US2267517A - Slotting knife - Google Patents

Description

' Dec. 23, 1941. BARNEY 2,267,517

SLOTTING KNIFE Filed March 6, 1941 2 Sheets-Sheet l ZOE Ymeman 'bame} I 127 -;-l6 Big Q a4. Atbmeg g 7 Dec. 23,1941.

I F. BARNEY 2,267,517

SLOTTING KNIFE Filed March 6 1941 Sheets-Sheet 2 Patented Dec. 23, 1941 UNITED STATES PATENT OFFICE SLOTTING KNIFE Freeman Barney, Spring Lake, Mich., assignor to The Challenge Machinery Company, Grand Haven, Mich., a corporation of Michigan Application March 6, 1941, Serial No. 382,036 12 Claims. (c1. 164-50) This invention relates in general to drilling and slotting machines which drill holes in and provide slots at the edges of sheets of paper which are to be used in loose leaf binders. My invention in particular is directed to a novel form of slotting knife adapted to be used on machines of this character. The operation and details of machines of this type are well-known to those skilled in the art and for a moreclear understanding of such operation and the mechanical parts of the machine reference may be had to the co-pending application bearing Serial No. 218,552, filed July 11, 1938.

In the operation of the machine a pack of paper sheets is located on a table, and the carriage having the slottingknife secured thereto is reciprocated and is moved to and through the pack tocut the slot in the edge thereof. When this occurs a stack of paper chips results from the cutting operation, and has long been a source of concern to operators of such machines to successfully remove these paper chips from the vicinity of the slotting knife so that they will not interfere with the succeeding operation thereof.

It is a further object of this invention to formv openings in the sides of the slotting knifewhich.

cooperate with suction means adjacent thereto in removing the paper chips. l

A still further object of the invention is the provision within the sides of the. slotting knife of camming means to force the paper chips away from the edge of the pack of paper sheets. as they are being cut to therebyrender. the cooperation of the suction means andthe slots in the knife more eflicient. A Other objects and purposes of the invention will appear more fully as the description proceeds. l l I 1 To the accomplishment of the foregoing and. related ends said invention, then, consists ofthe,

means hereinafter fully described and .parti'cu- Fig. l is. a fragmentary partvertical section 55 and part side elevation of a machine embodying one form of my invention. v

Fig. 2 is a fragmentary plan view of the slotting I knife with portions of the machine thereabove removed.

Fig. 3 is an enlarged vertical section through which it is secured.

Fig. 4 is a horizontal section through the device of Fig. 3.

Fig. 5 is a fragmentary plan view of a sheet of paper showing the form of slot cut in the edge thereof and made by the form of cutting knife shown in Fig. 4.

Fig- 6 is a vertical section through a modified form of slotting knifetogether with the carriage on which it is mounted.

Fig. 7 is a horizontal section through the slotting knife of Fig. 6. r a

Fig. 8 is a fragmentary part sectional and part elevational view of a portion of the machine showing a still further modified form of slottin knife 'mounted thereon together with the continuously rotating hollow drill.

Fig. 9 is an enlarged vertical section through the slotting knife of Fig. 8. but showing the tubular drill in side elevation.

Fig. 10 is a horizontal section through the device shown in Fig. 9 taken substantially half way between the upper and lower ends of the slotting knife.

Fig. 11 is also a horizontal section through the device of Fig. 9 but taken adjacent the bottom fore as may be more clearly seen by reference.

to the copending application abovementioned. These means, however, have not operated satisfactorily to those concerned and I have found.

that one means of increasing the ,efilciency of this removal is to place slots in the sides of the slotting knife. The chips which are removed from the edge of the pack of paper sheets will be received between the sides of the slotting knife, whether these sides be parallel or diverging, and the suctionwhich is createdadjacent the knife at. the endof its cutting stroke will operate more successfully to remove these chips when thesides of the knife are slotted. This efliciencyis fur.-

section through the ther increased by the use of camming means within the sides of the knife which force the paper chips away from the edge of the pack as they are being cut, all as more fully described hereinafter.

When the paper chips are first cut and are received between the sides of the cutting knife their edges will curve downwardly and there will be a considerable amount of side pressure against the chips as well as the chips having a certain amount of pressure outwardly against the sides of the knife by reason of their tendency to straighten out and lie flat. This pressure must be relieved in order to permit the machine to function properly inasmuch as such pressure may spread the sides of the knife. Also, it is difficult to remove the chips by the use of a suction when this side pressure is present. By the combined use of the camming means and the opening in the sides of the knife, after the clips reach a certain height upwardly from the cutting edge of the knife, the openings will permit the chips to expand and lie flat in a loose condition which enables the suction to efficiently withdraw them from the vicinity of the cutting knife.

Referring now more particularly to the drawings, the machine includes a supporting base I having a table 2 located thereon for the purpose of supporting a pack of paper sheets 3. An insert of wood or other suitable material 4 is located within the table 2 and directly beneath the reciprocating knife so that its cutting edge will not be dulled by coming in contact with the metallic surface of the table.

A back gauge 5 is adjustably mounted on top of the table 2 and is so formed that intermediate its ends and at spaced apart points it has the rearwardly extending portions 6 connected together by the bar I, so that between the confines of the two parts 6 and the bar 1 a recess is formed within which the slotting knife is received in its lowermost position,

An opening is provided in the table 2 to receive a tube 8 with which is associated the necessary mechanism for creating a suction therein. With reference to Fig. 2 it is to be seen that the upper end of thetube 8 terminates in the upper plane of the table 2 within the recess formed in the back gauge 5 and immediately behind the insert 4. This is one form which the suction tube may take. It will be obvious that the particular location of the end of the suction tube will not be material so long as it terminates adjacent. the cutting knife. In other words. it may also be possible to have the tube 8 above the table and terminate within the recess formed in the back gauge, the specific location being a mere matter of choice.

Above the table is located the head of the machine 9 which has located thereon the vertically reciprocating carriage In having the slotting knife ll secured thereto. Immediately in front of this knife is a presser foot I2 which has the rod l3 located thereabove which is surrounded by a compression spring 14. This operates to hold the pack of paper sheets in position during the cutting operation and the spring will compress after the top of the pack is reached and the knife continues downwardly.

The particular form of slotting knife shown in Figs. 1 to 5 comprises rearwardly extending portions I5 having openings therein through which the screws I'S pass to rigidly secure the knife to the carriage Ill. The two sides then extend toward each other for a short distance-as at IT,

then extend forwardly in parallelism as at I 8 and the two cutting blades are connected together at their forward ends by the curved portion I9. Either one or both of the parallel blades l8 may have therein an opening such as shown at 20. The bottom edge of the sides l8 and the front l9 are sharpened to provide a cutting edge capable of cutting through a pack of paper sheets to result in the form of slot substantially shown at 2| in Fig. 5.

As briefly explained hereinbefore, a camming edge is provided between the sides of the slotting knife and in this particular instance I provide an insert 22, preferably formed of metal, which has a relative thickness capable of being beveled at its lower edge as at 23 downwardly and toward the front of the knife. It will be evident, then, that as the knife is lowered through the pack and the paper chips are cut therefrom, as they are so cut they will engage the beveled or camming edge 23 and will be urged away from the adjacent edge of the pack. As the chips move rearwardly and upwardly the side pressure thereon is relieved by their edges expanding into the slots 20, and they will lie loose and fiat. The suction created in the tube 8 will then act completely to force the paper chips away from the knife and remove them so completely from the area of the table that a succeeding slotting operation will not be interfered with. As stated heretofore, the suction method of removing the chips has been attempted without the aid of either the openings in the sides of the knife or the camming means therein. The efficiency of the vacuum in the tube 8 is increased tremendously by the aid of the openings in the sides of the knife. These could be used alone without any camming means and satisfactory results would be acquired, but to insure the greatest efiiciency I prefer also to include the camming means just described.

With reference to Figs. 6 and 7 I have here disclosed a different form of slotting knife, but the invention itself remains the same. In this case I also provide a carriage ill to which the knife may be rigidly secured by means of the screws Hi. In this case, however, the configuration of the knife is such as to provide the two parallel cutting blades 24 which are connected at their forward ends by a straight blade 25. This particular form of knife will cut a slot which is known to the trade as the Kalamazoo slot. Here again each of the side blades 24 is provided with openings 28a and against the inner side of the front blade 25 may be positioned one or more blocks or indentations 26 having their lower edges beveled as at 21 to provide a camming edge to urge the paper chips outwardly as they are being cut. The operation of this form of the invention is identical with that previously explained but provides a different shaped slot.

In Figs. 8 to 12 are shown slotting knives which are intended to be used in conjunction with a hollow drill. In these cases the drill and the slotting knife may be operated either separately or together. The result being a substantially circular hole near the edge of the sheet of paper but having a slot extending between the edge of the paper and the circular hole. The operation of this form of machine is also fully described in the co-pending application above referred to and it is only necessary here to describe in detail the slotting knife itself, inasmuch as that is where the invention resides. With particular respect to Figs. 8 to 11, the tubular drill is shown at 28 adjacent which isthe slotting knife which has two divergingblades 29, which diverge rearwardly' from adjacent-the lower end'of the tubular drill 28. These sideblades'2 9 extend rearwardly for a considerable distance and are mounted in the vertically reciprocating carriage 30 by means of the screws 3!.

In this particular form of the invention the bottom of the knife is separated into the two diverging blade portions 29 as clearly shown in Fig. 11. These blades then extend upwardly for a short distance as at 32 and are then joined by the connecting piece 33.which is curved rearwardly and upwardly as at 34. Above this point the two diverging blade portions are integral and the curved portion 34 acts as a camming edge which is integral with the knife and acts similarly to those previously described to force the paper chips away from the blade and the pack of paper sheets after they have been severed therefrom. Here again in the sides of the knife I provide openings 35 for the purpose of acting in conjunction with the vacuumcreated in the tube 8 to completely remove the chips from the knife for a succeeding operation.

In Fig. 12 is shown a further modification of the slotting knife wherein the two diverging blades 29a are integral from the bottom edge all the way to the top and are secured to the carriage 36 by means similar to that described heretofore. In this case an additional insert 31 is utilized at the front of the knife between the two diverging blades which has a camming edge at the bottom thereof to urge the chips rearwardly. The two blades of Fig. 12 also are provided with openings therein for the same purpose described above.

It should also be noted'here that, while it is not considered necessary, it may be advisable to form the carriage H) as a solid portion 38 at the rear side thereof which has an upwardly extending bottom edge as shown at 39. This has been found to increase the efliciency of the suction in the tube 8 when the knife and carriage are at their lowest position by cutting off the air which may be drawn into the tube from places other than that immediatelyadjacent the slotting knife.

Other modes of applying the principle of my invention may be used instead of the one here described, change being made as regards the structure herein disclosed provided, however, that the means stated by any of the following claims or the equivalent of such stated means be employed.

I, therefore, particularly point out and distinctly claim, as my invention:

1. In a paper slotting machine having a table to support a pack of paper sheets to be slotted, and a vertically reciprocating carriage over said table. a slotting knife on said carriage movable therewith to and through said pack having blades thereon between which the paper chips resulting by movement to and through said pack, said knife having side blades thereon between which the resulting paper chips are received, an opening in each of said side blades, and suction means cooperating with said openings to forcibly remove the chips from between saidblades after the completion of each slotting operation.

3. The combination with apaper slotting machine having a table to support a pack of paper sheets, of a slotting knife movable to and through said pack to slot the sheets therein, said knife having cutting blades thereon between which the resulting paper chips are received, openings in said blades, and suction means cooperating with said openings to thereby remove said chips from the knife.

4. The combination with a paper slotting machine having a table thereon to support a pack of paper sheets, of a slotting knife movable to and through said pack to cut slots in the sheets of paper therein, said knife having opposed spaced apart cutting blades between which the resulting paper chips are received, openings in said blades, and suction means adjacent said knife cooperating with said openings to thereby remove the chips from said knife.

5. The combination with a paper slotting machine having a table to support a pack of paper sheets, of a slotting knife adapted to slot the edges of said sheets by movement to and through said pack, an opening in a side of said knife,

and suction means cooperating with said opening to remove from said knife the paper chips which result from the slotting operation.

6. The combination of elements defined in claim 5, combined with camming means on said knife to move the paper chips away from the adjacent edge of said pack as they are cut.

7. The combination with a paper slotting machine having a table to support a pack of paper sheets, of a slotting knife movable to and through said pack to slot the paper therein, said knife including integral diverging blades at the upper portion thereof, the connecting portion of said blades curving downwardly and outwardly at the bottom thereof and terminating in two separate blades, said downwardly and outwardly curved portion acting as a cam to move away from said pack the resulting paper chips.

8. The combination of elements defined in claim 7, wherein each of said blades has an opening therein, and suction means cooperating with said openings to thereby remove the paper chips completely from said knife.

9. The combination with a paper boring and slotting machine having a paper drill and a table to support a pack of paper sheets, of a slotting knife having a cutting edge located closely adjacent the cutting edge of said drill and movable with said drill to and through said pack of paper sheets, said knife having cutting blades between which the resulting paper chips are received and camming means between said blades to move the chips in a direction away from said drill and out from between said blades.

10. The combination with a paper slotting machine having a table to support a pack of paper sheets, of a slotting knife movable to and through said pack to cut slots in the paper sheets therein, said knife having cutting blades between which the resulting paper chips are received and at least one of said blades having an exposed opening therein, camming means between said blades to aid in forcing the chips away from the adjacent edge of the pack of paper sheets and suction means cooperating with said opening in the blade to completely remove the chips from the knife.

11. In a paper slotting machine having a table to support a pack of paper sheets to be slotted, a slotting knife mounted for reciprocating movement relative to said table to and through said pack and having blades between which the paper chips resulting from the operation are received and at least one of said blades having an exposed opening whereby the pressure exerted by the blades upon the chips is relieved.

12. The elements in combination defined in claim 11 combined with camming means between said blades to aid in releasing the chips from between the blades.

FREEMAN BARNEY.

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