US3799028A

US3799028A - Copying machine

Info

Publication number: US3799028A
Application number: US00324249A
Authority: US
Inventors: J Coverdale
Original assignee: FRANKLIN MINT CORP
Current assignee: NEW FRANKLIN MINT; Warner Communications LLC
Priority date: 1973-01-17
Filing date: 1973-01-17
Publication date: 1974-03-26
Anticipated expiration: 1991-03-26

Abstract

A master pattern and a die blank rotate in the same direction at the same speed. A follower traverses the master pattern and is on a common support with cutting means for cutting the die blank. The master pattern support shaft is movable in an axial direction to permit the die blank to be cut with a concave or convex dome effect.

Description

United States Patent [191 Coverdale, Jr.

[ Mar. 26, 1974 COPYING MACHINE James C. Coverdale, Jr., Chadds Ford, Pa.

Assignee: Franklin Mint Corporation,

Franklin Center, Pa.

Filed: Jan. 17, 1973 Appl. No.: 324,249

Inventor:

US. Cl. 90/13.7, 90/139 Int. Cl. B23c 1/18 Field of Search 90/l3.4, 13.7, 13.9

References Cited UNITED STATES PATENTS Meyers 90/13.?

Primary Examiner-Francis S. Husar Attorney, Agent, or Firm--Seidel, Gonda & Goldhammer [57] ABSTRACT 10 Claims, 7 Drawing Figures PAIENTEBmes an i 3799.028

SHEEI 1 0F 4 PAIENTED MR 26 1974 SHEEI 2 0F 4- A VN U QN\ NN\ WM 0 m M 3 b o QM w Wm Q m Fl! N .$\L

PATENTED R26 I874 sum. 3 [IF 4 COPYING MACHINE This invention relates to a machine for copying a master pattern and reproducing the master pattern on the end face of a die blank. In a typical embodiment of the present invention, the die blank is used for making coins in conjunction with a mating die blank.

Devices for reproducing the master pattern on the end face ofa die blank are known. For example, see U. S. Ser. No. 043,897 filed June 5, 1971, now US Pat. No. 3,719,121, and the file wrapper references therein. The present invention enables the die blank to be made with a concave dome effect, enables a dome effect to be added when the master is flat, enables the dome effect to be changed when the master is made improperly, etc. The dome effect is attained by a control means for shifting the shaft supporting the master in an axial direction.

It is an object of the present invention to provide a copying machine which will permit the application of a dome effect.

It is another object of the present invention to provide a copying machine for copying a master pattern on a reduced scale with a dome effect.

It is another object of the present invention to provide a copying machine which permits a dome effect to be added or subtracted to the master pattern.

It is another object of the present invention to provide a copying machine which will permit the application of a dome effect with a variety of different curvatures.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is a partial perspective view of a copying machine in accordance with the present invention with most of the frame being deleted for clarity of illustration.

FIG. 2 is a front elevation view of the machine shown in FIG. 1.

FIG. 3 is a sectional view taken along the line 33 in FIG. 2.

FIG. 4 is a sectional view taken along the line 44 in FIG. 3.

FIG. 5 is a schematic layout of the drive shafts and gears.

FIG. 6 is a sectional view of a master pattern having a convex dome effect.

FIG. 7 is a sectional view of a die blank having a similar convex dome effect.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIG. 1 a copying machine in accordance with the present invention designated generally as 10. In FIG. 1, most of the frame has been deleted for clarity of illustration.

A master pattern 12 is removably bolted to a mounting plate 14 which is removably attached in any convenient manner such as by threads to one end of a drive shaft 16. As shown more clearly in FIG. 3, the shaft 16 is rotatably supported by

bearings

18 and 18 in the frame 20.

In FIG. 3, the shaft 16 is biased from left to right. The bias is preferably accomplished by means of a spring 22 which surrounds the shaft 16 and engages a collar 24. Collar 24 is adjustably positioned along the shaft 16 and removably connected thereto in any convenient manner such as by means of a set screw.

The shaft 16 includes splines 26 coupled to a gear 28 which surrounds the shaft 16. Gear 28 is in meshing engagement with a worm gear 30 on shaft 32. See FIG. I. A similar worm gear 34 on shaft 32 is meshed with a gear 36 connected to shaft 38. The shaft 38 is similarly supported by the frame 20. A mounting plate 42 on one end of shaft 38 has a die blank 40 removably attached thereto in any convenient manner. The die blank 40 has an exposed end face which is to be cut by means of a cutting tool 48. Cutting tool 48 is supported by an arm 46. A stylus 44 is likewise supported by the arm 46. Each of the cutting tool 48 and stylus 44 are adjustably positioned along the arm 46 in any convenient manner such as by use of a set screw. Arm 46 has its left end portion supported by a universal joint 52 whereby arm 46 may move about vertical and horizontal axes.

The cutting tool 48 is attached to a shaft which in turn is connected to a pulley 50. As shown more clearly in FIG. 2, pulley 50 is connected by means of a belt 54 to a pulley 56. Pulley 56 is connected to the output of a motor 58. Motor 58 is supported in any convenient location on the frame 20. Belt 54 is tensioned in any convenient manner such as by a spring-biased idler as shown in FIG. 2.

As shown more clearly in FIG. 1, the end of the arm 46 remote from the universal joint 52 is supported by a means designated generally as 60 for pivoting arm 46 about a horizontal axis in a controlled manner. The means 60 includes a weight 62 sized to balance or otherwise obtain the desired effective weight of arm 46. Weight 62 is connected to one end of a flexible member 64. Member 64 extends around

pulleys

66 and 68 on plate 70. Plate 70 is secured to a stationary vertical standard 71.

From the pulley 68, the flexible member 64 extends downwardly and is connected to pin 72. Thereafter, the flexible member 64 extends horizontally around pulley 74 and then upwardly around pulley 76. The free end of the flexible member 64 is connected to a weight 78 which is sized so as to control the pressure of the stylus 44 against the master pattern 12.

A drive screw 80 moves a slide 82 in an up and down direction depending upon the direction of rotation. Pulley 74 is supported by the slide 82. A roller 84 on the slide 82 extends into the jaw 87 at the righthand end of arm 46 as shown more clearly in FIG. 1 and is in contact with a roller 86 which is perpendicular thereto. Pin 72 is secured to the jaw 87.

As shown more clearly in FIGS. 3 and 4, the means for shifting the master pattern 12 to provide the dome effect includes a stationary upright standard 88 having upright ways 90. A slide 92 is engaged with the ways and moved in an up and down direction by the screw drive 94. A hand wheel 96 is connected to the upper end of the screw drive 94. A similar hand wheel is connected to one end of the screw drive 80.

A cantilever beam 98 is adjustably connected to the slide 92 at its upper end by means of clamp 100. I-Iorizontal deflection of beam 98 into and out of the plane of the paper is prevented by guide bracket II3. See FIG. 3. Slide 92 is provided with a way 102. A slide 104 is in engagement with and movable along way 102. An indicator 106 having an indicating pin 108 is mounted on the slide 104. Pin 108 engages the beam 98 and the amount of deflection is exhibited on the indicator 106.

A pressure applicator 110 is supported by the slide 104. Applicator 110 may be in the form of a threaded member having a head 112 at one end with its other end engaging the beam 98. Applicator 110 deflects the beam so that it may act as a cam.

Referring to FIG. 5, a motor 114 is provided for driving the various shafts and screw drives. Motor 114 has its output connected by way of a belt or chain 116 to drive shaft 118. Shaft 118 is connected to parallel shaft 122 by means of a belt 120 which extends around coneshaped portions on the shafts 118 and 122.

Shaft 122 is coupled to shaft 32 by means of a belt 124. Shaft 122 is connected to the input side of a speed reducer 128 by means of belt 126. The output from the speed reducer 128 is connected to upright shaft 130. Shaft 136 is driven by meshing engagement between the

beveled gears

132 and 134. Shaft 136 is connected to worm gear 136 which is in driving engagement with the screw drive 94.

Shaft 130 also drives shaft 146 by way of the meshing

bevel gears

142 and 144. A worm gear 148 on shaft 146 is in meshing engagement with screw drive 80. A set of matching worm gears exists for accomplishing feed rate changes on

feed screws

80 and 94. Thus, identical worm gears are placed on both shafts. The interchangeable gears also accomplish the directional change in rotation.

In operation, the stylus 44 is positioned at the center of the master pattern 12. On some jobs the stylus may initially be positioned on the outer periphery and run toward the center. The cutting tool 48 is similarly at the center of the die blank 40. Speeds are chosen so that the die blank 12 revolves at a slow speed such as 1 rpm. The speed reducer 28 and the various gear drives to the screw drive 80 are chosen so that the means 60 for pivoting the arm 46 will cause the arm to pivot through an arc at a slow steady speed whereby the stylus 44 will traverse the radius of the master pattern over a substantial period of time such as four to sixteen hours depending upon the radius of the master pattern and the feed rate selected.

As the stylus 44 follows the contour of the master pattern 12, the cutting tool 48 reproduces the contour on the end of the die face 40. In FIGS. 6 and 7, there is shown a sectional view of the master pattern 12 and the die blank 40, each provided with a convex dome effeet. The amount of the dome is designated as X. On coining dies, the amount of the dome is generally not more than 0.150 inch.

In FIG. 3, a zero or null point on the beam 98 is in contact with the rounded end of the shaft 16. The slide 104 has been moved to a position so that the pin 108 for the indicator 106 is spaced from the axis of shaft 16 by a distance correspondingto a radius of the master pattern as measured by the expanded scale 200 (shown in FIG. 2). Head 112 is rotated in an appropriate direction to bend the beam 98 until the desired amount of dome is indicated on indicator 106. As the stylus 44 traverse the radius of the master pattern, the slide 92 is raised at the same rate so that beam 98 moves up wardly. When the stylus 44 has reached the outer periphery of the master pattern 12, pin 108 will be directly opposite the longitudinal axis of shaft 16.

As the beam 98 is raised upwardly, it causes the shaft 16 to move in an axial direction along its axis of rotation from right to left in FIG. 3. In doing so, the spring 22 is compressed. If a concave dome effect is desired,

it is only necessary to raise the entire slide 104 until the pin 108 is coaxial with shaft 16 and then cause'the slide 104 to descend. Slide 104 may be caused to descend by substituting a different worm gear in place of worm gear 138. Thus, as the beam 108 descends the spring 22 would gradually move the shaft 16 from left to right in FIG. 3.

The beam 98, whether it moves upwardly or downwardly, moves at the same speed that the stylus moves in a radial direction in respect to a master pattern. Thus, at the end of the travel of the beam 98, the stylus 44 will be at the end of its travel.

The cutting tool 44 is closer to the pivot axis of the universal joint 52 as compared with the stylus 44. If the arm 46 pivots about a vertical axis through an arc of 5, the stylus 44 will move through a greater distance than the cutting tool 48. The difference in the amount of movement between the stylus 44 and the cutting tool 48 is a function of their distances from the pivotable axis for the arm 46. These distances are mathematically computable using trigonometry and determine the reduction ratio between the master model and the die hub being cut.

The stylus 44 is displaced by the horizontal distance D from the pin 84, which is effecting the vertical rate of speed of arm 46. Since the support arm 46 moves in an arc about the universal joint 52, there is a difference in the vertical displacement of the

slides

82, 92, even though both feed screws 80, 94 have the same lead and are being rotated with identical RPM. This difference in vertical displacement is a function of the arc lengths traveled by the stylus 44 and the point of contact between the feed pin 84 and the support arm roller 86. This difference in vertical displacement is taken into account by means of an expanded scale 200 mounted in any convenient place on the slide 92.

The expanded scale 200 permits the operator of the machine to set the displacement of the indicator pin 108 with respect to the axis of shaft 16 at the same numerical value in inches as the radius of the master pattern 12. However, due to the scale expansion, the actual displacement of the pin 108 is equivalent to the distance traveled by the point of contact between pin 84 and roller 86. Since both feed screws 80, 94 have identical lead and are rotated in synchronization, the stylus 44 will terminate at the outer periphery of the master pattern 12 at the same time pin 108 is coaxial with shaft 16. Other equivalent devices may be utilized to accomplish the same result.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention. 8

I claim:

1. Apparatus for cutting a die comprising a frame, first shaft means on the frame for supporting and rotating a master pattern, second shaft means on the frame for supporting and rotating a die blank in the same direction and at the same speed as the master pattern, means on the frame for traversing a master on the first shaft means and for cutting a die blank on the second shaft means to reproduce the contour of the master, means supporting said first shaft means for axial movement along its axis of rotation, and shifting means for shifting said first shaft means in an axial direction along its longitudinal axis to create a desired dome effect on the cut die blank.

2. Apparatus in accordance with claim 1 wherein said shifting means is a cam.

3. Apparatus in accordance with claim 2 wherein said cam is a cantilever beam mounted for movement in a direction perpendicular to the longitudinal axis of said first shaft means, and means for deflecting said beam.

4. Apparatus in accordance with claim 3 including biasing means for biasing said first shaft means towards said beam.

5. Apparatus in accordance with claim 1 wherein said first and second shaft means includes horizontal parallel shafts, said means for traversing the master including a stylus mounted on a common support with the means for cutting the die blank end face, one end of said common support being connected to a universal joint so that the common support may move about a vertical and a horizontal axis, a first motor for driving said first and second shaft means, and a second motor for driving said cutting tool.

6. Apparatus in accordance with claim 1 wherein said shifting means includes a slide mounted on ways for movement in a direction perpendicular to the direction of the longitudinal axis of said first shaft means, a screw drive for said slide, gear means coupling said screw drive to a motor, and gear means coupling said motor to said first and second shaft means.

7. Apparatus in accordance with claim 6 wherein said shifting means includes a cantilever beam supported by the slide above and below the longitudinal axis of said first shaft means whereby the dome effect may be concave or convex.

8. Apparatus for cutting a die comprising means for supporting and rotating a die about a horizontal axis, means for supporting and rotating a master pattern about a horizontal axis and including a shaft, cam means for shifting the shaft along its longitudinal axis in timed relationship to a follower for following the contour of the master along a radius of the master as the master is rotating, and means connecting said follower to a cutting tool for cutting the die end face.

9. Apparatus in accordance with claim 8 wherein said cam means includes a cantilever beam which is perpendicular to the longitudinal axis of said shaft, means for deflecting the cantilever beam, said last-mentioned means and said cantilever beam being mounted on a common support for movement in a direction perpendicular to the longitudinal axis of said shaft.

10. Apparatus in accordance with claim 9 including a screw drive for moving said last-mentioned common support.

Claims

2. Apparatus in accordance with claim 1 wherein said shifting means is a cam.