GB2389812A

GB2389812A - Cutting implement

Info

Publication number: GB2389812A
Application number: GB0312933A
Authority: GB
Inventors: Yao-Chung Huang
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-06-05
Filing date: 2003-06-05
Publication date: 2003-12-24
Anticipated expiration: 2023-06-05
Also published as: FR2841434A3; GB2389812B; TW529332U; GB0312933D0; FR2841434B3; DE20308397U1

Abstract

The present invention provides a cutting implement comprising a fixed jaw plate 30 connected to a first handle 20, a second handle 21 pivotably connected to said fixed jaw plate 30 and having a push edge, a moveable jaw plate 40 pivotable relative to said fixed jaw plate 30, a gear 50 for meshing with cooperation means on the moveable jaw plate 40 such that rotation of said gear 50 causes pivoting of said moveable jaw plate 40 rotation means for engaging and rotating the gear 50 when the second handle 21 is moved towards the first handle 20, and a check plate 60 pivotably mounted on the fixed jaw plate 30 and biased towards the gear 50, said check plate 60 having a projection, wherein, in use, said check plate 60 prevents rotation of said gear 50, in a direction opposite to the rotation caused by the push plate 70 and hence movement of the moveable jaw plate 40 away from the fixed jaw plate 30 until the second handle 21 is moved to a release position in which the push edge of the second handle 21 abuts the projection on the check plate 60 causing the check plate 60 to pivot away from said gear 50.

Description

( 1 2389812

CUTTING IMPLEMENT

The present invention relates generally to a cutting implement, and more particularly to an implement 5 capable of a series of continuous scissors actions to facilitate, for example, the removal of dead or living twigs of a tree or shrub during gardening.

As shown in Fig. 1, a tree pruner of the prior art

comprises two handles 11 which are pivoted together by a 10 pivoting member 12 and are provided at one end thereof with a blade fastened therewith. A tree twig is placed between the two blades 10 and is then cut by the scissor action of the two blades 10 when the two handles 11 are moved toward each other, as illustrated in Fig. 2. In 15 the event that the tree twig is not severed by one scissor action, a second scissor action is called for.

In order to execute the second scissor action, the two handles 11 must be moved away from each other, thereby causing the cutting edges of the two blades 10 to move 20 away from the incision made in the tree twig during the first scissor action. It is conceivably inconvenient and timeconsuming for an operator to locate the displaced cutting edges back at the original incision before the second scissor action is effected. Without

manually placing the displaced cutting edges of the blades lO back at the original incision, the operator is likely to relocate the incision, i.e. produce a second incision remote from the first. This relocation of the 5 incision often results in a waste of energy and time as well as a failure in attaining the pruning objective that is intended.

The primary objective of the present invention is to provide a cutting implement which is free of the 10 shortcomings of the prior art implement described above.

In keeping with the principle of the present -

invention, the foregoing objective of the present invention is attained by a cutting implement comprising a fixed jaw plate connected to a first handle, a second 15 handle pivotably connected to said fixed jaw plate and having a push edge, a moveable jaw plate pivotable relative to said fixed jaw, a gear for meshing with cooperation means on the moveable jaw plate such that rotation of said gear causes pivoting of said moveable 20 jaw plate, rotation means for engaging and rotating the gear when the second handle is moved towards said first handle, and a check plate pivotably mounted on the fixed jaw plate and biased towards the gear, said check plate having a projection, wherein, in use, said check plate

prevents rotation of said gear in a direction opposite to the rotation caused by the rotation means and hence prevents movement of the moveable jaw plate away from the fixed jaw plate until the second handle is moved to S a release position in which the push edge of the second handle abuts the projection on the check plate causing the check plate to pivot away from said gear.

This arrangement allows the user to perform a cutting action by moving the second handle towards the 10 first handle and then, if the first cutting action does not sever the item to be cut, the user can move the second handle away from the first handle whilst the moveable jaw remains stationary in the incision made in the first cutting action such that a subsequent cutting 15 action can be carried out at the same incision. Moving the second handle away from the first handle by a greater amount to the release position causes the check plate to disengage from the gear and allows the jaws to open for cutting the next item.

20 In preferred embodiments, the moveable jaw plate is biased away from said fixed jaw plate by biasing means such that, when the second handle is in the release position, the biasing means cause the jaws to! open. The biasing means is preferably a coiled spring.

This arrangement allows the jaws to spring open once the second handle is moved to the release position so that the user can quickly move to cut the next item.

In preferred embodiments, the check plate is biased 5 toward the gear by a torsion spring.

Most preferably, the rotation means comprises a push plate pivotably mounted on said second handle, said push plate being biased towards said gear, for example by a torsion spring.

10 The gear is preferably a toothed gear. In this case, the cooperation means on the fixed jaw plate is preferably a toothed edge having teeth which mesh with the teeth of the gear.

The projection on said check plate may be locatable 15 in a first confining slot on the fixed jaw plate for limiting the extent of pivoting of said check plate.

Similarly, the push plate may include a pillar which is locatable in a second confining slot on the second handle for limiting the extent of pivoting of the 20 push plate.

In preferred embodiments, the fixed jaw plate comprises a serrated cutting edge for abutment with the moveable jaw plate. This aids gripping of the item to be cut.

( The fixed jaw plate may comprise two aligned segments spaced apart from one another with the check plate and rotation means sandwiched between them. This allows protection of the workings of the cutting 5 implement mechanism.

The second handle may further include resilient means such as a coiled spring to bias it towards the release position. This may be connected between the second handle and the fixed jaw plate. When such 10 resilient means are provided, the first handle may be elongated, the cutting implement further including a pulley system for moving the second handle towards the first handle. This allows the cutting implement to be used to prune high or remote twigs and branches.

15 The features and the advantages of the present invention will be more readily understood upon deliberation of the following detailed description of

the present invention with reference to the accompanying drawings. 20 Fig. 1 shows a perspective view of a prior art tree

pruner. Fig. 2 shows a schematic view of the prior art tree

pruner in action.

! Fig. 3 shows a perspective view of a first embodiment of the present invention.

Fig. 4 shows a first exploded view of the first embodiment. 5 Fig. 5 shows a second exploded view of the first embodiment. Figs. 6 to 10 are schematic views of the first embodiment in action.

Fig. 11 shows a perspective view of a second 10 embodiment of the present invention.

As shown in Figs. 3 to 10, a tree pruner embodied in the present invention comprises a first handle 20 and a second handle 21, a fixed jaw plate 30, a movable jaw plate 40, a gear 50, a check plate 60, and rotation 15 means 70.

The fixed jaw plate 30 is formed of two metal pieces 301 and 302 which are identical in shape and thickness and are arranged oppositely and spaced apart on the top end of the first handle 20. The fixed jaw 20 plate 30 has a top jaw portion 31 which is provided with a serrated edge 32.

The movable jaw plate 40 is fastened pivotally at its midsegment with the fixed jaw plate 30 by a first pivot 41 such that the movable jaw plate 40 is Opposite

( to the top jaw portion 31 of the fixed jaw plate 30.

The movable jaw plate 40 has an arcuate bottom end with the first pivot 41 serving as its circular centre. The arcuate bottom end is provided with cooperation means 42 5 such that it is a toothed edge. Biasing means in the i form of a recovery spring 43 is fastened between the movable jaw plate 40 and the fixed jaw plate 30.

The gear 50 is rotatably mounted on a second pivot 51 which is pivoted to a top end 22 of the second handle 10 21. The gear 50 has teeth which engage the cooperation means 42 of the movable jaw plate 40.

The check plate 60 is pivoted to the fixed jaw plate 30 by a third pivot 61 such that the check plate 60 is contiguous to the gear 50. The check plate 60 is 15 provided at a movable end with a projection 62, which is slidably received in a first confining slot 33 for confining the pivoting of the check plate 60. The projection 62 may be engaged by a push edge 23 of the top end 22 of the second handle 21 causing the check 20 plate 60 to pivot outwards away from the gear. The: check plate 60 is provided with a anticlockwise stop edge 63 and a clockwise guide edge 64. The check plate I 60 is provided with a torsion spring 65 with one end 66 1 thereof urging the movable end of the check plate 60 to

engage the gear 50. The check plate allows the gear 50 to turn in the clockwise direction to pass the guide edge 64 but causes anticlockwise rotation of the gear 50 to be stopped by the anticlockwise stop edge 63.

5 The rotation means comprises a push plate 70 which i is contiguous to the gear 50 and is pivoted with the second handle 21 by a fourth pivot 71. The push plate 70 has a movable end 72 which is provided with a pillar 73. The pillar 73 is slidably received in a second 10 confining slot 24 of the top end 22 of the second handle 21 so as to confine the swivelling of the push plate 70.

The push plate 70 is provided with a torsion spring 74 fastened therewith such that one end 75 of the torsion spring 74 urges the movable end 72 of the push plate 70 15 into contact with the gear 50.

As illustrated in Figs. 7 to 10, the movable jaw plate 40 is moved away from the fixed jaw plate 30 by the second handle 21 so as to accommodate a tree twig "A" to be cut. As the second handle 21 is moved away 20 from the first handle 20 to the release position, the: push edge 23 of the top end 22 of the second handle 21 pushes the projection 62 so as to cause the check plate I 60 to swivel and disengage the gear 50. In the I meantime, the movable end 72 of the push plate 70 moves

( along an arcuate guide edge 34 of the bottom end of the fixed jaw plate 30 so as to disengage the gear 50. As a result, the recovery force of the recovery spring 43 of the movable jaw plate 40 is released to force the S movable jaw plate 40 to move away from the fixed jaw plate 30.

In the process of executing the scissor action to cut the tree twig "A", the second handle 21 is moved toward the first handle 20, thereby causing the push 10 plate 70 to engage the gear 50 such that the gear SO is pushed by the push plate 70 to turn clockwise on the second pivot 51. As the toothed edge 42 of the movable jaw plate 40 engages with the gear 50, the movable jaw plate 40 is actuated by the gear 50 in motion to turn 15 anticlockwise on the first pivot 41 so as to pivot towards the fixed jaw plate 30 to bring about the scissor action in conjunction with the serrated edge 32! of the top jaw portion 31 of the fixed jaw plate 30, as shown in Fig. 9.

20 In the event that the tree twig "A" is not: successfully severed by the first scissor action as described above, the second handle 21 is pivoted in the I direction away from the first handle 20, as shown in I Fig. 10. The second handle is only moved away from the _

( first handle by a distance that prevents the push edge of the second handle from engaging the projection of the check plate. In this way, the push plate 70 moves past the serrated edge of the gear 50 without turning the S gear 50 and anticlockwise rotation of the gear 50 is arrested by the anticlockwise stop edge 63 of the check plate 60. As a result, the movable jaw plate 40 remains stationary such that the cutting edge of the movable jaw plate 40 remains in the incision which is made into the 10 tree twig "A" in the first scissor action.

A second scissor action can then be used to sever the tree twig "A".

As shown in Figs. 11, a second embodiment of the present invention further comprises a long rod 81 which 15 elongates the first handle. Resilient means in the form of a coiled spring 86 is provided between the second handle and the fixed jaw plate to bias the second handle in the release position. A pulley system comprising a first pulley 83 with a pull cord 84 and a second pulley 20 85 are provided to allow remote actuation of the scissor action.

Claims

1. A cutting implement comprising: a fixed jaw plate connected to a first handle; 5 a second handle pivotally connected to said fixed jaw plate and having a push edge; a moveable jaw plate pivotable relative to said fixed jaws a gear for meshing with cooperation means on the 10 moveable jaw plate such that rotation of said gear causes pivoting of said moveable jaw plate; rotation means for engaging and rotating the gear when the second handle is moved towards said first handle; and a check plate pivotably mounted on one [1X JEW plate and biased towards the gear, said check plate having a projection, wherein, in use, said check plate prevents rotation of said gear in a direction opposite to the rotation caused by the rotation means and hence 20 prevents movement of the moveable jaw plate away from the fixed jaw plate until the second handle is moved to a release position in which the push edge of the second handle abuts the projection on the check plate causing the check plate to pivot away from said gear.

2. A cutting implement according to claim 1 in which said moveable jaw plate is biased away from said fixed jaw plate by biasing means such that, when the second handle is in the release position, the biasing S means cause the jaws to open.

3. A cutting implement according to claim 2, wherein said biasing means is a coiled spring.

4. A cutting implement according to any one of the preceding claims, wherein the check plate is biased 10 toward the gear by a torsion spring.

5. A cutting implement according to any one of the preceding claims wherein said rotation means comprises a push plate pivotably mounted on said second handle, said push plate being biased towards said gear.

1S 6. A cutting implement according to claim 5 wherein said push plate is biased toward the gear by a torsion spring.

7. A cutting implement according to any one of the preceding claims, wherein the gear is a toothed 20 gear.

8. A cutting implement according to claim 5, wherein the cooperation means on the moveable jaw plate comprises recesses for meshing with the teeth of the toothed gear.

]3 9. A cutting implement according to any one of the preceding claims, wherein said projection on said check plate is locatable in a first confining slot on the fixed jaw plate for limiting the extent of pivoting 5 of said check plate.

10. A cutting implement according to any one of claims 5 to 9, wherein said push plate includes a pillar which is locatable in a second confining slot on the second handle for limiting the extent of pivoting of 10 said push plate.

11. A cutting implement according to any one of the preceding claims, wherein said fixed jaw plate comprises a serrated cutting edge for abutment with the moveable jaw plate.

15 12. A cutting implement according to any one of the preceding claims wherein the fixed jaw plate comprises two aligned segments spaced apart from one another with the check plate and rotation means sandwiched therebetween.

20 13. A cutting implement according to any one of the preceding claims, wherein said second handle further includes resilient means to bias it towards the release position.

14. A cutting implement according to claim 13, wherein said resilient means includes a coiled spring connected between the second handle and the fixed jaw; plate. 5 15. A cutting implement according to claim 13 or claim 14, wherein said first handle is elongated, said cutting implement further including a pulley system for moving the second handle towards the first handle.

16. A cutting implement substantially as any one 10 embodiment herein described with reference to the accompanying Figures 3 to 11.

17. A tree pruner comprising: a first handle; a second handle provided at a top end with a push 15 edge and a second confining slot; a fixed jaw plate formed of two pieces identical in shape and thickness and arranged at an interval on a top end of said first handle whereby said fixed jaw plate has a top jaw portion which is provided with a serrated 20 edge; a movable jaw plate fastened pivotally with said fixed jaw plate by a first pivot such that a cutting edge of said movable jaw plate is corresponding in location to said serrated edge of said fixed jaw plate,

said movable jaw plate being provided at an arcuate bottom end with a tooth edge, said movable jaw plate further provided with a recovery spring which is fastened between said movable jaw plate and said fixed 5 jaw plate; a gear mounted rotatably on a second pivot which is pivoted to the top end of said second handle whereby said gear is engaged with said toothed edge of said movable jaw plate; 10 a check plate fastened pivotally with said fixed jaw plate by a third pivot and provided at a movable end with a projection which is slidably received in a first confining slot of said fixed jaw plate for confining the swivelling of said check plate such that said projection IS is pushed by said push edge of the top end of said second handle so as to cause said check plate to swivel, said check plate further provided with a counterclockwise stop edge, a clockwise guide edge, and a torsion spring urging at one end thereof said check 20 plate to enable the movable end of said check plate to engage said gear, thereby enabling said gear to turn clockwise to pass said clockwise guide edge and causing said gear to be arrested by said counterclockwise stop edge; and

a push plate pivoted with said second handle by a fourth pivot and provided at a movable end thereof with a pillar which is slidably received in said second confining slot of the top end of said second handle so 5 as to confine the swivelling of said push plate, said push plate further provided with a torsion spring fastened therewith such that one end of said torsion spring urges said push plate to enable the movable end of the push plate to engage said gear; 10said second handle being swivelled away from said first handle so as to cause said movable jaw plate to move away from said fixed jaw plate, thereby resulting -

in an open space to accommodate a tree twig between said movable jaw plate and said fixed jaw plate whereby said IS push edge of the top end of said second handle pushes said projection of said push plate to cause said check plate to swivel to disengage said gear, with said movable end of said push plate moving along an arcuate guide edge of a bottom end of said fixed jaw plate to 20 become disengaged with said gear, thereby causing said movable jaw plate to be forced by said recovery spring of said movable jaw plate to move away from said fixed jaw plate;

a first incision being made into the tree twig by the cutting edge of said movable jaw plate in conjunction with said serrated edge of top jaw portion of said fixed jaw plate at the time when said second 5 handle is swivelled toward said first handle so as to cause said check plate and said push plate to engage said gear such that said gear is pushed by said push plate to turn clockwise on said second pivot, and that said gear in motion actuates said movable jaw plate to 10 turn counterclockwise on said first pivot to swivel = toward said fixed jaw plate; said second handle being swivelled again in the -

direction away from said first handle in the event that the first incision fails to sever the tree twig, with 15 said movable jaw plate remaining stationary by virtue of -

the fact that said gear is not pushed by said push plate to turn, and that said gear is arrested by said counterclockwise stop edge of said check plate.