Separating guide of fabric layers transformable in a straight guide for sewing machines
I United States Patent 1191 1111 3,875,881  
 Marforio 1 Apr. 8, 1975 [54] SEPARATING GUIDE 0F FABRIC LAYERS [56] References Cited TRANSFORMABLE IN A STRAIGHT GUIDE UNITED STATES PATENTS FOR SEWING MACHINES 3,392,691 7/1968 Pope 112/153 75 l N i Marforio. Milan l 3,786,768 1/1974 Kosrow et a1 112/143 73] A v R ld &amp; C S A M1 3.814.039 6/1974 Heller et a1 112/153 ss1 nee: 1r 1m 1m l g 5 p FOREIGN PATENTS OR APPLICATIONS [22) Filed Mar 26 1974 3.495 0/1871 United Kingdom 112/153 [21] App]. No.: 454,844 Primary E.\&#39;aminerH. Hampton Hunter [3&#39;0] Foreign Application Priority Data L d f l EZ T&#39;F h h h gu1 e or ayerso a no in asewmg mac me w 1c May {my 24371/73 includes fixed housing having spaced and slidable [52] U 8 Cl H2/]53 I 2,141 members selectively moveable therein between a first [5 H D65) 35/10 position to form separate superimposed guides for each fabric layer and a second position to form a sin- [58] Fleld of Search 112/153, 152, 141, 142, g or Straight guide for a&#34; of the fabric layers.  
 4 Claims, 4 Drawing Figures lii SEPARATING GUIDE OF FABRIC LAYERS TRANSFORMABLE IN A STRAIGHT GUIDE FOR SEWING MACHINES BACKGROUND OF THE INVENTION The present invention pertains to a separating guide for layers of work. convertible into a straight guide, for sewing machinesv The separating guides for the layers of work which are adapted to be assembled to a sewing machine have the function of separating the edges of the layers and to allow relative sliding of said edges in order to match them automatically. Without such guides it would not be possible to achieve relative sliding of the edges due to the excessive friction between the layers.  
  Said guides are essentially formed by two parallel and superimposed channels which define a C-shaped cross section extending parallel to the direction of movement of the work. With separating guides of known design, there is the disadvantage that when the layers of work to be assembled include thicknesses or increases in thickness due to the presence of pockets, etc., the layers can no longer slide along the two superimposed and parallel channels inasmuch as their sections are not sufficient to contain the fabric. In addition, it is not possible to provide guides with sections such as to allow the passage of said thickenings since they would lack the optimum conditions for guidance during sewing of layers of normal thickness. In anticipation of increases in thickness of the layer or layers to be assembled, said increases oridinarily due to the presence of pockets, belts, loops or the like, known technology provides that the guides be capable of being completely displaced from the work position. It is clear that this involves a significant loss of time on the part of the operator, who must continuously and manually adjust all of the guides separating the layers of work. Furthermore, there is the disadvantage that when the guide is displaced from its operating position in order to permit sewing layers with greater thickness, said layers (or more precisely, the edges of the layers to be sewed) no longer have any mechanical guides applied to them and the operator must therefore manually guide the layers to be assembled.  
 SUMMARY OF THE INVENTION The aim of the present invention is to eliminate totally the above-mentioned disadvantages and more pre cisely to transform with extreme simplicity a layerseparating guide into a straight guide. This purpose is achieved by a separating guide for layers of work which is convertible into a straight guide which is the object of the present invention. The guide is characterized by the fact that it includes a housing which is fixed and extends longitudinally perpendicular to the direction of movement of the layer of work. It includes one or more parallel and superimposed channels; one or more plate members located and slidable in said channels, means to extend them from the fixed housing, and means to move the plates within along said channels. The plates extending from the fixed housing define in combination with said fixed housing one or more parallel and superimposed C-shaped guides mounted parallel to the direction of movement of the layers of work, and with the plates retracted into the fixed housing define a straight vertical guide in combination with the fixed housing.  
  These and other characteristics are shown in greater detail in the description hereinbelow of a preferred but not exclusive embodiment illustrated by the appended sheet of drawings, wherein:  
 BRIEF DESCRIPTION OF THE DRAWING FIG. I shows in perspective the separating guide for the layers of work, applied to a conventional sewing machine;  
  FIG. 2 shows a perspective view of the guide converted to a straight guide;  
  FIG. 3 shows the guide in cross section along line III- III in FIG. 1;  
  FIG. 4 shows the guide in cross section along line lV-IV in FIG. 2.  
 DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, the separating guide for the layers of work in question has been applied to a conventional sewing machine, whose frame consists of a base 1 on which is mounted a standard 2 supporting an arm 3 to whose end is applied a known head 4, said head carrying known upper sewing elements consisting ofa needle 5 as well as a conventional presserbar 6 for supporting a fabric-engaging presserfoot 7 of known type. The separating guide for the layers of work is mounted on the conventional work table 8 forward of head 4 and parallel to arm 3 of the sewing machine. The separating guide for the layers of work includes a fixed housing 9 which is essentially flat and extends lengthwise perpendicular to the direction of travel of the work. Fixed housing 9 contains three planar elements or stationary plates identified by numerals I0, II and 12 respectively, which are spaced and parallel and fixed to the upper surface of the work table 8 by means ofscrews I3. In channels 10a and 10b, formed between one stationary plate and another, are inserted slidable plate members 14 and 15 respectively. and more specifically, slidable plate 14 is inserted in the channel between plate 10 and plate 11 while slidable plate 15 is inserted in the channel between plate 11 and plate 12. The slidable plates 14 and 15 are provided with slots I6 and 17 respectively, through which screws 13 extend that include guide rings 18 of anti-friction material assembled thereon which are disposed in correspondence (FIGS. 3 and 4) with said slots I6 and 17. Slots ]6 and 17 allow sliding of plates I4 and 15 in the channels between one plate and another so as to allow them to extend from the zone of the stationary plates and to form with the same, two parallel and superimposed guides 19 and 20, the configuration of which defines the letter C (FIG. 3). When, on the other hand, the slidable plates are located within the stationary plates, they form a straight vertical guide with said plates which is coplanar and has a guide member 21 attached to plate I0 (FIG. 4). Slidable plate 14 is perfectly flat and has a rounded corner into which the layers of work are introduced, and which corresponds to similar corners provided on the stationary plates 10 and 11. Slidable plate 15 has an edge which emerges from the fixed housing and turns upwardly so as to facilitate the entry of the layers of work into the guides I9 and 20. Slidable plates I5 and 16 are both attached by means of screws 22 to an angle bracket 23 which is supported on piston 24 of a pneumatic cylinder 25 mounted on an integrally formed and upwardly directed bracket 26 of plate 10. Plate 10 has two parallel slots 27 in which slide the heads of screws 22. Pneumatic cylinder 25 is double-acting and is provided with two hoses 28 and 29 (FIG. 1) coming from a conventional air compressor, not shown. On the compressed-air line which feeds cylinder 25, there is a solenoid valve controlled by a start-stop button 30 which is carried by a support bracket 31 attached to head 4 of the sewing machine (FIGS. 1 and 2). The following is a description of the operation of the separating guide for the layers of work, which is convertible into a straight guide as described above. Under conditions in which two layers of work of normal thickness are to be assembled, the two slidable plates 14 and 15 protrude from the edge of the fixed plates so as to form the two essentially C-shaped. parallel, and superimposed guides 19 and 20.1n the course of the sewing of the two layers, when the operator encounters a thickening of the fabric, due for example to the presence of a pocket, she presses the start-stop button 30 which activates the solenoid valve incorporated in the line-powering cylinder 25, whose rod shifts the slidable plates 14 and 15 between the stationary plates 10 and 11 and 12 so as to form a single vertical straight guide in combination with guide member 21. After finishing sewing the layers with greater thickness, the operator releases button 30 and the cylinder returns the movable layers to their initial positions within the stationary plates. It is clear that the operator obtains a significant advantage with the guide described above in contrast to using other guides which must be continuously moved from their opera tional positions; in addition, even with movable plates that move between fixed layers, there is usually a vertical straight guide which significantly facilitates the operation of sewing. In the particular case described above, specific reference is made to a separating guide for two layers of work but it is clear that one could provide more than two slidable plates capable of being extended from a fixed housing so as to form more than two parallel and superimposed guides 19 and 20 and of using a pneumatic cylinder to shift the slidable plates, one could provide other electromechanical or mechanical means instead which could be controlled by means of a button. pedal, or toggle switch without thereby limiting the scope of protection of the&#39;present patent.  
 I claim:  
  1. An apparatus for guiding a plurality of layers of fabric to be sewn together on a sewing machine work table, said apparatus comprising:  
 a. a housing secured to the machine work table which includes a plurality of planar elements superimposed in spaced relation with respect to each other to define guide channels therebetween;  
 b. a plurality of plate members slidably contained within the channels; and  
 0. means operatively connected to said plurality of plate members for moving the same within said housing between one position for forming separate guides for each layer of fabric and another position for forming a single straight line guide for all of the fabric layers.  
  2. The apparatus according to claim 1 wherein said planar elements define stationary plates disposed in a plane perpendicular to the direction of travel of the lay ers of fabric.  
  3. The apparatus according to claim 1 wherein said moving means includes a pneumatic cylinder having a piston interconnected with said plate members and a control means for selectively actuating said piston for sliding said plate members between their two positions.  
  4. The apparatus according to claim 3 wherein said control means includes a manually operable start-stop button operatively connected to said pneumatic cylin-