This invention relates to a paper punch, in particular such a paper punch suitable for paper crafting purposes.
BACKGROUND OF THE INVENTION
In the field of paper crafting, pieces of paper or cardboard of various shapes are punched out from sheets of paper or cardboard by paper punches. A first conventional paper punch is shown in FIG. 1 and generally designated as 10. The conventional paper punch 10 has a generally U-shaped body 12 with an open end 14 through which a sheet of paper or cardboard 16 may be inserted. Upon downward pressing of a button 18, a die (not shown) in the body 12 is brought down to punch out a piece of paper or cardboard 16a, as shown in FIG. 3. A second conventional paper punch is shown in FIG. 2 and generally designated as 20. The structure of the paper punch 20 is similar to that of the paper punch 10, with the major difference being that, in the paper punch 20, a lever 22 is downwardly pivoted to bring down a die (not shown) to punch a sheet of paper or cardboard.
It is well known in the field of production of paper punches that the performance of a paper punch highly depends on the proper alignment between the die and the die holder of the paper punch. In this connection, FIGS. 4a to 4c show various views of the internal components of the paper punch 10 during a punching action. As shown in particular in FIGS. 4a and 4b, when the button 18 is pushed down, a die 24 is brought down against the upwardly biasing force of a coil spring 26. During such a movement, and as shown in more detail in FIGS. 4c and 4d, an upper jaw 28 of a die holder 30 will bend downwardly towards a lower jaw 32, thus causing misalignment between the die 24 and the die holder 30. FIG. 4c shows clearly that a cutting edge 34 on a lower end of the die 24 strikes on an upper face of the lower jaw 32 of the die holder 30 during the punching movement, thus damaging the cutting edge 34, and the performance of paper punch 10 is adversely affected.
A similar situation also occurs in the second conventional paper punch 20, as shown in FIGS. 5a to 5d.
It is thus an object of the present invention to provide a paper punch in which the aforesaid shortcomings are mitigated, or at least to provide a useful alternative to the trade and public.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a paper punch including an operating member; a die; and a die holder with an upper jaw member and a lower jaw member which are spaced apart from each other; wherein said operating member is operable to move said die relative to said die holder to punch at least a piece of paper out from a sheet of paper received within said paper punch; and wherein said die holder includes a restrictor adapted to limit the extent of relative movement between said upper and lower jaw members.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of a first conventional paper punch;
FIG. 2 is a perspective view of a second conventional paper punch;
FIG. 3 shows a piece of shaped paper or cardboard cut out from a sheet of paper or cardboard;
FIG. 4
a is a sectional view of the conventional paper punch shown in FIG. 1 before a punching action;
FIG. 4
b is a sectional view of the paper punch shown in FIG. 4a after a punching action;
FIGS. 4
c and 4d are enlarged views of the two encircled parts in FIG. 4b;
FIG. 5
a is a sectional view of the conventional paper punch shown in FIG. 2 before a punching action;
FIG. 5
b is a sectional view of the paper punch shown in FIG. 5a after a punching action;
FIGS. 5
c and 5d are enlarged views of the two encircled parts in FIG. 5b;
FIG. 6
a is a sectional view of a paper punch according to a first embodiment of the present invention;
FIG. 6
b is an enlarged view of the encircled part in FIG. 6a;
FIG. 7
a is an exploded perspective view showing the wheel of the paper punch shown in FIG. 6a;
FIG. 7
b is a perspective view showing the wheel assembled to the paper punch shown in FIG. 6a;
FIGS. 8
a to 8c show the relative movement among the upper jaw, lower jaw and the wheel of the paper punch shown in FIG. 6a before, during and after a punching action;
FIG. 9
a is a sectional view of a paper punch according to a second embodiment of the present invention;
FIG. 9
b is an enlarged view of the encircled part in FIG. 9a;
FIG. 10
a is an exploded perspective view showing the wheel of the paper punch shown in FIG. 9a;
FIG. 10
b is a perspective view showing the wheel assembled to the paper punch shown in FIG. 9a; and
FIGS. 11
a to 11c show the relative movement among the upper jaw, lower jaw and the wheel of the paper punch shown in FIG. 9a before, during and after a punching action.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Although the present invention will hereinafter be referred to as and described in the context of a paper punch, it is also envisaged that the present invention is also suitable for a punch for punching cardboard and such like materials, and that the scope of protection should be construed accordingly.
FIG. 6
a shows a sectional view of a paper punch according to a first embodiment of the present invention, generally designated as 100. The paper punch 100 has a body 102 housing a die 104 and a die holder 106. The die 104 is biased away from the die holder 106 by a coil spring 108. Secured on the die 104 is a button 110 which may be depressed, e.g. by a user, to move the die 104 relative to the die holder 106 in the direction indicated by the arrow in FIG. 6a, so that a lower cutting edge 112 passes through a correspondingly shaped hole in an upper jaw 114, a slot 115 between the upper jaw 114, and a correspondingly shaped hole in a lower jaw 116 of the die holder 106, which is spaced apart from the upper jaw 114, to punch or cut out a piece of shaped paper from a sheet of paper 117. In FIG. 6a, the die 104 is in its lowermost position relative to the die holder 106, in which position part of the cutting edge 112 is below the lower jaw 116 of the die holder 106.
As shown in more detail in FIGS. 6b to 7b, a restricting mechanism is provided adjacent the front end of the upper jaw 114 for limiting the extent of downward movement of the upper jaw 114 towards the lower jaw 116. The restricting mechanism includes a wheel 12030 carried by a pair of ears 121 fixed with the upper jaw 114 via a pin 122. The wheel 120 has an inner hole of a diameter larger than the outer diameter of the pin 122, so that the wheel 120 can rotate and move up and down (in the sense as shown in FIGS. 6a and 6b, and along a path parallel to the path of movement of the die 104 relative to the die holder 106 relative to the pin 122. The pin 122 cannot, however, exhibit any up and down movement relative to the pair of ears 121. Normally, in the absence of any paper received within the slot 115 of the paper punch 100, the wheel 120 contacts an upper surface 116a of the lower jaw 116.
Turning now to FIGS. 8a to 8c, such show operation of the restricting mechanism of the paper punch 100 of the present invention. As shown in FIG. 8a, when no paper is received within the slot 105 of the paper punch 100, the wheel 120 sits on top of the lower jaw 116, and the pin 122 contacts an upper part of the inner hole of the wheel 120. When a piece of paper 117 is inserted into the slot 105 of the die holder 106 via the front end of the die holder 106, the wheel 120 is caused to rotate and also move upward relative to the pin 122 by a distance equal to the thickness of the piece of paper 117, and sits on the sheet of paper 117.
It can be seen in FIG. 6a that, in this configuration when at the end of the downward punching action, a plate 118 of the die 104 sits on top of an upstanding wall of the upper jaw 114 of the die holder 106, and thus exerts a downward pressure on the upper jaw 114. Thus, as shown in FIG. 8c, at the end of the downward movement of the die 104 relative to the die holder 106, the die 104 will bend the upper jaw 114 downward towards the lower jaw 116. However, the maximum distance d of downward movement of the upper jaw 114 towards the lower jaw 116 which is allowed in this arrangement is limited to:
Diameter of inner hole of wheel 120—Outer diameter of pin 120—Thickness of Paper 117
Thus, when in the configuration as shown in FIG. 8c, the upper jaw 114 cannot move any closer to the lower jaw 116.
Incidentally, the restricting mechanism also limits the thickness of paper which may be received within the slot 105 of the die holder 106, as the sheet of paper 117 cannot be thicker than the difference between the diameter of the inner hole of the wheel 120 and the outer diameter of the pin 120.
A paper punch according to a second embodiment of the present invention, as shown in FIGS. 9a and 9b and generally designated as 200, is structurally similar to the paper punch 100 discussed above. A major difference between the paper punches 100, 200 is that, in the paper punch 200, and as shown in more detail in FIGS. 10a and 10b, a wheel 202 is carried by a holder 204 via a pin 206. The holder 204 is fixed to a pair of ears 207 of an upper jaw 208 of a die holder 210 via a pin 212, such that the holder 204 is prevented from exhibiting any up and down movement (in the sense shown in FIGS. 11a to 11c) relative to the pair of ears 207. On the other hand, as the diameter of an inner hole of the wheel 202 is larger than the diameter of the pin 206, the wheel 202 can rotate and move up and down relative to the pin 206 and the holder 204.
Turning now to FIGS. 11a to 11c, such show operation of the restricting mechanism of the paper punch 200 according to the present invention, which is similar to the principle of operation of the restricting mechanism in the paper punch 100, discussed above.
It should be understood that the above only illustrates examples whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention.
It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations.
Patent Application
20080168878
