SEAM INDICATING ARRANGEMENT IN A SEWING MACHINE

Abstract: The seam indicating arrangement in an electronic sew­ ing machine shall show all the seams that can be sewn. The seam illustrations (A-H) are performed on an electronic display where several groups of seam illustrations can become visible by means of electric signals. Thus, the arrangement shows the seam illustration as well as the marker and is connected to seam selecting means (13) by which the groups can be presented one by one and the marker moved between several illustrations.

Description: The present invention relates to a seam indicator in an electronic sewing machine with several seams which can be sewn after an adjustment of a seam selecting means. It is a problem by an electronic sewing machine with several seams to show them all that can be sewn. The number of seams is so great that the illustrations of them together cover a great surface. Another problem is how to arrange a seam selection device, where one seam at the time can be selected. In prior art a solution is known from a case, where the seams are allotted a number of cassettes, whereby just a limited set of seams is shown simultaneously. In another case the seams are shown on a lid or the like where each seam has a number and the same is selected by setting the number on a numerical input arrangement on the machine. The density of illustrations in an indicating arrangement is restricted by the fact that there must be a certain distance between the illustrations. Without such a distance the illustrations will run into each other and be difficult to survey. A possibility to solve this problem is presented by the present invention. The seam illustrations are performed on an electronic indicating arrangement according to this invention so that several groups of seam indications become visible one by one by means of electric signals. In such an arrangement the seam illustrations can abut each other whereby every second one, for instance, belongs to one group and the others to another group. By means of an operating member the operator can change showing the different groups. In an arrangement of this kind there must also be markers to show a selected seam. The markers can be made of spots which are made visible by electronic means, one for each seam illustration. Also devices making the selected seam illustration deviate in brightness, preferably higher, can be markers. They are controlled by a seam selecting means so designed that a given measure on it brings about a movement of the marker to the next visible seam illustration in a given direction. The means used to achieve these properties are given the name multiplex driving which is an effective mode to decrease the number of driving steps in the indicating arrangement. If it has many segments on a common plate, the number of connections to the arrangement is decreased which may be of the type LCD (Liquid Crystal Display) or ELD (Electroluminiscens-display). In these arrangements the wiring is performed on at least one of two parallel glass discs which simultaneously as being wire carriers serve as liquid enclosing surfaces. By a combination of a special wiring and multiplex driving the problem of indicating seams in groups and a moveable marker has been solved by the invention so that one for the sewing machine desired number of seam illustrations more than well is fulfilled. The characterizing properties of the invention are resumed in the characterizing clause of Claim 1. An embodiment of the arrangement according to the invention will be described in the following with reference to the accompanying drawings which show in Fig. 1 a - d a simple indicating arrangement with seam illustrations and their performing, Fig. 2 a - d diagrams showing wave forms, Fig. 3 a scheme of control signals, Fig. 4 a wiring diagram including modules, Fig. 5 a wiring diagram of change-over switches in the arrangement, Fig. 6 a variation of the arrangement. A display of the indicating arrangement is envisaged in Fig. 1a where eight seam illustrations in the form of the characters A - H and marker arrows are visible when all segments 10, 11 in the arrangement are active. Usually, all segments are not active, so a typical illustration on the display can look like Fig. 1b. The display is constituted of a pair of glass discs on which the segments in the shape of transparent foils are applied and separated by a layer of liquid crystal (LCD). The foils form the said characters and arrows on the discs according to Fig. 1a. In order to put tension to the segments a wiring pattern is required on the discs. Such a pattern has horizontal (H₀, H₁, H₂) as well as vertical (V₁, V₂, V₃) wires and the composition of them on the disc with characters and arrows is shown in Fig. 1c, and on the disc with a corresponding foil in Fig. 1d. The appearance of an illustration according to Fig. 1b takes place by supplying pulses in a multiplex system with a multiplier 2 on wires involved, i.e. the segments are divided into two phases which are supplied cyclically one by one. The time of a cycle is short, some 30 ms, so the eye will see the illustration constant. In one of the phases the illustrations of A, B, C, and D are included and in the second phase the markers. The supply to multiplex arranged LCDs is effected by complex alternating waves, and in the following the waves on one disc are denoted H t(o) and H f(rom) and on the other disc V t(o) and V f(rom) , see Fig. 2 a - d. In Fig. 3 the four waves H t , H f , V t and V f are shown as diagrams for producing the illustration in Fig. 1b by a wiring pattern according to Figs. 1c, 1d. The waves H t and H f are passed to H₀, H₁ and H₂, respectively. The wave V t is passed to V₁, V₃, and the wave V f to V₂, V₄, respectively. Then the characters A, B, C, D appear. Moreover, H t is passed to H₁, and H f to H₀, H₂ and V t to V₃ and V f to V₁, V₂, V₄. Then the arrow appears at B. Fig. 3 shows the curves during a cycle (30 ms) which is formed by two phases I = characters, II = marker. The procedure is repeated identically during all the following cycles. In practice, a so-called multiplexer 12 is used for producing the waves and constituted, as shown by the example in Fig. 4, of a CMOS-module number CD 4052. A counter CD 4024 and an oscillator CD 4047 are connected to it. The oscillator produces a control pulse at every 7,5 ms to the counter which prepares and supplies to the multiplexer a number series 0, 1, 2, 3, 0, 1, 2 etc. cyclically with 7,5 ms between the units. The multiplexer is divided into departments for the waves V₁, V₂, V₃ etc and every department has four inputs 0, 1, 2, 3, some of which having constant tensions +U and -U, respectively. When the counter addresses on inlets 0 in each department the tension U occasionally connected on these inlets passes to the respective outlet V₁, V₂, V₃ etc. By stepping on to 1 the tension occasionally connected to inlets 1 passes to the outlets. A cycle (30 ms) thus includes addressing on all inlets 0, 1, 2, 3, one by one. Then the counter repeats the number series during the following cycles, whereby the waves thus shown in Fig. 3 are produced in an infinite succession. The tensions +U and - U can by means of change-over switches 13 be moved to other inlets than the ones shown. Hereby other waves arise resulting in appearance of another illustration than the one shown in Fig. 1b. By change-over switching it is thus possible to indicate all the eight characters A - H by the marker. What the wiring diagram of such change-over switches can look like is shown in Fig. 5. The example shows producing of +U and -U on the respective outlets according to Fig. 4. A twelve-bits memory 14 has been programmed in columns and the one giving the illustrations in Fig. 1b is shown. Outlets having common inlets to a switch-module 16 are gathered on gates 15 and the tensions +U and -U are distributed with respect to the inlets so that 1 on the inlet means closing of the respective switch and 0 means breaking. A set of resistors 17 on the outlets to earth makes stability to the tensions which then are passed directly to the multiplexer (Fig. 4). Fig. 1b shows one of the illustrations the arrangement can display. By addressing the waves to other wires the illustration can thus be varied. The arrangement is a simple example of showing a few seams and a marker on a display; the number can, of course, be multiplied by means of a corresponding number of segments and a wiring pattern belonging thereto. Possibly can, for instance, 100 seams be illustrated on the display distributed as 10 x 10. Analogously to the foregoing example the number of supply wires will be H₀, H₁, H₂, ...H₁₀ + V₁, V₂...V₁₀ = 21. As a further development of the system more phases can be added and thus further segments be supplied, e. g. for showing stitch length and bight. Then the multiplex multiplier increases with 1 for every further phase. In certain types of displays it is possible to displace the whole illustration stepwise in a horizontal or vertical direction. By such advanced indicating arrangements it is possible to envisage another group of seam illustrations constituting the previously shown group displaced a step horizontally and presenting further seam illustrations utmost on the display. A corresponding number of seam illustrations vanishes simultaneously at the opposite side of the display. Such a feeding of further illustrations is generally called "scrolling" and may be achieved by a network of modules according to Fig. 6. Two manually operated switches 18, 19 are connected to a decade counter 20 for a marker with the module number MM 74 C 192 which on a signal from the switch 18 counts up a step and on a signal from the switch 19 down a step . The switches are provided with arrows so that the operator sees in what direction the marker will move when the switch is actuated. The counter has a connection with a decoder 21 with the number MM 74 C 42 with ten outlets 22 which supply marker lamps or the like, and with a decade counter 23 for the seam illustrations, which counter is also connected to a decoder 24. The outlets 25 of it supplies tension to a segment of illustration or the like, which shows, e.g., illustrations with the numbers 1 - 10. When the counter 20 has stepped from 1 - 10 and thus moved the marker across the whole display, another actuation of the switch 18 has the effect that a signal is output on a connection wire 26 to the counter 23 which then counts up so that the illustrations with the numbers 2 - 11 become visible. An actuation of the switch 19 then gives a signal on a connecting wire 27 which makes the counter 23 count down and restore the illustrations number 1 - 10. Thus, the switches bring about counting both up and down on both sides of 10 with a presentation of further seam illustrations as far as the illustration series is extending.

Claims: Seam indicating arrangement in an electronic sewing machine comprising a pair of parallel discs with an intermediate layer of liquid crystal and the two side surfaces facing each other provided with segments (10,11) of a transparent foil and wiring patterns with wires to every separate segment, wherethrough the two segments of every part surface of an illustration have tensions actuating the said layer (polarization) which then becomes visible in the respective part surface, characterized in that a multiplex distributor (12) of tensions supplies the wiring patterns which thereby feed tension cyclically to the segments during at least two time phases and that in one time phase the segments of one group of part surfaces of illustrations, e.g. performing seams (A - D) have tension, and in another time phase the segments of a part surface performing a marker have tension. Seam indicating arrangement according to Claim 1, characterized in that a change-over switch (13) is disposed at the distributor of tensions in order to selectably connect the tension to one of at least two groups of said seam illustrations. Seam indicating arrangement according to Claim 2, characterized in that two manually operated switches (18,19) are connected to a counter (20) and a decoder (21) with connection to the change-over switch of the marker which by repeating actuation of one of the switches is moved along the seam illustrations in one direction and by actuation of the other switch is moved in the other direction. Seam indicating arrangement according to Claim 3, characterized in that the said counter also is connected to another counter (23) and a decoder (24) which are connected to the change-over switches of seam illustrations and by occurence of an end position of the marker effect a counting up or down in a numbering of a seam illustration group and therewith perform another group of seam illustrations (E - H) in the arrangement.

Inventors: BERGVALL, BENGT ALLAN
Applicants: HUSQVARNA AKTIEBOLAG
Application year: 1986
Main classification: D05B19
IPC codes: D05B19