Ultrasonic perspective carving

Carving of perspective designs in transparent objects with ultrasonic abrasive slurry machining is obtained by using at least two tools each having a different configuration at the working surface and sequentially carving each tool in the object on a surface thereof in partially overlapping relation to each other at different depths. Means are provided wherein the object is sequentially advanced from tool to tool to be multiply carved with each carving being of a different depth than the prior carving to obliterate same and to present to the viewer a perspective carving when viewed from the opposite surface than the surface carved.

BACKGROUND OF THE INVENTION 
The invention relates to the method and apparatus or system for producing a 
perspective three dimensional type carving of various sizes in an object 
utilizing an interrelated set of tools or dies. The products obtained by 
the present invention exhibit a unique visual effect which may be used on 
a variety of shaped objects. 
The present invention refers to ultrasonic abrasive slurry machining, also 
known as ultrasonic impact grinding. Ultrasonic slurry machining has been 
disclosed in U.S. Pat. No. 2,580,716 issued to L. Balamuth dated Jan. 1, 
1952, entitled "Method and Means for Removing Material from a Solid Body" 
and is described also in Ultrasonic Engineering (book) by Julian R. 
Frederick, John Wiley & Sons, Inc., New York, NY (1966) pages 171 to 183. 
The ultrasonic abrasive slurry machining process involves the use of an 
ultrasonically vibrating tool which is in contact with or slightly spaced 
from a workpiece. Abrasive particles suspended in a fluid are fed into the 
gap between the tool and the object or workpiece and are driven with a 
percussive impact against the workpiece. The high velocity impact of the 
particles on the workpiece causes an abrading action which is used for 
producing accurate odd-shaped holds and recesses in hard materials, such 
as carbides, ceramics, glass, and semi-conductors. 
The above process has been used for the carving of glass or crystal to 
obtain a variety of objects on plates, blocks, ash trays, paper weights, 
etc. One of the limitations of the above process relates to the diameter 
of the carving which has been handicapped by the practical limitations of 
existing vibration transmitting members. The limitations are in the planes 
perpendicular to the direction of the vibrations to be transmitted. The 
technical reasons for this are fully explained in U.S. Pat. No. 3,113,225 
to Kleesattel et al., of which the present applicant is a co-inventor. 
With increases in the effective or working dimension of the vibration 
transmitting member beyond a certain value, the costs of producing a 
transducer increase disproportionately to become prohibitive. 
Although the above Kleesattel et al. patent is applicable to both 
longitudinal and circular configurations, there are limitations for 
circular vibration transmitting members. At 20 KHz a tool in excess of 
approximately 3 inches in diameter presents carving problems as to the 
flow of abrasive slurry between the tool output surface and the object. 
Towards this end applicant has found that not withstanding the Klessattel 
et al. teachings a larger circular tool produced in accordance therewith 
still presents ultrasonic carving problems. In addition, the power to 
vibrate a tool of approximately 5-6 inches in diameter exceeds that of 
generally available conventional instruments. 
The prior carving systems due to the inherent limitations of the diameter 
of the tool as explained above initially led the inventor to attempt to 
separate a single totality into say two or more carving tools since a 
single tool could not carve the design in one movement. Upon separating of 
the carving into individual sections and then carving each one adjacent 
the other, the inventor found that for most carvings horizontal 
registration of the tools became a time exacting task that could not be 
jigged. When the registration on a horizontal plane was not obtained a 
dividing line was visible in the end product that was not acceptable for 
commercial sale. Accordingly, the carving of a 5 inch diameter carving 
with a 20 KHz motor was not practicable with the prior art teachings even 
if carved in adjacent sections. Applicant found that variations in 
mounting of the replaceable tools to be ultrasonically vibrated could not 
be reproduced with an exactness to avoid a visible spacing between the 
carved sections. 
OBJECTS OF THE INVENTION 
One object of this invention is the provision of a new and improved method 
and system for ultrasonic abrasive slurry machining to obtain perspective 
carvings. 
Another object of the invention is the provision of a method and system for 
increasing the area carved of an interrelated design with ultrasonic 
abrasive slurry machining. 
Another object of this invention is the provision of a method and system 
employing at least two dies inter-related for machining in partially 
overlapping relation to each other at different depths to obtain a 
singular carving void of any discernable machining marks between the 
carved sections. 
Other objects of the invention will become apparent as the disclosure 
proceeds. 
SUMMARY OF THE INVENTION 
The present invention permits the creation of a variety of perspective 
carvings on a host of materials without the inherent problems of the prior 
art problems. The inventor faced with the problems of horizontal 
registration or alignment of the individual tools to form the total 
carving conceived of the idea of separating the carving in a manner that 
sections or portions thereof are carved by different tools in separate 
steps and that a portion of each carving after the first overlapped a 
preceding carving to thereby blend one portion of the total carving into 
another portion thereby eliminating the horizontal registration parting 
line. 
The inventor also found that a prespective dimension could be added to the 
total effect when viewed by carving each section to a different depth. 
Although the invention will be particularly discussed for use in 
conjunction with a transparent object such as glass or crystal, the 
invention is adapted for use on various stones or synthetic materials that 
may be ultrasonically carved. Toward this end one aspect of the invention 
discloses the carving of a first section to a given depth of say 
approximately 0.050 inches and thereafter carving a second section with a 
second tool in partially overlapping relation to said first section and 
say approximately 0.100 inches. In the area of overlap say from 3 to 50% 
of the area of the first carving is covered by the second tool. The second 
tool eliminates the overlapping portion of the first carving and in turn 
the parting line problem discussed above is eliminated. This produces a 
single design without any discernable machining marks between the carved 
sections. 
In another embodiment of the invention, the carving procedure is reversed 
in that the shallow carving is first formed and secondly the deeper 
carving is formed in partially overlapping relation to the first carving 
penetrating and eliminating the overlapped portion of the first carving. 
In this way, when the total carved design or configuration is viewed at 
the opposite side of the object no parting line is visible and the problem 
of horizontal registration has been eliminated. 
It is appreciated that two or more dies or tools may be used to obtain a 
single total carving of varying size and depth. In this manner a complete 
scene, design, etc. may be carved having a multiple number of individual 
sections yet blended together with no preceptible marks from the tools 
used.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring now to the figures and FIGS. 1-7 particularly, we have 
illustrated an object or article of manufacture 100 which may take various 
forms, shapes, and sizes, from a paper weight or block to a plate, 
ashtray, etc. The article 100 is novel in that in accordance with the 
teachings of the present invention a final or total carving of a design or 
scene 102 is formed that when viewed from the front or viewing surface 104 
of the transparent article 100 will be perspective in nature to the eyes 
of the viewer. The front surface 104 may be flat as illustrated or curved 
as in a paper weight. 
The carving 102 is formed on the rear or carved surface 106 with the upper 
surface or edge 108 spaced from the lower surface or edge 110 and spaced 
apart side surfaces or edges 112 and 114 defining the outline of the 
object which may vary in shape and size. The carving 102 is a single 
totality illustrated as being comprised of three separate sections, namely 
a first section or portion 116 carved to a first depth, illustrated in the 
form of a man; a second section or portion 118, carved to a second depth, 
illustrated in the form of a fence; and a third section or portion 120 
carved to a third depth, illustrated in the form of a tree. Each of the 
sections being carved to a different depth and configuration. As will be 
apparent, these particular designs are merely illustrative of the 
invention and have been selected for purposes of disclosing the invention. 
The perspective carving 102 is formed of at least two sections or portions 
that when viewed in its totality provide the viewer with a perception of 
depth not heretofore obtainable. 
FIG. 1 illustrates the finished product and as seen in FIG. 2 the initial 
or first carved section 116 is machined to a depth of say approximately 
0.100 inches as illustrated in FIG. 3 from the surface 106. The carving 
116 is formed from a first tool as hereinafter explained in detail that 
may be carved to a depth in the range of 0.050 to 0.250 inches. 
Hereinafter, a second carved section 118, in the form of a fence, is 
formed on the surface 106 which as illustrated in FIGS. 4 and 5, is to a 
depth lesser than the first section to approximately 0.060 inches. The 
depth of the second carving may be in the range of 0.010 to 0.200 inches. 
The separate carving of sections 116 and 118 avoids the horizontal 
alignment problem of registration of starting one tool where a prior tool 
finished. Another feature is that by first carving the deeper section 116, 
the fence 118 is then carved behind it. In the area of overlap between the 
fence 118 and the first carving 116 which is deeper, the material removed 
will not be carved again. Accordingly, no registration or alignment of 
extreme accuracy must be relied upon. Further, although a tool the size of 
the fence 118 or man 116 is feasable, individually a tool of the size 
incorporating both is impracticable for the reasons set forth above with 
respect to the area of the tool generally expressed in terms of its 
diameter. For approximately a 20 KHz ultrasonic motor a 3 inch diameter 
tool is feasible. Therefore, although the fence 118 or man 116 each can be 
placed on an individual 3 inch diameter tool, a combined tool for both 
would require say a 5 inch diameter tool which is impracticable at 20 KHz. 
FIGS. 6 and 7 illustrate the third carved section 120 in form of a tree 
which is carved on rear surface 106 and is of a depth of approximately 
0.030 inches. The shallowness is such that in perspective the tree 120 
stands behind the fence 118. Once again the registration or alignment 
problems have been eliminated in that the tree 120 will not be carved in 
those areas that the fence 118 exists. 
Accordingly a complete perspective carving may be on a block say 5 inches 
by 5 inches, or smaller, or even 1 or 2 feet square and consisting of a 
dozen carvings some of which or all of which overlap a portion of another 
carving. 
Each carving may vary in depth but in the area of overlap there has to be a 
difference to avoid the registration problem. In this manner the deepest 
carving extends perspectively in front of the other carving when the 
completed carving is formed. For example, although the second carving of 
fence 118 is of an average depth of 0.060 inches it may be deeper as it 
extends from the first carving 116 to obtain further perspective effects. 
The above process of carving inter-related sections as illustrated in FIGS. 
1-7 may be carved in reverse with the elimination of the registration and 
other problems set forth above. FIGS. 8-11 illustrates the process in 
which the shallow section of the carving is first formed to obtain in the 
work object 100a a complete design 102a. As illustrated in FIGS. 8 and 9, 
the third section 120a may first be carved to say 0.030 inches on the 
surface 106a, then the second section 118a of the fence is carved as 
illustrated in FIGS. 10 and 11 to a depth of approximately 0.060 inches. 
In this manner the fence 118a obliterates the overlapping portions of the 
tree 120a so that when viewed from surface 104a the fence 118a in in front 
of the tree 120a. When the man 116a is carved as illustrated in FIGS. 10 
and 11 to the depth of approximately 0.100 inches which extends through 
the fence 118a in the area of overlap. Accordingly, the article 100a may 
be manufactured by sequentially carving from the deep to shallow sections 
or in reverse from the shallow to deeper sections. 
The sections may each overlap each other a minimal amount so that an entire 
scene of a variety of objects or portions of a building, etc., may be 
formed to create a composite picture in say crystal or other medium 
capable of ultrasonic machining. The area of overlap may be from 
approximately 3 to 50% of the area of each section of the total design. 
Although the object has been illustrated in that the viewing surface is in 
spaced relation to the carving surface, the present invention also 
includes intaglio engraving such that a raised surface is obtained. 
FIGS. 14-19 illustrate the invention with the object or article 100b in the 
form of a transparent plate with a viewing surface 104b and rear surface 
106b having carved therein the design 102b in the form of a tree composed 
of three sections 116b for the trunk, 118b for the left side, and 120b for 
the right side. By carving the three sections at different depths the 
perspective carving is obtained. Particularly by having an area of overlap 
between sections horizontal registration is not critical. 
FIGS. 14 and 15 illustrate the final product. FIG. 14A illustrates the rear 
surface 106b to obtain the depth perception and the blending of the three 
sections illustrated to obtain the design 102b of a single totality. FIGS. 
16 and 17 illustrate the tree trunk 116b being carved first and to the 
shallowest depth so that it is farthest from the viewer seeing the design 
102b through the surface 104b. FIGS. 18 and 19 illustrate the section 118b 
carved into the surface 106b and to a greater depth. FIG. 14 illustrates 
the object 100b when the last section 120b is carved therein to an even 
greater depth. Each carved section removes the overlapped portion and the 
three sections each overlap each other to blend the sections together. If 
desired the process could be reversed with the carving of section 120b 
then 118b and finally 116b to obtain the same end result. 
By utilizing a plurality of tool sections, the circular area encompassing 
the perspective carving is in a range of approximately 2 to 12 inches. 
Accordingly the fact that one tool overlaps another, and each has a 
contoured configuration adapted to blend with each other projects a single 
totality of design to the viewer. If desired, the depth of each section 
may be substantially the same in order to increase the size of the design. 
Each section may form an integral part of the total design as illustrated 
with respect to the fence, tree, and man. If desired, each section blends 
with each other to project the single totality, as exemplified by the tree 
trunk, and branches. 
Referring to FIGS. 20 and 21, therefore, there is illustrated apparatus 10 
for ultrasonically carving the object, article or work member 100. As 
indicated by the crosshatching in FIG. 21, the work member 100 is of a 
glass material, but it will be realized that rigid bodies or sheets of 
materials such as crystal, metal, gems, stones, etc., may be machined in 
accordance with the present invention. However, for the purpose of the 
explanation of the figures to follow, it will be assumed that the 
apparatus is working with glass materials. 
The basic structure for carving materials as well understood by those 
skilled in the art, comprises a vibrator support assembly in the form of a 
support stand 15 that is provided for maintaining the vibrator assembly 25 
in proper position, and may include a base 16 with an upright wall 17 
extending upwardly from one end of said base and a head 18 extending from 
the upright wall 17 and in overlapping relationship to the base 16. 
Mounted on the upright wall 17 is a mounting channel 19 which engages a 
support block 20 which is slidably connected by a dovetail connection (not 
shown) to the mounting member 19 to permit vertical movement of the 
vibrator assembly 25 between the base 16 and head 18 of the support stand 
15. The vibrator assembly 25 is suitably secured to the support block 20, 
for example, by means of bands 26 which encompass the casing 27 of the 
vibrator assembly and are secured to the support block 20 by means of 
bolts 28. A support member or mounting fixture 22 of any suitable type for 
holding the work member 100 is provided on the base 16 and has a recess 23 
therein for receiving the work member. 
Drive means 29 to effect vertical movement of the vibrator assembly 25 
toward and away from the support member 22 is provided and may be in the 
form of a cylinder 30 vertically mounted to the head 18 and having a shaft 
31 extending therefrom and through the head 18 and coupled to a horizontal 
flange 21 of the support block 20 in any conventional manner. The air 
cylinder 30 may be operated by supplying compressed air conveyed by a 
conduit 32 from an exterior source (not shown) and extended from the rear 
of the cylinder. The exact height of adjustment is generally determined 
prior to the commencement of the carving cycle and will determine the 
depth of the textured or carved surface. 
The mechanical vibrator assembly 25 includes a transducer (not shown) which 
may be any one of a number of electromechanical types, such as, 
electrodynamic, piezoelectric or magnetostrictive. The operating frequency 
may be in the sonic or ultrasonic range between approximately 1 to 100 
KHz, but preferably in the range from 10 to 30 KHz. The vibrator assembly 
25 is of the type generally disclosed in the art. The transducer 35 housed 
within the casing 27 may be cooled as by water or air. 
The vibrator assembly, 25, generally includes a driver unit made up of a 
transducer secured to an acoustic impedance transformer or connecting 
member 36 that extends from the casing 27. The transducer of mechanical 
vibrations may comprise a stack of laminations of magnetostrictive 
material, for example, nickle, and surrounded by a coil winding (not 
shown) adapted to carry a biased, high-frequency alternating energizing 
current. The lower ends of the laminations making up the stack of the 
transducer are fixedly secured, as by welding or soldering, to the upper 
end of the transformer 36. The transformer 36 has an enlarged section (not 
shown) in the general area of a nodal plane of motion, and this section 
constitutes a flange secured to the casing 27. 
A biased, high-frequency alternating current is supplied to the winding 
through conductors 38 extending from a suitable oscillation generator 40, 
well known in the art. An oscillation generator is effective to supply a 
biased alternating current to the winding at a resonant frequency of the 
driver unit of transducer and is further effective to vary the frequency 
of the supplied biased, alternating current when the resonant frequency of 
the driver unit is varied due to changes in temperature, or changes in the 
loading thereof. The frequency of the supplied biased alternating current 
is adjusted in the oscillation generator in response to a feedback signal 
from a capacitor-type pickup connected in the transducer; it is to be 
understood that other types of pickups may be employed. Oscillation 
generators may be employed, in which adjustment of the frequency of the 
alternating current supplied by the oscillation generator is obtained 
through the use of a feedback signal which varies with the impedance of 
the transducer. 
The lower output end 37 of transformer 36 is coupled to the input end 47 of 
tool member 44 with a replaceable tool member 45 so that when the vibrator 
assembly 25 is operated, by electrical oscillations supplied from 
generator 40, compressional waves are generated in the vibrator 25, the 
transformer 36, member 44, and tool 45, so as to cause vibrational 
movements in the vertical direction, that is along the longitudinal axis 
of the transducer. For the purposes of the present invention, such 
vibrations preferably have a frequency in the range between approximately 
1,000 cycles per second and 100,000 cycles per second, and are of sizable 
amplitude, for example, in the range between approximately 0.0001 and 0.01 
inch. In order to ensure that the maximum amplitude of vibration in the 
vertical direction is obtained at the lower end or textured tool surface 
48 of the tool member 45, as indicated by the double headed arrow 46, thus 
ensuring the maximum transmission of working acoustical energy, the 
overall length of the motor, the transformer 36, tool 44, and the tool 
member 45 is selected so that, at the frequency of the electrical 
oscillations a loop of longitudinal motion of the generated compressional 
waves occurs at or near the tool surface 48 of the tool member 45. 
The tool member 45 as seen in FIGS. 20 and 21 is of a metallic material 
having good acoustical transmission properties so that the vibrations 
transmitted from the input surface 47 are propogated through the member to 
its output tool surface 48. The coupling between the output end 37 of the 
vibrator assembly 25 and the tool 44 may be of any conventional form for 
example as by a threaded coupling (not shown). 
The output surface 48 of the tool member 45 may have any number of desired 
configurations so that a replica of the tool surface is carved on the work 
member 100 which is generally of a hard material. As seen in FIG. 22, 
which is an enlarged view showing the interfacial contact area between the 
tool member 44 and the work member 100 to more clearly illustrate the 
carving, the output surface 48 has a textured surface which consists of a 
series of valleys 49 and peaks or hills 50 that when blended together with 
various radii, form a desired surface configuration which is to be 
reproduced in the object 100. The pump means 52 through a tubing 54 
directs an abrasive slurry 56 toward the interface between tool surface 48 
and workpiece 100. 
It will be apparent that the front end 45 of the tool 44 is a replaceable 
member firmly secured as by brazing or soldering. The replaceable tool or 
member 45 may be cast, etched, stamped, or manufactured in a conventional 
way known in the art with the workpiece 100 carved to the desired 
configuration. 
The system for carving the object 100 may be done on a production basis in 
that rather than change the tool a series of machines may be used, one for 
each section to be carved. FIG. 23 illustrates the system in which machine 
10b has tool 45b for carving the first section 116 as illustrated in FIG. 
1. The second machine 10c has tool 45c associated therewith for carving 
the second section 118 and machine 10d has tool 45d for carving the third 
section 120d. The inter-relation of the carving system is that each tool 
is designed to extend in overlapping relationship with a portion of the 
previously used carving tool. Obviously as explained above, the carvings 
may be from deep to shallow or in reverse with the same end result. 
In addition the carving system will include means for collecting the spent 
abrasive slurry and recirculating same in a manner well known in the art. 
The replaceable tool member that is brazed to the tool may last from five 
to fifteen deep carvings before replacement is required. The alignment 
difficulty of the prior art as discussed above results in part due to the 
need for changing of the tool and the inability to perform a carving 
without discernable machining marks between the sections. In the manner 
described by positioning each tool adjacent the object and urging contact 
between the tool and the object as an abrasive slurry is supplied abrading 
machining of the object is obtained while the tool is ultrasonically 
vibrated. By overlapping each tool an endless design can be created, in a 
manner not previously known. 
CONCLUSION 
Accordingly, applicant has invented and disclosed herein a new and novel 
process and system that may be used commercially for the carving of 
various objects to obtain a perspective carving of various sizes. Although 
artistic designs have been illustrated, it is appreciated that a variety 
of uses and applications may be utilized that are within the scope of the 
invention. 
Many other changes could be effected in the particular constructions, and 
in the methods of use and construction, and in specific details thereof, 
hereinbefore set forth, without substantially departing from the invention 
intended to be defined herein, the specific description being merely of 
preferred embodiments capable of illustrating certain principles of the 
invention. 
Accordingly, although illustrative embodiments of the invention have been 
described in detail herein with reference to the accompanying drawings, it 
is to be understood that the invention is not limited to those precise 
embodiments, and that various changes and modifications in addition to 
those mentioned above may be effected therein by one skilled in the art 
without departing from the scope or spirit of the invention, except as 
defined in the appended claims.