Needle selection device for a circular knitting machine
United States Patent 3890805
A circular knitting machine includes at least one selection station on a fixed part surrounding the machine cylinder, and pivotal jacks associated with the accessories to be controlled, each jack and an associated accessory being disposed in a respective guide groove of the machine cylinder. Each selection station includes magnetic selection means disposed on a cam-box of the machine, a setting cam acting on the tongues of the jacks to pivot the jacks towards the exterior of their guide grooves, a thrust cam for acting on a deformable part of each jack, and a fixed bearing surface for bearing against the jacks which are submitted to the influence of the magnetic means. The bearing surface as well as the thrust cam and polar surfaces of the magnetic means are located at the exterior of the machine cylinder, and the magnetic means are so arranged between the bearing surface and the thrust cam that at the moment of selection portions of each jack are applied against stationary parts of the machine which are independent of the inner surface of the guide grooves of the needle cylinder.
US Patent References:
KNITTING MACHINE WITH SLIDE LATCH NEEDLES CONTROLLED BY JACKS
Schmidt et al. - October 1970 - 3535892
/3605448.html
Ribler - September 1971 - 3605448
DEVICE FOR THE SELECTION OF THE NEEDLES OR KNITTING ACCESSORIES OF CIRCULAR KNITTING MACHINES
Bourgeois - January 1973 - 3710594
KNITTING MACHINE
Paepke - June 1971 - 3742733
JACK AND NEEDLE ACTUATOR FOR A CIRCULAR KNITTING MACHINE
Engelfried - May 1974 - 3812691
KNITTING MACHINE WITH SLIDE LATCH NEEDLES CONTROLLED BY JACKS
Schmidt et al. - October 1970 - 3535892
/3605448.html
Ribler - September 1971 - 3605448
DEVICE FOR THE SELECTION OF THE NEEDLES OR KNITTING ACCESSORIES OF CIRCULAR KNITTING MACHINES
Bourgeois - January 1973 - 3710594
KNITTING MACHINE
Paepke - June 1971 - 3742733
JACK AND NEEDLE ACTUATOR FOR A CIRCULAR KNITTING MACHINE
Engelfried - May 1974 - 3812691
Application Number:
05/346793
Publication Date:
06/24/1975
Filing Date:
04/02/1973
View Patent Images:
Export Citation:
Assignee:
Etudes et Bonneterie S.A. (Nyon, CH)
Primary Class:
International Classes:
D04B15/78; D04B15/66; D04B15/78; D04B15/66; D04B15/68
Field of Search:
66/25,36A,36B,5R,75,154A
Primary Examiner:
Reynolds W. C.
Assistant Examiner:
Falik A. M.
Attorney, Agent or Firm:
Wenderoth, Lind & Ponack
Claims:
What is claimed is
1. A device for the selection of knitting accessories such as needles of a circular knitting machine including a needle cylinder and at least one selection station on a fixed part of said machine surrounding the needle cylinder and pivotal jacks associated with the accessories to be controlled, each jack and an associated accessory being disposed in a respective guide groove of the needle cylinder, the improvement wherein:
2. A device as claimed in claim 1, wherein said means for pivoting said pivotal jacks towards the exterior of said guide grooves acts on said elastically deformable part of each jack, said means for pivoting being arranged to cause deformation of said deformable parts in the direction towards the exterior of said guide grooves to place said jacks in an operative position in which a non-deformable part of each jack is precisely applied against and is submitted to the magnetic influence of said magnetic selection means.
1. A device for the selection of knitting accessories such as needles of a circular knitting machine including a needle cylinder and at least one selection station on a fixed part of said machine surrounding the needle cylinder and pivotal jacks associated with the accessories to be controlled, each jack and an associated accessory being disposed in a respective guide groove of the needle cylinder, the improvement wherein:
2. A device as claimed in claim 1, wherein said means for pivoting said pivotal jacks towards the exterior of said guide grooves acts on said elastically deformable part of each jack, said means for pivoting being arranged to cause deformation of said deformable parts in the direction towards the exterior of said guide grooves to place said jacks in an operative position in which a non-deformable part of each jack is precisely applied against and is submitted to the magnetic influence of said magnetic selection means.
Description:
BACKGROUND OF THE INVENTION
The invention relates to devices for the selection of knitting accessories such as needles of a circular knitting machine including at least one selection station on a fixed part surrounding the machine cylinder and pivotal jacks associated with the accessories to be controlled, each jack and an associated accessory being disposed in a respective guide groove of the machine cylinder, and each selection station including magnetic selection means disposed on a cam-box of the machine, means fixed on the cam-box for pivoting the pivotal jacks towards the exterior of the guide grooves, and a thrust member also fixed on the cam-box for acting on a deformable part of each jack.
Such a device is described and shown in U.S. Pat. No. 3,710,594 and, in one particular embodiment, comprises a pivotal needle jack associated with each needle and having, between one end which serves as pivoting point and an actuating butt disposed towards its other end, an elastically deformable tongue made in one piece with the needle jack. This tongue is located on the same side as the actuating butt, i.e. on the outer side of the guide groove provided in the machine cylinder, facing the cam-box which carries, at each selection station, a thrust cam for deforming the tongues as they pass by and magnetic selection means exerting a selective action on the actuating butts of the needle jacks.
The particular disposition of the deformable tongue between the point of pivoting or oscillation of the needle jack and its actuating butt submitted to the influence of the magnetic means implies that the tongue must be capable, from a deformation of relatively small amplitude, of producing a mechanical force which although it is less than the attractive force of the magnetic means must be sufficient to pivot a non-selected needle jack into its inoperative position. Each thrust cam must thus be disposed with a great precision.
Moreover, at the moment of deformation of its elastic tongue, each needle jack has (apart from the point of contact of the deformable tongue with the thrust cam) only a single point of support formed by the bottom (i.e. the inner surface) of its guide groove. In view of the fact that a certain lack of precision may result either because of the relative movement between the set of needle jacks and the thrust cams, or because of slight differences of depth that may occur in the various guide grooves, it is difficult to obtain a strictly identical deformation for each of the deformable tongues of the oscillating needle jacks.
SUMMARY OF THE INVENTION
The present invention aims to remedy the stated drawbacks and to facilitate the mounting of certain members while ensuring improved operating conditions.
According to the invention, there is provided a device for the selection of knitting accessories such as needles of a circular knitting machine including at least one selection station on a fixed part surrounding the machine cylinder and pivotal jacks associated with the accessories to be controlled, each jack and an associated accessory being disposed in a respective guide groove of the machine cylinder, in which each selection station includes magnetic selection means disposed on a cam-box of the machine, means fixed on the cam-box for pivoting the pivotal jacks towards the exterior of the guide grooves, a thrust member also fixed on the cam-box for acting on an elastically deformable part of each jack, and a fixed bearing surface for bearing against the pivotal jacks which are submitted to the influence of the magnetic means, the bearing surface as well as the thrust member and polar surfaces of the magnetic means being located at the exterior of the machine cylinder, and the magnetic means being so arranged between the bearing surface and the thrust member that at the moment of selection each jack is applied against stationary parts of the machine independent of the inner surface of its guide groove.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings show, by way of example, an embodiment of the selection device according to the invention. In the drawings:
FIG. 1 is a view in axial cross-section of a part of a circular knitting machine showing a needle jack in a rest position;
FIG. 2 is a schematic cross-section taken along line II--II of FIG. 1; and
FIGS. 3 to 6 are cross-sections similar to FIG. 1, but taken respectively along lines III--III, IV--IV, and V--V and VI--VI of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
A needle cylinder 1 of the circular knitting machine shown in FIG. 1 is fixed for rotation with a driving ring 2 and comprises at its periphery a series of axial grooves 3 in which are slidably mounted independent needles 4 each provided with an actuating butt 5 able to cooperate with the usual cams such as 6 and 7 at an upper part 8 of an annular cam-box fixed by its lower part 9 to a stationary plate 10 fixed to the frame on the machine.
Below each needle 4, movably mounted in the same guide groove 3, is disposed a needle jack 11 able to pivot about its rounded upper end 12.
Each needle jack 11 includes two longitudinally distinct parts 13 and 14 respectively facing the exterior and the bottom (i.e. the inner surface) of guide groove 3. The outer part 13 includes a protruding actuating butt 15 which can cooperate with a raising cam 16, fixed to part 8 of the cam-box, when the needle jack 11 is placed in an operative position by pivoting towards the exterior of its groove 3. The inner part 14 of needle jack 11 is elastically deformable and has an enlarged end 17 extending below the actuating butt 15 and protruding out of the lower end of guide groove 3. Each needle jack 11 also includes, between its pivoting point 12 and its actuating butt 15, a return butt 18 located above a protruding part 19 which is adapted to come to bear against a bearing cam 20 disposed in the upper part of an opening 21 provided in cam-box 8.
At each selection station (FIG. 2) the needle jacks 11 are selected in the following manner:
Upstream of each selection station, a setting cam 22, disposed on the lower part 9 of the stationary cam-box and below the rotary cylinder 1, acts on the rear face of the end 17 of the deformable parts 14 as they pass by, and outwardly pivots all of the needle jacks 11 into their operative position. In this operative position, a front face 23 of the actuating butts 15 is placed under the influence of magnetic selection means 25.
As in the referred-to patent specification, these magnetic means comprise an electro-magnet 24 selectively controlled by impulses provided by reading an information program (not shown). The electro-magnet 24 is disposed, in relation to the direction of motion of the needle jacks, between a lead-in magnet 25 and a holding magnet 26; these two magnets may be permanent magnets or permanently supplied electro-magnets. The three magnetic members 25, 24 and 26 are equally spaced apart by an amount less than the width of an actuating butt 15, and are fixed on a support 27 in a non-magnetic material which is itself fixed onto the lower part 9 of the cam-box by means of screws 28.
As shown in FIG. 3, the actuating butts 15 of all of the needle jacks 11 are firstly influenced by the lead-in magnet 25, the setting cam 22 slightly deforming the deformable parts 14 towards the exterior of guide grooves 3 in order to ensure a perfect magnetic adherence. During this magnetic attraction exerted by magnet 25 on butts 15, the action of setting cam 22 ceases, and the protruding part 19 of each needle jack 11 (FIG. 4) is made to bear against the cam 20, by the action of a thrust cam 29, which is fixed in a housing of support 27 and protrudes through an opening in cam 16 so as to exert a thrust on the front faces of the ends 17 of the deformable parts 14 as they pass by; this causes a deformation of parts 14 towards the interior of the guide grooves 3 against the attraction of magnet 25 which, as that of the electro-magnet 24 and of the holding magnet 26, is greater than the mechanical force produced by the reaction of each part 14 to tend to return to its initial undeformed position.
An important advantage resulting from the disposition of the bearing cam 20 resides in the fact that at the moment of deformation of their elastically deformable parts 14 by the thrust cam 29 the needle jacks 11, whose actuating butts 15 are submitted to the influence of the magnetic means are in contact only with stationary parts of the machine independent of guide grooves 3, which enables a total independence of possible differences which may exist in the depth of the guide grooves 3, as well as of a possible eccentricity of cylinder 1.
As they pass before the selection station, the needle jacks 11 whose rear parts 14 are still deformed are delivered to the selection electro-magnet 24. Those needle jacks (FIG. 5) whose actuating butts are not retained by the electro-magnet 24 pivot towards the interior of their respective guide grooves 3 by the relaxation of their deformable part 14 which, by reacting against the cam 29, causes return of these needle jacks 11 to the inoperative position out of alignment with raising cam 16. The actuating butts 15 which are held by the selection electro-magnet 24 are submitted to the influence of the holding magnet 26, and during this phase the cam 29 ceases to act on the deformed parts 14 which return to their initial undeformed position; the thus selected neddle jacks 11 remain in the operative position and, as shown in FIG. 6, by action of raising cam 16, control the displacement of the corresponding needles 4 to a raised working position.
The special features of the needle jacks 11, notably that the elastic part 14 which extends from a point close to the pivot point 12 to beyond the part of the jack submitted to the influence of the magnetic means, enables a relatively large amplitude of movement of these deformable parts 14, which requires a lesser tolerance of the common thrust cam 29. This particular arrangement also enables a notable reduction of the mass of the part of each needle jack 11 which undergoes movement at the moment of non-selection by the electro-magnet 24, i.e. a reduction of its inertia at the moment of return to the inoperative position.
The invention relates to devices for the selection of knitting accessories such as needles of a circular knitting machine including at least one selection station on a fixed part surrounding the machine cylinder and pivotal jacks associated with the accessories to be controlled, each jack and an associated accessory being disposed in a respective guide groove of the machine cylinder, and each selection station including magnetic selection means disposed on a cam-box of the machine, means fixed on the cam-box for pivoting the pivotal jacks towards the exterior of the guide grooves, and a thrust member also fixed on the cam-box for acting on a deformable part of each jack.
Such a device is described and shown in U.S. Pat. No. 3,710,594 and, in one particular embodiment, comprises a pivotal needle jack associated with each needle and having, between one end which serves as pivoting point and an actuating butt disposed towards its other end, an elastically deformable tongue made in one piece with the needle jack. This tongue is located on the same side as the actuating butt, i.e. on the outer side of the guide groove provided in the machine cylinder, facing the cam-box which carries, at each selection station, a thrust cam for deforming the tongues as they pass by and magnetic selection means exerting a selective action on the actuating butts of the needle jacks.
The particular disposition of the deformable tongue between the point of pivoting or oscillation of the needle jack and its actuating butt submitted to the influence of the magnetic means implies that the tongue must be capable, from a deformation of relatively small amplitude, of producing a mechanical force which although it is less than the attractive force of the magnetic means must be sufficient to pivot a non-selected needle jack into its inoperative position. Each thrust cam must thus be disposed with a great precision.
Moreover, at the moment of deformation of its elastic tongue, each needle jack has (apart from the point of contact of the deformable tongue with the thrust cam) only a single point of support formed by the bottom (i.e. the inner surface) of its guide groove. In view of the fact that a certain lack of precision may result either because of the relative movement between the set of needle jacks and the thrust cams, or because of slight differences of depth that may occur in the various guide grooves, it is difficult to obtain a strictly identical deformation for each of the deformable tongues of the oscillating needle jacks.
SUMMARY OF THE INVENTION
The present invention aims to remedy the stated drawbacks and to facilitate the mounting of certain members while ensuring improved operating conditions.
According to the invention, there is provided a device for the selection of knitting accessories such as needles of a circular knitting machine including at least one selection station on a fixed part surrounding the machine cylinder and pivotal jacks associated with the accessories to be controlled, each jack and an associated accessory being disposed in a respective guide groove of the machine cylinder, in which each selection station includes magnetic selection means disposed on a cam-box of the machine, means fixed on the cam-box for pivoting the pivotal jacks towards the exterior of the guide grooves, a thrust member also fixed on the cam-box for acting on an elastically deformable part of each jack, and a fixed bearing surface for bearing against the pivotal jacks which are submitted to the influence of the magnetic means, the bearing surface as well as the thrust member and polar surfaces of the magnetic means being located at the exterior of the machine cylinder, and the magnetic means being so arranged between the bearing surface and the thrust member that at the moment of selection each jack is applied against stationary parts of the machine independent of the inner surface of its guide groove.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings show, by way of example, an embodiment of the selection device according to the invention. In the drawings:
FIG. 1 is a view in axial cross-section of a part of a circular knitting machine showing a needle jack in a rest position;
FIG. 2 is a schematic cross-section taken along line II--II of FIG. 1; and
FIGS. 3 to 6 are cross-sections similar to FIG. 1, but taken respectively along lines III--III, IV--IV, and V--V and VI--VI of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
A needle cylinder 1 of the circular knitting machine shown in FIG. 1 is fixed for rotation with a driving ring 2 and comprises at its periphery a series of axial grooves 3 in which are slidably mounted independent needles 4 each provided with an actuating butt 5 able to cooperate with the usual cams such as 6 and 7 at an upper part 8 of an annular cam-box fixed by its lower part 9 to a stationary plate 10 fixed to the frame on the machine.
Below each needle 4, movably mounted in the same guide groove 3, is disposed a needle jack 11 able to pivot about its rounded upper end 12.
Each needle jack 11 includes two longitudinally distinct parts 13 and 14 respectively facing the exterior and the bottom (i.e. the inner surface) of guide groove 3. The outer part 13 includes a protruding actuating butt 15 which can cooperate with a raising cam 16, fixed to part 8 of the cam-box, when the needle jack 11 is placed in an operative position by pivoting towards the exterior of its groove 3. The inner part 14 of needle jack 11 is elastically deformable and has an enlarged end 17 extending below the actuating butt 15 and protruding out of the lower end of guide groove 3. Each needle jack 11 also includes, between its pivoting point 12 and its actuating butt 15, a return butt 18 located above a protruding part 19 which is adapted to come to bear against a bearing cam 20 disposed in the upper part of an opening 21 provided in cam-box 8.
At each selection station (FIG. 2) the needle jacks 11 are selected in the following manner:
Upstream of each selection station, a setting cam 22, disposed on the lower part 9 of the stationary cam-box and below the rotary cylinder 1, acts on the rear face of the end 17 of the deformable parts 14 as they pass by, and outwardly pivots all of the needle jacks 11 into their operative position. In this operative position, a front face 23 of the actuating butts 15 is placed under the influence of magnetic selection means 25.
As in the referred-to patent specification, these magnetic means comprise an electro-magnet 24 selectively controlled by impulses provided by reading an information program (not shown). The electro-magnet 24 is disposed, in relation to the direction of motion of the needle jacks, between a lead-in magnet 25 and a holding magnet 26; these two magnets may be permanent magnets or permanently supplied electro-magnets. The three magnetic members 25, 24 and 26 are equally spaced apart by an amount less than the width of an actuating butt 15, and are fixed on a support 27 in a non-magnetic material which is itself fixed onto the lower part 9 of the cam-box by means of screws 28.
As shown in FIG. 3, the actuating butts 15 of all of the needle jacks 11 are firstly influenced by the lead-in magnet 25, the setting cam 22 slightly deforming the deformable parts 14 towards the exterior of guide grooves 3 in order to ensure a perfect magnetic adherence. During this magnetic attraction exerted by magnet 25 on butts 15, the action of setting cam 22 ceases, and the protruding part 19 of each needle jack 11 (FIG. 4) is made to bear against the cam 20, by the action of a thrust cam 29, which is fixed in a housing of support 27 and protrudes through an opening in cam 16 so as to exert a thrust on the front faces of the ends 17 of the deformable parts 14 as they pass by; this causes a deformation of parts 14 towards the interior of the guide grooves 3 against the attraction of magnet 25 which, as that of the electro-magnet 24 and of the holding magnet 26, is greater than the mechanical force produced by the reaction of each part 14 to tend to return to its initial undeformed position.
An important advantage resulting from the disposition of the bearing cam 20 resides in the fact that at the moment of deformation of their elastically deformable parts 14 by the thrust cam 29 the needle jacks 11, whose actuating butts 15 are submitted to the influence of the magnetic means are in contact only with stationary parts of the machine independent of guide grooves 3, which enables a total independence of possible differences which may exist in the depth of the guide grooves 3, as well as of a possible eccentricity of cylinder 1.
As they pass before the selection station, the needle jacks 11 whose rear parts 14 are still deformed are delivered to the selection electro-magnet 24. Those needle jacks (FIG. 5) whose actuating butts are not retained by the electro-magnet 24 pivot towards the interior of their respective guide grooves 3 by the relaxation of their deformable part 14 which, by reacting against the cam 29, causes return of these needle jacks 11 to the inoperative position out of alignment with raising cam 16. The actuating butts 15 which are held by the selection electro-magnet 24 are submitted to the influence of the holding magnet 26, and during this phase the cam 29 ceases to act on the deformed parts 14 which return to their initial undeformed position; the thus selected neddle jacks 11 remain in the operative position and, as shown in FIG. 6, by action of raising cam 16, control the displacement of the corresponding needles 4 to a raised working position.
The special features of the needle jacks 11, notably that the elastic part 14 which extends from a point close to the pivot point 12 to beyond the part of the jack submitted to the influence of the magnetic means, enables a relatively large amplitude of movement of these deformable parts 14, which requires a lesser tolerance of the common thrust cam 29. This particular arrangement also enables a notable reduction of the mass of the part of each needle jack 11 which undergoes movement at the moment of non-selection by the electro-magnet 24, i.e. a reduction of its inertia at the moment of return to the inoperative position.