrier under the effect of a spring and other parts of the taking carrier. Borne in the shell 5 is a small crown 6 which i is secured in its position by two splints or pins, (FIG. 7). The inner bore of the crown 6 is free. The bore for these pins is shown in FIG. 7 by 50 and 6a. The crown 6 is provided with teeth on one side for the purpose of rotary drive of the shell 5. This rotation effects pressing the movable jaw 5a against the fast jaw 4 (FIG. A head 7 is arranged in the shell 5 with sufficient play to allow the head 7 to rotate in the shell 5. The front face of this head 7 is provided with teeth 7a which can be brought into engagement with teeth 6b of the crown. The front side of the head 7 has a slot 7b so that the head can be turned with the help of a screw driver. The back side of the head 7 has extensions 70 into which the torsion spring 8 can engage. The torsion spring 8 is also arranged in the inside of shell 5. The arrangement of the

parts

5, 6, 7 and 8 can also be seen in FIG. 11 showing the two carriers A and B in the first moment of penetration. The back of the body 1 (FIG. 7) is closed by a cover 9. The cover 9 is provided with a cylindrical seat 9a which can be fitted into the bore of the body 1. A second cylindrical seat 9b is an extension of the seat 9a and fits into the shell 5 (FIG. '12). The extension 9b is provided with a bore 90 to take the rear end of the torsion spring 8 (FIG. 7). If necessary, the extension 9b can again be provided with an extension to center the torsion spring 8. The cover 9 with its

extensions

9a and 9b is provided with a notch 9d into which a pawl 10 is inserted. The pawl 10 is pivotable on a stud 11 (FIGS. 7, l2 and 13). A compression spring 12 mounted in a bore 9e tends to keep the pawl or latch in active or latching position. The pawl 10 is provided with a rounded face 10a (FIG. 12) projecting out of the body 1. The pawl 10 is furthermore provided with a nose 10b projecting into a cutout of the shell 5 in order to hold the shell in open position of the movable jaw 50 in relation to the fast jaw 4, that is, in nonclamping position.

The cover 9 can be fixed to the body 1, for example, by means of a screw which through the body 1, is pressed against the cylindrical face 9a. The number 10 in FIG. 7 shows the bore in body 1 into which the fixing screw is inserted.

The torsion spring 8 in the carrier A has the tendency to turn the movable jaw 5a so that itpresses against the fast jaw 4. A filling thread which becomes situated between the two jaws will thus be clamped. The clamping pressure applied to the carriers to hold a filling thread can be adjusted by turning the head 7 with a screw driver. The teeth 6b ad 7a prevent unintended reversing of the head 7. In closed position of the carrier A, the pawl 10 and the cutout 5d are positioned as shown in FIGS. 12 and 13, i.e. the nose 10b of the pawl 10 is outside or withdrawn from the cutout 5d. The spring 12 presses the pawl 10 only against the inside wall of the shell 5. If the movable jaw 5a is rotated against the spring 8, the nose 10b of the pawl 10 will engage into the cutout 5d of the shell 5. The pressure of the spring 12 now presses the nose 10b into the cutout 5d and thereby keeps the carrier A with its jaws in open position, as shown in FIGS. 14 and 15.

The foregoing process corresponds with the position of the carriers A and B in FIG. 4. To close the carrier A it is sufficient to push back the pawl 10 in direction of its stud until the nose 10b leaves the cutout of the shell 5, FIGS. 12 and 13. The shell is now released and under the effect of the spring 8, goes automatically into closing position. The pawl 10 is actuated by the cam G of FIG. 1. As shown in FIG. 16, the cam G incorporates a flat lever 13 which is pivotable on a horizontal shaft 14. Through supports 15 the horizontal shaft is connected with a fixed part of the loom. A spring 16 keeps the lever 13 in horizontal position. The lever 13 can be depressed only until it reaches a stop on the support body 150. Laterally attached to the lever 13 is an arm 13a extending toward the shed and having a tapered face 13b on its lower side. The part 10a of the pawl 10 has a tapered face 100 which can contact the tapered face 13 b of the lever 13.

After having been opened by carrier B, the carrier A returns from the middle of the shed to the outside of the loom. At the end of the return the two tapered faces 10c and 13b contact each other, whereby the lever 13 is lifted against the pressure of the spring 16. On this return of the carrier the pawl 10 is not actuated so that the carrier remains open. On the forward movement of the carrier, when the filling yarn C has been caught by the

jaws

4 and 5a, the face 10a of the pawl 10 and the arm 13a of the lever 13 contact each other. Thereby the pawl 10 is pivoted around the shaft 11 and so unlatches the sleeve and permits closing of the carrier.

The taking carrier B is identical in its main parts with the giving carrier A. For easier understanding of the description the parts identical with the giving carrier A have been numbered with the same figures and with a prefigure 2. FIG. 8 shows the carrier B with a body 21. The lateral opening of the body is covered by a plate 22. A shell is rotatably mounted in a longitudinal bore of the body 21. A crown 26 fixed with pins is arranged in the shell 25 and is provided with teeth 26b on one side which is engaged with corresponding teeth 27a of a head 27. The end of the head 27 is provided with a slot 27c into which spring 28 is inserted. The other end of spring 28 is inserted into a bore 290. The cover 29 is provided with an extension 29a and serves to lock the back end of the body 21. The spring 28 is a torsion spring which by means of

teeth

26b and 27a turns the shell 25 clockwise in order to press the movable jaw 25a against the fast jaw 24. The fast jaw 24 is made of one piece with the plate 22. Whereas the fast jaw 4 of the carrier A is located at the bottom of the plate 2, the fast jaw 24 is arranged in the upper half of the plate 22. A further difference is that the saddle 22a engages into a recess 21a in the upper part of the body 21. The movable jaw 25a is formed by an extension of the shell 25 and is provided with a toothshaped tip 25e which projects beyond the part 25f. 25g is a recess in the jaw 25a.

The plate 22 carries on its inner side a threaded shaft 30, FIG. 18, onto which is mounted a holding pawl 31 with a spring 32. The spring 32 holds the pawl 31 in open position of the carrier in such a way that the lateral nose 31a rests against the recess 25g and thereby prevents the jaw 25f from being pivoted by the spring 28. In closed position of the carrier the nose 31a is lowered and rests against the inside of the movable jaw 250.

For better explaining the function of the pawl 31, details of the taking carrier are shown in FIGS. 11 and 17 to 20. As can be seen from FIG. 11, the pawl 31 has a sufficiently long arm extending from the axis of the shaft 30 to be pivoted against the effect of the spring 32 by the fast jaw 4 of the giving carri- In FIGS. 11, 17 and 18 the taking carrier B is drawn in open position and therefore shows the pawl 31 in engaged position. From FIG. 18 it can be seen that the nose 31a prevents the shell 25 from being pivoted clockwise by the effect of the spring 28. In FIGS. 19 and 20 the pawl 31 is in the position of commencing the release. The upper face of the nose 31a is about to free the edge of the recess 25g. The FIGS. 21 and 22 show the pawl after release. The nose 31a has pivoted to the inside of the shell 25 so that the movable jaw 25a can press itself against the fast jaw 24.

The taking carrier B is provided with an arm 33 (FIG. 8) being fixed to the outside of the shell 25 by means of screws 34. FIGS. 18 and 20 show that the arm 33 projects out of the profile of the body 21 through the cutout 21:. The arm 33 is sufficiently rounded and polished at its back and front sides in direction of movement, so as not to damage the warp ends. A last difference between the carriers A and B is the fact that the plate 22 of the carrier B is provided with a rib 22b which penetrates into the inside of the rib 2b of the carrier A in order to center the two carriers. This centering provides a guidance both lengthwise and crosswise for the movement of the carriers and also prevents one carrier from twisting in relation to the other.

The spring 28 of the taking carrier B has a higher torque than the spring 8 of the carrier A. With springs of equal dimensions this difference in torque can be set by differentiatshown in FIG. 1. As shown in FIG. 23, the cam H is provided with a supporting bracket 44 fastened to the loom by means of screws 35. A plate 37 is attached to the vertical part of the bracket by means of screws 50. The lower edge of plate 37 is provided with a comparatively long oblique face. This face is followed by a horizontal face 37b, followed by a further comparatively short oblique face 37d. The supporting bracket 44 is provided with a downtumed part 44b adjacent to a horizontal part 44a of the supporting bracket. The vertical part 44b of the supporting bracket carries four studs 38 on which freely rotatable rollers 39 are borne.

In FIG. 23 the carrier drawn in a dot and dash line in the position which the carrier has reached in FIG. 1. The nose 33 has reached the part 370 of the plate 37 and is thereby pivoted from its upper position to its lower position. The carrier B is brought to open position. The pressure acting on the carrier through the arm 33 tends to twist the carrier, however, the rollers 39 hold it in position. At the beginning of a filling insertion of the loom, the arm 33 is in its lower position and can therefore easily pass under the plate 37. It is possible that the arm 33 is touched by the horizontal face. This contact has, however, no influence on the carrier B which enters the shed in open condition. The carrier B is automatically closed by the carrier A at the proper time as described above.

The following is a description of details of the two carriers A and B in the position of mutual penetration. At this moment the carrier A is closed and carries a filling thread C clamped by the jaws of the carrier A. The carrier B reaches the middle of the shed in open condition. The filling thread is guided into the open jaws of the carrier B. In this position closing of the jaws of the carrier 13 and opening of the jaws of the carrier A takes place simultaneously, or at least, with the release by the carrier A not preceding the clamping by carrier B. FIG. 25 shows the two carriers shortly before transfer of the filling thread C.

As shown in FIG. 26, the filling thread is clamped between the fast jaw 4 and the movable jaw 5a of the carrier A. The pawl is in nonlatching position. FIG. 27 shows the corresponding position of the

jaws

25a and 24 of the carrier B. The arm 33 is in its lower position. The nose 31a of the pawl 31 is in locking position, i.e. the jaws are kept in open position.

From FIGS. 11, 17 and 18, it can be seen that on penetration of the carrier B into the carrier A, the rib 22b slides into the notch of the rib 2b of the giving carrier A. The rib 2212 has sufficient play to correct deviations of the two carriers from the middle and thereby to effect centering of the two carriers to each other. On transfer of the filing thread C the filling is guided into the opening between the

jaws

24 and 25a of the taking carrier. At the same time the fast jaw 4 actuates the lower part of the nose 31 of the carrier B (position as per FIGS. 19 and 20). By actuating the pawl 31 the jaws of the carrier B are closed. This process is shown in FIGS. 19 and 20. The end of this closing process is shown in FIGS. 21 and 22. The shell 25 actuated by the spring 28 effects closing of the carrier B. During the closing movement the jaw 5b and the shell 5 are pivoted by the jaw 25c against the torque of the spring 8. because the torque of the spring 28 is considerably higher than the torque of the spring 8. While the carrier B closes, the carrier A opens and is kept in this condition. At the same time the filling thread C has been transferred from the giving carrier A to the taking carrier B. The opening process of the carrier A, against the torque of its spring 8, effects a torque on this carrier, trying to twist the whole carrier. This twisting is, however, prevented by the fact that the rib 22b penetrates into the notch 2b.

FIG. 29 shows the giving carrier A after the transfer of the filling thread C. The movable jaw has moved away from the fast jaw 4. The pawl 10 has swung out. FIG. 10 shows the taking carrier B, the movable jaw 25a of which presses the filling thread C against the fast jaw 24. The nose 31 is now in its lower position.

In this condition the two carriers commence their return (FIG. 31). The filling is carried along by the carrier B and layed in the shed until the carrier B is opened by the nose or cam I-i (FIGS. 1, 24 and 34).

The invention allows one to produce a loom with carriers and two rapiers or tapes, on which the insertion of the filling is effected by jaws, the opening of which is dimensioned very large in relation to the diameter of the filling yarn. This measure ensures a safe function of a shuttleless loom using filling yarn of any type and any required diameter without making it necessary to readjust the carriers.

In order to prevent damage to the cloth in case the two carriers do not penetrate completely, at least one of the two rapiers can be replaced by telescoping tubes which are withdrawn to basic position by means of springs. With such a configuration of the rapiers and carriers it is possible to reduce the forces for the filling insertion. It it also possible to stop the loom by means of an electric contact if the filling transfer has not been completed.

This disclosure of a preferred embodiment of the invention is to be interpreted as illustrative of one form the invention may take and modifications will readily occur to those skilled in the art.

The invention is not to be restricted except by the scope of the appended claims wherein the novel features desired to be protected by Letters Patent are set forth in the claims:

1. Filling carriers for shuttleless looms of the type having reciprocable members in the form of rapiers or tapes to which the carriers are attached, characterized in that, each carrier has a fixed jaw and a movable jaw, resilient means to press each said movable jaw against its respective fixed jaw to clamp the filling between them, a means to latch each movable jaw in an open (nonclamping) position, and means forming a part of each carrier and operable upon its companion carrier for unlatching the movable jaw of one carrier to clamp filling and to open and latch the movable jaw of the other carrier to release the filling.

2. A filling carrier as defined in claim 1, further characterized in that, the jaws are axially disposed in the direction of movement of the carrier and the movable jaw forms a part of a rotating cylindrical member.

3. A filling carrier as defined in claim 2, further characterized in that, a torsion spring is provided for elastically pressing the movable jaw against its fixed jaw.

4. A filling carrier as defined in claim 2, further characterized in that, an axially disposed torsion spring is provided to rotate said cylindrical member in a direction to press the movable jaw into contact with the fixed jaw and a latching means is incorporated to hold the cylindrical member in a position to retain the jaws in open relationship.

5. A filling carrier as defined in claim 2, further characterized in that, an axially torsion spring is provided to rotate said cylindrical member in a direction to press the movable jaw into contact with the fixed jaw and a latching means is incorporated to hold the cylindrical member in a position to retain the jaws in open relationship, said latching means having a part projecting from a face of the carrier to be contacted and actuated by an externally positioned cam in its pathway.

6. Filling carriers as defined in claim 1, further characterized in that, the fixed jaw of one carrier unlatches the movable jaw of the other.

7 Filling carriers as defined in claim 1, further characterized in that, the movable jaw of one carrier engages between both jaws of the other and opens the movable jaw of that carrier.

8. Filling carriers as defined in claiml, further characterized in that, one said carrier is provided with a notched rib and the other has a rib aligned to enter into said notched rib to 3 terized in that, the tuming force acting upon said cylindrical member is applied through toothed means relatively adjustable to set the pressure between the fixed jaw and the movable jaw.

Claims

2. A filling carrier as defined in claim 1, further characterized in that, the jaws are axially disposed in the direction of movement of the carrier and the movable jaw forms a part of a rotating cylindrical member.
3. A filling carrier as defined in claim 2, further characterized in that, a torsion spring is provided for elastically pressing the movable jaw against its fixed jaw.
4. A filling carrier as defined in claim 2, further characterized in that, an axially disposed torsion spring is provided to rotate said cylindrical member in a direction to press the movable jaw into contact with the fixed jaw and a latching means is incorporated to hold the cylindrical member in a position to retain the jaws in open relationship.
5. A filling carrier as defined in claim 2, further characterized in that, an axially torsion spring is provided to rotate said cylindrical member in a direction to press the movable jaw into contact with the fixed jaw and a latching means is incorporated to hold the cylindrical member in a position to retain the jaws in open relationship, said latching means having a part projecting from a face of the carrier to be contacted and actuated by an externally positioned cam in its pathway.
6. Filling carriers as defined in claim 1, further characterized in that, the fixed jaw of one carrier unlatches the movable jaw of the other. 7 Filling carriers as defined in claim 1, further characterized in that, the movable jaw of one carrier engages between both jaws of the other and opens the movable jaw of that carrier.
8. Filling carriers as defined in claim 1, further characterized in that, one said carrier is provided with a notched rib and the other has a rib aligned to enter into said notched rib to align the carriers at transfer of filling to resist torsional forces acting thereon.
9. Filling carriers as defined in claim 1, further characterized in that, the said resilient means for one of the carriers is stronger than the other so that it dominates at transfer.
10. A filling carrier as defined in claim 2, further characterized in that, the turning force acting upon said cylindrical member is applied through toothed means relatively adjustable to set the pressure between the fixed jaw and the movable jaw.