The present application claims the priority of European Patent Application No. 07 023 817.5, filed Dec. 8, 2007, the subject matter of which, in its entirety, is incorporated herein by reference.
The invention relates to a needle bed for a knitting machine.
Knitting machines have been known, for example, designed as circular knitting machines or as flat-bed knitting machines. While the latter comprise at least one essentially flat needle bed, the needle beds of circular knitting machines are designed as hollow cylinders acting as knitting cylinders or in a ring-shaped manner to represent rib dials. Each needle bed has needle channels into which are set the knitting tools such as, for example, needles or sinkers. During operation, the knitting tools are moved back and forth in the needle bed.
German Patent Document DE 24 16 626 A1 discloses such a needle bed and also teaches to provide the needle bed with grooves extending in a direction transverse to the needle channels and to blow an air/oil mixture through bores into these grooves. The groove walls that delimit the guide channels of the knitting tools may be provided with recesses, so that the lubricant may better spread between the knitting tools and their guide channels.
Considering this arrangement, it is quite difficult to maintain control over the spreading of the lubricant in the needle bed.
German Patent Document DE 1 635 836 A discloses a knitting cylinder as well as a rib dial in a circular knitting machine. Both may be provided with annular grooves that intersect the guide grooves of the knitting tools. Pressurized air may be blown into the cam ring through these annular grooves.
Furthermore, the injection of pressured air into the needle bed has been known from document DD 37 345 A, whereby the pressurized air is to prevent the accumulation of debris in the cam area of the affected knitting machine.
Pressurized air is a process medium that, when used, is connected with considerable operating costs. Therefore, one objective must be to lower the amount of pressurized air required for the operation of a knitting machine.
Furthermore, the accumulation of debris in the needle beds of knitting machines represents a problem that promotes wear and shortens maintenance intervals. Consequently, it must be an objective to avoid the accumulation of debris in the needle carriers of knitting machines.
Also, with increasing operating speeds of knitting machines, the reliability of the lubrication of the knitting tools becomes of importance. Knitting tools that run partially dry result in an increased use of energy and in wear of the knitting tool and of the knitting machine.
Considering this, it is the object of the invention to produce a knitting machine displaying improved air supply.
The above object is achieved with the needle bed that displays the features of Claim 1:
The needle bed in accordance with the invention may be designed as a knitting cylinder, a rib dial, a flat bed or as a similar needle carrier of a loop-forming machine. Said needle bed comprises a base element having one surface that is provided with a plurality of grooves as well as with a fluid channel that extends in a direction transverse to the longitudinal direction of the grooves and, preferably, at one end of the grooves. Strips are set into the grooves that—between them—form guide grooves for the knitting tools. Each of the strips has a number of recesses that create a fluid connection between the fluid channel and the guide grooves.
On its side seated in the groove, i.e., on its underside, the strip has several recesses similar to a comb, the depth of said recesses being slightly greater than the depth of the grooves provided in the base element. (In so doing, the “depth” is measured perpendicular to the groove, i.e., in radial direction in the case of a knitting cylinder.) Most of these tooth-like projections do not touch the groove bottom of the needle carrier. As a result of this, a flow channel extending in longitudinal direction inside the groove is created, whereby said channel can be used for dispensing a fluid such as, for example, dry pressurized air, oil-containing pressurized air or a similar fluid, into the needle channel in the desired distribution along the length of the strip. Thus, most of the tooth-like projections hover over the groove bottom of the needle carrier. The thickness of the strip and its teeth is preferably consistent with the groove width at each point of the strip. The upper side of the strip is preferably closed, i.e., does not have any recesses. Preferably, the strip is delimited at the top by a surface that is narrow, straight, continuous and strip-shaped.
A preferred embodiment may have several fluid channels performing different functions. For example, a first fluid channel is located in the immediate vicinity of the receiving grooves for the channel strips, as has already been described. This fluid channel has the form of a circling groove and can act as a distributor groove. A second fluid channel may be provided within the base element and communicate via a connecting channel, preferably several connecting channels, with the first fluid channel.
The front and the rear ends, respectively, are used for supporting and adjusting the strips inside the groove.
In addition, one of the tooth-like projections may touch—between its front end and its rear end of the strip—the bottom of the groove in order to effect a flow interruption, i.e., a barrier between the recesses. This tooth-like projection thus divides the recesses into two groups, namely, a first group that communicates with the fluid-conducting channel and a second group that communicates with a fluid-draining channel, for example. As a result of this, a well-controlled fluid flow can be achieved in each needle channel, said flow supplying to the knitting tool—in the desired distribution—the required fluid, for example, oil-carrying pressurized air, and again draining the optionally debris-loaded fluid at a desired location. In this manner, dirt particles, fuzz, abraded material, excess lubricant and the like that had entered the needle channel can be drained in a controlled manner.
Consequently, the invention permits the controlled and adequate lubrication of knitting tools, on the one hand, as well as prevents knitting tools and needle channels from being soiled, and lubricant from being carried into the environment, or prevents lubricant from excessively contaminating knit material with lubricant, on the other hand.
As a result of the controlled supply of the fluid to the knitting tool through an array of recesses in the strips, the required amount of fluid is reduced to a minimum. This is successful because, due to the controlled distribution of the fluid over the length of the knitting tool, both an uncontrolled escape and an excess of fluid at specific points are avoided, and a lack of fluid at another point is also avoided.
Additional details of advantageous embodiments of the invention are the subject matter of the drawing, the description and the subclaims.
The description is restricted to essential aspects of the invention and other existing situations. The drawings disclose additional details and are thus to be used as a supplementary reference. The description and the drawings represent exemplary embodiments of the invention.
The needle channels 5 are formed between the strips 4, whereby, in accordance with
In the case, in which the inventive needle bed is implemented as a rib dial 8, as shown by
Additional details are illustrated by
As illustrated by
Extending from the fluid channel 15 is a connecting channel 20 to a distributor groove 21 that is configured, e.g., as a ring groove and is arranged concentrically with respect to the ring-shaped base element 10. The ring groove 21 intersects all grooves 12, 13, 14. Preferably, the component 10a has a number of such connecting channels 20 that connect the distributor groove 21 to the fluid channel 15 at several, preferably at many, different, points. Preferably the distributor groove 21 is covered, i.e., it does not reach the surface 11 representing the bottom of the guide grooves of the knitting tools. This can be achieved, for example, in that the distributor groove 21, as shown by
The fluid channel 16 that is preferably disposed to drain fluid communicates, via at least one, preferably more, connecting channels 24, with a distributor groove 25 that acts as a collecting groove that is preferably arranged concentrically with respect to the distributor groove 21. While the distributor groove 21 is arranged at one end of the groove 12, the distributor groove 25 is arranged at its other end. The distributor groove 25 is machined into the surface 11 and is thus open toward the needle channels 5.
The strips 4 are preferably shaped the same relative to each other. Preferably, they have the shape of thin planar flat elements that are set erect in the grooves 12, 13, 14. Said flat elements' ends 26, 27 abut against the bottom 23 of the groove 12 or against other fitting or alignment surfaces of the base element 10, and thus positioning the strip 4.
The strip 4 is provided with a number of recesses 28 through 37, between which projections having the form of teeth 38 through 46 are provided. The recesses 28 through 37 take away material from the lower edge of the strip 4, said edge being seated in the groove, and have a size such that they project beyond the surface 11 when the strip 4 is seated in the groove 12. The teeth 38 through 46 seated in the recesses 38 through 46 have a length such that they sink into the groove 12. Preferably, at least one tooth 38 has a length such that it touches or almost touches the groove bottom 23. Consequently, it represents a barrier that essentially prevents the fluid flow along the groove 12. Preferably, the remaining teeth 39 through 46 are shorter so that they do not reach the groove bottom 23. Consequently, the long tooth 38 divides the recesses 28 though 37 into two groups: a first group (29 through 37) that communicates with the fluid-supplying distributor groove 21 and a second group 28 that communicates with the fluid-draining distributor groove 25.
The needle bed 1 described so far works as follows:
During operation, the knitting tools 6 seated in the needle channels 5 between the strips 4 are moved back and forth in longitudinal direction (in
As explained, the air/oil mixture arrives in an orderly manner in the needle channels and at the loop-forming tools. As a result of the evacuating effect of the collecting channel 25 and the fluid channel 16, the oil/air mixture is discharged again, together with fiber dust, abraded material and so on. A defined circulation occurs.
The balance between air supply and air discharge can be selected in such a manner that a slight excess pressure prevails at all times in the region of the loop-forming components, so that dust and debris are kept away.
The invention may be modified in numerous ways. For example, as shown by
In addition, it is possible, as shown by
In addition, the distribution of the air or the oil/air mixture can be optimized in that the volume of the fluid channels 15, 16 is adapted to existing flow situations, i.e., in that the volume of the fluid channels, in particular the fluid channel 15, through which the air or the oil/air mixture is supplied, is reduced starting from the connection 18. It is also possible that the volume of the fluid channel 15 enlarges starting from the connection 18, should this permit an optimization of the existing flow situations. The same applies analogously to the fluid channel 16.
As previously mentioned, it is possible to configure all the strips of the needle bed 1 as described above. Furthermore, it is possible to provide, alternately, a conventional strip without teeth and recesses and a strip with teeth and recesses in order to supply the air/oil mixture to the individual needle channels on only one side.
The needle bed 1 in accordance with the invention comprises strips 4 in order to form needle channels 5, said strips being configured in a comb-like manner. Between the individual teeth of this comb, recesses 28 through 37 are formed, said recesses being disposed to supply fluid to the needle channel 5 and to drain said fluid. The groove 12 that accommodates the strip 4 forms a distributor space where the distribution of the fluid to be supplied to the knitting tools takes place over a section of the strip 4, said section being preferably greater than half the length of said strip.
It will be appreciated that the above description of the present invention is susceptible to various modifications, changes and modifications, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
Number | Date | Country | Kind |
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07 023 817.5 | Dec 2007 | EP | regional |