GB2190321A - A folding knife - Google Patents

Abstract

A folding knife has a blade 1 pivoting in the handle 2 so that it folds sideways into the handle. A spring 3, contained within the handle and biased against a projection 5 on the tang of the blade, controls the movement of the blade, so that it cannot open by the force of gravity or by centrifugal force. Further means, to lock the blade in the open position, consist of a spring 6 extending along the top and over the front of the handle, and shaped so as to form a catch in which the top edge of the blade engages. Means to withdraw the blade from the handle consist of a relieved section 4 in the edge of the handle, which may be used on its own or in conjunction with an opening in the handle. <IMAGE>

Description

SPECIFICATION A folding knife This invention relates to a folding knife.

Folding knives may be hinged at right angles to the plane of the blade, or may be hinged in the plane of the blade so that the blade folds sideways into the knife.

United Kingdom patent application 8511564 discribes a folding knife hinged in the plane of the blade. A spring, biased against a projection on the tang of the blade, controls the movement of the blade, so that the blade cannot open by the force of gravity or by centrifugal force. A further spring, formed at one end in the shape of a catch, is used to lock the blade in the open position.

To control the movement of the blade, the knife described in application 8511564 incorporates a spring fixed to the outside surface of the handle, operating on the tang of the blade through an opening in the handle. The handle is also provided with a further opening by means of which the user may press the blade out of the handle with the finger. In practice, however, the spring referred to may require to be of such a size and shape that a further opening in the handle cannot be incorporated.

According to the present invention there is provided a folding knife with a blade hinged in the plane of the blade, so that it folds sideways into the handle, a spring being provided within the handle to control the movement of the blade, so that it cannot open by the force of gravity or by centrifugal force; means being provided to lock the blade in the open position; and means other than an opening in the handle being provided to withdraw the blade from the handle.

A specific embodiment of the invention will now be described by way of example, with reference to the accompanying drawing in which: Figure 1 shows the view of the knife with the blade in the open position.

Figure 2 shows a sectional view on the iines A-A shown in Fig. 1.

Figure 3 shows a perspective view of the spring and thumbpiece fitted to the top of the knife.

Referring to the drawing, the blade 1 pivots in the handle 2 by means of pivot pins or other means not shown. The handle 2 has a recess shaped to accomodate the blade 1 and the spring 3. Both pivot pins are anchored in the handle. The spring 3, contained within the handle 2, is fixed at its rearward end to the handle by means not shown, and is biased against a projection 5 on the tang of the blade. A further spring 6 is fixed at its rearward end to the handle by means not shown, and extends over the front of the handle and downwards, where its forward end is shaped so as to form a catch. The spring 6 is fitted with a thumbpiece 7. The edge of the handle 2 has a relieved section 4.

The blade is held in the closed position by the biasing of the spring 3 against the projection 5 on the tang of the blade 2. To open the knife, the user inserts the tip of his finger into the relieved section 4 and pulls the blade out of the handle.

This method of opening may be used in conjunction with an opening in the handle of the knife, of such dimensions as the size and shape of the spring 3 permit.

The movement of the blade is controlled by the biasing of the spring 3, and also by friction between the pivot pins and the handle caused by the biasing of the spring 3, so that the blade cannot open by the force of gravity or by centrifugal force.

As the blade reaches the fully open position the forward part of the spring 6 is pushed upwards by the back of the blade 1 and then returns to its former position so that the blade is located in the catch on the spring 6, and is thus locked in the open position. The thumbpiece 7 is shaped so that it may be used to pull up the forward part of the spring 6 and so release the blade.

1. A folding knife with a blade pivoting in the handle in the plane of the blade, so that it folds sideways into the handle, means being provided within the handle to control the movement of the blade so that it cannot open by force of gravity or by centrifugal force, and means also being provided to lock the blade in the open position.

2. A folding knife as claimed in claim 1, wherein the means provided to open the knife consists of a relieved section in the edge of the handle of the knife, which may be used on its own or in conjunction with an opening in the handle of the knife.

3. A folding knife substantially as described above, with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A folding knife This invention relates to a folding knife. Folding knives may be hinged at right angles to the plane of the blade, or may be hinged in the plane of the blade so that the blade folds sideways into the knife. United Kingdom patent application 8511564 discribes a folding knife hinged in the plane of the blade. A spring, biased against a projection on the tang of the blade, controls the movement of the blade, so that the blade cannot open by the force of gravity or by centrifugal force. A further spring, formed at one end in the shape of a catch, is used to lock the blade in the open position. To control the movement of the blade, the knife described in application 8511564 incorporates a spring fixed to the outside surface of the handle, operating on the tang of the blade through an opening in the handle. The handle is also provided with a further opening by means of which the user may press the blade out of the handle with the finger. In practice, however, the spring referred to may require to be of such a size and shape that a further opening in the handle cannot be incorporated. According to the present invention there is provided a folding knife with a blade hinged in the plane of the blade, so that it folds sideways into the handle, a spring being provided within the handle to control the movement of the blade, so that it cannot open by the force of gravity or by centrifugal force; means being provided to lock the blade in the open position; and means other than an opening in the handle being provided to withdraw the blade from the handle. A specific embodiment of the invention will now be described by way of example, with reference to the accompanying drawing in which: Figure 1 shows the view of the knife with the blade in the open position. Figure 2 shows a sectional view on the iines A-A shown in Fig. 1. Figure 3 shows a perspective view of the spring and thumbpiece fitted to the top of the knife. Referring to the drawing, the blade 1 pivots in the handle 2 by means of pivot pins or other means not shown. The handle 2 has a recess shaped to accomodate the blade 1 and the spring 3. Both pivot pins are anchored in the handle. The spring 3, contained within the handle 2, is fixed at its rearward end to the handle by means not shown, and is biased against a projection 5 on the tang of the blade. A further spring 6 is fixed at its rearward end to the handle by means not shown, and extends over the front of the handle and downwards, where its forward end is shaped so as to form a catch. The spring 6 is fitted with a thumbpiece 7. The edge of the handle 2 has a relieved section 4. The blade is held in the closed position by the biasing of the spring 3 against the projection 5 on the tang of the blade 2. To open the knife, the user inserts the tip of his finger into the relieved section 4 and pulls the blade out of the handle. This method of opening may be used in conjunction with an opening in the handle of the knife, of such dimensions as the size and shape of the spring 3 permit. The movement of the blade is controlled by the biasing of the spring 3, and also by friction between the pivot pins and the handle caused by the biasing of the spring 3, so that the blade cannot open by the force of gravity or by centrifugal force. As the blade reaches the fully open position the forward part of the spring 6 is pushed upwards by the back of the blade 1 and then returns to its former position so that the blade is located in the catch on the spring 6, and is thus locked in the open position. The thumbpiece 7 is shaped so that it may be used to pull up the forward part of the spring 6 and so release the blade. CLAIMS

1. A folding knife with a blade pivoting in the handle in the plane of the blade, so that it folds sideways into the handle, means being provided within the handle to control the movement of the blade so that it cannot open by force of gravity or by centrifugal force, and means also being provided to lock the blade in the open position.

2. A folding knife as claimed in claim 1, wherein the means provided to open the knife consists of a relieved section in the edge of the handle of the knife, which may be used on its own or in conjunction with an opening in the handle of the knife.

3. A folding knife substantially as described above, with reference to the accompanying drawing.