Patent Application
20100101098
(1) Field of the Invention
The present invention relates to a blade unit for rotary paper trimmers, and more particularly, to a replaceable blade unit for rotary paper trimmers.
(2) Description of the Prior Art
A conventional rotary paper trimmer is shown in
When changing the blade 75, the knob 76 is pushed so as to remove the locking pieces 77 away from the sliding member 73, and the knob 76 is rotated to shift another blade 75 to the operation position.
However, the reaction force to the blade 75 during use is applied to the locking pieces 77 which affect the stable of the blades 75. Once the blades 75 shake during use, the trimming result will not be satisfied.
The present invention intends to provide a replaceable blade unit which includes only one blade and the blade unit can be quickly and easily removed from the trimmer and replace with a new blade.
The present invention relates to a rotary paper trimmer which comprises a work board having a rail connected thereto and a blade unit is slidably engaged with the rail. The blade unit includes a top part, a blade carrier and a locking member, wherein the top part includes a first side and two second sides. A recess is defined in an underside of the top part and open to the two second sides. A protrusion extends from the first side and two insertion holes are defined through the first side. The locking member is movably inserted into a space defined in the top part and includes hooks which are located corresponding to the insertion holes. The blade carrier has a body which has a pressing side facing the top part and a blade is located between the pressing side and the protrusion. The body has two lugs extending from the pressing side thereof and the lugs are inserted into the insertion holes and hooked with the hooks of the locking member. Therefore, the blade carrier can be removed from the top part to replace a new blade by pushing the locking member to disengage the hooks from the lugs.
The primary object of the present invention is to provide a replaceable blade unit for a rotary paper trimmer and the blade unit includes only one blade which is firmly positioned so as to prevent from shaking during use.
Another object of the present invention is to provide a replaceable blade unit for a rotary paper trimmer wherein the blade unit can be easily removed from the work board to replace a new blade.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.
Referring to
A protrusion 24 extends from the first side 221 and two insertion holes 23 defined through the first side 221. The protrusion 24 is located between the two insertion holes 23. Two connection holes 231 are located beside the two insertion holes 23. A concavity 241 is defined in a center of the first side 221 of the top part 22 and the protrusion 24 is located around the concavity 241.
The space 25 has a closed end 251 and a spring 34 is located in the space 25. The locking member 30 includes an elongate body 31 and is movably inserted into the space 25 and the spring 34 is biased between the closed end 251 and the locking member 30. The locking member 30 includes two L-shaped hooks 32 extending from one side thereof and the two hooks are located corresponding to the insertion holes 23.
The blade carrier 50 has a body 51 which has a pressing side 511 facing the top part 22 and a blade 40 has a mounting hole 41 with which an axle 54 extending from the pressing side 511 extends. The axle 54 is inserted into the concavity 241 of the top part 22 so that the blade 40 is firmly clamped between the pressing side 511 and the protrusion 24. The body 51 has two lugs 52 extending from the pressing side 511 thereof and the axle 54 is located between the lugs 52, the lugs 52 are inserted into the insertion holes 23. The lugs 52 on the blade carrier 50 have through holes 521 to which the hooks 32 are hooked. A flange 53 extends from the body 51 and is located on a side opposite to the pressing side 511.
An arc part 27 is connected to the first side 221 of the top part 22 and includes an arc-shaped space. The body 51 of the blade carrier 50 is engaged with the arc-shaped space. Two insertions 271 extend from a side of the arc part 27 and are inserted into two connection holes 231 located beside the two insertion holes 23. The arc part 27 further has two positioning legs 272 which are engaged with two notches in the first side 221 of the top part 22.
When trimming paper, the user puts paper sheets on the work board 10 and holds the handle 26 to move the blade unit 20 along the rail 11, the blade 40 is rotated to trim the paper sheets about the axle 54.
When replacing a new blade 40, the user simply pushes the locking member 30 to remove the hooks 32 from the through holes 521 of the lugs 52 of the blade carrier 50, the user then pulls the flange 53 on the blade carrier 50 to remove the blade carrier 50 together with the blade 40 out from the top part 22. The old blade 40 can be replaced with a new one. The blade carrier 50 with the new blade 40 is then connected to the top part 22 by inserting the lugs 52 into the insertion holes 23 and the hooks 32 are pushed aside a little bit and then hooked to the through holes 521 again.
While we have shown and described the embodiment 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.
