摘要:
A tensiometer for measuring thread tension, provided with a bending element fixed at one end and tensioned at the other end by the thread, at least one sensor element and damping device for oscillating the bending element. The damping device has at least one mass damper fixed to the bending element by means of a spring body.
摘要:
The invention relates to a yarn tensioning device (B) comprising a braking body (K) embodied in the form of a truncated conical jacket (3) which is coaxially positioned on the rounded discharge end (2) of a storage body (1) and is pushed to a small diameter end (5) by the elastic axial force defining a braking effect between the braking body and the discharge end (2), an axial force generator (P) disposed between a fixed holding element (10) and the braking body and a centering device (C) provided with a radial working direction and disposed between the holding element (10) and the braking body, wherein said axial force generator (P) consists of at least one pair of axially superimposed permanent magnets, an intermediate slit is arranged between said permanent magnets and the centering device (C) which is embodied in the form of a axial slide guideway (9, 12, 24, 23) which is structurally and functionally separated from the permanent magnet pair or contactlessly formed thereby.
摘要:
An opto-electronic device (S) for detecting the movement of yarn (Y) (10) passing transversely through a detection zone (11) on the storage drum (3) of a yarn feeder (F), has at least one light source (L) directed on the detection zone (11), at least one reflector (B) fitted on the storage drum (3) a short distance away on the side of the detection zone (11) away from the light source (L) and at least one signal-generating receiver (R) directed towards the detection zone. The opto-electronic device also has a reflector which includes (B) at least one narrow and approximately flat reflection area (15, 15', 15") extending essentially parallel to the longitudinal direction of the yarn and in the circumferential direction of the storage drum (3). The reflection area is bounded at its longitudinal sides by either a strip diaphragm fitted between the reflector (B) and the yarn passage plane (13), or diaphragmed regions (17) arranged approximately in the reflector plane.
摘要:
A yarn feeder includes a storage drum, and an unwinding brake which has a storage drum counter-braking surface continuous in the peripheral direction and coaxial to the axis of the storage drum. The unwinding brake further has a braking component supported on the counter-braking surface axially counter to the direction of yarn unwinding so as to produce spring action and having a coaxial braking surface also continuous in the peripheral direction. The yarn feeder also has a mounting for the braking component, and a pneumatic brake opening device which has a pressure chamber with a pneumatically loadable, axially movable boundary wall. The boundary wall is connected to the braking component so as to transmit movement at least in the direction of movement thereof counter to the action of the spring. When the boundary wall is pressurised by excess pressure or a vacuum, the braking component can be moved axially into a threading position in which the braking surface is lifted from the counter-braking surface.
摘要:
A controllable output brake for a thread feed device includes actuating elements that are connected to a control member and are used for effecting a controlled displacement of a thread brake element. The controlled displacement is an axial play with which a supporting ring for the thread brake element is supported in a holding member. The controlled displacement is used for controlling the tension of a thread. In the case of such a thread feed device, a push drive connected to the holding member is provided for each direction of movement in which the thread brake element is adjusted. The push drive for at least one direction of movement is a pneumatic push drive connected to a pneumatic drive control unit. In a projectile weaving machine, the controlled output brake is disengaged and re-engaged approximately in synchronism with a controlled thread brake which is provided as well. The engagement is preferably carried out in advance of the engagement of the controlled thread brake. In a gripper weaving machine, the controlled output brake is disengaged and re-engaged several times during each picking operation.
摘要:
In a device for guiding and braking a yarn, a yarn brake comprises braking elements that are pressed flexibly against each other and act on the yarn in a pinch zone. The yarn brake is arranged in the yarn running path between a yarn feeder and a yarn receiver. A pneumatic threader also is provided which includes at least one air and yarn guide element that is disposed in the yarn brake and surrounds the pinch zone without contact. The air and yarn guide element comprising a receiving end, a delivery end and a guide channel provided therebetween, which is open towards the braking elements and from which the yarn is introduced into the pinch zone. The yarn is conveyed into the guide channel by means of an air flow past the pinch zone to the yarn receiver and is introduced into the pinch zone under the action of a produced drawing force.
摘要:
A device for feeding weft yarns to a weaving machine which includes a rotatingly driven retainer that is constructed such that it has little mass. The retainer is coupled to a rotary drive unit such that the retainer cannot move radially with respect to a storage drum axis so that, when viewed in the direction of circulation of the withdrawal point, the retainer continuously extends through a circulatory path ahead of the weft yarn. The rotary drive unit is additionally connected to a control device which controls the acceleration and deceleration of the retainer in accord with a speed profile and determines the process of weft insertion in the weaving machine.
摘要:
A thread feeding system including a thread regulator having a fixed housing, a hollow rotatable shaft extending through the fixed housing, a rotatable winding section secured to the rotatable shaft, an angled thread duct extending through the thread regulator, an inlet positioned at an upstream end of the duct, and ejectors positioned along the duct portions. The ejectors supply a working medium from a pressurized working medium source to the duct to facilitate threading of a thread through the thread duct. The inlet receives a free end of the thread from a thread spool assembly positioned upstream from the thread regulator. The feeding system also includes an arrangement for controlling the ejectors so that the ejectors generate a pressure proximate to the inlet to develop a flow of the working medium into the inlet, and an arrangement for feeding the thread through the thread regulator in a pulsating manner to insure that the free end of the thread passes unobstructed through the thread duct.
摘要:
A yarn storage and feed device for textile machines, comprising a storage body defining a storage surface as well as a winding member for the yarn, the winding member and the storage member being adapted to be rotated relative to each other for transporting the yarn from a feed side of the device onto the storage surface of the storage member and for forming a yarn supply from which the yarn is removed towards the take-off side of the device, and further comprising yarn guide members, which are arranged in the yarn path from the feed area to the take-off area and which are provided with yarn guide surfaces coated with sintered ceramic material or consisting of sintered ceramic material, the yarn being deflected on the yarn guide surfaces at various angles. With regard to particularly advantageous frictional conditions, at least the yarn guide surface (L) having the largest deflection angle (180.degree.-.alpha.) is made of a high-density sintered material containing mainly nitride, carbide and/or carbonitride hard materials. This sintered material is formed in an encapsulation in accordance with an isostatic hot-press sintering method for producing thus a yarn guide member.
摘要:
In a method for controlling a yarn storage and feeding device, particularly for a mechanical loom, comprising a storage surface adapted to have windings of a yarn wound thereonto and withdrawn therefrom by a consumer, and a control unit for a winding drive mechanism operable to adjust the winding speed in accordance with the consumption rate and in response at least to the actual value of the number of yarn windings on the storage surface, for adjusting the actual value towards a predetermined desired value, the desired value is altered in response to at least one alteration of the winding speed to thereby obtain an optimum smallness of the yarn supply on the storage surface. In a yarn storage and feeding device for performing this method, the control unit cooperates with a reference value memory (18) for the supply of desired values (nV) varying in a predetermined manner.