US3522752A

US3522752A - Paper trimmer

Info

Publication number: US3522752A
Application number: US727121A
Authority: US
Inventors: Robert B Ford
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-04-05
Filing date: 1968-04-05
Publication date: 1970-08-04
Anticipated expiration: 1987-08-04

Description

United States Patent [72] Inventor: Robert B. Ford 8834 E. Naomi Avenue, San Gabriel, California 91775 [2]] Application No.: 727,121 [22] Filed: April 5, 1968 [45 Patented: Aug. 4, 1970 [54] PAPER TRIMMER 5 Claims, Drawing Figs.

[52] U.S. Cl. 83/389,

83/397, 83/453, 83/520, 83/6l1 [51] Int. Cl. B26d 5/42 [50] Field ofSearch 83/389,

397, 398, 611,544,546, 520,453; 74/lnq [56] References Cited UNITED STATES PATENTS 1,0985l0 6/l9l4 Krauth 83/61lX 1,998,245 4/1935 Laukhuff. 83/397 2,380,257 7/1945 Ruth 2,506,610 5/1950 Mueller 83/520X FOREIGN PATENTS 697,809 9/ l 953 Great Britain.

Primary Examiner- Frank T. Yost Attorney- Norman L. Chalfin ABSTRACT: This invention relates to an improvement in paper trimmers of the type generally used throughout industry and educational institutions. The improvements are directed to a special blade construction and the means for mounting the blade on the movable member of the trimmer as well as a safety guard arrangement in combination with the blade arrangement which greatly improves the anticipated safety factor over the prior art.

Patented -Aug. 4, 1970' Sheet 1 of 2 ROBERT 8. FORD INVENTOR.

AGENT.

us. PATENT 3,522,752 PAPER TRIMMER SUMMARY OF THE INVENTION The paper trimmer of the type set forth in my invention has not been improved for many years. The present paper trimmer has a platform for holding the paper to be cut and a fixed blade disposed thereon. A large lever holds the moving blade and is pivoted adjacent one end of the fixed blade. The paper to be cut is generally placed on the platform in a manner so that it must be lined up against the guides which are situated on the sides opposite the operator. When the blade is moved downward to cut the paper it is mandatory that care be taken that the paper does not slip from the initial position. At the end of the cut or near the end thereof, one often experiences difficulty in that the leverage is shortened and the cutting is made more difficult and often errors occur because the mov ing blade opens away from the fixed blade allowing the paperto come between the blades rather than being cleanly cut.

This invention is directed to correcting these problems by providing a rotary blade action as well as adding a combination safety guard and automatic holding means for holding the work in place during the cutting action.

OBJECTS OF THE INVENTION 7 throughout the cutting action as well as serving as a safety guard.

DESCRIPTION OF THE FIGURES These and other objects of my invention will be more clearly realized and understood when referring to the following detailed description and related drawings wherein;

FIGURE I is an elevational view looking down on the machine.

FIGURE 2 is a sectional view 2-2 of FIGURE 1 showing the blades and the blade holder and the spring biased operating lever.

FIGURE 3 is a sectional 3-3 of FIGURE 2 showing the length ofthe blade holder and means for mounting.

FIGURE 4 is a partial sectional view 4-4 of FIGURE 3 and directed to the details of the construction and operation of the safety cover.

FIGURE 5 is'a fragmented view of the cutting surfaces showing the construction and arrangement in respect to one another.

FIGURE 6 is an elevational view of the blade holder.

FIGURE 7 is a sectional view 7-7 of FIGURE 6.

FIGURE 8 is a sectional view 88 of FIGURE 7.

DESCRIPTION OF THE INVENTION Reference is now directed to the figures. A substantially square work platform 1 is provided with at least two oppositely disposed downwardly directed

sides

2 and 3 of equal width which serve as supporting members. One edge of the work platform I is provided with a fixed cutting surface 4. A pair of bracket members 5 and 6 are disposed on the

side members

2 and 3 adjacent the end of the fixed blade and in parallel relationship to oneanother. The brackets are arranged so as to have equal portions extending outwardly from the ends of the sides so as to provide axially aligned bearing

members

7 and 8 for mounting a rotatable blade holding member 9 therebetween, the rotatable member being held parallel to the fixed cutting surface 4. The member 9 is formed in the general configuration of an elongated cylinder being partially sectioned substantially the length thereof and generally obliquely to the fixed blade as is clearly illustrated in FIGURES 6, 7 and 8. The two ends of the cylinder 10 and II are left circular to provide means for supporting a pair of shaft members l2 and I3 axially aligned thereon and adapted to be rotatably mounted in the

bearings

7 and 8 as shown in FIGURE 3.

A partially cylindrical rotating blade 14, having a radius slightly larger than the blade holder, as is shown in FIGURES 7 and 8, is disposed on the rotating member by a plurality of studs 15. The rotating blade is so disposed so that when the member 9 is rotated the cutting surfaces of the blades progressively cooperate from one end of the blades to the other to accomplish the cutting action.

The blade 14 is mounted on the blade holder by one of its edges in such a way as to cause the cutting edge thereof to be biased radially outwardly away from the holder. A lead-on tongue member 17 is formed on the blade at the point where it begins a cut and is so arranged to extend the surface of the blade annularly downward so that the moving blade is always in contact with the fixed cutting surface as is illustrated by FIGURE 5.

A return arm I8 formed on one end of the blade holder 9 is downwardly disposed so as to cooperate with a spring member 19 which is attached under the work platform 1 and operably attached to the return arm. The spring I9 is a regular expansion type spring and constantly biases the cutting blade in a direction opposite the cutting action.

An operating lever 20 is disposed opposite the return arm on the blade holder and extends upward of the work platform and is adapted to move parallel to the

support members

2 and 3 thereof.

A generally L shaped elongated Plexiglas cover 21 is mounted over the cutting area with the leading edge of the foot of the L 22 adapted to move into contact with and up ward from the surface of the work platform I. A thin spring steel elongated sheet like member 23 is mounted to the Plexiglas member 21 and to a sheet metal cover member 24 which extends between the end brackets 5 and 6.

The spring member 23 serves to bias the Plexiglas member 21 toward the work platform I.

A plurality of elongated arms 25 are attached to the upper surface of the blade holder by one end while the other end extends inwardly over the work platform under the Plexiglas cover 21 in a manner so as to contact the cover 2l lifting it off the work platform when the blade is rotated back for the next cut.

I claim:

I. An improved paper trimmer comprising:

a. a work platform;

b. a fixed cutting surface disposed along one edge of said platform;

c. a pair of brackets extending vertically upward from opposite edges of said platform perpendicular to said cutting surface;

d. a solid, partially cylindrical blade holder rotatably mounted between said brackets and parallel to said fixed cutting surface;

. a blade member, partially cylindrical and contoured to match the cylinder dimension of said blade holder, and having a cutting edge, rigidly attached to said blade holder, so as to engage said cutting edge of said platform, said blade cutting edge being biased radially outward from said blade holder to contact said fixed cutting surface;

- an elongated clear plastic cover member enclosing said blade and said cutting surface, said cover being pivotally mounted to said work platform with a resilient means engaging said cover to bias said cover toward said work platform surface;

g. operating means attached to said blade holder for rotating said blade holder and said blade; and

h. cam means coupled between said cover and said blade holder for raising and lowering said cover and so disposed as to lift said cover when said blade is rotated to a position to begin a new cut and to drop said cover before cutting action begins.

2. An improved paper trimmer as described in claim 1 wherein said blade holder is cast as a solid member having a main body generally semicircular in cross section so as to provide an opening under the blade member so that a portion of a work piece can be extended thereunder.

3. An improved paper trimmer as described in claim 2 wherein said blade member is formed from a tube having a diameter slightly larger than the diameter of said blade holder, said blade member consisting of a portion of said tube representing substantially a quarter circle and having said cutting edge of said blade member cut on a slight bias to provide a progressive cutting action in cooperation with said fixed cutting edge of said platform.

4. An improved paper trimmer as described in claim 3 wherein said resilient means for biasing said cover is an extending elongated sheet steel member extending between said brackets and having one edge rigidly attached to said brackets with the opposite edge being rigidly attached to said cover and adapted to be movable therewith.

5. An improved paper trimmer comprising:

a. a substantially square work platform; b. a movable blade disposed in a rotatable blade holder; c. a fixed blade on an edge of said platform, said rotary blade holder being mounted rotatably on said platform so that said movable blade therein is moved scissorsfashion along said fixed blade as said blade holder is rotated;

said moveable blace being resiliently biased in said holder so as to be urged against said fixed blade; and a clear plastic cover member movably attached to said work platform and extending over said fixed and said movable blades, and having a flat spring to urge said cover down over said work platform to hold paper to be cut in place during the cutting operation thereof.