GB2536039A

GB2536039A - A cutting device

Info

Publication number: GB2536039A
Application number: GB1503738.5A
Authority: GB
Inventors: Calder Marc
Original assignee: VTX GLOBAL Ltd
Current assignee: VTX GLOBAL Ltd
Priority date: 2015-03-04
Filing date: 2015-03-04
Publication date: 2016-09-07
Also published as: GB201503738D0

Abstract

Cutting device 10 comprises a housing 100, 200, to contain a slide ably moveable blade 2 which can move from a first retracted position to a second extended position in which the blade 2 extends through a slot 101 in the closed end. Stop member 50 is positively engageable in the housing and is located between the blade carrier 300 and the closed end. The stop member 50 may be separately formed from the housing. The stop member may be of the type to provide a plate to abut the blade carrier 300 at the blades maximum extension length. A plurality of differently sized stop members may be provided to abut the blade carrier at different points on the pair of rails 131, effectively differing the protruding length of the blade when different stop members are used. A latching system may lock the blade in a retracted position.

Description

I

A CUTTING DEVICE

FIELD OF INVENTION

The present invention relates to a cutting device and specifically, but not exclusively, to a utility knife with an auto-retractable blade.

There are various types of cutting devices suited for general utility purposes, and the present invention is of particular relevance to what is commonly referred to a utility knife with an auto-retractable blade. The invention relates more specifically, to a utility knife that comprises a mechanism for holding securely a blade in an extended position.

BACKGROUND OF THE INVENTION

A cutting device is a commonly used hand tool for cutting e.g., wood, paper, cardboard, leather, plastic and any other material generally in the form of sheets or panels.

A cutting device typically comprises a housing that acts as both a handle and a container for a carrier which is slideably received therein and on which is secured a blade. An actuator is provided on the blade carrier which extends through the housing, which actuator forms a button for moving the blade from a retracted position to an extended position.

Cutting devices with an auto-retractable blade are receiving a great deal of attention as they reduce or eliminate the chances of accidental cuts that may occur to a user of a knife or towards others. Normally, in cutting devices with an auto-retractable blade mechanism, a blade automatically retracts back into the housing when a user releases an actuator for extending the blade after cutting.

A mechanism to adjust the length of a blade protrusion and hold the blade in a desirable extended (i.e. cutting) position so that to be suitable for an intended purpose, has received considerable attention over the last decades as it can be inferred for example from the recently disclosed U.S. Pat. No. 8,769,826 B2.

With regards to the present invention, the Martor Secunorm Multiset (1) product represents the closest prior art. The Manor's product relates to a handed cutting knife with an auto-retractable blade wherein a slider on the side of the knife enables movement of a blade from a retracted position to an extended position. The blade is secured in a blade carrier which is slideably received in a housing and can be easily flipped over so that to enable either left or right handed cutting operations. The length of the protruding blade can be adjusted by means of a locking screw that engages a rear end of the slider to which the blade is secured.

The slider can be friction locked in different positions so that to be adjusted to vary the extent by which the blade protrudes from the housing.

A problem associated with this mechanism of controlling the extent to which the blade protrudes from the housing, and in particular of holding firmly the blade in an extended position, is that it is based on a friction coupling which is susceptible to slippage, particularly when the cutting device is used with a great deal of force and over time as the system wears.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a more robust and reliable stopping mechanism so as to hold the blade in an extended position and to avoid the abovementioned slippage problem. Another objective of the present invention is to provide a cutting device wherein the stopping mechanism can be configured to vary the extent by http://www.martorco.uld which the blade protrudes from the housing. It is also an objective of the present invention to provide a latching system which prevents unintentional movements of the blade from the retracted position to an extended position.

The present invention provides a cutting device comprising a housing; a blade carrier mounted in the housing so as to be slideably moveable therein between a first retracted position in which, in use, a blade mounted on the carrier is retracted into the housing and a second extended position in which, in use, the blade extends through a slot formed in a closed end of the housing so as to protrude from said housing; and a stop member positively engageable in the housing, by means of complementary engaging means provided on the stop member and the housing, between the blade carrier and the closed end of the housing, which stop member is engageable by the blade carrier as it moves from the retracted position towards the closed end of the housing so as to limit the movement of said blade carrier and hence, in use, the distance by which the blade extends from the housing.

The present invention has the advantage that, by providing the stop member in front of the blade carrier which positively engages with the housing rather than relying on frictional engagement, a much more reliable and secure stopping mechanism that holds the blade in an extended position is provided without suffering from the slippage problems associated with the prior art. Another advantage of the present invention over the prior art, is to provide a cutting device with less construction parts that would be less complicated as well as less expensive to manufacture and assemble.

The stop member is a separate plate which operates to limit the movement of the blade carrier towards the closed end of the housing and thereby control the extent by which the blade protrudes from the housing when the carrier is in its extended position. Preferably, a number of stop members each having different sizes can be utilised so as to enable different blade protrusion lengths to be set depending on the particular requirements of the knife.

Furthermore, the present invention includes a latching system that locks the blade in the retracted position. This system has the advantage to prevent unintentional movements of the blade from the retracted position to an extended position during cutting operations.

It should be recognized that the present invention differs from the disclosed U.S. Pat. No. 8,769,826 B2 wherein there is a locking mechanism which engages directly the blade (and not the blade carrier) at a specific location.

These objectives and other aspects, features and advantages of the present invention will become clear from the following descriptions, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 shows an exploded perspective schematic view of the cutting device of invention; Figure 2 shows a top view of the cutting device comprising a short stop member in a retracted position; Figure 3 shows a top view of the cutting device comprising a short stop member in an extended position, and Figure 4 shows a top view of the cutting device comprising a long stop member in an extended position.

DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 shows an exploded perspective schematic view of the cutting device 10 comprising an outer housing 100, an inner housing 200, a stop member 50, and a blade carrier 300 where a blade 2 (shown in Figures 2 to 4) is secured.

In the embodiment shown in Figure 1, the outer housing 100 ads as a handle of the cutting device and the inner housing 200 comprises a blade carrier 300 which is slideably moveable therein. The inner housing 200 is received slideably into the outer housing 100 along the longitudinal axis (A) by an open end 102 towards a closed end 101 so as to form a unity element which will be named thereafter as housing 100,200. The inner housing 200 is secured into the outer housing 100 by a snap-fit system comprising a resiliently deformable lug 220 and a recess 150 being arranged in a front side of the inner housing 200 and the outer housing 100, respectively. It will be appreciated that other snap-fit means and arrangements can be used.

The closed end 101 has a slot formed therein through which the blade 2 can extend so as to protrude from the housing. The outer housing 100 comprises an opening 103 that extends substantially from the open end 102 towards the closed end 101 on the top side of the outer housing 100.

The outer housing 100 has a pair of rails 131 (only one of which is visible) upstanding from the bottom wall of the inside surface and extending longitudinally from the closed end 101 to about half length of the outer housing 100.

The outer housing also has a pair of rails 161 (only one of which is visible) protruding downwardly from the edges of the inside surface which define the opening 103. These rails enable the inner housing 200 to be received slideably in the outer housing 100 by the open end 102 and to constrain the blade carrier 300 to move only along the longitudinal axis. The rails 161 further comprise a pair of downstanding protrusions 163 (only one of which is visible) extending longitudinally which lock the blade carrier 300 by a latching system as it will be described later.

The inner housing 100 comprises a plate 165 at the closed end 101, which plate is offset from the top side of the outside surface so as to form a seat for the stop member 50. In the embodiment shown in Figure 1, the plate 165 has three holes 168 formed therein and the stop member 50 has a complementary set of locating pins formed thereon by means of which the stop member 50 may be located and retained on the plate 165 by snap-fit means. It will, however, be understood that the exact form of the locating system for the plate on the housing is not critical for the invention. For example, the pins may be provided on the housing and the holes in the plate, or a completely different locating system may be used.

The stop member 50 controls the forward movement of the blade carrier 300 so as to limit the distance by which the blade 2 extends beyond the housing by engaging a front end of the blade carrier 300 as it slideably moves from the retracted position towards the closed end 101 of the housing. It will be appreciated that a number of stops 50 having different sizes can be provided each limiting the movement of the blade carrier 300 to a different distance and hence giving different blade protrusion distances from the housing (see e.g. a short stop member 50 in Figures 2 and 3 and a long stop member 51 in Figure 4). It will be also appreciated that the stop member 50 is an insert of the housing having a shape which complements substantially the shape of the plate 165 at the closed end 101 of the housing.

The inner housing 200 consist substantially of a C-shaped cross section which is separated at the front end by a longitudinal extending central slot 210 comprising a two-tine fork, which central slot 210 receives slideably the blade carrier 300 therein. The tines 201,202 of the fork extend longitudinally and are parallel to each other.

The blade carrier 300 includes a lower plate 310 and an upper plate 330 joined by a middle plate 320 which slides along the central slot 210. The lower plate 310 and the upper plate 330 overlay laterally (i.e. along the axis B) the slot 210 so as to hold in place the blade carrier 300 along the tines 201,202 and avoid undesirable lateral movements of the blade carrier when in use. A plurality of ridges 222 (only one of which is visible) is also arranged along the tines 201,202 to guide the longitudinal movement of the blade carrier 300 through the housing so as to further minimise such unwanted lateral movements.

The blade 2 is secured on the lower plate 310 of the blade carrier 300 and moves slideably between the tines 201,202 and the pair of rails 131. The blade 2 can be removed from the blade carrier 300 and from the housing by removing the inner housing 200 from the outer housing 100. It is understood that the blade 2 can be flipped over so that to enable either left or right handed cutting operations, and that either pointed or rounded blades can be used depending of the needs of the user of the cutting device 10.

The blade 2 can be extended from the housing by means of a slideably moveable slider button 301 that is slotted on the inner housing 200 and is accessible by the opening 103. In the embodiment shown, the slider 301 has a gripping portion with a substantially "curved" shape so as to provide an ergonomic sliding button that improves the handle operations. The slider 301 has a pair of laterally extending lugs 306 (only one of which is visible) that locks the blade 2 in the retracted position so as to prevent unintentional movements of the blade 2, when in use, from the retracted position to an extended position.

It is understood that when extending the blade 2 from the retracted position to an extended position, the aforementioned protrusions 163 in the outer housing 100 latch the slider 301 by means of the pair of lugs 306 which slideably moves along a pair of cuts out 213 (only one of which is visible) that is fitted in the inner housing 200. The latching system requires the slider * 301 to be pressed downwardly against the action of biasing means (not shown) into the housing so as to enable the lugs 306 to engage with the protrusions 163 thereby enabling movement of the blade carrier 300 forward. It should be noted that when the inner housing 200 is received in the outer housing 100 the lugs 306 engage with the side rails 161 of the outer housing 100 so as to prevent the blade carrier 300 to be pulled out of the inner housing 200.

In the embodiments of the present invention, the inner housing 200 further comprises a back end portion having an oval recess 280 that can be used as a hook for the cutting device 10.

With reference to Figures 2, 3 and 4, the functioning of the cutting device 10 is described as follows. To move the blade 2 from the retracted position to an extended position, the slider 301 needs to be pressed downwardly so as to disengage the abovementioned latching system, after which it can be pushed longitudinally towards the closed end of the housing until the blade carrier 300 abuts the stop member 50,51. When the slider 301 is released after cutting operations, a spring 4 forces the blade carrier 300, and hence the blade 2, to retract back longitudinally from an extended position (see Figures 3 and 4) towards the retracted position (see the area delimited by the lines 5,6 in Figure 2) where the inner housing 200 limits further backwards movement of the blade carrier 300.

Claims

Claims 1. A cutting device comprising a housing; a blade carrier mounted in the housing so as to be slideably moveable therein between a first retracted position in which, in use, a blade mounted on the carrier is retracted into the housing and a second extended position in which, in use, the blade extends through a slot formed in a closed end of the housing so as to protrude from said housing; and a stop member positively engageable in the housing, between the blade carrier and the closed end of the housing, which stop member is engageable by the blade carrier as it moves from the retracted position towards the closed end of the housing so as to limit the movement of said blade carrier and hence, in use, the distance by which the blade extends from the housing.
2. A cutting device according to claim 1, wherein the stop member is separately formed CO from the housing and takes the form of a plate which locates in the path of movement of theCDblade carrier so as to limit the minimum separation between the closed end of the housing and the blade carrier and thereby control the extent by which the blade protrudes from the housing when the carrier is in its extended position.
3. A cutting device according to claim 1 or claim 2, wherein the stop member and housing include complementary engaging means which interact with each other to positively secure the stop member to the housing.
4. A cutting device according to claim 3. wherei the complementary engaging means comprises a plurality of protrusions formed on one of the stop member and the housing and a complementary plurality of recesses formed on the other of the stop member and the housing into which the protrusions are engageable.
A cutting device according to any of the preceding claims, further including a latching system operable to lock the blade in the retracted position.
6. A cutting device assembly comprising a cutting device according to any of the preceding claims and a plurality of stop members of different sizes, each stop member being separately engageable with the housing to define a different stop point for the movement o the blade carrier towards the closed end of the housing and thereby to define a different maximum protrusion of a blade beyond the closed end of the housing. can be utilised so as to enable different blade protrusion lengths to be set depending on the particular requirements of the knife.
7. A cutting device substantially as herein described with reference to the accompanying drawings.
8. A cutting device assemble substantially as herein described with reference to the co accompanying drawings.CD