Patent Application
20100251869
The present invention relates to double-sided punch die which permits a single die to accommodate two or more lines of pins for different sized punch hole patterns, each to put holes in stacks of pages.
Paper punches for punching sheets for loose leaf, perforated or mechanically (spiral, metal or plastic, double loop or twin wire binding and comb binding) bound books are well known in the art. Since mechanically bound books or other stacks of sheets of any material, such as paper, metal or synthetic materials, come in a variety of sizes and require a large variety of binding elements, hole sizes, shapes and pitches, some method for accommodating two permutations with a single punch die was sought. The solution is a punch design which accepts two or more punch patterns, rows of set pins, which fit into and are engaged by the punch ram mechanism of the punch machine. Each of the punch patterns would accommodate a single line of punches (commonly called pins) to punch a stack of sheets, such as book pages or other stacked sheets with holes of the proper size and shape at the proper pitch and distance from the edge to accept the mechanical binding element being used. So another die is required for each permutation. The die is an expensive part and it must withstand substantial force and must maintain precision hole punching of the paper stack. Dies for a variety of jobs therefore represent a significant capital investment; they also require space for storage.
In the past there were dies made where one could engage or disengage an individual punch pin from the row of pins by loosening a screw above the pin within the pin bar retainer or by pulling a rod above the pin there by allowing the pin to float and preventing it from punching the paper when the pin bar pushes the other pins through the paper and into a female plate located in the base. The preferred embodiment allows for the quick engagement and disengagement of an entire row of pins at once without the time and expense of making an engage/disengage mechanism for each pin, saving money and change over time as well.
It is therefore an object of the present invention to provide a single die to accommodate two or more lines of pins.
It is also an object of the present invention to provide a die which reduces the need for multiple punch dies.
It is a further object of the present invention to provide for quick engagement and disengagement of a row of punch pins.
It is yet another object to provide a punch die which swings and floats pins not being used out of the way from contact with pages being punched.
Other objects which become apparent from the following description of the present invention.
A typical punch die has a heavy steel base with a side slot to accept a stack of book pages or other sheets of any material, and locate them with a stop member to locate the pages or other kind of sheets relative to the stripper plate above, so the edge of the sheets is at the proper distance from the center of the line of holes through which the pins will emerge. The pin retaining bar above the base is engaged by the punch ram when the die is inserted in the punch. This bar is guided over the stripper plate such that all of the pins are in registration with the line of holes. The pins are retained in the pin retaining bar by a pin bar cover which is removable to permit exchange or sharpening of the pins as they wear. The stripper often guides the pins into their respective holes.
The double-sided punch die of this invention permits a single die to accommodate two lines of pins, each with particular pin size and shape, pitch, and distance from the sheet's spine edge. Thus the number of separate dies to accommodate a given set of permutations can be reduced by 50% or more through the use of this invention. Great cost savings can therefore be obtained since a single double-sided die or other multi-row die would be substantially less costly than two single dies because major subassemblies with minor modifications are now used for two or more different book designs. Storage is also reduced since a double-sided die requires no more space than a prior art single die.
In the preferred embodiment, a half-width pin bar cover is used with the double-sided die of this invention. This would cover only one line of pins. It would be placed over the heads of the pins to be used in a particular run prior to insertion in the punch, but the unused pins would not have to be removed. In operation, the unused pins would just float harmlessly upward as their cutting ends impact the paper stacks, since there is no cover above them to keep them pushing down through the paper during the downward excursion of the pin retaining bar while the covered set of pins are actually punching holes in the paper stack.
To switch patterns in the preferred embodiment one does the following. Remove the die from the machine, switch the pin bar cover screwed over one row of pins to the other side. Then put the die into the punch the other way. The original paper entrance slot is now the exit slot and visa versa.
It is possible to make a multi-row punch with more than two rows in the die. This would save more money and eliminate the need to turn the die around. One method is to just cover the pins with the pin bar cover of the row in use and stop the paper with the correct distance of the row and the spine edge of the paper or synthetic sheets to be punched.
In an alternate embodiment, a pin locking rod is used to lock the pins in the desired row of the pin retaining bar by sliding the rod through a hole centered on each row of the bar and through transverse holes in each of the pins.
In yet another variation on the use of a locking rod, the rod rests on the top surface of the pin head instead of going through a transverse hole in each pin.
While, in general, the rows in a multi-row die have different configurations of pins and/or pitch, two or more rows can be made identical to increase the longevity of the die before a row of pins would need sharpening or replacement.
Therefore, a multi-row punch die for punching a stack of sheets includes in general:
a) a female member for accepting a stack of sheets to be punched to form a row of holes of a specific configuration and pitch;
b) the female member has at least two rows of holes, whereby the holes in one row may differ in configuration and pitch from holes in the other respective rows;
c) a pin retaining bar has two or more rows of holes, in registration with corresponding holes in said female member, for accepting pins, and
d) a pin row selection means for insuring that pins in only one selected row of holes in the retaining bar are enabled to enter the holes in the corresponding row of the female member so as to punch holes in the stack of sheets.
The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
Companion
In
As shown in
Stack 45, which is stopped by stop 44 put within female base 12, enters through slot 24 of female base 12. To punch using punches 22 on this run, pin bar cover 30 is simply be moved over pins 22 with no need to remove pins 18.
While
If more intimate contact than a line contact is desired between rod 80 and each of the pin heads is desired, the pin heads 97 can be made concave as in pins 96 shown in
In
In
A tighter circular groove can also be used instead (not shown). With the concave or grooved pin heads, some alignment rotation will be required to insert rod 80 in the desired row. Other pin head configurations (not shown) can also be retained by retaining rod 80. For example, if a pin head has an “F” or “S” shaped configuration, retaining rod 80 can engage in the recesses of the “F” or “S” shaped head to retain these fasteners with other pin head configurations. The rod can be mounted along the edge of grooved or slotted pins, or under the heads of each pin. Any fastener pin head with any kind of geometric configuration forming a cantilever or recess can be retained by retaining rod 80.
In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.
It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.
