Gebruder Loepfe Ag

Loepfe Brothers Limited

Gebrueder Loepfe Ag

Erich Weidmann

Erich Loepfe

Walter Schumperli

Walter Graf

Alfred Ruegg

Hans Zollinger

Walter Schümperli

The thread braking device comprises a pair of braking members, which are arranged symmetrically in respect to the path of the thread. Each of the braking members has a spring member. Between these spring members a line-shaped, vertically arranged braking zone is defined. For braking, the spring members are pivoted on rockers towards the thread path. Due to this movement as well as due to the vertical arrangement of the spring members, the deposition of contaminations in the braking zone is avoided. The elasticity of the spring members reduces the danger of damage in the presence of thickened thread sections.

Thread braking device having magnetically driven spring braking members

In order to monitor the correct receiving of an inserted weft yarn by a gripper in a receiving unit of a shuttleless weaving loom a detector is provided which is stationary mounted on the receiving side in an interspace between said gripper and a slay bar or reed of said weaving loom. Said detector comprises a plate-member projecting into said interspace or gap and having an inclined flank which is contacted by the weft yarn on his path between the inserting position and the beaten-up position. The passing of the weft yarn over this flank is detected by measuring potential variations in the detector during a defined phase of the machine cycle.

Weft yarn detector for a shuttleless weaving loom

A method and an apparatus for braking a moving thread are described, in which the braking effect is not brought about by a clamping of the thread but by looping same around braking elements. The braking effect can be adjusted in several ways, whereby an adaptation to the material and the working conditions can be achieved. In addition, the thread can be braked continuously or discontinuously.

Method for braking a moving thread-like material and thread brake for

Electronic control device on a gripper shuttle or projectile weaving machine or loom containing a lathe beam and thereto fixed teeth for guiding the gripper shuttle or projectile which inserts the weft or filling thread into the weaving shed, and a thread brake located at the picking side of the loom. The electronic control device comprises a sensor arranged on the lathe beam at least at one of the guide teeth and which furnishes an electrical sensor signal when the projectile passes by, an evaluation circuit connected to the sensor, and an electromagnetic device operatively connected to the evaluation circuit such as to actuate the thread brake upon appearance of an electrical sensor signal.

Inductive projectile sensor on a gripper shuttle weaving machine

A novel electronic weft thread monitor on a gripper shuttle weaving machine of the Sulzer type is designed such as to make possible the continuous monitoring of the weft insertion and the succeeding weft tensioning phases. The weft thread monitor comprises a thread sensing device provided with a guide member and is structured and positioned such as to exhibit a first range of high response sensitivity, and a second range of no or low response sensitivity. The weft thread when sweeping over the guide member is guided from the first to the second range of response sensitivity. When entering this second range, the monitoring process is stopped, and thus the end of the signal indicative of weft travel or tensioning is clearly defined.

Electronic weft thread monitor

The electronic weft stop motion is designed for monitoring the weft thread in a last phase immediately following the weft insertion into the weaving shed when a thread tensioning device located on the picking side of the machine laterally deflects the weft or filling thread and thus holds it tensioned. A tactile thread sensor is arranged in the region of the lateral deflection of the weft thread in such a manner that the thread sensor goes free from the weft thread in the undeflected condition thereof, however is frictionally contacted by the weft thread when the latter is being laterally deflected.

Electronic weft stop motion on a gripper shuttle weaving machine

An electronic weft or filling thread monitoring device on a gripper shuttle weaving machine provided with a rotatable color changing mechanism comprises a signal generator or weft thread travel sensor fixedly mounted in the area between the color changer and the point where the weft thread is transferred to the gripper shuttle or projectile. Only the one of the weft threads which is ready for transfer to the gripper shuttle is located in front of the signal generator without touching the same, and is lead in contact with the signal generator only when the projectile is driven into the weaving shed.

Electronic device for monitoring the weft insertion on a gripper shuttle

At each work position of a textile machine having a plurality of work positions driven by a common drive unit (warper's creels, winder or spooling and spinning machines, or circular knitting machines, for example), an electronic monitor device is provided which is responsive to thread travel. An indicator device is associated with each travel monitor and comprises a storage element and an indicator connected thereto, for the permanent indication of a thread breakage. To prevent false indications of thread breakage when the machine is stopped, a control signal is generated when the machine's drive unit is operating. Each indicator device further includes an electronic switch responsive to the control signal to insure the storage unit can be set to indicate a thread breakage only during operation of the drive unit.

Electronic device for monitoring a plurality of running threads on a

The invention is concerned with an electronic weft or filling thread monitoring device on a gripper shuttle weaving machine provided with means for moving the gripper shuttle, at the end of the shuttle insertion, back from a stop position to a yarn releasing position, and simultaneously tensioning the thread. The monitoring device comprises thread sensing means responsive to thread travel as well as to thread tensioning and provides machine stopping signals when neither continuous thread travel nor thread tensioning occurs in predetermined, machine-controlled monitoring intervals.

Electronic thread monitoring device for gripper shuttle weaving machines

The invention is concerned with an electronic device enabling an operator to easily and correctly adjust the time interval in which the weft insertion in shuttleless looms fitted with an electronic weft or filling thread monitor is to be monitored. A safety interval of some milliseconds' duration is provided at the end of said time interval taking into account the unavoidable fluctuations of the weft insertion period.

Electronic weft thread monitor for shuttleless weaving machines

Novel device for detecting knot-like thick places in travelling textile threads, comprising a plate-shaped or rectangular vibratory member which is fixed at one end and has a straight edge at its other end. A plate-shaped piezoelectrical transducer element is fixed at one of the major surfaces of said vibratory member. A thread guiding member having a straight edge is arranged in essentially parallel relationship to the straight edge of the vibratory member such as to form a thread passage gap between said straight edges. Means adjust the width of said thread passage gap, and a case or support structure is provided for receiving the vibratory member, electromechanical transducer element and thread guiding member.

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Wetzikon, Switzerland

Erich Weidmann