Circular cutter

[0001] 1. Field of the Invention

[0002] The present invention relates to a round cutter (such as plastic slice, leather piece, woodiness piece, scrip, cardboard, etc.), and more particularly to a round cutter for increasing cut angle automatically and easy operation.

[0003] 2. Description of the Prior Art

[0004] A manual circular cutter for linearly cutting sheet-like articles (such as plastic sheet, leather sheet, wood sheet, cardboard, etc.) appears on the marks nowadays, and generally comprises a round blade pivotally mounted to a handle, and a hood slideably arranged perpendicular to the axes of the handle. The effective cutting area of the circular cutter can be closed or open by moving the hood (the circular blade can contact the object to be cut after being blocked by the hood). The cutting tool is quite easily operated and practical, but also has some disadvantages. For example:

[0005] Firstly, the effective cutting area of the circular cutter can be adjusted by the slide of the hood in the axial direction of the handle of the circular cutter, but effective cutting area of the circular cutter is vertical to the forefront of the axes of the handle of the cutting tool, and therefore the effective cutting angle of the circular cutter is not large enough in consideration of the gripping direction that the user holds the handle.

[0006] Secondly, the conventional cover is slidable in the direction of the axes of the handle of the circular cutter, therefore, the effective cutting area of the round cutter begins from the forefront thereof. If the object to be cut is kind of thick, the handle of the circular cutter should be arranged in a vertical manner to the object to be cut, so that the maximum cutting depth can be achieved.

[0007] To solve the abovementioned shortcomings, another manual circular cutter appeared on the market (as shown in FIG. 1), which comprises a circular blade 10 pivotally mounted to the front end of the handle 13. On the hood 11 is formed a slant slot 111 located correspondingly to the pivotal shaft 101 of the circular blade 10. The control button 12 for controlling the hood 11 is to be pressed by the user's thumb, the slanting direction of the slot 111 must be set according to the user's habit. This manual circular cutter also has its own shortcomings.

[0008] First, since the slanting direction of the slot 111 must be set according to the user's habit, a right hander and a left hander can't share the same circular cutter, and they only can choose one of the two circular cutters as shown in FIGS. 2 and 3.

[0009] Second, the adjustable length of the hood 11 is determined by the button 12, and if the adjustable length of the hood 11 is not enough, then the effective cutting depth of the circular blade 10 will be affected adversely.

[0010] The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.

[0011] The primary objective of the present invention is to provide a circular cutter that can be used comfortably and easily both by a left hander and a right hander. The hood is defined with a T-shaped hole located correspondingly to the center of the circular blade and arranged outside of the shaft of the circular blade. When the hood is drawn back by the slide member, the T-shaped hole allows the hood to move left and right freely whatever the user uses the circular cutter with right hand or left hand.

[0012] The secondary objective of the present invention is to provide a circular cutter that has a wider cutting angle and a deeper cutting depth. When the hood is drawn back by the slide member, the T-shaped hole allows the hood to move left and right freely whatever the user uses the circular cutter with right hand or left hand. Furthermore, the deviation space A of the handle is big enough for allowing the hood to move left and right freely so as to provide enough cutting area for the circular cutter, and the edge of the hood will abut against the object to be cut smoothly as the cutting depth increases, thus helping stabilize the cutting operation.

[0013] Another objective of the present invention is to provide a circular cutter that is formed with an arc gap located in the cutting direction of the circular cutter, and the front edge of the circular blade will protrude out of the hood for cutting purpose after the hood is drawn back.

[0014] The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.

[0023] Referring to FIGS. 4, 5 and 6, a circular cutter in accordance with the present invention is shown and comprises a handle 20, a slide member 30, a shaft assembly 40, a circular blade 50 and a hood 60.

[0024] The handle 20 comprises a first housing 201 and a second housing 202. At the front end of the second housing 202 is formed a deviation space A, and at the front end of the handle 20 are formed a pivotal hole 21, an elongated slot 22 and a protective cover 221 is arranged on the outer edge of the pivotal hole 21. The first housing 201 of the handle 20 is interiorly formed with a slide groove 23 for cooperating with the elongated slot 22, and the slide groove 23 extends in the extending direction of the handle 20. On the second housing 202 is further defined an elongated limit hole 24 located correspondingly to the slide groove 23 of the first housing 201.

[0025] The slide member 30 is slideably disposed in the slide groove 23 of the handle 20 and is formed at the front end thereof with a protrusion 31 that is to be inserted in the elongated slot 22 of the handle 20. A press button 33 is connected to the mid portion of the slide member 30 by a spring 32 and is confined in the elongated limit hole 24 of the handle 20.

[0026] The shaft assembly 40 comprises a shaft 41, a first washer 42, a second washer 43, and a nut 44. The shaft 41 has a head portion 411 formed at an end thereof and has a plurality of threads 412 formed at another end thereof for meshing with the nut 44. The shaft 41 and the nut 44 are inserted in the pivotal hole 21 (the shaft 41 is covered with the protective cover 211) in such a manner that the first washer 42 and the second washer 43 are disposed outside of the first and second housings 201 and 202 of the handle 20. The washer 43 has elasticity and serves to clamp the respective components of the handle and to prevent the nut 44 from getting loose. The first washer 42 is formed with an annular abutting portion 422 for abutting against the head portion 411 of the shaft 41, so that the circular blade 50 can be clamped more tightly through the cooperation between the annular abutting portion 422 of the first washer 42 and the second washer 43.

[0027] The circular blade 50 is formed at its outer periphery with a wave cutting edge 52 and is defined with a pivotal hole 51 through which the circular blade 50 is mounted on the shaft 41 of the shaft assembly 40.

[0028] The hood 60 comprises a first shell 601 and a second shell 602 that are jointed together by inserting locking protrusions 603 into locking cavities 604. The hood 60 has a space 605 for accommodation of the wave cutting edge 52 of the circular cutter 50 and is defined with an arc gap 606 located in the cutting direction of the circular cutter 50. The hood 60 is further formed with an extension 61 for mating with the slide member 30. On the extension 61 is defined a locating slot 611 for engaging with the protrusion 31 of the slide member 30, and the locating slot 611 is made by inserting a protruding portion 613 of the second shell 602 into a slot 612 of the first shell 601. The hood 60 is further formed with a T-shaped hole 62 for engaging with the shaft 41 of the shaft assembly 40. The T-shaped hole 62 includes a central locating area 621 for mating with the center of the circular blade 50, a left gap 622 and a right gap 623. The T-shaped hole 62 is provided for insertion of the shaft 41 (the shaft 41 is covered with the protective cover 211) and is located at either side of the circular blade 50. The deviation space A of the handle 20 provides a big enough space for allowing the hood 60 to move left and right freely therein, and at the rear edge of the hood 60 is formed a protective flange 624 through which the rear portions of the first and second shells 601 and 602 can be jointed closely for keeping the circular blade 50 from the user.

[0029] For a better understanding of the present invention, its operation and function, references should be made to FIGS. 5-8. When the circular cutter is not in use, the slide member 30 is kept in the front of the slide groove 23 of the handle 20, the protrusion 31 is kept in the front of the elongated slot 22 of the handle, and the press button 33 is kept in the front of the elongated limit hole 24. At this moment, the hood 60 covers the circular blade 50 completely, and the shaft 41 is engaged in the central locating area 621 of the T-shaped hole 62, and thus the circular blade 50 is well protected.

[0030] The hood 60 can be prevented from moving left and right when an external force is applied on both sides of the hood 60, due to the shaft 41 is confined in the central locating area 621 of the T-shaped hole 62.

[0031] When want to use the circular cutter, the user can make the slide member 30 move backward by pushing the press button 33. When the slide member 30 moves backward within the slide groove 23, the protrusion 31 will move the hood 60 backward within the elongated slot 22 by pushing the extension 61. In this way, the hood 60 will withdraw from the circular blade 50, and the shaft 41 will be located between the left and right gaps 622 and 623 of the T-shaped hole 62.

[0032] At this moment, whatever a left hander or a right hander uses the circular cutter, the hood 60 can be pushed toward whichever side of the left and right gaps to meet the user's habit once a side of the hood 60 presses against the object B to be cut, due to the shaft 41 is located between the left and right gaps 622 and 623 of the T-shaped hole 62. That is to say that both left hander and a right hander can use the same circular cutter. In addition, the edge of the hood 60 will abut against the object B smoothly, thus helping stabilize the cutting operation, and the unused wave cutting edge 52 of the circular blade 50 is still covered in the space of the hood 60.

[0033] When the hood 60 is drawn back by the slide member 30, the T-shaped hole 62 allows the hood 60 to move left and right freely whatever the user uses the circular cutter with right hand or left hand, therefore, the device of the present invention is ergonomic. Furthermore, the deviation space A of the handle 20 is big enough for allowing the hood 60 to move left and right freely to provide enough cutting area for the circular cutter, and the edge of the hood 60 will abut against the object B smoothly as the cutting depth increases, thus helping stabilize the cutting operation.

[0034] In addition, the present invention is not limited to the regular circular blade 50 and also suitable for the irregular circular blades, including wave, flat and other circular blades.

[0035] While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.