US3903599A

US3903599A - Impact engraving tool

Info

Publication number: US3903599A
Application number: US523993A
Authority: US
Inventors: Archie C Ray
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-11-15
Filing date: 1974-11-15
Publication date: 1975-09-09
Anticipated expiration: 1992-09-09

Abstract

A hand-held, impact engraving device including a flexible sheathed cable which is reciprocated in the sheath by attachment to a rotary eccentric, and a hammer connected to the cable repeatedly strikes a piston which actuates an engraving tool. Shock of the impact of the hammer on the piston is cushioned by a compression spring between the hammer and the anvil.

Description

United States Patent Ray 1 Sept. 9, 1975 [5 IMPACT ENGRAVING TOOL 598,45l 9/1925 France 30/362 [76] Inventor: Archie C. Ray, Rt. l, Box l5,

Powell, y 82435 Primary Exuminer-Al Lawrence Smith [22] Filed: Nov. 15 1974 A.ssistunt Exuminer-J. T. Zatarga Attorney, Agent, or FirmRichard D. Law [2]] Appl. No.1 523,993

[52] US. Cl 30/362; 30/362 [57] ABSTRACT [51] Int. Cl. B26F 1/34 [58] Field of Search 30/362 A hand-held, impact engraving device including a flew ible sheathed cable which is reciprocated in the sheath [56] Reierences Ci d by attachment to a rotary eccentric, and a hammer UNn-ED STATES PATENTS connected to the cable repeatedly strikes a piston 249 29] 11/1881 Bends 30/162 which aetuates an engraving tool. Shock of the impact 1, 4/I890 30/1462 of the hammer on the piston is cushioned by a compression spring between the hammer and the anvil. FOREIGN PATENTS OR APPLICATIONS 5 [2,807 lU/l920 France 30/362 7 Claims, 3 Drawing Figures IMPACT ENGRAVING TOOL Various types of engraving machines have been known, mostly using rotary engraving tools. For some types of engraving, however, the rotary tools have been found to be only partially satisfactory. and for some other types of jobs only a percussion type of tool has been found to be satisfactory. Even in todays highly mechanized arts, many engravcrs still use a mallet and chisel or engraving tool for certain types of engraving jobs.

A precision hammer was proposed by Warner, US. Pat. No. 2,787,179, proving a manual actuated, spring loaded hammer. Difierent types of tools are stated to be attachable to the unit. Another type of percussion machine was developed by Oehlerking, US. Pat. No. 3,440,861 for marking items with a pointed marker. This unit integrates a push-pull type electric driver to reciprocate a marking point. Bautrey, US. Pat. No. 1,375,680, describes a reciprocating perforator, mounted on a lever arm which is spring supported. An electric motor and drive mechanism is incorporated in the perforating head. A paper trimmer, US. Pat. No. 953,856, invented by Pierce et al., utilizes a cam actuated reciprocating needle. In this device a horizontal, internal rotary cam track causes reciprocation ofa cam follower with no percussion involved in the reciprocation of the tool.

According to the present invention there is provided a hammer which is reciprocated by means of a reciprocable flexible cable, actuated by an electric motor rotated eccentric for adjustably striking a piston, through a compression spring. The piston in turn strikes the chuck for an engraver, adjustably reciprocating the engraver. The engraving tool is held in the chuck which is mounted in a small, easily handheld tool mount at the end of the flexible cable providing complete freedom of the engraving tool for engraving jobs.

Included among the objects and advantages of the present invention is to provide a hand-held percussion engraving device.

Another object of the invention is to provide a handheld percussion engraving device utilizing a flexible cable from an electrical actuating device to reciprocate an impact piston for striking a chuck for an engraving tool.

Still further object of the invention is to provide a small, light-weight hand grip mounted on a flexible cable for free movement of an engraving tool held in such holder.

Yet another object of the invention is to provide a simple and easily changed adjusting system for changing the impact of a hammer on an engraving tool.

These and other objects and advantages of the invention may be readily ascertained by referring to the following description and appended drawings in which:

FIG. 1 is a generally schematic perspective of an engraving tool according to the invention;

FIG. 2 is an enlarged cross-sectional side clevational view of a hand grip of an engraving tool according to the invention; and

FIG. 3 is a cross-sectional, detail view of the drive mechanism of a flexible cable arrangement for the engraver of the invention.

In the device selected for illustration in FIGS. 1 through 3, a frame member is provided for the drive mechanism of the engraver. As shown, the frame is a box type arrangement which may be attached to a work bench, wall, or the like. but it may take other desired forms for holding the elements of the device in their proper orientation. The drive of the engraver of the invention includes an electric motor 12 having a belt pulley 14 for driving a belt 16. The belt 16 is arranged to drive a driven pulley 18 mounted on an axle rotatable in a pillow block or other bearing arrangement 20. The pulley 18 includes a hub 22 provided with a series of holes 24a, 24b and the like, each spaced from the center of the hub to provide different distances from the center for driving a crank arm 26 which is arranged to be attached thereto by means of a pivot pin 28. The belt 16 is shown as a V-belt and the pulleys arranged to support such a V-belt, however various types of belts may be used with accordingly configurated pulleys. The motor 12 is of necessary horsepower for driving the unit, and it preferably should be a variable speed motor which may be controlled by a foot or a hand controlled rheostat, not shown.

The piston rod or crank 26 reeiprocates a crank follower 30 mounted in a guide 32 having a guide slot 34 formed therein. Bolts 36 secure the guide block 32 to the frame and provide means for adjusting the guide block to the correct line. The follower 30 reciprocates with the end of crank 26 and its stroke is variable, depending on the placement of the other end of the crank arm. Also, the slot 34 should be of sufficient length to permit the follower to move through the maximum stroke caused by the arm mounted in the outermost hole in the hub of the pulley. The follower 30 includes a headed pivot pin 31 which rides in the slot 34 for maintaining the end of the crank rod 26 in a reciprocal motion. A flexible cable 40 is secured in the head 30 by means of a set screw 42 whereby the cable 40 reciproeates with the head 30 on actuation of the eccentric mechanism. The cable 40 is mounted in a flexible sheath 44 which is secured by means of a ferrule 46 and a grommet 48 to an adjusting screw 50. The adjusting screw 50 is mounted in an angle frame member 52 which is mounted on the frame 10.

The tool holder, shown in FIG. 2, includes an outer tube 60 which is arranged to be held in a user's hands, and the opposite end of the sheath 44 is held by means of a ferrule 62 to a hollow double ended nut 64 which in turn is secured to an adjustable hollow bolt 66 threaded to the threads 68 of the tube 60. The adjusting bolt 50 and the adjusting bolt 66 provide means for the adjustment of the length of the flexible sheath 44. The flexible steel cable 44 passes through the ferrule 62 and the adjusting screw on its end extends into a piston 70 having a short bore 72 therein. The open end of the bore 72 is provided with a hollow screw 74 which prevents the removal of the cable 40 from the bore 72. A hammer 76 is soldered, welded, or otherwise secured to the end of the cable 44 and it is mounted in the bore 72, and is prevented from exiting the bore by means of the hollow screw 74. The hammer 76 is arranged to impinge on a compression spring 78 so a part of the impact of the hammer is taken up by the spring when the hammer reciprocates to strike the piston 70. The piston 70 reciprocates in the tube 60 and its end 71 strikes an anvil 80 secured to the tube by means of a pin 82. A tool holding chuck 84 is threadedly attached to the end of the anvil 80 and it provides an opening 86 for holding generally square tool ends, in the manner of conventional tool holding chucks such as found in ta chucks, brace and bit, and the like.

The steel cable 40 and flexible sheath 44 are of a length sufficient for maneuvering the graver as desired and to drive the reciprocating hammer 76 for actuating a graving tool 90 (FIG. 1) which is mounted in the chuck of the hand held tool holder 60. The adjusting screws at the upper and lower ends of the flexible sheath provide adjustment for the desired travel of the hammer 76 and subsequent travel of the piston, to vary the compression of the compression spring 78 inside the piston portion 70. This permits variance of the impact on the graver tool. Lock nuts should be used with each of the adjusting bolts for securing proper setting of the adjusting bolts in their respective frame.

The crank arm 26 mounted on the eccentric hole of the hub provides reciprocation of the head 30 and, also. the steel cable 40. The reciprocation of the steel cable 40 rcciprocates the hammer 76 which drives the hammer 76 onto the compression spring inside of the piston 70, which in turn drives the piston 70 against the upper end of the chuck. The compression spring 700 prevents the wire from breaking if the adjustment of the wire is not precise and at the smae time permits a very delicate adjustment of the reciprocation to be made. The driven chuck 84 is arranged to hold different types of graver chisels or carving chisels which are, of course, driven by the impact of the piston 70 set in motion by the compression spring.

The various hollow adjusting screws and bolts are ar ranged to permit free reciprocating action of the steel cable 40 therein. The reciprocal movement of the cable is illustrated as being actuated by an eccentric crank arm 26 mounted on a pulley. however, other types of reciprocating mechanisms may be used to reciprocate the steel cable 40 in the flexible sheath, and for its action in the reciprocation of the hammer 76. The variable speed motor 12 provides means for controlling the rate of reciprocation of the crank. The attachment of crank arm to the hub of the pulley 18 provides means for controlling the length of movement of the hammer 76 and thereby control the impact of the piston 70 on the chuck for holding a graver tool. By adjusting the length of travel of the reciprocating hammer 76 and, of course, by changing the type of tool mounted in the chuck, the engraving machine is arranged to engrave all types of metal and further provides an excellent carving machine for wood, plastic, and other types of soft carving material. The flexible cable provides means for free movement of the handle held by the user permit ting a high degree of movement of the graver tool held in the unit.

I claim:

1. A hand held impact engraving tool comprising a. frame means;

b. an elongated, flexible cable reciproeably mounted in a sheath adjustably secured to said frame means;

c. means including an electric motor for variably reciprocating said cable in said sheath;

d. housing means mounted on the end of said sheath and arranged to be hand held and including a reciprocable graving tool chuck means;

e. piston means reciprocably mounted in said housing means and arranged to impinge on said chuck means;

f. hammer means secured to the end of said flexible cable and mounted in said piston means and reciproeable therein; and

g. compression spring means in said piston means positioned to be impinged on by said hammer means for reciprocating said piston means against said graving tool chuck means.

2. A hand held impact engraving tool according to claim 1 wherein said means for reciprocating said cable includes a rotary eccentric means rotated by said electric motor.

3. A hand held impact engraving tool according to claim 2 wherein said rotary eccentric means is variable.

4. A hand held impact engraving tool according to claim 1 wherein said electric motor is a variable speed II'lOKul'.

5. A hand held impact engraving tool according to claim 1 wherein said housing means is adjustably mounted on said sheath.

6. A hand held impact engraving tool according to claim 1 wherein said hammer means is welded to said cable and is freely reeiprocable in said piston means.

7. A hand held impact engraving tool according to claim 1 wherein said housing means is a small cross section tube easily hand held for manipulating.

Claims

1. A hand held impact engraving tool comprising a. frame means; b. an elongated, flexible cable reciprocably mounted in a sheath adjustably secured to said frame means; c. means including an electric motor for variably reciprocating said cable in said sheath; d. housing means mounted on the end of said sheath and arranged to be hand held and including a reciprocable graving tool chuck means; e. piston means reciprocably mounted in said housing means and arranged to impinge on said chuck means; f. hammer means secured to the end of said flexible cable and mounted in said piston means and reciprocable therein; and g. compression spring means in said piston means positioned to be impinged on by said hammer means for reciprocating said piston means against said graving tool chuck means.

4. A hand held impact engraving tool according to claim 1 wherein said electric motor is a variable speed motor.

6. A hand held impact engraving tool according to claim 1 wherein said hammer means is welded to said cable and is freely reciprocable in said piston means.