Title of Invention

A DEVICE FOR THE UPWARD AND/OR DOWNWARD MOVEMENT OF A DOFFER BEAM OF A SPINNING FRAME

Abstract

ABSTRACT: The invention relates to a device for the upward and/or downward movement of a doffer: beam (11) of a spinning frame, in «'*'particular of a ring spinning frame, where the movement of the doffer beam (11) is controlled by means of a predetermined schedule. Along the moving path of the spindle (19), Initiators (14) are arranged at predetermined spaces, which, when the spindle (19; passes then deliver a signal of presence to a processor (15.1) of a control unit (15), which, based on the signals of presence and in timed interval calculates the momentary velocity and acceleration values of the spindle nut (12) and thus of the doffer beam (11) and which delivers a control signal to the doffer drive (16), which at first accelerates and then decelerates the doffer beam (11) . PRICE: THIRTY RUPEES r

Full Text

The invention relates to a device for the upward and/or downward movements of a doffer beam of a spinning frame, in particular of a ring spinning frame. It is already known (DE-OS 22 18 580) to continuously measure the shifting velocity of the doffer beam by means of a macho-alternator and to form a control signal from the thus registered actual speed, said control signal controlling the doffer beam drive in such a way that the doffer beam is lifted or lowered with constant velocity. By this it can be avoided that the doffer beam, in connection with the use of a conventional scissor-type shifting mechanism, at the beginning is moved at high velocity and at the end of the movement with low velocity, in case the drive motor runs with constant revolutions. It is the object of the present invention to provide device of the kind mentioned at the beginning, through which, without excessive acceleration strains on the doffer beam, the time for the upwards and downwards movement of the doffer beam can be minimized. The task as object of the invention is solved according to the characteristic features of claim 1. The idea of the invention therefore is based on the fact that the considerable part of the distance which the doffer beam has to move from its lowest position to its highest position and vice versa is utilized to accelerate the doffer beam continuously or practically continuously or to reduce the acceleration, whereby the average upwards velocity, downwards velocity respectively, can be increased so distinctly, in that the normally needed doffing time of about two minutes can be reduced down to 1,5 minutes, without causing excessive values of acceleration strain on the doffer beam of the cinematically connected structural parts. The value of acceleration and deceleration of the doffer beam movement can be changed in such a way that the strains developing on particularly a scissor-type shifting mechanism are kept within pre-determined limits, whereby the time for the movement of the doffer beam from one operating position to the next, is still kept at a minimum. Of particular advantage is the embodiment, which makes it possible in a simple way to employ a digital control of the doffer beam shifting mechanism. The start and the end of a programme phase can preferably be determined through the doffer or its initiators mounted on the shifting mechanism, while the small time steps within a programme phase are preferably predetermined by a timer. As object of the invention the device according to claim 1 is provided with a control device, which is furnished with a processor, a memory and a timer, in order to, in relation to the signals delivered by the initiators, enable the retrieval of the stored parameters at any time which are stored for the respective programme phase as well as for the step by step velocity increase, velocity decrease respectively, in timely measured steps. A particularly simple realisation of the idea based on the invention is assured by application of a frequency transformer according to claim 2. Suitably structural arrangements are described in claims 3 to 5. Accordingly, the present invention provides a device for the upward and/or downward movement of a doffer beam of a spinning frame, in particular of a ring spinning frame, in which the movement of the doffer beam is controlled according to a pre-determined schedule, wherein along the moving path of the doffer beam or of structural parts, kinematically connected to it, initiators are arranged at pre¬determined intervals which, when passing a transmitter mounted on the doffer beam and/or a structural part kinematically connected to it, release a signal of presence to a control device and wherein the control device is provided with a memory stored with retrievable parameters of the velocity increase, velocity decrease respectively, and of the critical velocity and with a timer which subdivides the schedule phases into a number of small timed intervals and further wherein within the control device a processor is provided which calculates, from the presence signals transmitted by the initiators and the retrieved parameters from the memory, the predetermined critical velocity for the respective schedule step and for the velocity increase, velocity decrease respectively, of the doffer beam for each of the number of small steps and which delivers a signal to the doffer drive, which increases, decreases respectively, step by step the velocity up to the end of the schedule step by predetermined values. The object of the invention is hereafter described by way of exemplified embodiments and with reference to the accompanying drawings, in which: fig. 1 a schematic view of a doffer beam arrangement in a ring spinning frame in connection with a drive and a control unit according to the invention, fig. 2 a diagram which shows the relation to the velocities of the doffer beam indicated in random intervals to the time in ms within three successive programme phases. fig. 3a a diagram of the doffer arrangement in a and 3b first and in a second position According to figure 1 a doffer beam 11 is shifted by a conventional scissor-type mechanism 18 through a stationarily mounted nut which is rotated by an electric motor 16 via a chain, to shift a spindle 19 horizontally, for either an upwards or downwards movement of said doffer beam in direction of the double arrow 21. The scissor-type mechanism 18 consists of several inclined hinge rods 22, of which only two are shown in drawings 1 and 3. The hinge rods 22 are connected through joints 23, 24 on guides 38 and 39 with the doffer beam 11, the spindle 19 respectively, which is shifted through the rotation of the nut 12. Approximately in the middle of the hinged rod 22 a support arm 25 branches off, which at one end is connected by means of a joint 26 with the hinged rod 22 and which at its other end by means of a joint 27, is connected with a sleeve 28, which is stationarily mounted on the machine frame and which sleeve supports the spindle extension 19 so that it can rotate freely. Through rotation of the nut 12 by the electric motor 16 in one or the other direction, the doffer beam 11 can be thus lifted and lowered vertically in the known manner. According to the invention a first transmitter 20.1 is arranged near the sleeve 28 mounted fixedly on the frame which transmitter is mounted on a guiding rod 37 which can be moved resiliently in vertical direction with regard to the doffer guide sleeve 38 (see fig. 3b), which transmitter is effective in such a way that, together with initiators 14, arranged fixedly at predetermined spaces along the moving path of the guide rod 37 and between which there is a programme phase, that during passage of the transmitter 20.1 of one of the initiators 14, via a control line 29 a signal of presence is released to a suitable entry connection of a control device 15, said device containing a processor 15.1, a memory 15.2, a timer 15.3 and a digital-to-analog converter 33. According to the invention a second transmitter 20.2 is arranged on the spindle 19, which transmitter is effective in such a way that, together with a second set of initiators 14, arranged fixedly in horizontal direction at predetermined spaces along the moving path of the spindle 19 and between which there is a programme phase, that during passage of the transmitter 20.2 of one of the initiators 14, via a control line 29, again a signal of presence is released to the entry connection of the control device 15. The initiators 14 preferably release an ON/OFF signal when passing the respective transmitter 20.1 respectively 20.2, so that a simple entry connection is sufficient, where preferably for each initiator an own control line 29 and an own digital processor entrance is provided. It is not necessary to provide both horizontally and vertically arranged initiators, even though by means of the vertically arranged initiators it is easy to sense the actual height for the lowest position of the doffer beam. The predetermined spaces between two separate pairs of initiators do not need to be identical, they can also vary. The output signal of the digital-to-analog converter 33 of the control device 15 is connected to the electric motor 16 through of a line 34, a frequency transformer 17 and a further line'31. In the memory 15.2 data words Dwx are stored for each position of the transmitter 20 in relation to a defined initiator 14 in a corresponding doffing step, which contain values for the maximum velocity, of the doffer beam 11 and values for the differential velocity increase, velocity decrease respectively within a programme phase. The timing of the differential velocity increases, velocity decreases respectively is effected by the timer 15.3. The control device 15 controls the output frequency of the frequency transformer 17 in such a way that it drives the electric motor 16 in a rotating direction and at a speed depending on the initial signal of the control unit 15. The way the described device works is as follows: If the doffer beam 11, as shown in figure 3b, is in its lowest position, the transmitter 20.1 is opposite the lowest vertical initiator 14, which is situated at a position 13i, and/or the transmitter 20.2 is opposite the horizontally arranged initiator 14 shown in the drawing on the furthest left, which is located at a position 134. If now the motor 16 - initiated by a signal from the machine -is switched to lifting movement, the spindle 19 and thus the transmitter 20.1 moves along the initiators from the position 13i to the position 132 up to the position 133, the transmitter 20.2 moves along the initiators from the position 134 to the position 135 etc. up to the position 138 respectively. When the transmitter 20 passes one of the initiators 14 the presence at the respective position 13n of the transmitter 20 is signalled to the control device 15. If the transmitter 20 first passes the initiator 14 at the position 13i, the processor 15.1 of the control device 15 retrieves a data word DW1 from the memory 15.1, which effects a constant speed of the doffer beam within a time of for instance 250 ms depending on the momentary velocity and the predetermined space to the following initiator. Figure 2 shows the constant velocity of the doffer beam 11 during the programme step 10-1 between the positions 13.1 and 13.2 as a horizontal line parallel to the time axis t. If then the transmitter 20 passes the initiator 14 at the position 132, then the corresponding signal arriving at the control device 15 effects the processor 15.1 do retrieve a data word DW2 from the memory 15.2, which determines on one hand the maximum speed of the doffer beam 11 within the succeeding programme phase 10-1 and on the other hand a certain velocity increase within a number, for instance of five small timed steps of for instance 50 ms. The time interval of approximately 250 ms of the programme phase 10-1 depending on the momentary velocity and the space between the initiator is thus divided into approximately five equally timed steps by the timer 15.3. During each of these steps the velocity of the doffer beam 11 increases by a predetermined value, which is determined by the data word DW2. In the example in figure 2 thus the velocity of the doffer beam increases by an amount of five equally timed steps, which corresponds with the fivefold of the single step. At first the velocity increase during the programme phase 10-1 is still relatively moderate. Due to the inertia the velocity of the doffer beam however increases steadily, as this is indicated in figure 2 by a dotted line. If the transmitter 20, according to figure 1, now reaches the initiator 14 at the position I33, the processor 15.1 retrieves a further data word DW3 from the memory 15.2, which again contains the maximum allowable velocity of the doffer beam 11 and additionally an acceleration signal, which is somewhat greater than the one of the programme phase 10-1. This way in each of the 50 ms steps the velocity increase in the programme phase 10-2 is slightly greater than in the programme phase 10-1. According to the invention thus the initiators 14 divide the moving path of the doffer beam 11 into different programme phases 10-0, 10-1. 10-2... which are determined by the positions, which themselves are divided into single small timed steps by the timer 15.3. For each programme phase the memory 15.1 contains a certain data word which determines the maximum velocity and acceleration, which effects that in each programme phase a certain maximum velocity of the doffer beam 11 is not exceeded and that in each small timed interval determined by the timer 15.3 a predetermined velocity increase takes place. The processor 15.1 in the control device 15 provides a control signal, which, via the digital-to-analog converter 33 and the control line 30 controls the frequency transformer 17 in such a way that said frequency transformer releases a frequency signal to the electric motor 16, which at first accelerates the doffer beam 11 according to figure 2 and in a second movement step, not shown in figure 2, decelerates the velocity to zero within a corresponding programme phase and in small short timed steps. Thereby the accelerations are set in such a way that there is no excessive strain on the doffer beam 11 and on the structural elements 19, 12, 22, 15, 28 connected to it. The transmitter signals received from the initiators are preferably not only applied in the described control of the velocity pattern, but can also be used, for instance at certain doffer positions to initiate necessary operating steps such as to inflate the grippers. The location of the initiators can thus be partly or completely selected in such a way that this is appropriate for transmitting of the additionally required operating steps, where for instance three of the eight initiators are provided solely for measuring of the height level and where five initiators are provided with a double function. Reference list 11 doffer beam 12 nut 13 position 14 initiators 15 control device .5.1 processor .5.2 memory ,5.3 timer 6 doffer drive (electric drive) 7 freque.icy transformer 8 scissor-type mechanism 9 -spindle 0.1 transmitter 0.2 transmitter 1 double arrow 2 hinge rod 3 joint 4 joint 5 support arm 6 joint 7 joint 8 sleeve 9 control line 10 control line L line i analog-to-digital converter conductor chain guide rod guide guide WE CLAIM; 1. A device for the upward and/or downward movement of a doffer beam (11) of a spinning frame, in particular of a ring spinning frame, in which the movement of the doffer beam is controlled according to a pre-determined schedule, wherein along the moving path of the doffer beam (11) or of structural parts (19, 37), kinematically connected to it, initiators (14) are arranged at pre-determined intervals which, when passing a transmitter (20) mounted on the doffer beam (11) and/or a structural part (19, 37) kinematically connected to it, release a signal of presence to a control device (15) and wherein the control device (15) is provided with a memory (15.2) stored with retrievable parameters of the velocity increase, velocity decrease respectively, and of the critical velocity (Dwx) and with a timer (15.3) which subdivides the schedule phases (10-1,...) into a number of small timed intervals and further wherein within the control device (15) a processor (15.1) is provided which calculates, from the presence signals transmitted by the initiators (14) and the retrieved parameters (Dwx) from the memory (15.2), the predetermined critical velocity for the respective schedule step (10-1...) and for the velocity increase, velocity decrease respectively, of the doffer beam (11) for each of the number of small steps and which delivers a signal to the doffer drive (16), which increases, decreases respectively, step by step the velocity up to the end of the schedule step by predetermined values. 2. The device according to claim 1, wherein the drive consists of an electric motor (16) which is controlled by a frequency transformer (17) with a frequency which is determined by the control device (15) connected to the frequency transformer (17). 3. The device according to claim 1 or 2, wherein the doffer beam (11) is driven through an electric motor (16) by means of a scissor-type mechanism (18) and a spindle (19), whereby the initiators (14) are arranged to a transmitter (20.2) mounted on the spindle (19) and/or to a transmitter (20.1) mounted on a guide rod (37) which is vertically shifted through the movement of the doffer beam. 4. The device according to one of the claims 1 or 3, wherein the initiators (14) are directly connected to the control device. 5. The device according to one of the claims 1 to 4, wherein the analog-to- digital converter is integrated within the control device. 6. A device for the upward and/or downward movement of a doffer beam of a spinning frame substantially as herein described and exemplified with reference to the accompanying drawings.

Documents:

0124-mas-1996 abstract.jpg

0124-mas-1996 abstract.pdf

0124-mas-1996 claims.pdf

0124-mas-1996 correspondence-others.pdf

0124-mas-1996 correspondence-po.pdf

0124-mas-1996 description(complete).pdf

0124-mas-1996 drawings.pdf

0124-mas-1996 form-2.pdf

0124-mas-1996 form-26.pdf

0124-mas-1996 form-4.pdf

0124-mas-1996 form-6.pdf

0124-mas-1996 others.pdf

0124-mas-1996 petition.pdf