TOOTH WITH TWO HEADS AND TWO SLOTS FOR ZIPPERS THAT CAN BE OPERATED IN TWO DIRECTIONS

Abstract: In a bilaterally symmetrical zipper tooth (1n) for opening in two directions which is equipped with attachment tabs (2, 7), two tapered heads (3, 4), and two anchoring slots (5, 6) which make it possible to both open and close the zipper with the aid of either of two slides that face in opposite directions, distance (d) between tops (3a, 4a) of two tapered heads (3, 4) is greater than maximum thickness (t) of the other parts of the tooth itself, such that the heads can act as a support inside of which the tooth can turn under to action of gravity.

Description: Tooth with Two Heads and Two Slots For Zippers That Can be Operated in Two Directions. This invention pertains to the area of technology of the production of zip fasteners, also known as zippers. As we know, these devices make it possible to reversibly connect two edges made of, e.g. , cloth or leather, on both of which are mounted a number of adjacent teeth that are arranged facing one another and shaped in such a way that the teeth fit together, thus being locked together, as a result of the action of a slide that is moved by hand in such a way as to cause it to travel along the zip fastener line that is to be closed. By operating said slide in the opposite direction, the teeth are disengaged and the zipper is thus opened. The securing, with respect to one another, of the teeth that are mounted on the two opposing edges is accom¬ plished by means of the slide, which causes the projecting parts of the heads on each tooth to mate with the recesses with matching zipper slots provided on a opposing adjacent tooth. In some embodiments of zippers that are suitable for closing purses or suitcases, the teeth are shaped in such a way that the zipper can be opened or closed by activating either of two slides that face in opposite directions. For this purpose said teeth are made in a shape having bilateral symmetry and each have two tapered heads that face in opposite directions and two matching anchoring slots that are shaped accordingly. The meshing of a series of teeth is accomplished by gripping their two attachment tabs on an edge of the element to which the zipper is to be secured, whereby the attachment operations are preceded by the orienting of each tooth, which is taken from a feed magazine, in the position that is appropriate for the methods of operating the device that then secures said teeth. In view of the limited dimensions of the teeth and the large number of curves and corners that they have, the task of selecting and orienting the teeth is fairly complex and often requires the use of sophisticated devices that produce high-frequency vibration, as well as various devices that help align the teeth in the desired position. The inventor of this invention has conceived of a zipper tooth which opens in both directions and which has characteristics that make the above-described operations of selection and orientation very simple. The main characteristic of this invention is the fact that the two above-mentioned tapered symmetrical heads both project to a predetermined extent with respect to the lateral profile of the tooth and can serve as supports around which the teeth, which are previously arranged vertically, can turn under the action of gravity alone, thus arranging themselves in identical adjacent and perfectly aligned positions, e.g., inside a guide channel whose width is less than the distance between the tops of the heads themselves, which consequently rest on its outer edges. The object of this invention is actually a bilater¬ ally symmetrical zipper tooth that can open in two directions and is equipped with attachment tabs, two tapered heads, and two anchoring slots which make it possible to both open and close the zipper using either of two slides that face in opposite directions, wherein the distance between the tops of the two tapered heads is greater than the thickness of the other parts of the tooth itself, so that the two heads can act as a support around which the tooth can turn under the action of gravity. The object of the invention also includes a process for ensuring the selection and orientation of the teeth that are made according to the invention. A more detailed description will now be given of a zipper tooth according to the invention and of the process; in said description reference will be made to the attached drawings, where: - Fig. 1 shows a front view of an embodiment of the tooth according to the invention; - Fig. 2 shows a side view of two adjacent teeth of the type depicted in Fig. 1 hooked together; - Figs. 3, 4, and 5 show the major phases of the process of selecting and orienting the teeth with the aid of a guide channel; - Fig. 6 shows a top view of the guide channel that support a tooth. The shape of a tooth In that is produced according to the invention is shown in Figs. 1 and 2; said tooth includes two tabs 2, 7 stretched apart, two slots 5, 6, and two tapered heads 3 , 4 that are symmetrical with respect to median plane γ of tooth in itself. Distance d between tops 3a, 4a of two heads 3, 4 is greater than the thickness of the other parts of tooth In, i.e., maximum transverse thickness t of tabs 2, 7, such that said two heads 3, 4 can be used as support points for tooth In on two opposing flat supports 8b, 8d (see Figs. 5 and 6) that are less far apart than distance d between tops 3a, 4a and further apart than maximum trans¬ verse thickness t of tabs 2, 7. Thus, tooth In can be made to turn around the support points on two tapered heads 3, 4 with their tabs 2, 7 interposed between said opposing flat supports 8b, 8d. Said opposing flat supports 8b, 8d constitute the inner walls- of a guide channel 8 (Figs. 5, 6) in order to advantageously simplify, as indicated in the preamble, the process of selecting and aligning the teeth so that they can be placed on the edges of the zip closure that is to be made. When teeth made according to this invention are used, this process includes only the phases of picking up the teeth (Fig. 3) from a feed magazine (not shown) , orienting the teeth in the vertical direction (Fig. 4) , noting their position in order to align them (Fig. 5) with respect to one another in a vertical plane υ , and moving them forward (see arrow A) in this position until they reach a vertical guide channel 8 whose width 1 is smaller than distance d between tops 3a, 4a of heads 3, 4 of teeth In and larger than the thickness of all the other parts of the teeth themselves (in practice larger than transverse thickness t of tabs 2, 7) . At this point, regardless of its angular orienta¬ tion, each tooth In is oriented, turning as shown in Fig. 5 around the contact points between two tapered heads 3, 4 and edges 8b, 8d of guide channel 8, in such a way as to assume the position from which the force of gravity applied to its center of gravity turns out to be perpendicular to the segment that connects the two support points of the two symmetrical heads and all of the teeth, which are alike, turn out to be aligned and oriented in an identical fashion. If the appropriate slope a is imparted to guide channel 8, each tooth slides (see arrow B) along channel 8, supported by heads 3, 4, toward its lower end 8i, which is located close to device 9 which is supposed to grasp the teeth and clamp them in such a way as to form the edges of a zipper. In Fig. 5 the device is depicted in schematic form only since its characteristics, which are well known to one skilled in the art, are not the object of this invention. Also, the devices for orienting the teeth before they are directed into guide channel 8 are not depicted since there are various types of such devices (rollers, parallel walls, etc.) that are well known to one skilled in the art. The zipper tooth according to the invention, as well as the procedure for aligning a number of them in order to direct them at the grasping stage have been described herein and depicted according to preferred implementations, which may be modified by one skilled in the art in accordance with various production requirements. Other implementations that are different but can be traced back to the attached claims thus fall within the scope of the protection conferred by this patent application.

Claims: Claims 1. Bilaterally symmetrical zipper tooth (In) for opening in two directions which is equipped with attachment tabs (2, 7) , two tapered heads (3, 4) , and two anchoring slots (5, 6) which make it possible to both open and close the zipper with the aid of either of two slides that face in opposite directions, characterized by the fact that distance (d) between tops (3a, 4a) of two tapered heads (3, 4) is greater than maximum thickness (t) of the other parts of the tooth itself, such that the heads can act as a support around which the tooth can turn under the action of gravity. 2. Procedure for selecting, aligning, and directing to their application points on the edges of a zipper bilater¬ ally symmetrical teeth (In) as described in Claim 1, each of which is equipped with attachment tabs (2, 7) , two tapered heads (3, 4) , and two anchoring slots (5, 6) that make it possible to both open and close the zipper with the aid of either of two slides that face in opposite directions, characterized by the fact that the following phases are included: a) picking up of teeth (In) from a feed magazine; b) orienting of the teeth in the vertical direction; c) noting their position in such a way as to align them with one another in a vertical plane ( υ ) ; d) moving said teeth (In) , thus aligned, forward and directing them into a vertical guide channel (8) whose width (1) is less than distance (d) between two tops (3a, 4a) of two heads (3, 4) of a tooth and greater than thickness (t) of all the other parts of the tooth itself, such that each tooth (In) , upon entering said channel, is automatically oriented by gravity with said tapered heads that rest on edges (8b, 8d) of the channel itself, whereby said channel is inclined with regard to horizontal (o) at an angle {a) that is sufficient to cause the teeth, supported on edges (8b, 8d) of channel (8) itself by heads (3, 4) , to slide along the channel down to its lower end (8i) , which is arranged close to a device (9) that is able to grasp each tooth and secure it in a predetermined position on the edges of the zipper.

Inventors: BERNASCONI SERGIO, BERNASCONI, SERGIO
Applicants: BERNASCONI SERGIO, RIRI SA, BERNASCONI, SERGIO, RIRI S.A.
Application year: 1997
Main classification: A44B19
IPC codes: A44B19