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Title:
SCISSORS
Document Type and Number:
WIPO Patent Application WO/1997/007944
Kind Code:
A1
Abstract:
A hand held cutting tool comprises first and second elongate blades (11) movably connected together so that they are oppositely faced. At least one of the blades is provided with a cutting edge (14) and a guard portion (10) adjacent the cutting edge.

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Inventors:
WARD JEREMY LUKE (GB)
Application Number:
PCT/GB1996/002022
Publication Date:
March 06, 1997
Filing Date:
August 20, 1996
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
WARD JEREMY LUKE (GB)
International Classes:
B26B13/06; B26B29/04; (IPC1-7): B26B29/04; B26B13/06
Foreign References:
EP0584488A11994-03-02
DE325532C1920-09-14
EP0543199A11993-05-26
GB2067476A1981-07-30
US4753009A1988-06-28
US5379521A1995-01-10
US2557553A1951-06-19
US3325897A1967-06-20
US2249378A1941-07-15
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Claims:
CLAIMS:
1. A hand held cutting tool comprising: a first elongate blade (11); a second elongate blade (11); the first and second blades being movably connected to each other so that the first and second blades face oppositely each other, characterised in that at least one of said first or second blades is provided with a cutting edge (14) and a guard portion (10) adjacent said cutting edge.
2. A hand held cutting tool as claimed in claim 1, wherein a said guard portion projects beyond the cutting edge in a direction of cut of the blade.
3. A hand held cutting tool as claimed in any preceding claim, wherein the first blade is provided with a first guard portion, and the second blade is provided with a second guard portion.
4. A hand held cutting tool as claimed in any preceding claim, wherein a said guard portion is elongate, and has a main length which runs substantially parallel to the corresponding cutting edge.
5. A hand held cutting tool as claimed in any preceding claim, wherein the guard portion comprises a separate guard member which is attachable to the blade.
6. A hand held cutting tool as claimed in any preceding claim, wherein said cutting edge is defined at an intersection of a side face (30) of the respective blade and a back face (31) of the blade and wherein a blade angle (18) defined between said side face and said back face in a plane peφendicular to a tangent of the cutting edge is in the range 40° to 90°.
7. A hand held cutting tool as claimed in any preceding claim further comprising a catching means (20) arranged to allow the capture and retention of a moving textile thread or filament or the like.
8. A hand held cutting tool as claimed in any preceding claim further comprising a hook comprising an arcuate portion (21) which extends or faces towards a handle of the tool.
9. A hand held cutting tool according to claim 8, wherein the arcuate portion extends from a lower part of a blade, the cutting edge (14) being on an upper part of the blade.
10. A hand held cutting tool according to claim 9, wherein the hook comprises a further cutting edge (31) positioned substantially between the arcuate portion of the hook, and the lower part of the blade from which the arcuate portion extends.
Description:
SCISSORS

This invention relates to scissors which reduce the risk of the user cutting themselves.

It is a well known problem that conventional metal scissors can easily result in the user inadvertently cutting themselves when their finger comes between the blades of the scissors.

Several attempts have been made to reduce the risk of a user cutting themselves. Scissors have been made of plastics to try and reduce any injury which might result should the user trap a finger or another part of their body between the blades of the scissors. Problems arise with plastic scissors because the potential for causing damage is still not inconsiderable. Additionally, the cutting efficiency of the scissors is reduced because the blades are more prone to flexing. Because of this the scissors are less able to produce a straight cut.

A particular problem is encountered during the production of synthetic filaments e.g. nylon or polypropylene, during which production the filament must be cut. Filament issues from the production machine at speeds of up to 30 ms '1 . A person grasping the filament with one hand and attempting to cut the filament with a pair of scissors in the other hand, as is common practice, is in great danger of inadvertently cutting their hand with the scissors because of the great speed of the filament. The speed of the filament may cause the filament to "snatch" the conventional scissors out of the user's grasp, leading to danger of cutting the user, particularly as the user must be quite nimble in

order to cut the filament to a required length before too much filament passes by.

Another particular cutting problem is encountered in the production of plastics sheet material. A strip of such a material is continuously fed from a hot roller, the strip having a width of a few metres. If the production process down-line of the roller is stopped for any reason, because the roller is heated, it is more efficient to keep the roller running, and producing material, than to shut down the roller. The plastics sheet material coming off the roller, must be quickly cut, as it comes off the roller and then removed in order to avoid a build up of excess sheet material.

It is an object ofthe present invention to provide scissors which at least reduce die risk of a user inadvertently cutting themselves.

According to one aspect of the present invention there is provided a hand held cutting tool comprising:

a first elongate blade; a second elongate blade; the first and second blades being movably connected to each other so that the first and second blades face oppositely each other, characterised in that at least one of said first or second blades is provided with a cutting edge and a guard portion adjacent said cutting edge.

The provision of the guard portion may allow the blade to cut a thin flexible sheet material or compressible material, (e.g. threads or paper) which can deform around the guard portion, whilst thicker objects such as fingers

may be protected from the cutting edge because the thicker object cannot deform around the guard portion.

Preferably a said guard portion projects beyond the cutting edge in a direction of cut of the blade.

Preferably the first blade comprises a first cutting edge at one end of the first blade, and a first handle portion at an opposite end of the first blade, and the second blade member comprises a second cutting edge at one end of the second blade and the second handle portion at an opposite end of the second blade.

Preferably the first blade is provided witii a first guard portion, and the second blade is provided with a second guard portion.

Preferably the first and second blades are pivotally connected to each other so that the first and second cutting edges can engage each other in a shearing motion.

Adjacent guard portions on adjacent blades may be sufficiently close together that an operator cannot inadvertently put part of their body between the guard portions and hence between the blades.

A said guard portion may be elongate, and may have a main length which may run substantially parallel to the corresponding cutting edge.

The guard portion may extend continuously along the cutting edge of the blade.

The guard portion may have a rounded profile which extends forward of the cutting edge in a direction of cut of the blade, which profile, in use, will not penetrate human skin.

The guard portion may comprise a separate guard member which is attachable to the blade.

The guard portion may comprise a plastics strip.

The guard portion may be attached to the blade such that it is tamperproof and can only be removed with difficulty.

The guard portion may be attached to the blade with rivets.

The rivets may be hot-staked. This may prevent users removing the guards from the tool, to use the tool for example, to unscrew screws.

A said cutting edge may be defined at an intersection of a side face of the respective blade and a back face of the blade. A blade angle defined between said side face and said back face in a plane peφendicular to a tangent of the cutting edge may be in the range 40° to 90°.

The blade angle a said tool, when adapted for cutting textile material may be in the range 60° to 90°.

The blade angle of a said tool, when adapted for cutting a sheet material, e.g. paper, card or the like, may be in the range 75° to 90°. An

angle of around 90° has been formed to give adequate cutting performance on sheet material, whilst giving the best safety.

The cutting edges of the blades may be arranged for minimum deformation of the material being cut by having a blade angle not substantially deviating from 90°. However, blade angles in the range 70° to 90° give good performance in cutting sheet material and textile materials.

The blades, which are arranged for minimum deformation of the material being cut, may be reinforced by the elongate guard portions attached to each blade.

The cutting tool may comprise a catching means which is arranged to allow the capture and retention of a moving textile thread or filament or the like, and allows the thread to be pulled into a position in which it can be cut safely whilst still moving. The catching means may be arranged to allow the thread to be captured and released quickly.

The cutting tool may comprise a hook. The hook preferably comprises an arcuate portion which extends or faces toward the handle end of the tool, enabling a thread to be drawn towards the user.

Preferably the hook is provided on a said one end of a said blade.

Preferably the arcuate portion extends from a lower part of a blade, the cutting edge being on an upper part of the blade.

In particular, by providing a hook on a lower part of a blade of the cutting tool, at an end of the blade distal from the handle end, a user may quickly catch a fast moving thread using the hook, and cut the thread between the blades. The provision of the elongate guard portions which extend beyond the blades in a direction of cut of the blades, may prevent the blades cutting skin, fingers or the like which may be in the vicinity of the blades. Further, the moving thread may slide over the guard portions, which may be of a low friction material such as nylon, hereby reducing the risk of the moving thread catching the blades and snatching the tool out of the user's hand.

The guard portions may be arranged for fitting retrospectively to a pair of prior art scissors.

The hook may comprise a further cutting edge positioned substantially between the arcuate portion of the hook, and the lower part of the blade from which the arcuate portion extends. The further cutting edge preferably comprises a ground cutting edge. The further cutting edge is preferably positioned such that it is protected by an overhanging portion of the arcuate portion. The overhanging portion may extend along the lower edge of the blade, spaced apart therefrom, and forming a channel between the overhanging portion and the lower edge such that, in use, a material to be cut may be guided along the channel and towards the further cutting edge. The cutting edge is preferably provided at a closed off end of the channel, at which position the further cutting edge is protected by the overhanging portion from being contacted by a finger or the like.

The provision of the hook portion on the lower edge of the tool, and the guiding action between the overhanging portion and the lower edge of the

blade may enable use of the tool as a knife, for quickly cutting a large expanse of sheet material. By combining the elongate guards along the opposed blades of the cutting tool, and providing a further cutting edge on a lower edge of one of the blades, there may be provided a dual puφose cutting tool, for cutting sheet material in scissor like manner, whilst enabling quick cutting of an expanse of sheet material by pulling the tool in a rearward direction towards the handles of the tool, the sheet material being guided by the overhanging portion and the lower edge of the blade towards the further cutting edge. Further, as the cutting edges and the further cutting edge are each protected by a guard portion or the overhanging portion as appropriate, there is minimal risk of injury in using such a tool, even where cutting actions need to be made relatively quickly.

By way of example three specific embodiments of the invention will now be described with reference to the accompanying drawings, in which :-

Figure 1 is an exploded perspective partial view of a pair of safety scissors according to a first specific embodiment of the invention;

Figure 2 is a cross-section through blades of the safety scissors in an open position according to a first specific embodiment of the invention;

Figure 3 is a plan view of the safety scissors according to a first specific embodiment of the invention;

Figure 4 is a plan view of a second set of safety scissors according to a second embodiment of the invention;

Figure 5 is a partial perspective view of the second set of safety scissors, in use cutting a piece of sheet material; and

Figure 6 is a plan view of a third set of safety scissors according to a third embodiment of the invention.

Referring to Figures 1 and 2 of the accompanying drawings, a pair of safety scissors comprises two plastic guard strips 10, one attached to each blade 11 of the scissors. The guard strips 10 have a profile (best seen in Figure 2) which matches the outer face 12 of each blade 11. A leading edge 13 of each guard strip 10 has a rounded cross-section which is forward of the cutting edge 14 of each blade 11 in a direction of cut of the blade, being vertical as shown in Figure 2.

As seen in Figure 1 two holes 15 are present in each blade 11.

Matching projections 16 are inserted into the holes 15. The projections 16 form rivets which are "hot-staked" with a jet of hot air which melts the plastic projections 16 which spread out into a wider portion 17 of the hole 15 and sets to secure the guard strip 10 to its blade 11.

The cutting edge of each blade is formed at the intersection of a side face 30 of the blade, which is substantially parallel to a direction of cut, and a back face 31 of the blade which is transverse to the direction of cut. A cutting angle 18 of the blades 11 is selected depending on the material with which it is intended to use the scissors. Safety scissors for cutting sheet material or textile material optionally have a cutting angle 18 with range 70° to 90°.

An angle 18 of 90° has been found optional for safety, whilst a cutting angle in the range 70° to 90° gives good cutting ability and adequate safety.

The safety scissors are ideally, but not exclusively, used for cutting thin flexible materials. When the blades 11 of the scissors are moved together the cutting edges 14 of the blades 11 are preceded by the leading edges 13 of the guard strips 10. The two guard strips 10 have a narrow gap 19 between them. The combination of the leading edges 13 preceding the cutting edges 14 and the narrow gap 19 between the guard strips 10 has the effect of allowing only thin flexible material to come between the cutting edges and so be cut.

The advantage resulting from the above is that a user cannot inadvertently, or even intentionally, place a finger or another part of their body in contact with the blades. Consequently the user cannot cut themselves with the safety scissors described herein.

This safety aspect is particularly desirable when used with machines which produce synthetic fibres. Such machines can issue fibre at speeds of 30 ms "1 . During the production of fibre it is necessary to cut the fibre. This task is usually done with conventional scissors or a knife. The use of either conventional scissors or a knife often leads to the user cutting themselves. A user must grasp the fibre as it is moving at great speed before it can cut. Attempting to maintain some tension in the fibre to use the knife or scissors is very difficult and requires very good coordination of the hands a lack of which results in the user cutting themselves. It is in this situation that the safety features of the present safety scissors herein described are particularly useful.

A second set of scissors, according to another embodiment of the invention, shown in Figure 4, has the same guard strips 10 attached to the scissor blades 11 in the same manner as described above.

Additionally, on the back of one of the blades 11 there is a hook 20, the open part 21 of which faces towards the handles of the scissors.

In use the hook 20 is used to snare a fibre issuing from a machine as described in the first embodiment. The use of the hook considerably simplifies the operation of cutting a fibre described in the previous embodiment. The fibre can be pulled forcefully from the machine and with a shaφ movement the fibre can be cut by releasing the fibre from the hook 20 and thrusting the scissors forwards over the fibre and cutting in the usual way.

The benefits of the hook 20 are that the fibre can be cut much more simply and with less need to repeat the operation when the fibre is dropped or missed with the scissors.

Referring to Figure 6 of the accompanying drawings, there is shown the blades of the second set of scissors in use in cutting a large expanse of sheet material 30. The blades are in a closed position, and the cutting action of the sheet material is provided by a further cutting edge 31 provided at an intersection of a lower edge of one of the blades, and the arcuate hook portion 20. The further cutting edge 31 comprises a ground edge of substantially arcuate form. The hook portion 20 comprises an overhanging portion 32 which extends between the tip of the blade, distal from the handle end, backwardly toward the handle end. The guard portion forms a blunt rounded

feature which protects large objects, such as fingers, skin etc from encountering the further blade 31. The overhanging portion forms a channel 32 between the overhanging portion and the lower edge of the blade, through which the sheet material is guided, as the blade is drawn along the sheet material in a direction towards the handle portion of the scissors.

In this manner the second set of scissors may perform a dual function of being able to cut sheet material in scissor-like manner between the first and second cutting edges on the first and second blades, or also for very quick cutting of the sheet material, being able to be drawn along the sheet material using the further cutting edge 31 to cut through the sheet material, the further cutting edge 31 being guided through the sheet material by the overhanging portion 32 of the hook. This is combined with the safety feature of including the elongate guards extending along the first and second cutting edges, and the overhanging hook portion which effectively protects the user from inadvertently cutting himself on the further cutting edge 31.

A further embodiment of the invention is shown in Figure 6. The scissors are constructed and used substantially as described in the first embodiment, except as follows. In this example the guard strips 10 have been modified to have a rearwardly directed protrusion 22 which is decorated to resemble a frog's eye. This embodiment is intended for use by children. The safety scissors have the attribute emphasising the necessity of the safe use of potentially dangerous equipment, whilst providing all the necessary protection as described in the first embodiment.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this

application and which are open to public inspection with this specification, and the contents of all such papers and documents are incoφorated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar puφose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.




 
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