GB1575285A

GB1575285A - Knives

Info

Publication number: GB1575285A
Application number: GB1701978A
Authority: GB
Original assignee: Nippon Tenshashi KK
Current assignee: Nippon Tenshashi KK
Priority date: 1978-02-13
Filing date: 1978-04-28
Publication date: 1980-09-17
Also published as: FR2416772A1; DE2827381C2; FR2416772B1; JPS54120800U; JPS5751010Y2; DE2827381A1

Description

(54) IMPROVEMENTS IN AND RELATING TO KNIVES (71) We, NIPPON TENSHASHI KABUSHIKI KAISHA, a Japanese Company organised and existing under the laws of Japan, of 172-6, Nakano-cho, Higashisumiyoshi-ku, Osaka, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a knife and is particularly concerned with a knife having a magazine which stores spare blades. Each blade is scored on its surface to provide a break line to present a new cutting edge for subsequent use. The knife is provided with a slider, the forward movement of which results in the corresponding movement of a blade.

Hitherto in such knives, a magazine has been so structured as to comprise a spring which presses outwardly the blades stored in the magazine, and that when all the blades have been used, a whole new magazine storing new blades must be refilled. Each refilling or replenishment is wasteful in that it forces a user to throw away a whole magazine which comprises a magazine case, a spring, a base plate and other components. This wastefulness is not desirable. In addition to the above, the magazine includes a spring therein and the magazine case is necessarily thick and bulky. Furthermore in conventional knives, the magazine is not biassed outwardly, which can mean that a lug provided inwardly on the slider does not engage an opening in the outermost blade, thus hindering smooth ejection of the blade.

According to the present invention, there is provided a knife comprising: a holder having a longitudinal cavity, a blade magazine disposed within said cavity and adapted to accomodate a plurality of dispensable blades, a blade dispensing member provided on a first wall of said holder and arranged to engage a blade in the magazine juxtaposed thereto for progressively dispensing of the blade from the holder, and spring means carried by said holder and acting on at least one blade in said magazine to bias said blades and the magazine containing them towards said first wall.

The dispensing member may be a slider adapted to slide longitudinally of the holder in a slot provided in said first wall. The slider may include a projection adapted to engage a blade in said magazine juxtaposed thereto, the arrangement being such that said spring means maintains said blade in engagement with said slider as dispensing of said blade progresses.

The magazine may have a window in a side thereof juxtaposed each spring means whereby each spring means acts directly on an adjacent blade in the magazine. Furthermore the knife in accordance with the present invention may include a dispensing opening for the dispensing of a blade from a forward end of the holder and an opening at a rearward end of the holder for the insertion of said magazine into said cavity.

The knife may further include releasable locking means for securing the magazine within said holder.

The invention further provides a sheathed knife in which the lug provided inwardly on the slider flawlessly engages the opening in the outermost blade in the magazine and the smooth forward and backward movement of the blade in correspondence with the corresponding movement of the slider is assured, the magazine being indirectly pressed outwardly by the spring attached (or secured) to the holder which extends through a window in the guide body and the window in the magazine whereby the magazine is kept pressed and retained firm in position.

In another aspect of the present invention a sheathed knife which is so structured as to have the holder and the guide body put together by a single fastening member (or means) and the front end of the holder guided through a forward window in the rear wall of the guide body and rested in the foward end cavity of the guide body, whereby assembly of the knife maybe easy and components of the knife may be limited.

Following is a description by way of example only and with reference to the accompanying drawings of methods of carrying the invention into effect.

In the drawings: Figure 1 is a top view of preferred embodiment of this invention; Figure 2 is a front view of the same in Figure 1; Figure 3 is a back view of the same in Figure 1; Figure 4 is a left side view of the same in Figure 1; Figure 5 is a right side view of the same in Figure 1; Figure 6 is an oblique view of the same in Figure 1; Figure 7 is a section view taken along line VII-VII in Figure 2; Figure 8 is an enlarged vertical section view of the invention in Figure 1 taken along a line crossing the lock with the lock in locking position:: Figure 9 is an enlarged vertical section view of the invention in Figure 1 taken along a line crossing the lock with the lock in unlocking position; Figure 10 is a partial section view taken along line VII-VII in Figure 2 showing a slider being disposed at the forward most position for removal of a blade; Figure 11 is an oblique view of the components of the sheathed knife such as a holder, a guide body, a lock, a slider, a screw and others; Figure 12 is an oblique view of components of a magazine such as a magazine case, a base plate, a cap and others; Figure 13 is a back view showing engagement of the base plate and the cap.

A knife 10 comprises a holder 12; a guide body 14; a magazine 18 (best shown in Figure 12) adapted for insertion into the guide body 14 from the rearward end thereof; a slider 22 mounted in a groove in the guide body 14 to advance a blade 20; a lock 24 adapted in the opening at the rearward portion of the holder 12, the lock 24 performing functions to lock and unlock the guide body 14 and the magazine 18; a spring (s) 26 (shown in Figure 11) pressing outwardly a plurality of blades 20 stored in the magazine 18, the spring (s) 26 extending through a window in the guide body 14 and a window in the magazine 18 and a screw 28 disposed at the forward portion of the guide body 14 to retain an ejected blade in position.

The present invention is primarily characterized by attachment of the spring (s) 26 to the holder 12, not to the magazine 18.

The holder 12, which is made of aluminium, and has a weight suitable for its intended use, has a longitudinal groove 30 open on the front, as shown in Figure 11, and is provided with a plurality of recesses thereon to improve the knife's appearance and to stop slipping when used.

The holder 12 has a head portion 34 through which an opening 36 runs said opening 36 being engaged with the screw 28, and the holder has a hole 38 at the rearward portion thereof to locate the lock 24. In the groove 30 of the holder 12 there are provided, as shown in Figure 7, at the forward, central and rearward portions thereof recesses 40, 42 and 44 to be engaged with screws 46, 118 and 48 respectively, the screws 46, 48 securing the spring (s) 26.

The spring 26 used in this example is sheet springs 50, 52 intended to occupy a minimum space, the sheet spring 50 being bent at the forward and backward ends thereof, and the sheet spring 52 being bent at the forward and rearward ends thereof and also bent bow-like at the central portion. The sheet spring 52 is provided with a longitudinal opening inside. The spring 26 may be replaced by any elastic member such as a coil spring, or suitably shaped rubber member.

The recess 42 is provided on a base 56 constituted by a outwardly projected part of a rear wall 54 of the holder 12. In this example the forward recess 40 and backward recess 44 are provided on the rear wall 54 directly and on a base 60 respectively, the base 60 being projected half way inside the groove 30.

The guide body 14 is made of thin steel, being pressed into a channel type. As shown in Figure 11, an upper wall 62, a lower wall 64, a rear wall 66, a front upper wall 68 and a front upper wall 70 of the guide body 14 all together define a cavity 71, the front upper and lower walls 68, 70 together defining a longitudinal slot 74 to mount a slider 22 therein. The slot 74 is provided with a plurality of zig-zag projections 72 on its upper surface, each constituting a slider locking portion.

The rear wall 66 is provided with longitudinal windows 76, 78 through which the spring 26 secured to the holder 12 extend into the guide body 14. The front upper and lower walls 68, 70 are so shaped that the forward ends 82, 84 of the front upper and lower walls 68, 70 are receded inwardly whereby the slider 22 may bear against them as shown in Figure 10 when the slider 22 is moved to its foremost position.

The guide body 14 is provided with a cut away portion 90 at the rearward portion thereof which a projection 112 of a lock 24 may engage or disengage to lock or unlock respectively. At the central portion of the rear wall 66 is provided, as shown in Figure 7, an opening 92 used to secure the guide body 14 to the holder 12.

The lock 24 is made from synthetic resin and comprises as shown in Figure 11, a round rear wall 94 adapted movably in an opening 38 disposed at the rearward portion of the holder 12, a half round front wall 96, two bridges 98, 100 linking the round rear wall 94 and the half round front wall 96, two pillars 104, 106 provided vertically on the front side of the round rear wall 94, a flap 110 provided on the back side of the front wall 96, the flap 110 projecting inwardly and horizontally and being provided with a lug 108 mounted thereon, and a projection 112 disposed on the back side of the front wall 96 and on the backward bridge 100 together.

The rear and front walls 94, 96 accommodate elliptical openings 114, 116 respectively whereby a user may, for example, hang the knife on a nail on the wall.

To assemble the knife, the holder 12, the guide body 14 and the lock 24 may be put together at first. The head portion 34 of the holder 12 is guided through the forward window 76 in the guide body 14 and rests in the foremost position of the cavity 71, the foremost portion 80 of the rear wall 66 supporting the head portion 34.

Next the guide body 14 and the lock 24 may be engaged with the groove 30 and the hole 38 respectively, with the projection 112 being engaged with the cut away portion 90 in the guide body 14 and the rearward end of the guide body 14 being disposed between the round rear wall 94 of the lock 24 and the half round front wall 96 of the same.

A screw 118 may be driven into the recess 42 disposed at the central portion of the holder 12 through the opening 92 in the guide body 14.

The lock 24 after assembly can be moved inwardly and outwardly, from the locking position shown in Figure 8 to the unlocking position shown in Figure 9. When the lock 24 is in the unlocking position, elasticity of the flap 110 of the lock 24 forces the lug 108 on the flap 110 to press the lower side of lower wall 64 of the guide body 14 thereby retaining in position the lock 24, while in the locking position the same lug 108 is so disposed as to be in contact with the lower portion of the rear wall 66 of the guide body 14.

The slider 22 which moves a blade 20 forwardly and rearwardly comprises, as shown in Figure 11, a crown 120 made, for example, of aluminium and a spring strip 122 made of steel, the crown 120 having a serrated outer portion and the spring strip 122 having a forward end bent outwardly and a lug 126 provided at the forward portion of the back side of the spring strip 122, the lug 126 engaging an opening 124 in the outer most blade, as shown in Figures 7 and 10. The slider 22 is mounted in the slot 74 from the opening at the rearward end of the guide body 14. The front upper wall 68 and the front lower wall 70 on the front side of the guide body 14 are disposed between the strip 122 and the crown 120 of the slider 22.

There is provided a spring 130 in the crown 120, the spring 130 having its top disposed in a cut away portion 132 in the crown 120. The top of the spring 13 is engaged with a trough 72 of the guide body 14, the trough serving to retain the slider 14 in position. The head portion 34 of the holder 12 has the opening 36 which the screw 28 engages, and at the same time the window 76 in the guide body 14 has a cut away portion which the screw 28 engages, the screw 28 having a coil spring 134, as shown in Figure 7, to stop a backlash of the screw 28. This enables the screw 28 to run through the head portion 34 of the holder 12 whereby the screw 28 presses and retains in position the blade 20, which is disposed in a cavity 136 defined by the front side of the head portion 34 of the holder 12 and the forward ends 82, 84 of the front upper and lower walls 68, 70.

The structure of the magazine 18 used in the sheathed knife 1 will now be explained.

The magazine 18 comprises, as shown in Figure 12, a magazine case 138, a base plate 140, a cap 142 and spare blades 20. The magazine case 138 is made of thin steel, being pressed into desired shape and is sized to be inserted in the cavity 71 in the guide.

body 14 from the rear end thereof. The magazine case 138 comprises an upper wall 144, a lower wall 146, a rear wall 148, a front upper wall 150 and a front lower wall 152 all of which define a longitudinal cavity 143.

The rear wall 148 is provided with a cut away portion 154 and a window 156 in longitudinally spaced relationship which correspond to the windows 76 and 78 in the guide body 14 respectively. The cut away portion 154 is provided for an easy insertion of the magazine 18. Provided at the rearward portion of the rear wall 148 of the magazine case 138 is a flap 158 which is used to retain in position or fix a cap 142 to be described below. Additionally provided at the rear portion of the magazine case 138 is a cut away portion 160 which the projection 112 of the lock 24 engages.

The base plate 140 is made for example of spring steel and is almost as wide as the blades 20. The forward end of the base plate 140 is bent inwardly and the backward end thereof has a hook 162. Provided at the backward portion of the base plate 140 is a flap 164 which is bent outwardly at the end thereof to provide an abutment 166. The abutment 166 engages with opening 124 in the blades 20, thereby retaining in position all the blades and disengages by depression of the abutment 166.

The cap 142 is located at the rear end of the magazine case 138, the cap 142 having a knob 168 with a serrated outer portion on the front side thereof, and on the back side, as shown in Figure 13, a recess 174 engaged with the flap 158 in the magazine case 138.

There is provided a cut away portion 176 on the front side of the cap which corresponds to the co-operating cut away portion 160 in the magazine case 138 when the cap 142 is located in the magazine case 138.

The above mentioned components may be assembled as to be stated below to provide the magazine 18. The hook 162 in the base plate 140, as shown in Figure 13, may be engaged with the recess 170 in the cap 142. The base plate 140 with the cap 142 associated therewith may be inserted into the magazine case 138 from the rearward end thereof and the flap 158 in the magazine case 138 may be bent to be engaged with the recess 174 as shown in Figure 7. Next a plurality of blades are entered into the magazine case 138 one by one from the forward end portion thereof to be disposed between the base plate 140 and the front upper and lower walls 150, 152 of the magazine case 138. The insertion of the blades 20 forces the flap 140 in the base plate 140 to bend inwardly, thereby moving the abutment 166 inwardly, too.

When the blades 20 are entered so deep that the abutment 166 is engaged with the opening 124 in the blades 20, elasticity of the flap 164 forces the flap 164 to flip back to the original position whereby the abutment 166 stops the free movement of the blades 20.

The magazine 18 thus assembled may be inserted into the guide body 14 from the rear end thereof. When the insertion is completed, the lock 24 may be locked to have the projection 112 engaged with the cut away portion 90, the cut away portion 160 and the cut away portion 176 in the guide body, the magazine case 138 and the cap 142 respectively, as shown in Figure 8.

When the magazine 18 need be pulled out, the rear wall 94 of the lock 24 may be pushed outwardly to disengage the projection 122 thereby unlocking the lock 24 as shown in Figure 9.

When the outer most blade is ejected for use, the slider 22 is moved rearwardly to a position whereby the lug 126 is juxtaposed projection 166 in the base plate 140, the lug 126 depressing the projection 166 by deformation of the flap 164 to disengage the projection 166 from the opening 124 in the outermost blade to substitute therefore the lug 126 on the slider 22. The forward movement of the slider 122 results in corresponding advancement of the outer most blade. When the blade portion in use in the cutting process has become dull or blunt, the blade portion is broken off along a scored line on the blade, the slider 22 being advanced until the spring 130 engages the next depression in the zig-zag portion to expose the next new blade portion for cutting. This process or sequence may be continued with the renewable blade portions until the slider 22 is at the foremost position.In this case the strip 122 of the slider 22 enters the forward window on the front side of the guide body 14 defined by the cut away portions 86, 88 in the front upper walls 68, 70 of the guide body 14 respectively. The further forward advancement of the slider 22 causes the strip 122 of the slider 22 to run on the forward end portions 82, 84 of the front upper and lower walls 62, 64, thereby disengaging the lug 126 from the opening 124 in the blade 20.

When the disengaged blade is pulled out, the spring 26 urges a new blade 20 to the outer most position to take up the place left by the discharged blade. The slider 22 disposed forwardly as shown in Figure 10 may be moved backwardly to have the lug 26 engaged with the new spare blade 20.

When the spare blades in the magazine 18 have all been used, the magazine 18 may be pulled out of the guide body 16 from the rear end thereof. The magazine may be refilled with a new supply of blades.

As described above, the present invention has a spring attached (or secured) to the holder, the spring pressing blades outwardly through windows in the guide body and the magazine, which enables the knife to have a considerably bigger spring which can press the blades with more strength than in the conventional knives and to have a compact magazine because the spring is secured to the holder, not to the magazine.

The spring attached to the holder presses outwardly not only the blades directly but also the magazine indirectly, whereby the magazine is retained inmovably in position and consequently the lug mounted on the slider never fails to engage the opening in the blade because the blades and the magazine are kept pressed outwardly toward the slider mounted in the guide body.

In addition the present invention has a considerably bigger lock which locks and unlocks the magazine by pushing the inwardly and outwardly respectively, whereby users have no difficulties refilling the blades as it is easy to operate.

Finally the knife is so structured that the forward end of the holder is rested in the forward end of the cavity (or channel) in the guide body and the central portion of the guide body is secured to the holder by a single screw whereby it is easy to assemble the knife.

WHAT WE CLAIM IS: 1. A knife comprising: a holder having a longitudinal cavity, a blade magazine dis posed within said cavity and adapted to accommodate a plurality of dispensable blades, a blade dispensing member provided on a first wall of said holder and arranged to engage a blade in the magazine juxtaposed thereto for progressive dispensing of the blade from the holder, and spring means carried by said holder and acting on at least one blade in said magazine to bias said blades and the magazine containing them towards said first wall.

2. A knife as claimed in Claim 1 wherein the dispensing member is a slider adapted to slide longitudinally of the holder in a slot provided in said first wall.

3. A knife as claimed in Claim 2 wherein the slider includes a projection adapted to engage a blade in said magazine juxtaposed thereto, the arrangement being such that said spring means maintains said blade in engagement with said slider as dispensing of said blade progresses.

4. A knife as claimed in any preceding claim wherein the magazine has a window in a side thereof juxtaposed each spring means whereby each spring means acts directly on an adjacent blade in the magazine.

5. A knife as claimed in any preceding claim including a dispensing opening for the dispensing of a blade from a forward end of the holder and an opening at a rearward end of the holder for the insertion of said magazine into said cavity.

6. A knife as claimed in Claim 5 includ ing releasable locking means for securing the magazine within said holder.

7. A knife as claimed in any preceding claim wherein a blade clamp member is provided at or towards the forward end of the holder to clamp said blade with respect to the holder during use.

8. A knife as claimed in any preceding claim wherein the slider has a lug adapted to engage a hole in the blade.

9. A knife as claimed in any preceding claim wherein the holder is configured at its forward end to define a blade dispensing slit through which a blade is forwardly or rearwardly movable with respect to the holder.

10. A knife as claimed in any preceding claim wherein the holder has a hole at a rearward end portion thereof and a locking member accommodated within said hole for movement laterally of said holder said locking member being provided with a projection adapted to engage cut away portions in the magazine.

11. A knife as claimed in any preceding claim wherein the holder comprises a handle portion carrying said spring means and a longitudinal guide body defining said cavity and said first wall, and carrying the blade dispensing means.

12. A knife as claimed in Claim 11 wherein the guide body has a window defined by an expanded portion of the slot at the forward end thereof the slot being closed by a forward end of said window and wherein the slider has a forwardly projecting strip carrying said lug the extremity of said strip being adapted to enter said window so as to engage said forward end of said windows whereby further forward movement of said slider causes the strip to be urged towards said first wall to disengage said lug from the opening in the blade.

13. A knife as claimed in any one of Claims 7 to 12 wherein the forward portion of the holder has an opening which runs through said portion, said opening being threaded and carrying a clamping screw to clamp the blade against the first wall thereby retaining the blade in position.

14. A knife as claimed in any preceding claim wherein the magazine has a base plate and accommodates a plurality of blades, said base plate being provided with a flap movable inwardly and outwardly, said flap having an abutment which can engage all the openings in all the blades stored in the magazine and said abutment retaining in position blades excluding the outermost blade when said outermost blade is moved forwardly of the remaining blades in the magazine.

15. A knife as claimed in Claim 1 and substantially as herein described with reference to and as illustrated in Figures 1 to 13 of the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. forward end of the cavity (or channel) in the guide body and the central portion of the guide body is secured to the holder by a single screw whereby it is easy to assemble the knife. WHAT WE CLAIM IS:

1. A knife comprising: a holder having a longitudinal cavity, a blade magazine dis posed within said cavity and adapted to accommodate a plurality of dispensable blades, a blade dispensing member provided on a first wall of said holder and arranged to engage a blade in the magazine juxtaposed thereto for progressive dispensing of the blade from the holder, and spring means carried by said holder and acting on at least one blade in said magazine to bias said blades and the magazine containing them towards said first wall.