US3748872A

US3748872A - Needle bed racking mechanism in a flat knitting machine

Info

Publication number: US3748872A
Application number: US00219483A
Authority: US
Inventors: W Hadam; A Muller
Original assignee: H Stoll GmbH and Co KG
Current assignee: H Stoll GmbH and Co KG
Priority date: 1971-01-20
Filing date: 1972-01-20
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31
Also published as: DE2102450C3; DE2102450B2; IT943998B; GB1320477A; FR2122881A5; DE2102450A1; CH526660A; JPS5225462B1

Abstract

A racking cam for producing needle bed shogging steps of respectively different extents in a flat knitting machine. A racking cam carrier carries about its periphery a racking cam having a plurality of shogging positions. Each shogging position includes a device for varying the form of the cam at that position. The device may include a block on the periphery of the racking cam carrier and forming a part of the racking cam at each shogging position. This block may be mounted by a connecting structure including an eccentric element such that movement of this eccentric element moves the block in a direction generally parallel to the axis of rotation of the racking cam carrier.

Description

United States Patent [1 1 Hadam et al.

[ NEEDLE BED RACKING MECHANISM IN A FLAT KNITTING MACHINE [75] Inventors: Wilhelm Hadam; Adam Miiller,

both of Reutlingen, Germany [7 3] Assignee: H. Stoll and Company, Stollweg,

Germany [22] Filed: Jan. 20, 1972 [21] Appl. No.: 219,483

[30] Foreign Application Priority Data 943,921 12/1909 Dubied et a]. 66/69 [451 July 31,1973

' FOREIGN PATENTS 0R Al PLICATI ONS 217,147 2/1942 Switzerland 66/69 Primary Examiner-Ronald Feldbaum z trb friey iloberts B. Larson/Marvin Petry et al.

[5 7] ABSTRACT A racking cam for producing needle bed shogging steps of respectively different extents in a flat knitting machine. A racking cam carrier carries about its periphery a racking carn having a plurality of shogging positions. Each shogging position includes a device for varying the form of the cam at that position. The device may include a block on the periphery of the racking cam carrier and forming a part of the racking cam at each shogging position. This block may be mounted by a connecting structure including an eccentric element such that movement of this eccentric element moves the block in a direction generally parallel to the axis of rotation of the racking cam carrier.

i0 Claim, t timing Figures NEEDLE BED RACKING MECHANISM IN A FLAT KNITTHNG MACHINE The type of knitting machine to which this invention relates, and the general relationship of a racking cam thereto is shown in U.S. Pat. No. 1,992,982, the disclosure of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION This invention relates to a needle bed racking, i.e. shogging, mechanism in a flat knitting machine equipped with a racking cam for producing needle bed shogging steps of respectively different extents.

In the production of rack stitch patterns on automatic flat knitting machines, particularly those having jacquard patterning arrangements, an oblique pull is exerted on the needles by the racking or shogging of the needle beds and this may result in lateral bending of the resilient needles out of their normal plane of movement. Bending of the needles in this way jeopardizes positive cooperation between the needles which transfer and the needles which receive stitches or the co-action between the needles and the transfer jacks during stitch transferring operations. It would, therefore, be of advantage if the magnitude of the shogs in the racking steps could be adjustable to the extent of a few tenths of a millimeter to take into account the lateral bending of the needles caused by the oblique pull on the stitches.

Shogs of the needle bed to required extents, for example over one to six needles, are usually effected with the assistance of continuously rotating cam tracks which, for instance, are either formed on the racking carriage by an oblique straight edge or defined by a helical line on a rotatable racking cam carrier. The shogging strokes in such prior mechanisms could be corrected by a variation in the amount of movement of the racking carriage or degree of movement of the rotating cam carrier per shog, for example by driving the carriage or the rotary cam by stepped motors at an appropriate stepdown ratio, or by varying the gradient of the racking cam. Both these possibilities of adjustment can, however, only be carried out with great difficulty, and experience has shown that the problem cannot be solved by correction of the partial shogs which are proportional to the overall shogging stroke of the mechanism, but that differing correction values must be applied to the individual shogs.

SUMMARY OF THE INVENTION Thus, it is a purpose of this invention to provide a new and improved arrangement in racking cams for flat knitting machines which will facilitate the task of providing shogging steps of respectively different extents.

It is a further purpose of the present invention to provide a needle bed racking mechanism for a flat knitting machien which, while overcoming the aforementioned difficulties, will allow in respect of each shog produced by a racking step for a desired degree of shogging to be set within a range of correction, and for this value to be chosen individually for each step independently of the values chosen for the other steps.

This purpose is achieved according to the present invention by the fact that the racking cam carrier has mounted therein, at each shogging step position of the Each control means may be in the form of a block which is inserted into and is movable relatively to the cam carrier for adjustment through the medium of an eccentric. These eccentrics therefore allow for infinitely variable adjustments of the control blocks.

In a preferred constructional embodiment of the invention, the control blocks are of the same width as a part of the racking cam carrier constituting the actual racking cam, each such block being formed with a groove which extends parallel to the edges of the racking cam and transversely with respect to the direction of shogging of the needle bed and accomodating a bored block member having a hole serving to locate, with a close working fit, an eccentric flange on a central boss which is arranged for turning movement adjustably within the racking cam carrier and is adapted to be secured in position, after an adjustment, by means of a tighting screw.

Advantageously, the eccentric flange of each central boss has a transverse slot in which a screwdriver can be inserted, and the corresponding bored block is provided around the edge of the hole therein with an annular scale designed to indicate the degree of adjustment of the boss.

The invention can be used with any type of racking cam carrier, that is to say both a known form of racking straight edge or a known form of rotary racking body. A control block is provided for each needle bed shogging position of the racking cam and this block can be set to a required corrected shogging position independently of the other control blocks and will determine the exact degree of shogging of the needle bed for the racking steps concerned.

Thus, it is a purpose of this invention to provide, in a flat knitting machine, a new and improved racking cam for producing needle bed shogging steps by difiering amounts.

It is another object of this invention to provide, in a flat bed knitting machine, a new and improved racking cam having means at each shogging position for changing the form of the cam thereat to produce shogging of differing amounts at different shogging positions, the adjustment at each shogging position being independent of the adjustments at the other shogging positions.

It is another object of this invention to provide, in a flat bed knitting machine, a racking cam having a block at each shogging position thereof, the sides of the block forming the racking cam at that position, each block being connected to the racking cam carrier by connecting means including an eccentric element, the turning of which eccentric element adjusts the block to determine the extent of shogging at that position.

It is another object of this invention to provide a new and improved racking cam for use in a flat knitting machine comprising means at each shogging position thereof for changing the extent of shogging thereat independently of the extent of shogging at other shogging positions of the racking cam.

It is another object of this invention to provide a racking cam for a flat knitting machine including blocks located at various shogging positions of the racking cam, each block being connected to the racking cam carrier by means including an eccentric element, the turning of which element adjusts the position of the block.

Other objects and advantages of the invention will become apparent from the detailed description to follow, together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS There follows a detailed description of one preferred embodiment of the invention which is to be read together with the accompanying drawings.

FIG. 1 is an elevational view, as seen in the axial direction, of a rotatable type racking cam constructed to include the features of the present invention.

FIG. 2 is a sectional view taken along line 11-11 of FIG. 1.

FIG. 3 is a partial development of the racking cam of FIG. 1 on the racking cam carrier, this development spanning three successive racking steps.

FIG. 4 is a detailed sectional view taken along the line IVIV of FIG. 3 and drawn on an enlarged scale.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT:

Referring now the drawings, like elements are represented by like numerals throughout the several views. As noted earlier, the features of the present invention may be applied either to an oblique straight edge cam or a cam defined by a helical line on a rotatable racking cam surface. For simplicity, however, the invention will be described in detail only with respect to the latter.

In the drawings is shown a racking cam carrier which is in the form of a rotatable body known per se. This carrier has a racking cam constituted by a helically-extending edge 12 of a flange 11 on a cam plate 100. The racking cam carrier 10 is mounted on a shaft 30 which extends parallel to the needle bed and constitutes a part of the racking assembly of the machine operable at the dictates of a control mechanism.

The flange ll of the cam plate 10a of carrier 10 is provided in and around its periphery with regularly spaced transverse grooves 13 which extend parallel to the direction of racking of the needle bed and correspond in each case to the racking of the needle bed to the extent of one needle. A control block 14 is fitted accurately into each of these transverse grooves 13, each such block being of the same width as the flange 11 and having the same gradient, i.e. angle of obliquity, as the latter relative to the direction of racking. These blocks 14 are each provided with a transverse groove 15 extending parallel to the helical edges 12 of flange 11. Where there are severe inclinations in the racking curve represented by the edges 12 the grooves 15 in the blocks 14 may even be disposed transversely with respect to the rotary axis a of the carrier 10.

Fitted into the transverse groove 15 of each control blcok l4 is a counter-bored block member 16 having therein a circular hole I6 to accomodate, with a close working fit, an eccentric flange 17 on a central boss 18. This boss 18 is mounted within a hole 19 in the cam plate 10a which latter is formed integrally with the racking cam carrier 10. The inner end of the mounting hole 19 terminates in a co-axial threaded bore 20 in the cam plate 10a, and a tightening screw 21 concentric with the central boss 18 is screwed into the said bore 20.

The eccentric flange 17 of boss 18 has formed therein a transverse slot 22 for the insertion of the bit of a screwdriver, and a scale 23, is marked on the block member 16 around the edge of the hole 16' therein accomodating the said flange.

When any one of the tightening screws 21 is un locked, the corresponding boss 18 can be turned by a screwdriver inserted into the slot 22. By this means the relevant bored block member 16, together with the block 14 into which it is fitted, can be shifted in one or other direction parallel both to the direction of racking of the needle bed and also to the rotational axis a of the cam carrier 10 so that such block 14 will project over one or other of the two edges 12 of the flange ll. Positioning of the slot 22 relatively to the scale marking 23 on block member 16 enables the degree of adjustment of the corresponding control block 14 to be determined and controlled. This shifting of a control block 14 varies the extent of the shog in a racking stage of the needle bed which is determined by the position of the racking cam on which the said block is located. This enables the differing values to be given to the racking stage shogs for the differing shogging stages, one of the control blocks 14 being associated with each such stage.

In the application of the present invention to a straight edge racking cam, such a cam might appear in plan view just like the development view of FIG. 3 herein, the straight edges being arranged obliquely relative to the direction of racking which would be parallel to the line in FIG. 3, the block 14 and their associated and connecting adjusting elements being arranged along the length of the straight edge cam.

Although the invention has been described in considerable detail with respect to preferred embodiments thereof, it will be apparent that the invention is capable of numerous modifications and variations apparent to those skilled in the art without departing from the spirit and scope of the invention.

We claim:

1. A flat knitting machine having a racking cam means for producing needle bed shogging steps comprising, a racking cam carrier, a racking cam mounted on the racking cam carrier and extending in a generally oblique direction relative to the direction of racking, the racking cam including a plurality of shogging step positions spaced therealong, and control means for varying the extent of shogging at each shogging step position of the racking cam means said control means comprising the construction in which said cam includes a block at each shagging step position, the surface of the block forming the form of the cam at that shogging step position, each block being adjustable relative to the racking cam carrier and independently of the blocks at the other shogging step positions in a direction generally parallel to the direction of racking of the racking cam carrier.

2. The invention of claim 1, each block being mounted on the racking cam carrier by connecting means which includes an eccentric element, the turning of which element adjusts that block in said direction.

3. The invention of claim 2, wherein the blocks are of the same width, taken in the said direction of racking, each such block being formed with a groove which extends parallel to the edges of the racking cam and transversely with respect to the direction of shagging of the needle, a bored member accomodated in said groove and including a hole passing therethrough which locates, with a close working fit, an eccentric flange on a central boss, said eccentric flange constituting the said eccentric element and being arranged for turning movement adjustably within the racking cam carrier to move the bored member and hence the block in said direction to adjust the block.

4. The invention of claim 3, including a screw passing through the eccentric flange and central boss and threadedly engaged in a racking cam plate which is fixed with respect to the racking cam carrier such that when screwed into the racking cam plate it secures in place the eccentric flange and central boss and hence also the bored member and the said block.

5. The invention according to claim 4, wherein each eccentric flange has a transverse slot adapted to receive a screwdriver or the like for turning it, and its corresponding bored member is provided around the edge of the hole therein with an annular scale designed to indicate the degree of adjustment of the eccentric flange and hence also the degree of adjustment of the block.

6. The invention of claim 1, wherein said racking cam carrier is mounted for rotation about an axis and the racking cam is located on the periphery thereof and extends in a helical path thereabout, the axis of rotation of said racking cam carrier and said racking cam being parallel to the said direction of racking.

7. A racking cam mechanism for use in a flat knitting machine comprising: a racking cam carrier having a racking cam mounted thereon and extending in an oblique direction relative to the direction of racking, said racking cam including a plurality of discrete opposite shogging positions spaced therealong, the racking cam, at each of said positions, including a control means for varying the form of the cam thereat independently of the form of the cam at the other shogging position.

8. A racking cam mechanism according to claim 7, said control means comprising the construction in which said cam includes a block at each shogging position, the surface of the block forming the form of a cam at that position, each block being adjustable relative to the racking cam carrier in a direction generally parallel to the direction of racking of the racking cam carrier, each block being the same width, taken in said direction of racking, as the racking cam, each such block being formed with a groove which extends parallel to the edge of the racking cam, a bored member accom' modated in said groove and including a hole passing therethrough which locates, with a close working fit, an eccentric flange on a central boss, said eccentric flange being arranged for turning movement adjustably within the racking cam carrier to move the bored member and hence the block in said direction of racking to adjust the block.

9. A racking cam mechanism according to claim 8, including a screw passing through the eccentric flange and central boss and threadedly engaged with respect to the racking cani carrier such that when screwed inwardly with respect to the racking cam carrier it secures in place the eccentric flange and central boss and, hence also the bored member and the said block, each eccentric flange having a transverse slot adapted to receive a screwdriver of the like for turning it, and its corresponding bored member being provided around the edge of the hole therein with an annular scale designed to indicate the degree of adjustment of the eccentric flange, and hence also the degree of adjustment of the block.

10. The invention of claim 7, wherein said racking cam carrier is mounted for rotation about an axis and the racking cam is located on the periphery thereof, and extends in a helical path thereabout, the axis of rotation of said racking cam carrier and said racking cam being parallel to the said direction of racking;

Claims

1. A flat knitting machine having a racking cam means for producing needle bed shogging steps comprising, a racking cam carrier, a racking cam mounted on the racking cam carrier and extending in a generally oblique direction relative to the direction of racking, the racking cam including a plurality of shogging step positions spaced therealong, and control means for varying the extent of shogging at each shogging step position of the racking cam means said control means comprising the construction in which said cam includes a block at each shogging step position, the surface of the block forming the form of the cam at that shogging step position, each block being adjustable relative to the racking cam carrier and independently of the blocks at the other shogging step positions in a direction generally parallel to the direction of racking of the racking cam carrier.

3. The invention of claim 2, wherein the blocks are of the same width, taken in the said direction of racking, each such block being formed with a groove which extends parallel to the edges of the racking cam and transversely with respect to the direction of shogging of the needle, a bored member accomodated in said groove and including a hole passing therethrough which locates, with a close working fit, an eccentric flange on a central boss, said eccentric flange constituting the said eccentric element and being arranged for turning movement adjustably within the racking cam carrier to move the bored member and hence the block in said direction to adjust the block.

8. A racking cam mechanism according to claim 7, said control means comprising the construction in which said cam includes a block at each shogging position, the surface of the block forming the form of a cam at that position, each block being adjustable relative to the racking cam carrier in a direction generally parallel to the direction of racking of the racking cam carrier, each block being the same width, taken in said direction of racking, as the racking cam, each such block being formed with a groove which extends parallel to the edge of the racking cam, a bored member accommodated in said groove and including a hole passing therethrough which locates, with a close working fit, an eccentric flange on a central boss, said eccentric flange being arranged for turning movement adjustably within the racking cam carrier to move the bored member and hence the block in said direction of racking to adjust the block.

9. A racking cam mechanism according to claim 8, including a screw passing through the eccentric flange and central boss and threadedly engaged with respect to the racking cam carrier such that when screwed inwardly with respect to the racking cam carrier it secures in place the eccentric flange and central boss and hence also the bored member and the said block, each eccentric flange having a transverse slot adapted to receive a screwdriver of the like for turning it, and its corresponding bored member being provided around the edge of the hole therein with an annular scale designed to indicate the degree of adjustment of the eccentric flange, and hence also the degree of adjustment of the block.

10. The invention of claim 7, wherein said racking cam carrier is mounted for rotation about an axis and the racking cam is located on the periphery thereof, and extends in a helical path thereabout, the axis of rotation of said racking cam carrier and said racking cam being parallel to the said direction of racking.