WO2001015873A1

WO2001015873A1 - Scissors

Info

Publication number: WO2001015873A1
Application number: PCT/BR2000/000099
Authority: WO
Inventors: Enio Kolodsieski
Original assignee: Zivi Sa- Cutelaria
Current assignee: Zivi Sa- Cutelaria
Priority date: 1999-09-01
Filing date: 2000-09-01
Publication date: 2001-03-08
Anticipated expiration: 2002-03-01
Also published as: AU7634800A; BR9903987A

Abstract

A pair of scissors is described, the pressure of which on the hinge is easily adjusted by the user in order to compensate for wear due to prolonged use and to adapt the scissors to cutting different materials. According to the presently preferred embodiment of the invention, the hinge of the scissors includes a concave-convex washer (5) interposed between the nut (4) of the scissors and an outer side of the cutting blades (1), to determine the tightening pressure on the hinge, according to the angular position of the nut (4). The washer (5) is held against rotation with respect to the blade (1) and has, on its upper surface, a shoulder (9) that cooperates with grooves (11) in the lower surface of the nut (4). Thus, when the nut is turned to increase or decrease the hinge pressure, the shoulder (9) actuates like a ratchet while passing from one groove to the other in the lower surface of the nut. Once the desired adjustment has been achieved, the user stops turning the nut, which is held in its angular position because the shoulder (9) remains engaged in one of the grooves (11).

Description

Title "SCISSORS"

The present invention refers to a pair of scissors provided with an hinge system that permits adjustment of the pressure between the cutting members or blades.

Background of the Invention

In conventional scissors, the hinge screw is fixed, its tightness having been adjusted during manufacture. This adjustment is predetermined according to the materials that are to be cut. This technique, however, has the serious drawback that, as the scissors wear with use, cutting efficiency is gradually lost. In addition, when the scissors are used to cut materials other than those foreseen in the initial adjustment, and which have a different strength or thickness, cutting efficiency is also impaired. Object of the Invention The object of this invention is to provide a hinge of relatively simple construction, the pressure of which can be accurately adjusted by the user. Description of the Invention

According to the present invention, a pair of scissors comprising first and second cutting members hinged to each other by means of a hinge in the form of a screw, which passes through the two members, and a tightening nut, is characterized in that the hinge between the cutting members includes elastic means placed between the nut and an outer side of the first cutting member, to determine the tightening pressure in accordance with the angular position of the nut, the elastic device being fixed against rotation with respect to the first cutting member and cooperating with the nut to secure it elastically in different angular rotational positions, thus enabling a good adjustment by predetermined increments of tightening pressure.

In the presently preferred embodiment, the elastic means is an oblong washer, the part of which that is farthest from the screw axis forming a tip bent downwards for engagement in a recess in the surface of the first cutting member. The outer surface of the washer has a shoulder that cooperates with a number of radial grooves in the lower surface of the tightening nut. As the nut is turned to tighten the hinge, the grooves pass over the shoulder on the washer like a ratchet. When the desired tightening adjustment has been achieved, the assembly is locked in position due to shoulder being received in one of the grooves.

Brief Description of the Drawings

The invention will be better understood from following detailed description, given by way of example, with reference to the accompanying drawings, in which:

- Figure 1 is a top plan view of a pair of scissors according to the presently preferred embodiment of the invention;

- Figure 2 is a side view of the left side of the scissors shown in Figure 1 ;

- Figure 3 shows a detail, partly in section, of the hinge between the cutting blades of the scissors;

- Figure 4 is a top view of a tightening washer of the hinge;

- Figure 5 is a side view of the washer, and

- Figure 6 is a bottom view of the tightening nut of the scissors.

Detailed Description of the Drawings Referring now to the drawings, a pair of scissors manufactured in accordance with a presently preferred embodiment of the present invention comprises first and second cutting members or blades 1 and 2, hinged to each other by means of a screw 3 and a tightening nut 4.

An elastic tightening means in the form of a pressure washer 5 is interposed between the outer or upper surface of the first cutting member 1 and the nut 4. As can better be seen in Figures 3 and 5, the tightening washer is slightly concave- convex in order to have the elasticity necessary to permit adjustment of the pressure applied to the hinge of the scissors.

The pressure washer 5 has a generally oblong shape, defining a tip 6 on one side. The end of tip 6 is bent downwards to form a tooth 7, which, in the assembled configuration of the scissors, fits into a recess or blind hole 8 in the upper or outer surface of the first cutting member 1. This anchors the pressure washer 5 against rotation, thus allowing nut 4 to be tightened without the washer accompanying the rotation. The washer 5 also has a small shoulder or protuberance 9 on the upper or outer surface, which faces the lower side of the tightening nut 4. The shoulder 9 has the shape of a small radial crest with respect to the central bore of the washer. The nut 4 is knurled at 10 on its side face to facilitate its rotation by the user when the latter wishes to adjust the hinge pressure. Underneath, on the inner face of the nut, there is a number of radial grooves 11. Shoulder 9 and grooves 11 are dimensioned in such a way that, when the nut is turned, shoulder 9 successively enters the radial grooves 11 , in a ratchet-like manner. When the desired pressure has been achieved and the user stops turning the nut, the shoulder is retained under pressure in one of the grooves, thus maintaining the selected hinge pressure of the scissors.

Evidently, as the scissors wear and the hinge pressure decreases, the user has only to turn the tightening nut 4 by one or more "clicks" until the desired pressure adjustment has been achieved again. Equally, if the user wishes to use the scissors to cut a material other than that for which the pressure was initially adjusted, he has only to turn the nut 4 in the adequate direction, increasing or decreasing the hinge pressure so as to achieve the necessary adjustment. It should be understood that the scissors illustrated in the drawings and described herein are just an example of embodiment of the invention, although this embodiment is presently preferred. There could be more than one shoulder 9 on the pressure washer 5, and the number of grooves 11 in the nut could vary. Alternatively, the lower face of the tightening nut could have a number of shoulders instead of grooves, and in this case the pressure washer would have one or more grooves.

Although it is well to form radial grooves in the lower surface of the tightening nut (see Figure 6) and a radial shoulder on the pressure washer, the grooves could be in the form of small circular recesses, and the shoulder, in such a case, would be in the form of an equally circular protuberance. These and other modifications fall into the concept and spirit of the invention, and it should be understood that its scope is only limited in function of the interprettion of the following claims.

Claims

1. Scissors comprising first and second cutting members hinged to each other by means of a hinge in the form of a screw that passes through the two cutting members and a tightening nut, characterized in that the hinge includes elastic means (5) interposed between the tightening nut (4) and an outer side of the first cutting member (1), to determine the tightening pressure on the hinge, according to the angular position of the nut (4), the elastic means (5) being held against rotation with respect to the first cutting member (1) and cooperating with the tightening nut (4) to secure the latter elastically in different angular positions of rotation, thus permitting adjustment of the tightening pressure by predetermined increments.

2. Scissors according to claim 1 , characterized in that the elastic device comprises a pressure washer (5) having a region (7) formed to cooperate with a complementary formation (8) on the first cutting member (1), thus preventing relative rotation between the two of them.

3. Scissors according to claim 2, characterized in that said region on the pressure washer (5) comprises a tooth (7), and the complementary formation on the first cutting member (1) comprises a recess (8) in the outer surface of the latter.

4. Scissors according to claim 3, characterized in that the pressure washer (5) has a generally oblong shape defining a tip (6) farthest from the axis of the screw (3), which is bent downwards to the outer surface of the first cutting member (1) in order to form said tooth (7).

5. Scissors according to claim 4, characterized in that the recess in the outer surface of the first cutting member (1) comprises a recess (8).

6. Scissors according to claim 3, 4, or 5, characterized in that the surface of the tightening nut (4), facing the outer surface of the pressure washer (5), has at least one radial groove (11), and the outer surface of the pressure washer (5) has at least one shoulder (9) that fits into the groove as the tightening nut (4) is turned.

7. Scissors according to claim 6, characterized in that there is a plurality of said radial grooves (11) in the tightening nut.

8. Scissors according to claim 7, characterized in that there is a single shoulder (9) on the pressure washer (5).