EP0089303A1 - Blade holding and adjusting device for a general purpose knife - Google Patents

Abstract

This device essentially comprises, on the one hand, a leaf spring (12) arranged in the body of the device and comprising a head (16) projecting laterally with respect to the said body of the device and ensuring the positioning of the device by cooperation of the head of the leaf spring with a notch of the catch mechanism and, on the other hand, a locking pin (24) cooperating with the said catch mechanism and capable of being released from the latter by manual pressure of the user, the head of the leaf spring and the axis of the pin being separated by a distance equal to a multiple of the pitch of the catch mechanism. <IMAGE>

Description

The present invention relates to a carriage for advancing and blocking the blade of a cutting instrument, of the type comprising a separable blade capable of sliding in a sheath under the action of said device, said sheath having a longitudinal opening in which said carriage slides, said longitudinal opening comprising on at least one of its edges a notch intended to cooperate on the one hand with at least one elastic element for positioning the advance and locking carriage and on the other hand with at least one blocking element cooperating with the notch, the positioning element and the blocking element being able to be erased by manual pressure from the user.

A device of this type is known, and has already been the subject, for example, of patent application in France 80-13209. Other patents have also been filed on neighboring constructions.

Thus, for example, Japanese patent 405,718 already discloses a feed and blocking carriage comprising a ratchet spring blade cooperating with a toothing of the sheath in which the separable blade moves.

Neither of these two devices gives full satisfaction.

Thus, the device of the request 80-13209 is of excessively complex design which is a drawback at the level of the manufacturing and the cost price, as well as at the level of the use, because one thus increases the risks of malfunction .

The device of Japanese patent 405,718 is not effective enough to ensure real locking of the blade in position, the spring disappearing due to the traction carried out on the blade during the cutting movement or accidentally simply of the user support socket on the handle of the tool and therefore on the movement button.

There are also known cutting instruments comprising a positioning element and a blocking element but in none of the disclosed devices the blocking is obtained automatically and without additional operation or position adjustment.

The object of the invention is to overcome these various drawbacks and to propose a feed and blocking carriage for a cutting instrument blade ("cutter") of simpler design and ensuring effective and automatic blocking of the blade when it has been positioned and the user no longer requests the carriage.

This result is obtained in accordance with the invention with a carriage for advancing and blocking the blade of a cutting instrument, of the type comprising a fractionable blade capable of sliding in a sleeve under the action of said carriage, said sleeve having a longitudinal opening in which said carriage slides, said longitudinal opening comprising on at least one of its edges a notch intended to cooperate on the one hand with at least one elastic element for positioning the advance carriage and for blocking and on the other hand with at least one blocking element cooperating with the notch, the positioning element and the blocking element which can be erased by manual pressure of the user, characterized in that it essentially comprises on the one hand a leaf spring arranged in the body of the carriage having a head projecting laterally relative to said body of the carriage and ensuring the positioning of the carriage by cooperation of the head of the leaf spring with a notch of the notch and on the other hand a locking pin cooperating with said notch and being able to be erased from the latter by manual pressure of the user, the head of the leaf spring and the axis of the pin being separated by a distance equal to a multiple of the pitch of the notch.

By this configuration, it is ensured that, when the head of the leaf spring is positioned in a notch, the pin is automatically opposite another notch, the relaxation of the stress of the user on the carriage bringing the pin in the locking position in said notch.

The leaf spring will be erased due to its elasticity by simple manual pressure from the user having a component directed parallel to the length of the opening of the sheath, provided that the locking pin has been previously released.

The pin will be erased by action on return springs integral with the carriage and bearing on the bottom of the sleeve, by manual pressure of the user perpendicular to the plane of the opening of the sleeve.

It therefore requires a double action of the user to respectively unlock and then advance the carriage.

• - la figure 1 est une vue en élévation latérale d'un chariot conforme à l'invention ;
• - la figure 2 est une vue de dessus du chariot de la f igure 1 ;
• - la figure 3 est une vue de dessous du chariot de la figure 1 ;
• - la figure 4 est une coupe selon A-A de la figure 1 ;
• - la figure 5 est une vue de dessus analogue à la figure 2, en coupe partielle, la partie supérieure du chariot étant enlevée ;
• - la figure 6 illustre pour mémoire un fourreau d'instrument à découper, de type en lui-même connu, à une échelle différente.

The invention will be better understood with the aid of the description below of a preferred embodiment, with reference to the appended drawings in which:

• - Figure 1 is a side elevational view of a carriage according to the invention;
• - Figure 2 is a top view of the carriage Figure 1;
• - Figure 3 is a bottom view of the carriage of Figure 1;
• - Figure 4 is a section along AA of Figure 1;
• - Figure 5 is a top view similar to Figure 2, in partial section, the upper part of the carriage being removed;
• - Figure 6 illustrates for the record a sheath of an instrument to be cut, of a type known per se, on a different scale.

First of all, reference is generally made to FIGS. 1, 2 and 3.

• - une plage (2) faisant office de rampe de poussée et comportant par exemple des cannelures (3) pour éviter que le doigt ne glisse sur celle-ci,
• - un téton (4) disposé sur l'avant du chariot et venant se positionner dans un orifice de la lame de l'instrument à découper,
• - deux nervures telles que (5) symétriques et permettant au chariot de coulisser dans le fourreau sans pouvoir sortir par l'ouverture longitudinale de celui-ci,
• - deux pattes ressort (6,7) solidaires du chariot prenant appui sur le fond du fourreau et conférant audit chariot une élasticité en flexion lorsque l'on presse sur le bouton (2) dans le sens de la flèche F (figure 1).

The carriage (1) essentially comprises:

• a range (2) acting as a push ramp and comprising, for example, grooves (3) to prevent the finger from sliding on it,
• - a stud (4) disposed on the front of the carriage and positioned in an orifice in the blade of the instrument to be cut,
• - two ribs such as (5) symmetrical and allowing the carriage to slide in the sheath without being able to exit through the longitudinal opening thereof,
• - Two spring tabs (6,7) integral with the carriage bearing on the bottom of the sheath and giving said carriage elasticity in bending when the button (2) is pressed in the direction of the arrow F (FIG. 1).

According to a preferred embodiment, all of these elements will have come in one piece by molding.

The carriage (1) is able to move, carrying with it a blade thanks to the stud (4), in a sheath (8) shown in FIG. 6, which has a longitudinal opening (9) one of the edges of which comprises a notch (10) in which the notches are arranged according to a determined pitch. The notches have a section corresponding to a portion of cylinder.

The blade is positioned in the sheath by a device which will be described in detail with reference to FIG. 5.

In the body (17) of the carriage (1) is provided a reservation (11) in which is disposed a leaf spring (12) whose two ends (13,14) bear on one of the walls (15) of the reservation.

The leaf spring has a head (16) projecting laterally relative to the body (17) of the carriage so as to constantly cooperate with the notch (10). The head (16) is positioned exactly in the bottom of a notch of the notch, thus ensuring the precise positioning of the carriage and therefore of the blade.

The reservation (11) will be made when the carriage is molded. It opens onto the rear face of the carriage through an oblong opening (18) through which the spring can be inserted into the carriage.

The head (16) of the carriage (12) projects through the second wall (19) of the reservation (11) through an opening (20) formed in the latter. In order to reinforce the efficiency and the rigidity of the positioning, the edges (21, 22) of the opening (20) in contact with the leaf spring when the head of the latter is positioned in a notch will be chamfered to increase maximum the support surface of the leaf spring on said edges and allow its release from the notch with less effort.

With the blade and the carriage positioned, the assembly must now be locked in position.

This is achieved using the device shown in Figure 4.

On the rear part (23) of the carriage (1) a pin (24) of generally cylindrical shape is chased comprising a large diameter section (25), the diameter of which corresponds to that of the notch (10), and a diameter section lower (26).

The diameter of the section (26) is determined so as to allow the passage, during the translation of the carriage, of the edges (27) of the notch (10).

The operation is as follows. When the carriage is in position (see above), the user still has his finger on the track (2) and the rear part (23) of the carriage is therefore urged towards the sheath.

When the pressure is released, the springs (6,7) recall the rear part of the carriage and engage the section (25) of the pin in a notch of the notch. The blocking is then effective and automatic. To optimize positioning, the border of the upper face of the section (25) will be chamfered.

To achieve this result, the head of the leaf spring and the axis of the pin must be at a distance from each other corresponding to a multiple of the notching pitch.

Multiple modifications could be made without departing from the scope of the invention.

Thus for example one could conceive a double notching on the sheath, with corresponding duplication of the positioning and locking device. Similarly, the leaf spring and the pin can for example cooperate each with a different notching, each on one of the edges of the sheath.

Claims (6)

1. Trolley for advancing and blocking the blade of a cutting instrument, of the type comprising a fractionable blade capable of sliding in a sleeve under the action of said carriage, said sleeve having a longitudinal opening in which said carriage slides, said longitudinal opening comprising on at least one of its edges a notch intended to cooperate on the one hand with at least one elastic element for positioning the advance and blocking carriage and on the other hand with at least one blocking element cooperating with the notch, the positioning element and the blocking element which can be erased by manual pressure from the user, characterized in that it essentially comprises on the one hand a leaf spring (12) disposed in the body of the carriage and comprising a head (16) projecting laterally with respect to said body of the carriage and ensuring the positioning of the carriage by cooperation of the head of the leaf spring with a notch of the notch (10) and further by t a locking pin (24) cooperating with said notching and can be removed from it by manual pressure from the user, the head of the leaf spring and the axis of the pin being separated by a distance equal to one multiple of the notching pitch. 2. Trolley according to claim l, characterized in that it comprises two tabs (6,7) coming from molding and bearing on the bottom of the sheath to give said trolley an elasticity in bending when the user presses the button ( 2) of said carriage. 3. Trolley according to any one of claims 1 and 2, characterized in that the pin (24) is driven into the rear part (23) of the trolley. 4. Trolley according to any one of claims 1 to 3, characterized in that the pin has a section of larger diameter (25) whose diameter corresponds to that of the notch (10) and a smaller diameter section (26) determined so as to allow the passage of the edges (27) of the notch (16) during the translation of the carriage. 5. Trolley according to any one of claims 1 to 4, characterized in that the leaf spring (12) is arranged in a reservation (11) of the body of the trolley, the head (16) of the spring projecting laterally relative to to the body (17) through an opening (20) formed in a wall (19) of the reservation, the ends (13,14) of said spring bearing on the other wall (15) of the reservation. 6. Trolley according to any one of claims 1 to 5, characterized in that the reservation (11) opens on the rear face of the trolley according to an oblong opening (18).

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