Description:
FIELD OF THE INVENTION
This invention relates to automatic apparatus for producing piped pockets in apparel.
BACKGROUND AND SUMMARY OF THE INVENTION
Automatic devices for use in making piped or welted pockets of the type to which the invention relates have been manufactured for some time by, for example, the Necchi Company, of Pavia, Italy, under Model No. 1702, and by the Reege Company, of Boston, Massachusetts. Machines of this type are disclosed in commonly assigned U.S. Pat. Nos. 3,745,946 and 3,653,345, issued July 17, 1973, and Apr. 4, 1972, respectively. Such devices or machines are also disclosed in publications of the Necchi Company, such as a pamphlet entitled "Necchi Mechanization Series, Class 1701, Class 1702, Class 1703, Class 1705," a pamphlet entitled "A Treasure in Your Pockets," and an instruction manual on the use and maintenance of the machines, entitled "Necchi Automatic Units Class 1700." These devices have been used widely in Europe and the United States. In these known machines, the upper material, that is, the material in which a piped pocket is to be sewn, together with the pocket material, is thrust under the material presser frame, and clamped by this presser frame, and the piping material is then laid on a shaping rail or side presser, shaped to a piping by the piping shaper foot and the side presser, and then sewn together with the upper material, the pocket opening being cut at the same time. Depending upon whether a piping seam is to be made on both sides or only on one side of the pocket, one speaks of a double or a single piping. In any case, heretofore upon depression of the material presser frame, its two arms clamped the upper material on both sides of the pocket simultaneously.
Such machines have some drawbacks. Thus, with simultaneous clamping of the material to the right and left of the pocket, it becomes practically impossible to smooth and tension the upper material by hand ahead of time. This makes itself disagreeably evident in seat pockets in trousers, over which ordinarily there are wedge shaped tucks previously sewn, running crosswise with reference to the piping seams, and causing a bulge because these deformations cannot be eliminated before the sewing of the piping, so that the latter may turn out inaccurately.
The known machines were also generally not suitable for production of pockets from elongated piping material, especially of knit goods, because in this case the material had to be laid on the appurtenant side presser and guided under the other arm of the material presser, which was extremely difficult.
Depending upon the kind of material and its thickness, the two arms of the material presser and the two shaping rails or side pressers have different distances separating them. To adjust this, the presser frames formally had to be exchanged, and it was necessary to stock a number of frame sizes.
Finally, in known machines it was disturbing that even with single piping the applied piping in the presser frame method had to be slipped back from the forward position to the retracted position in which the piping was formed, because clamping of the piping in the forward position was not feasible. Placing of the piping only in the rear position of the pressure frame is awkward. Since there are single pipings, especially in the case of knit goods, that often have a pattern, flaws occurring that are attributable to the retracted piping show up.
The invention is directed to the problem of developing an automatic device of the type mentioned for making piped pockets, wherein the disadvantages will be largely eliminated. The new device makes possible a smoothing of the top material, and in the case of single piping it likewise makes it possible to smooth out the piping material before the clamping, as well as production of piped pockets from a long piping piece.
These problems are generally solved in accordance with the invention in that the material presser is in the form of two clamping arms or bars which are individually movable into the clamped setting. Divided material pressers are basically known in somewhat similar machines, such as, for instance, the button holing machine of German Pat. No. 582,940. In such known machines of other types, however, the material pressers have another function, and in contrast to the invention they clamp the materials simultaneously with both arms.
In use of the new device of this invention, for example in production of seat pockets, the material can be tensioned on one side, and then either automatically or manually smoothed out until the other arm of the material presser is lowered. With single piping, after one-sided clamping of the upper material, the piping material may be applied on this side and held against a stop, while it is smoothed to the other side, and then in this position it is clamped by the lowering of the other arm of the material presser. In production of piped pockets, the long piping can be introduced without difficulty between the separated arms of the material presser while one arm is in the clamped position and the other is disengaged. If a change of distance between the two arms is required, this can readily be adjusted. It is not necessary to exchange the entire material presser.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention will be apparent from the following description and drawings, in which:
FIG. 1 is a front view of a sewing machine provided with the material presser in accordance with the invention;
FIG. 2 is a section view along line 2--2 of FIG. 3;
FIG. 3 is a section view along line 3--3 of FIG. 2;
FIG. 4 is a detailed view of the material presser;
FIG. 5 is a perspective schematic view showing the material presser in an operative phase; and
FIG. 6 is a pneumatic layout for controlling the operation of the material presser.
With reference to FIG. 1, a sewing machine is indicated generally by reference character 50, the machine being equipped to make piped or welted pockets, and comprising a bed 51, a base 52, a standard 53, an arm 54 extending parallel to bed 51, and a head 55, a needle bar 43 projecting from the head and carrying a pair of needles 18 and 20 suitable for forming two longitudinal parallel stitchings, and a blade 22 driven by needle bar 43, movable with needles 18 and 20 for making a slit parallel to the stitching and central relative to them.
At one end of the upper shaft, not shown in the drawings, two pulleys 56 and 57 are mounted suitable to receive the driving belt, also not shown, connected to the electric motor of the sewing machine. The displacement of the belt from pulley 56, integral with the upper shaft, to pulley 57, idly mounted on said shaft, is obtained through a belt shifter connected to a well-known lock mechanism generally indicated at 58. A rod 59 is connected with lock mechanism 58 and is adapted to slide in the upper part of arm 54. The front end of rod 59 acts on opposed axes of two well-known thread tension devices 60 to neutralize the thread tension when the machine is locked. All of this is well-known in the art as will be seen from the patents and publications referred to previously.
A slidable support 12 (FIGS. 2, 3 and 5) is slidable in bed 51 and receives driving movement from a double acting pneumatic cylinder 61 and from a hydraulic fluid control cylinder 62 adapted to make the speed of work plate 12 uniform and adjustable. A material presser generally indicated by reference character 24 (FIGS. 1, 4 and 5), formed by two separated clamping bars 32 and 34, for clamping a pocket material 36 (FIG. 5) onto slidable support 12 is drivingly connected with slidable support 12 through a pair of levers 26, 28 and a kinematic chain, which will be described in more detail hereafter. A pair of side pressers 63 (FIG. 1) and a piping shaper foot 16 are provided for positioning and suitably folding a piping material 38 in a known manner, as described in the previously mentioned patents and publications. Side pressers 63 are connected with levers 64 shown in FIG. 3 fastened to the lower portion of hubs 65 which can slide along the axis of shaft 66 by means of a pneumatic cylinder 67 (FIG. 1), as described in more detail in the aforesaid U.S. Pat. No. 3,745,946.
Shaft 66 is pivoted, free to rotate, in mountings 66 (FIG. 3) fixed to support 12.
Lever arm 28 of material presser 24 is fixed by means of a screw 70 to a plate 71 slidably mounted in a slot in lever 72 which is rotatably mounted on shaft 66, and thus can rotate around the axis of shaft 66. Lever 72 is also fixed to a member 74 by means of screws 73. Member 74 is connected through a pin 75 to the end of a connecting rod 76. Connecting rod 76 is pivoted at its other end by pin 77 to the end of a V-shaped member 78 which can pivot about a pin 79 fixed to mounting 68. The other free end of V-shaped member 78 is pivotally connected at 80 to rod 81 of a pneumatic cylinder 82, the function of which will be explained hereinafter. A similar kinematic chain and motion are provided for lever arm 26 through rod 101 of a pneumatic cylinder 98.
Apart from the arrangement of presser 24 as two separate clamping bars 32 and 34, and the arrangement for individually and independently raising and lowering these clamping bars, the illustrated and described structure is generally known in the art from the previously mentioned patents and publications.
Referring now to FIG. 6, when the operator, acting on treadle 83, causes it to make a first angular displacement, valve 84 opens by virtue of the action of member 105 rotating around pin 106 connected with the threadle through rod 107, thus opening part of the circuit to main air line 85. Air flow from valve 84 through valve 86 and tee valves 87 and 88 reaches pilot 89 of valve 90, changing it over. Air flow from general feed is passed by valve 90 through duct 91 to cylinder 82. The rod of cylinder 82 is thereby brought to the position of FIG. 2, corresponding to the position of clamping bar 34 lowered onto pocket material 36. When treadle 83 makes a second angular stroke, member 105 opens valve 92, whereby air flow coming from main feed 85 passes through tee valves 93 and 94 to pilot 95 of valve 96. Valve 96 controls air flow from general feed, and passes such air flow through duct 97 to cylinder 98. Cylinder 98, therefore, has its rod 101 moved to the position of FIG. 2, corresponding to the lowered condition of clamping bar 32. At the end of the sewing and cutting of the pocket pipe, valves 90 and 96 are changed over, whereby air flow through flow regulators 99 and 100, respectively, reaches cylinders 82 and 98 to actuate their rods in the opposite direction, which causes, through the separate kinematic chains formed by elements 78, 76, 74, and 72, the rotation of levers 72 around the axis of shaft 66 with the consequent raising of both arms of material presser 24.
If it is desired to lower clamping bar 32 before the lowering of clamping bar 34, it is only necessary to displace lever 102 of valve 86 as indicated in dotted line in FIG. 6 to change over valve 86. Thereafter, when treadle 83 makes its first angular stroke, opening valve 84, air flow from feed duct 85 passes through valve 84, valve 86 (changed over), duct 103, tee valves 93 and 94, and reaches pilot 95 of valve 96, changing it over. Air flow which is connected from general feed to valve 96 is passed therefrom through duct 97 to cylinder 98, thus causing lowering of clamping bar 32. When treadle 83 reaches the end of its stroke, air flow changes over valve 90, and the changing over of valve 90 causes driving of cylinder 82 and consequently of clamping bar 34. In this way, the opportunity is provided of varying the lowering sequence of clamping bars 32 and 34 of material presser 24.
The side pressers of shaping rails are not shown in any substantial detail in the drawings, since they are well known in the art, and are disclosed in detail in the previously two mentioned patents. The manner of operation of the instant invention will be also readily apparent to those skilled in the art, and hence a detailed discussion is unnecessary. Other details of a machine incorporating the invention, apart from the novel features herein disclosed and claimed, will be readily apparent to those skilled in the art, and are adequately disclosed in the previously mentioned patents and publications. Accordingly, only so much of the machine has been described and illustrated herein as will facilitate an understanding of the instant invention.