Industrial sewing machine for simultaneously performing a plurality of improved seaming lines

Abstract: The sewing machine comprises two or more driven shafts which are driven with timed rotary speeds,on one shaft cam members being mounted which,­ through mechanical motion transmitting members,­ causes the needle bars,transportation clamps and hooks to swing,these members being so arranged and designed as to perform a plurality of simultaneous seaming lines either of rectilinear,curved or broken configuration.

Description: BACKGROUND OF THE INVENTION The present invention relates to a sewing machine,for industrial use,which has been specifically designed for simultaneously performing a plurality of different seaming lines. As is known,in the garment industry frequently arises the need of performing several seaming lines which can be,for example,of the overlock or chain stitch type. Also known is the fact that the mentioned main stitches must frequently be performed on a given portion of the same cloth or garment. For example,for seaming a shirt sleeve,it is necessary to provide overlock stitches and then this seaming arrangement must be "stopped" by means of a chain stitch. These different types of stitches,in particular, must be made on different sewing machines,with different working passes,which,as it should be apparent,in addition to requiring long operating times, frequently provides not perfectly finished products, because of the difficulty of holding the several seaming lines in a properly aligned condition. SUMMARY OF THE INVENTION The document GB-A-2 188 951 relates to a seaming machine having two needle bars which are parallel to one another and perform on a same fabric piece two separated seamings, parallel and with the same type of stitch. The machine disclosed in this document, accordingly, is not adapted to carry out two consecutive seamings of different types as those which can be performed by Applicant's seaming machine disclosed in the new main claim. The document DE-C-72258 discloses a seaming machine which is tilted on a side and enclosed in a casing in order to prevent possible lubricating materials from contacting the fabrics being seamed. This is a machine including a single needle bar and which, accordingly, can not perform simultaneously different seaming operations Practically, the machine of this document operates as a conventional seaming machine in order to perform a single type of stitch at a time. The document US-A-2 238 796 relates to a seaming machine which does not comprise any needle bar, since the needle of this machine is controlled by a lever and can perform exclusively a type of stitch. The seaming machine of this document has been designed for facilitating the operation of seaming the edge portions of the fabrics, in particular a tubular fabric piece. The machine disclosed in this patent can not perform simultaneously two types of seaming operations. The documents DE-O-3 407 271 and CH-O-665229 relate substantially to the same machine. In fact, the document CH-O-665229 is an improvement of the document DE-O-3407271. These documents relate to a seaming machine which can simultaneously perform seaming operations on the opposite edges of a half-finished product. Practically there is herein disclosed a seaming machine having two symmetrical and opposite seaming heads which perform separately two equal seams on opposite flaps of a same fabric piece. The type of machine disclosed in these patents is not adapted to perform simultaneously two different types of seams. The document FR-O-691277 relates to a seaming machine having two needle bars in a single block. Thus, the positions of the control mechanisms and several control members are fixed Because of this reason, this machine can perform exclusively a type of work. More specifically, in this machine, the control unit of the several control mechanism consists of a single shaft which drives a horizontal needle bar parallel to the shaft and a vertical needle bar perpendicular to the preceding one, operating the single provided crochet. Because of this reason, the seaming machine of this document can exclusively form a chain stitch with the horizontal needle, since this needle bar is parallel to the shaft driving it and since the crochet discloses during its stroke an ellipsoidal configuration perpendicular to the needle. The vertical needle bar, on the other hand, can form exclusively an ornamental stitch since in order to carry out a different type of stitch there are necessary two crochets. In fact, as is known, in forming an overlock stitch, the lower or bottom crochet is used for latching the yarn of the needle in the bottom portion of the seam, whereas the top crochet is used for latching the yarn of the bottom crochet so as to bring it under the needle on the top portion of the seam. Moreover, the machine disclosed in this FR-A-691277 document has a single drive for the fabric, perpendicular to the vertical needle bar and is arranged bridging the vertical needles. The horizontal needle bar does not include any drive for the fabric. None of these two needle bars is associated with a differential drive and accordingly the fabric, between the two needle bars, can not be spread or caused to shrink depending on the requirements. Accordingly, the main object of the present invention is to overcome the above mentioned drawbacks, by providing a sewing machine,for industrial use,which is specifically designed and arranged to perform,in a single pass, two or more seaming lines, either of the like or different type. Another object of the present invention is to provide such a sewing machine in which the fabric being sewn can also be fed or transported with different angles. Another object of the present invention is to provide such a sewing machine in which the fabric flaps or portions to be sewn can be oriented in all of the working orienting directions,independently from the fact that said fabric portions are in a loose condition or in a partially assembled condition. According to one aspect of the present invention,the above mentioned objects,as well as yet other objects,which will become more apparent hereinafter,are achieved by a sewing machine for industrial use, according to the main claim. BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the industrial use sewing machine according to the present invention will become more apparent from the following detailed description of a preferred embodiment thereof,which is illustrated,by way of an indicative but not limitative example in the figures of the accompanying drawings,where: Figures 1,2 and 3 are respectively elevation, side and top plan schematic views illustrating the industrial use sewing machine according to the present invention; Figure 5 is a vertical cross- section view of the subject sewing machine,taken along the line V-V of figure 4; Figure 6 is a vertical cross-section view of the subject sewing machine,taken along the line VI-VI of figure 4; Figure 7 is a cross-sectional view of figure 6; Figure 8 shows an embodiment of the operating assembly for driving hook members included in the sewing machine; and Figure 9 shows several guide members for properly guiding edge portions of the cloth being sewn. DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the figures of the accompanying drawings,the sewing machine for industrial use according to the present invention comprises a supporting frame which has been specifically designed for supporting at least a main shaft 1 which is driven by an electric motor (not shown). On this main shaft 1 there are keyed at least two pulleys,indicated respectively at 2 and 3,provided for transmitting a rotary movement to corresponding driven shafts 4 and 5 through corresponding belts 6 and 7. Said driven shafts can also be driven by other driving sources,in a timed manner. The driven shaft 4 supports a first cam member 8 which,through a connecting rod 9,a ball joint 10 and a swinging pivot sleeve 11,drives a lever 12 for controlling two or more needle bars 13. These needle bars can be arranged in different planes,with different angles( with a single and timed driving assembly) and can support,by means of clamp members 14,corresponding or respective needles 15 which can be selectively operatively driven. On the driven shaft 4 there is moreover keyed a second cam member 16 which,through a connecting rod 17,a ball joint 18,a sleeve 19 and a swinging pivot pin 20 drives a trimming knife 21 supported on a curved supporting arm and the blade of which is indicated at 22. On the driven shaft 4 there is moreover keyed keyed a third cam member 23 which,through a connecting rod 24,a ball joint 25 and a sleeve 26,drives a first swinging pivot pin 27 which in turn,through a lever,drives a second pivot pin 28. These pivot pins,in particular,support respective eccentric levers 29 and 30 which can rise gripper bearing sliders,respectively indicated at 31 and 32. More specifically,the gripper bearing slide 31 fixedly supports the gripper or clamp 33 which operates to feed the fabric to a needle or to the needles. The slider 32,in turn,supports the gripper or clamp 34 for driving the fabric beyond the first needle assembly. In this connection it should be pointed out that the gripper 33 can also be called "differential gripper" since it can carry out a different operating stroke from that of the gripper 34 which, in turn,can be called " stitching gripper". On said driven shaft 4 there is moreover mounted a stitch stretching cam member 35 which, through the connecting rod 36, the ball joint 37 and sleeve 38 can drive a swinging pivot pin 39. This pivot pin drives rotatively the levers 40 and 41 which are respectively provided with driving pins 42 and 43,which,in operation,drives the respective gripper bearing sliders 31 and 32 so as to bring said sliders in contact with the fabric being sewn and cause said sliders to come back,in a lowered condition,under the control of the mentioned eccentric levers 29 and 30. It is to be added to the foregoing that the disclosed sewing machine also comprises means for orienting the fabric portions to be sewn in all of the directions,independently from the fact that said portions are loose or assembled. Thus,the timed operation of the mentioned grippers will provide a simultaneous and timed "transportation" of two or more seaming lines,owing to the different angles of the two or more seaming lines themselves. On the mentioned driven shaft 4,moreover, (as shown in fig. 6) there is provided a cam member which,through a connecting rod 45 and a ball joint 46 drives a sleeve 47. This sleeve,as is shown,restrains a swinging pivot pin 48 thereon there is keyed a lever 49 bearing the lower hook member 50,which can perform a rotary movement. On the same driven shaft 4 there is moreover keyed a further cam member 51 which,through a connecting rod and a ball joint 53 and sleeve 54 swingably drives a pivot pin 55. With this latter there is rigidly coupled a lever 56 to which there is articulated an arm 57 which in turn is slidingly coupled to a swinging ball joint 58 and supports,at the free end portion thereof, the upper hook member 59. A suitable protecting casing 60 is moreover provided,which advantageously also operates as an operating table.

Claims: A sewing machine for industrial use, characterized in that said sewing machine comprises a main driving shaft (1), driving at least two driven shafts (4, 5), rotatively driven with timed speeds, on one of said driven shafts (40) at least a cam member (8, 16, 23) being keyed which drives at least a needle bar (13), a top hook (59) and a bottom hook (50) and a first gripper (33) and a second gripper (34) for advancing a fabric to be seamed, said first gripper (33) being arranged before the working region of the needle or needles (15) of said needle bar(s) (13) and said second gripper (34) being arranged after said working region of the needle or needles (15) of said needle bar(s) (13), said first and second grippers (33, 34) being driven with a different stroke for a different transport of said fabric upstream of said working region and downstream of said working region of said needle or needles (15) of said needle bar or bars (13). A sewing machine according to Claim 1, characterized in that on said main driving shaft (1) there are keyed at least two pulleys (2, 3) rotatively driving said driven shafts (4, 5) through driving belts (6, 7). A sewing machine according to Claim 2, characterized in that said one (4) of said driven shafts supports a first cam member (8) which, through a connecting rod (9), a ball joint (10) and a sleeve (11) with a swinging pivot pin, drives a lever (12) in turn driving said needle bars (13), said needle bars (13) being arranged in different planes and with different angles and bearing, through clamp members (14), said selectively controlled needles (15). A sewing machine according to Claim 3, characterized in that on said one driven shaft (4) there is keyed a second cam member (16) which, through a respective connecting rod (17), a ball joint (18), a sleeve (19) and a swinging pin (20) drives a trimming knife (21) supported by a supporting arm. A sewing machine according to Claim 3, characterized in that on said one driven shaft (4) there is keyed a third cam member (23) which, through a respective connecting rod (24), ball joint (25) and sleeve (26) drives a first swinging pin (27) connected, through a lever, to a second swinging pin (28), said swinging pins (27, 28) being respectively connected to two sliders (31, 32) bearing respectively said first gripper (33) and second gripper (34). A sewing machine according to Claim 5, characterized in that said gripper (33) supported on one (31) of said sliders (31, 33) is a fabric feeding gripper, whereas said other gripper (34) supported on the other (33) of said sliders (31, 33) is a gripper (34) for conveying said fabric beyond said needles (15). A sewing machine according to Claim 3, characterized in that on said one driven shaft (4) there is moreover mounted a stitch stretching cam member (35) which, through a connecting rod (36), a ball joint (37) and a sleeve (38) drives a further swinging pin (39) in turn swingably driving two levers (40, 41) having driving pins (42, 43) which drive said gripper sliders (31, 32) so as to cause said sliders (31, 32) to contact said fabric and move back to a lowered position in cooperation with said cam members. A sewing machine according to Claims 1 and 3, characterized in that on said one driven shaft (4) there is moreover provided a further driving cam member (44) which, through a respective connecting rod (45),and a ball joint (46) and a sleeve (47) supporting a pivot pin (48), drives a lever (49) supporting rotatively said bottom hook (50). A sewing machine according to Claims 1 and 3, characterized in that on said one driven shaft (4) there is keyed yet a further cam member (51) which, through a respective coupling rod (52), ball joint (53) and sleeve (54), drives yet another swinging pin (55) therewith a lever (56) is rigid, said lever rotatively supporting an arm (57) slidingly coupled to a swinging ball joint (58) and supporting, at a free end portion thereof, said top hook (59). A sewing machine according to Claim 1, said sewing machine being so designed and arranged as to simultaneously transport two or more seaming lines, with different mutual transport angles.

Inventors: CARTABBIA GIOVANNI, CARTABBIA, GIOVANNI
Applicants: MACPI SPA, MACPI S.P.A.
Application year: 1989
Main classification: D05B1
IPC codes: D05B1, D05B57, D05B73, D05B35, D05B69