HK1024660A1 - Knife - Google Patents

Abstract

The knife (10) has two rigid protective pins (17) along a cutter (13) with a blade (12), held so that they can be moved parallel to their longitudinal axis (L) in a sliding guide cavity (19) of a handle (11) against a spring force (F). The pins form a safety arc device (16). The two pin regions extend parallel and spaced out from each other either side of the cutter. The free ends of the pin regions form guide ends (22) bent up above the knife blade tip (15).

Description

The invention relates to a knife as defined in claim 1.

A knife of this type is known, according to DE 31 16 354 A1, which, for protection against injury, has a protective pin extending along the edge of a blade, which is held translatively in a sliding guide compartment parallel to its longitudinal centre axis and which can be inserted into the handle against a spring-back force.

The familiar knife is particularly less costly to use than a sack-opener, because to open a sack, especially if it is made of strong plastic film, strong plastic fabric, paper-plastic composite, jute fabric, multilayer paper or strong paper, a hole must first be drilled into the sack before a pull-cutting motion can be made.

A rectangular blade is acceptable for a sack-opening knife, but a trapezoidal blade or similar would be preferable if it had a tip and therefore allowed the sack material to be pushed through.

In the case of another known knife (US-A-40 86 698), which is very similar to the knife described in DE 31 16 354 A1, the free end of the spring pin has a sliding cap, but the cap is designed so that, depending on the filling of the bag and the type of sack material, there is a risk of the sack material being buckled upwards, which prevents the cutting process, and also of the sack material becoming trapped in the sack material.

The cutter is known from DE-GM 18 99 717 as a knife with a protective cap enclosing the front of the handle body, which can be pushed back against the spring to release the blade.

Swinging protective caps with a U-shaped protective compartment, e.g. according to DE-AS 11 21 972, are less suitable than sack knives because they do not allow the sack material to penetrate the sack surface orthogonally, since the swinging protective cap does not necessarily recede.

A knife with a flexible protective bracket extending on both sides of the blade is known from US-A-53 25 594. To ensure the protective function of the flexible protective bracket, a swivel support is provided to prevent the elastic bracket from receding (see US 53 25 594 Fig. 3 item 55).

In the case of a knife of US-A-43 93 587, a blade carrying a pen-shaped knife holder at its free end in front of it can be dislodged from a diaphragmatic cavity in its cutting position against spring retention.

The two-piece guard, which extends on either side of the front of a rectangular blade, is known from US-A-27 43 523. This double guard, however, is made of an elastic material, so that when pressure is applied to the cutting material, the blade is pushed away along the blade, releasing the blade.

Finally, a knife is known from US-A-45 69 133 whose blade, rigidly arranged in the handle, has a rigid groove extending on both sides of the cutting edge.

The purpose of the invention, based on the subject-matter of DE 31 16 354 A1, is to create a knife particularly suitable for opening bags which, like the familiar knife, offers adequate protection against injury.

This task is solved in conjunction with the features of the general concept of claim 1 according to the invention with the features of the feature of claim 1.

In place of a safety pin as defined in DE 31 16 354 Al, a safety pin is provided, a safety pin arrangement in the form of a double safety pin, with one pin area on each side of the cutting edge of the blade, arranged at a parallel distance from each other, the leading ends of which are curved high on each side along the blade tip in relation to the fore-edge of the blade with a tip in front, preferably in the form of a trapezoidal blade.

The advantage of this invention is that the cutting edge is more inaccessible than at the present state of the art, firstly by means of a contact protection on both longitudinal sides of the cutting edge.

In addition, the fact that both pins are located at the same distance from the cutting edge and below it, provides a protection against contact at the bottom of the cutting edge.

On the other hand, the contact protection of the invention does not in practice impede the optical perceptibility of the cutting process.

In addition, the lifting and turning of the spring pins in front of the blade's front face, i.e. by the leads, provides a protection against contact with the blade's front face.

In addition, the new formation of a safety bracket does not impede the cutting work, in particular the punching of the sack material, since the safety bracket can support itself with the high curved ends, i.e. the leads, on which the sack material rests, and can support itself on a sufficiently large area, while when the gripper is lowered, the two parallel straight pin areas of the safety bracket can be pushed into the gripper against spring power points and the blade back tip can be pushed through the gap between the curved ends (guides) of the pin areas of the safety bracket.

On the one hand, the fact that the leads are not sharply bent around the blade-head side gives a favorable support of sufficient area, while avoiding the possibility of the safety-belt itself cutting through the material of the bag.

On the other hand, the highly curved frontal ironing area forming the two leads pushes the sack material down smoothly like a bracket, so that the blade always has a essentially smooth, wrinkle-free cutting surface.

It is also advantageous that the knife according to the invention, by the parallel stretching of the two pen areas, allows a convex guide of the knife along a cardboard edge in a favourable way.

In a further development of the invention, the high curved ends, the conductors, of the safety bracket pass into each other at their free ends, so that an ironing end, such as a hairpin, is obtained which increases the stability of the bracket.

In another embodiment of the invention, the high curved ends, the leading ends, of the safety bracket are additionally curved backwards starting from the frontal area of the safety bracket and preferably into the knife case.

This can be done by means of a longitudinal drain open to the outside on one side or, more advantageously, by means of a conduit open to the front of the knife handle.

The drawings show preferred embodiments of the invention, showing Fig. 1 a knife of a first design before the start of cutting work,Fig. 2 a partial side view corresponding to the arrow of view designated in Fig. 1 with II,Fig. 3 a front view corresponding to the arrow of view designated in Fig. 1 with III,Fig. 1A the knife according to Fig. 1 when the cutting work begins,Fig. 4 a modified design before the start of cutting work,Fig. 5 a side view corresponding to the arrow of view designated with V in Fig. 4,Fig. 6 a front view corresponding to the arrow of view designated with VI in Fig. 4 andFig. 4A the knife according to Fig. 4 when the cutting work begins.

The two different versions and their components are always designated with the same reference numbers, despite differences in design.

Each knife 10 has a handle 11 and a soluble blade 12 which is mounted on it, which is shaped as a trapezoidal blade in the examples shown and therefore has a straight cutting edge 13, a straight front face 14 inclined to the y-axis of the handle and a blade tip 15 in the front.

A safety bracket 16 has two parallel-spaced pins 17 whose approximately columnarly shaped inner ends 18 are translated along the longitudinal median axis L of the pins 17 in a conducting channel 19 in exit orientation x and in exit orientation z.

The insertion of the pins 17 in the z direction is only possible against a spring-resistance force, which is generally indicated by a force vector F and, in addition, in Figures 1 and 4, by a screw-pressure spring 20 inserted with a dash.

In front of the pins 17 two leads 22 are connected to each other by a circular arc 21 and drawn around the blade 12 at a distance in front of the blade tip 15 and the forehead surface 14.

From the overview of Figures 1-3 and 1A on the one hand and Figures 4-6 and 4A on the other, it is clear that the respective safety bracket 16 forms a protective space S to accommodate the cutting 13 on each side next to the cutting 13 and in front of the blade tip 15 if the safety bracket 16 is in its forward protective position according to Figures 1-3 on the one hand and 4-6 on the other.

The embodiment shown in Figures 4-6 and 4A differs from the embodiment shown in Figures 1-3 and 1A only in that the two leads 22 are each joined by a backward-facing solder 25 and both leads 25 are in turn connected by an solder 24 solder.

The function of both versions of the knife 10 is to place the knife 10 with the respective guide 22 on the surface of the sack E, while sharpening and leveling the sack material 22 between the two leads, as shown in particular in Figures 2 and 6.

Then the grip 11 is pushed downwards in the direction of pressure P, the safety grip 16 is inserted into the grip 11 along the slide z and the blade 12 penetrates the surface of the bag E. Then the cutting work can begin by moving the knife 10 in the direction of pressure A, cutting the bag.

The embodiments shown in Figures 4-6 and 4A may have an actuator stop operated by a button 27.

The first option may be that the button 27 is pressed down to unlock the safety brace 16 in its forward position (Fig. 4) so that the safety brace 16 can be pushed back in the z direction when the button 27 is pressed.

Once the button 27 is not pressed and the safety harness 16 has returned to its forward guard position (Fig. 4), a stop occurs which allows the safety harness 16 to be pushed back in the z direction only when the button 27 is pressed.

An alternative embodiment is that even with the button 27 continuously pressed and (what must be added) when cutting is interrupted or cutting is finished, the safety lever 16 returns to its advanced protective position (Fig. 4) but then, despite the button being pressed, remains in its stop position.

Claims (6)

1. Knife (10) having a rigid protective pin, which extends along a cutting edge (13) of an in particular exchangeable knife blade (12), which at its free front end forms a knife point (15), wherein the protective pin is mounted so as to be capable of translational displacement by sliding parallel to its longitudinal centre line (L) in a sliding guideway (19) of a handle (11) and is retractable into the handle (11) counter to a spring restoring force (F), characterized in that two protective pins each form a pin region (17) of a safety hoop arrangement (16), that both pin regions (17) extend parallel to and at a distance from one another and on either side of the cutting edge (13) of the knife blade (12), and that the free ends of the two pin regions (17) form guide ends (22), which are bent up beyond the knife blade point (15) on either side at a distance in front of the end face (14) of the knife blade (12).
2. Knife according to claim 1, characterized in that the knife blade (12) is formed by a trapezoidal blade.
3. Knife according to claim 1 or according to claim 2, characterized in that the two bent-up guide ends (22) of the safety hoop arrangement (16) verge into one another at their free ends (23) so as to provide an approximately hairpin-shaped hoop end (at 24), which increases the stability of the safety hoop arrangement (16).
4. Knife according to one of claims 1 to 3, characterized in that the bent-up guide ends (22), starting from the front region (23) of the safety hoop arrangement (16), are additionally bent round (at 25) backwards in the direction of the handle (11).
5. Knife according to claim 4, characterized in that the ends (25) of the safety hoop arrangement (16), which are bent round backwards, is introduced into the handle (11).
6. Knife according to claim 5, characterized in that the ends (25) of the safety hoop arrangement (16), which are bent round backwards, are accommodated in a longitudinal duct open in an outward direction or in a guide channel (26) of the handle (11).