Industrial sewing machine for simultaneously making different seaming patterns

Abstract: An industrial sewing machine comprises at least two driven shafts (4,5) which are rotatively driven in a timed manner, on one of these shafts (4) being keyed cam members (8,16,44,51) for reciprocately driving in a horizontal plane one or more needle bars (13), as well as grippers for feeding with fabric operating hook elements, the other driven shaft (5) operating a vertically displaceable needle bar (69) arranged downstream of the first mentioned needle bars, the spacing of the needle bars being so designed that the needles (15) supported thereby can make simultaneously rectilinear, curved and broken seaming lines.

Description: 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 a overlock stitch 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. Starting from the document EP-A-0 353 208 which discloses an industrial sewing machine comprising two driving shafts, rotatively driven with timed speeds, on one of said driven shafts being keyed cam members which, through mechanically operating assemblies, drive one or more needle bars in a horizontal plane, said cam members further driving fabric transporting grippers and hook elements, the other of said driven shafts driving a further needle bar which is displaced in a vertical plane and arranged downsheam of said needle bars, said needle bars being so spaced from one another as to make several simultaneous either rectilinear, curved or broken seaming lines, the object of the present invention is to provide an industrial sewing machine adapted to make either horizontal or vertical stitches. According to one aspect of the present invention, the above mentioned object is achieved by a sewing machine for industrial use, as claimed in the characterizing part of 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 apparente 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 4 is a top plan view of the sewing machine shown without its covering casing; Figure 4a is a partial perspective view of the subject sewing machine; Figure 5 is a vertical cross-section view of the subject sewing machine, taken along the line V-V of Figure 4; Figure 5a is a vertical cross-sectional view, with a top view, taken along the section line Va-Va of Figure 5; 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 cooperating with one or more needles operating in a horizontal direction included in the sewing machine. 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 a first and a second driven shafts 4 and 5 through corresponding belts 6 and 7. In this connection it should be apparent that said driven shafts 4 and 5 can also be driven by other driving sources, in a timed manner. The first 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 provided with a thread tension arm 12′ for controlling one or more needle bars 13. These needle bars are driven in a horizontal plane, possibly with different angles (but with a single and timed driving assembly) and support, by means of clamp members 14, corresponding 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 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 the needle or to the needles. The slider 32, in turn, supports the gripper 34 for driving the fabric beyond the needle or needles. 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 the "stitching gripper". On said 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, 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. On the mentioned first driven shaft 4, moreover, there is provided a cam member 44 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 a hook member 50, which can perform a reciprocating movement. On the same driven shaft 4 there is moreover keyed a further cam member 51 which, through a connecting rod 52 and a ball joint 53 and a 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, a further vertically movable hook member 59. Cooperating with the above mentioned grippers 33 and 34 there is moreover provided a needle plate 61, thereon a pressing small foot 62 abuts, said foot 62 being mounted on a lever 63 pivoted to a rod 64 resiliently urged by an adjustable sporing device 65. Downstream of the grippers there are provided guides 66, mounted on a guide supporting element 67 and adapted to convey the two seamed fabric portions, which have been seamed or stitched by the horizontal needle or needles 15, under a further needle 68 which is driven along a vertical axis and is adapted to perform a "riveting" or sealing sewing operation. This vertical needle or needles is/are assembled on a respective needle bar 69, which is reciprocately driven by the driven shaft 5 through any known driving means. With the vertical needle or needles 68, cooperate the foot 70, pressing on the horizontal plate 71, the hook elements 72 and 72' respectively driven by the mentioned driven shafts 5 and 1, through suitable driving means, as well as corresponding grippers 73. There is moreover provided a suitable enclosing casing 70 which, advantageously, is also adapted to be used as a working surface. In operation, the two fabric portions to be jointed are arranged on the mentioned working surface so as to arrange their corresponding edges with an adjoining relationship, with a vertical descending configuration, at the level of the horizontally operating needle or needles 15. More specifically, the mentioned fabric portions are arranged with horizontally opposite arrangements with the right side of the fabric upward directed. In this connection it should be pointed out that the timed driving of the grippers 33 and 34 will allow two or more fabric portions to be stitched to be simultaneously and timely driven, and, in particular, the fabric portions can be driven with different angles in order to perform the desired sewing operation. Moreover, the side edges, facing one another and downward directed, of the fabric portions entrained by the grippers will be trimmed at the free edge portions thereof, by the knife 31 and then they will be further stitched by the vertical needle 68. From the above disclosure it should be apparent that the sewing machine according to the present invention affords the possibility of making, in a single operating step, at a single working place and with a single operator, an assembling sewing operation on two fabric portions, followed by a "riveting" or sealing sewing operation. Moreover, the sewing machine according to the invention allows the fabric portions to be stitched to be arranged with a horizontal arrangement with the right side of the fabric upward turned. Moreover, it also affords the possibility of performing two subsequent sewing operations, by orienting or spreading apart the fabric portions as desired between the two stitching operations.

Claims: An industrial sewing machine comprising two driving shafts (4, 5), rotatively driven with timed speeds, on one (4) of said driven shafts (4, 5) being keyed cam members (8, 16, 44, 51) which, through mechanically operating assemblies, drive one or more needle bars (13) in a horizontal plane, said cam members further driving fabric transporting grippers (33, 34) and hook elements, the other (5) of said driven shafts driving a further needle bar (69) which is displaced in a vertical plane and arranged downstream of said needle bars, said needle bars being so spaced from one another as to make several simultaneous either rectilinear, curved or broken seaming lines, characterized in that cooperating with said grippers (33, 34) is moreover provided a needle plate (61), thereon a pressing small foot (62) abuts, said foot (62) being mounted on a lever (63) pivoted to a rod (64) resiliently urged by an adjustable spring device (65), downstream of the grippers (33, 34) being provided guides (66) mounted on a guide supporting element (67) and adapted to convey two seamed fabric portions, which have been seamed by a horizontal needle (15), under a further needle (68) which is driven in said vertical plane and is adapted to perform a "riveting" or sealing sewing operation. A sewing machine according to Claim 1, wherein said vertical needle (68) is mounted on a respective needle bar (69) which is reciprocately driven by the second driven shaft (5), with said vertical needle (68) a pressing foot (70) cooperating which presses on a horizontal plate (71), a further hook element (72) driven by said driven shaft, as well as corresponding grippers (73).

Inventors: CARTABBIA GIOVANNI, CARTABBIA, GIOVANNI
Applicants: MACPI PRESSING DIV, MACPI S.P.A. PRESSING DIVISION
Application year: 1991
Main classification: D05B1
IPC codes: D05B1, D05B35, D05B27, D05B73