U.S. patent number RE28,642 [Application Number 05/515,504] was granted by the patent office on 1975-12-09 for ultrasonic rigid horn assembly.
This patent grant is currently assigned to Dukane Corporation. Invention is credited to Paul H. Davis.
United States Patent |
RE28,642 |
Davis |
December 9, 1975 |
Ultrasonic rigid horn assembly
Abstract
A versatile rigid horn assembly for distributing ultrasonic
energy from at least one source to a plurality of spaced work areas
is provided. This rigid horn assembly includes an elongated tool
holder having an input region at one end and an output region at
the other end. The tool holder is a horn of suitable metal and will
have a length of at least one acoustic half wavelength, or any
desired number of integral half wavelengths. Secured to and
extending from the output end are rigid tool members, each of which
is a horn and has a length of at least one acoustical half
wavelength. Tool members may have lengths of integral half
wavelengths, it being understood that tool members need not
necessarily be of the same shape or length. The drawings illustrate
various arrangements of tool members. The output end of a tool
holder has means permitting attachment of a plurality of tool
members, the means being arranged so that one or more various tool
members may be disposed to provide different tool member patterns.
The means for attaching a tool member to a tool holder includes
threaded metal members each of which may be a threaded stud
extending into a tapped recess in the tool holder or elongated
bolts each having an enlarged head disposed in bores extending
longitudinally of the tool holder and having an interior shouldered
part for each bore. Alternatively, a tool member may include an
integral threaded boss, or the tool holder and tools may be of
brazable material and secured by brazing.
Inventors: |
Davis; Paul H. (St. Charles,
IL) |
Assignee: |
Dukane Corporation (St.
Charles, IL)
|
Family
ID: |
26947015 |
Appl.
No.: |
05/515,504 |
Filed: |
October 17, 1974 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
259023 |
Jun 2, 1972 |
03780926 |
Dec 25, 1973 |
|
|
Current U.S.
Class: |
228/1.1;
156/73.1; 228/110.1 |
Current CPC
Class: |
B29C
66/80 (20130101); B29C 66/8167 (20130101); B29C
65/08 (20130101); B06B 3/00 (20130101); B29C
66/21 (20130101) |
Current International
Class: |
B06B
3/00 (20060101); B29C 65/08 (20060101); B29C
65/00 (20060101); B23K 001/06 (); B23K
005/20 () |
Field of
Search: |
;228/1 ;29/470.1,470.3
;310/26 ;156/73.1,73.2,73.3,73.4,73.5,73.6 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Shore; Ronald J.
Attorney, Agent or Firm: Kahn; Robert L.
Claims
What is claimed is: .[.1. An ultra-sonic tool system for industrial
processing with acoustic energy, said system comprising an
elongated, straight, rigid, unitary tool holder of rigid material
having a longitudinal axis and a length of an integral number of
half-wave lengths at the operating frequency, the transverse
dimensions being so proportioned to the length thereof as to
minimize undesired modes of transmission other than along the tool
holder length, said tool holder having only two ends shaped to
provide finished flat sonic energy input and output areas, the tool
holder providing a common transmission path for all sonic energy
from the input to the output thereof, threaded means at the input
end for coupling at least one source of sonic energy thereto; at
least two, elongated, rigid tool members laterally spaced from each
other rigidly secured directly to a sonic output area of the tool
holder, each tool member having at one end a sonic input area
conforming to a sonic tool holder output area in the secured
positions of the tool holder and tool members, each tool member
having a sonic energy working output tip at its other end, the tool
holder output area being great enough to accommodate a plurality of
laterally offset, secured tool members arranged to create a desired
pattern of work areas, each tool member having a length of an
integral number of half-wave lengths; whereby said tool holder
material may be selected on a basis of acoustic properties, cost,
and ease of machining and the tool member material may be selected
on a basis of acoustic properties and toughness for working life,
said tool holder and tool members being each resonant to the
acoustic energy so that efficient transmissions of sonic energy to
the work areas result, each tool member being susceptible to
individual design with regard to tool member contours, amplitude of
sonic energy at a work area and physical length of a tool member;
the machining problem of the tool holder being distinct from any
problem of machining a tool member, said tool system being
sufficiently rigid so that it may be pressed against work without
accessories for guiding tool members..]. .[.2. The construction
according to claim 1 wherein said tool holder has a plurality of
holes extending from at least one output area thereof inwardly
toward the input end thereof and wherein threaded means are
provided for rigidly securing a tool member to said holder at a
desired hole..]. .[.3. The construction according to claim 2,
wherein threaded metal studs for rigidly securing said tool members
to the output of said tool holder are provided..]. .[.4. The
construction according to claim 2, wherein said tool holder has a
plurality of longitudinal bores extending parallel to and laterally
offset from the axis of the tool holder, and a bolt for rigidly
securing a tool member to the tool holder at a bore..]. .[.5. The
construction according to claim 1, wherein the tool holder is
shaped so that the transverse dimensions remains substantially
constant along the length of such holder..]. .Iadd. 6. An
ultra-sonic tool system for industrial processing with acoustic
energy, said system comprising an elongated, straight, rigid,
unitary tool holder of rigid material having a longitudinal axis
and a length of an intergral number of half-wave lengths at the
operating frequency, the transverse dimensions being so
proportioned to the length thereof as to minimize undesired modes
of transmission other than along the tool holder length, said tool
holder having only two ends shaped to provide finished flat sonic
energy input and output areas, the tool holder providing a common
transmission path for all sonic energy from the input to the output
thereof, threaded means at the input end for coupling at least one
source of sonic energy thereto; at least two, elongated, rigid tool
members laterally spaced from each other each rigidly secured
directly to a sonic output area of the tool holder, each tool
member having at one end a sonic input area conforming to a sonic
tool holder output area in the secured positions of the tool holder
and tool members, each tool member having a sonic energy working
output tip at its other end, the tool holder output area being
great enough to accommodate a plurality of laterally offset secured
tool members arranged to create a desired pattern of work areas,
each tool member having a length of an integral number of half-wave
lengths, said tool holder and tool members being each resonant to
the acoustic energy so that efficient transmissions of sonic energy
to the work areas result, each tool member being susceptible to
individual design with regard to tool member contours, amplitude of
sonic energy at a work area and physical length of a tool member,
said tool system being sufficiently rigid so that it may be pressed
against work without accessories for guiding tool members, at least
one of said tool members having at least part of its length of a
substantially different transverse dimension than corresponding
parts of other tool members so that vibration amplitude differs
from other tool members at the work areas..Iaddend..Iadd. 7. An
ultra-sonic tool system for industrial processing with acoustic
energy, said system comprising an elongated, straight, rigid,
unitary tool holder of rigid material having a longitudinal axis
and a length of an integral number of half-wave lengths at the
operating frequency, the transverse dimensions being so
proportioned to the length thereof as to minimize undesired modes
of transmission other than along the tool holder length, said tool
holder having two ends shaped to provide finished flat sonic energy
input and output areas, the tool holder providing a common
transmission path for all sonic energy from the input to the output
thereof, threaded means at the input end for coupling at least one
source of sonic energy thereto; at least two, elongated, rigid tool
members laterally spaced from each other rigidly secured directly
to sonic output areas of the tool holder, each tool member having
at one end a sonic input area conforming to a sonic tool holder
output area in the secured positions of the tool holder and tool
members, each tool member having a sonic energy working output tip
at its other end, the tool holder output area being great enough to
accommodate a plurality of laterally offset secured tool members
arranged to create a desired pattern of work areas, each tool
member having a length of an integral number of half-wave lengthss,
said tool holder and tool members being each resonant to the
acoustic energy so that efficient transmissions of sonic energy to
the work areas result, each tool member being susceptible to
individual design with regard to tool member contours, amplitude of
sonic energy at a work area and physical length of a tool member,
said tool system being sufficiently rigid so that it may be pressed
against work without accessories for guiding tool members, at least
one of said tool members having its working end at a level
different from that of other tool members..Iaddend..Iadd. 8. The
system according to claim 7, wherein said tool holder has a portion
of its output face at a level different from other portions so that
even if similarly dimensioned tool members are used, the working
ends of such tool members are at different levels, the difference
in level at the output of the tool holder being small in comparison
to the operating wavelength..Iaddend..Iadd. 9. An ultra-sonic tool
system for industrial processing with acoustic energy, said system
comprising an elongated, straight, rigid, unitary tool holder of
rigid material having a longitudinal axis and a length of an
integral number of half-wave lengths at the operating frequency,
the transverse dimensions being so proportioned to the length
thereof as to minimize undesired modes of transmission other than
along the tool holder length, said tool holder having two ends
shaped to provide finished flat sonic energy input and output
areas, the tool holder providing a common transmission path for all
sonic energy from the input to the output thereof, threaded means
at the input end for coupling at least one source of sonic energy
thereto; at least two, elongated, rigid tool members laterally
spaced from each other rigidly secured directly to a sonic output
area of the tool holder, each tool member having at one end a sonic
input area conforming to a sonic tool holder output area in the
secured positions of the tool holder and tool members, each tool
member having a sonic energy working output tip at its other end,
the tool holder output area being great enough to accommodate a
plurality of laterally offset, secured tool members arranged to
create a desired pattern of work areas, each tool member having a
length of an integral number of half-wave lengths, said tool holder
and tool members being each resonant to the acoustic energy so that
efficient transmissions of sonic energy to the work areas result,
each tool member being susceptible to individual design with regard
to tool member contours, amplitude of sonic energy at a work area
and physical length of a tool member, said tool system being
sufficiently rigid so that it may be pressed against work without
accessories for guiding tool members, at least two sonic flat
output area portions of the tool holder lying in different
non-parallel planes so that secured tool members have their
respective lengths in non-parallel relation, the angular departure
from parallelism being
small..Iaddend..Iadd. 10. The system according to claim 9, wherein
the tool members converge..Iaddend..Iadd. 11. The system according
to claim 9, wherein the tool members diverge..Iaddend.
Description
INTRODUCTION
This invention relates to an ultrasonic rigid horn assembly having
enhanced functional adaptability for distributing ultrasonic energy
from one or more sources to a plurality of tool members for
application to various work areas. The invention particularly
relates to applications of ultrasonics to plastics, such as
welding, staking or inserting. As an example, welding may be
accomplished by application of ultrasonic energy at predetermined
work areas. In many instances, such work areas are disposed at
spaced intervals in desired patterns for simultaneous treatment.
The ultrasonic energy is directed to such spaced work areas to
create simultaneously a pattern of weldments or other work.
It is not limited to plastics working, however, and may be useful
where ultrasonic energy is required at discrete locations. Thus
liquid at a number of locations may be cavitated.
It has been the practice to provide a unitary tool structure whose
input is connected to a suitable source of ultrasonic acoustic
energy and whose output is available at spaced sonic applicator
regions on the tool. The sonic regions may assume a variety of
forms, such as small separate circular or rectangular areas, all
adapted to operate on the work piece and provide the desired effect
at each of the sonic applicator regions. Inasmuch as the sonic
applicator regions must be supplied with ultrasonic energy, the
sonic wave transmission characteristics of a tool structure is
determined in a substantial manner not only by the nature of the
tool structure material (usually metal) but also by the
longitudinal and transverse dimensions of the tool structure
material. Such requirements involve shaping of a tool structure to
obtain the required sonic tuning and vibration amplitude. It is, of
course, well understood in this art that unless sonic energy is fed
to every one of the spaced sonic energy applicator areas, that the
desired action at the various regions to be operated upon may not
occur.
As a rule, customer requirements with regard to number and spacing
of sonic applicator regions in a tool structure differ greatly and
may change even with changes only in dimensions and number and
pattern of work areas.
In tool making for various customer requirements, the shaping of a
tool to obtain desired operation often involves difficult machining
operations to provide the desired shapes of the various parts of a
tool. Frequently, such tools can not utilize surfaces of revolution
in their manufacture. Consequently, the shaping of a tool may
require difficult milling operations or even hand work. The various
portions of a tool structure from the sonic input part to the
respective individual sonic outputs must all have precise tuning
and vibration amplitude characteristics.
The machining requirements for such tools are often made more
expensive by the fact that the tool metals used in ultrasonic work
may be special alloys, difficult to machine, such as titanium or
monel. Titanium, in particular, is very expensive as a raw
material. In some instances, special thicknesses of metal plates
for tool fabrication are required.
The resulting tool is useful for one particular job and rarely is
adaptable for a different pattern of work areas. Consequently, any
change in a work area pattern by customer's needs usually involves
a complete change in tooling. Furthermore, tool metals may not have
long life under conditions of rapid wear at working surfaces so
that in many instances total tool renewal becomes necessary.
GENERAL REQUIREMENTS FOR TOOL STRUCTURE
The structure which couples ultrasonic energy from the acoustic
source (piezoelectric or magnetostrictive transducer) to the
material to be processed must satisfy several requirements:
1. Provide a sufficiently large output area to encompass the
workpiece locations to be treated.
2. Provide whatever contours are necessary to provide concentration
of sonic energy so that the required vibration amplitude will be
available at the work locations.
3. The material must have sufficiently high strength to withstand
high stresses present along the contoured sections.
4. The material must have sufficiently good wear resistance to
withstand abrasion at the work faces.
According to prior art, structures are fabricated from one piece of
metal and at least the first three of the above requirements must
be met by this material. Unless the work areas can be provided with
wear-resistant inserts, all four requirements must be met. In cases
where a large work area must be handled, and high amplitude is
required, this means that the structure (or horn) must be made of
titanium or monel, materials which are both expensive as raw
materials and difficult to machine.
In some cases, it may be very difficult or impossible to provide
the contours necessary to produce the vibration amplitude required
at the work areas.
In the present invention, the requirements to be satisfied are
divided between a tool holder horn and one or more rigid tool
member horns which taken together make up a rigid horn
assembly.
The new tool holder provides for locating the tool members at the
necessary points across the area. It has relatively low stress
situations, no location of wear, and may be made of cheap, easily
machineable materials such as aluminum. It does not require
elaborate contours to be generated.
The new tool members deliver the ultrasonic energy to the material
being processed, and include whatever contours are required to
produce the vibration amplitude necessary to do the work. Contours
may be as elaborate as needed to give the required amplitude, high
stress points may be present, and high wear conditions may be
present at the work face. Special materials such as titanium 6al-4V
may be required, and these metals are both expensive and difficult
to machine. The size of these tool members can be held to a
minimum, proportionate to the input and output areas required to
couple the energy, thus material costs and machining time are held
down.
In practically all cases, at least part of the new tool member can
be round in section so that full use may be made of contouring
techniques to provide amplitude magnification.
ADVANTAGE OF THE INVENTION
The present invention to be hereinafter described makes possible an
ultrasonic rigid horn assembly having enhanced functional
adaptability, whose pattern of sonic applicator work areas may
usually be modified without requiring a completely new structure.
For one thing, a great advantage of a rigid horn assembly embodying
the present invention resides in the fact that the tool holder may
be a body having flat or cylindrical outer surfaces and is
susceptible to accurate economical machining. The sonic
transmission characteristics of such new tool holder portion may be
controlled accurately and will remain unchanged throughout the
various tool transformations which the invention permits.
The new tool holder must be longitudinally resonant to a desired
operating frequency range and has its output end portion or has its
entire body portion shaped or constructed in such a manner as to
accommodate a desired number of or pattern of rigid tool members.
These tool members similarly must be longitudinally resonant and if
more than one are used, are respectively adapted to receive sonic
energy from the tool holder and apply it to work areas. The number
and pattern of tool member positioning may be changed easily
without disturbing the tool holder design whose shape and
dimensions are adapted to provide different patterns of work
areas.
Each tool member is rigid and is individually attached to the tool
holder to project from the output end thereof. The attaching means
is adapted to be detachable and will include a threaded stud or
bolt of suitably strong material, usually specially strong
steel.
The attaching means itself may include tapped recesses or holes
extending into the output end of the tool holder and/or
longitudinal bores or holes extending parallel to the axis of the
tool holder but laterally offset therefrom, such bores preferably
each having an internal shoulder against which the enlarged head of
a steel bolt may be seated. The tapped recesses or holes and/or
longitudinally disposed bores or holes may be disposed in any
desired pattern so that any one or more tool members may be used in
different patterns and spacing arrangements. In all cases, it is
preferred to limit the number, spacing and depth of tapped recesses
and/or longitudinal bores to minimize substantial changes in the
sonic transmission characteristics such as resonance and internal
reflections of the tool holder between the input and output
thereof. It will generally be desirable to have the tool holder
output area sufficiently great to accommodate a number of tool
positions in a desired pattern. In all cases, however, the
transverse tool holder dimensions must be chosen and proportioned
with respect to the overall length to produce the desired
longitudinal mode of acoustical resonance, with undesired modes
minimized so that the tool members can produce the desired action
on the work areas.
Another substantial advantage obtainable with the invention is the
possibility of having tool members so inclined that their
longitudinal axes are non-parallel to the tool holder axis by a
small angle thus providing a working field which may be somewhat
larger or somewhat smaller than the working field obtainable when
the tool member and tool holder axes are parallel.
Other advantages will become apparent later with a more detailed
description of the invention.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be described in connection with the drawings
wherein FIG. 1 is an elevation of a rigid horn assembly
.[.embodying the present invention.]..
FIG. 1A is a bottom view showing the rigid horn assembly of FIG. 1
to illustrate a pattern of tool members.
FIG. 2 is an elevation of a modified form of rigid horn assembly
wherein certain tool members are dimensioned differently to provide
different vibration amplitudes.
FIG. 2A is a bottom view of the rigid horn assembly illustrated in
FIG. 2 showing the arrangement of tool members.
FIG. 3 is an elevation of a still further modified form of the
invention illustrating an arrangement of tool member tips at
different levels.
FIG. 3A is a bottom view of the rigid horn assembly illustrated in
FIG. 3.
FIG. 4 is an elevation of a still further modified form of rigid
horn assembly, this showing different means for attaching tool
members to the tool holder.
FIG. 4A is a bottom view of the tool member arrangement illustrated
in FIG. 4.
FIG. 5 is an elevation of a .[.still further modified form of a
rigid horn assembly embodying the present invention, this
illustrating.]. linear arrangement of tool members.
FIG. 5A is a bottom view of the tool member arrangement of the
structure illustrated in FIG. 5.
FIG. 6 is an elevation of a tool holder .[.embodying the present
invention.]. showing a pattern of recesses for tool member
attachment.
FIG. 6A is a bottom view showing the arrangement of recesses.
FIG. 7 is an elevation of a .[.still.]. further modified form of
rigid horn assembly embodying the present invention, this
illustrating tool members diverging at a slight angle to the tool
holder axis rather than being parallel.
FIG. 7A shows a modification of the form of the invention
illustrated in FIG. 7.
FIG. 7B is a detail of FIG. 7A on line 7B--7B.
FIG. 8 is a still further modified form of a rigid horn assembly
embodying the present invention showing two tool members having
different lengths, the two tool members having different contours
to maintain equality of dimensions in acoustical half
wavelengths.
DETAILED DESCRIPTION OF THE INVENTION
The .[.new.]. rigid horn assembly .[.embodying the present
invention.]. consists essentially of tool holder 10 and one or more
tool members 11, 11A, 11B, etc. Tool holder 10 is preferably of
metal having appropriate accoustical and strength properties and
may, for example, be of certain grades of aluminum, titanium, or
the like. As examples, an aluminum alloy 7075-T651 can be used. In
case of titanium, an alloy known as 6Al-4V may be used.
Tool holder 10 has its length equal to an integral number of half
wavelengths at the operating frequency to be used. As a rule, a
single half wavelength may be used. For a five inch diameter tool
holder of aluminum 7075-T651 for example, and using 20KHz, a length
of 4.345 inches may be used. This length is an actual example and
it is understood that different lots of material may vary in
acoustic properties, so the length may depart slightly from the
value given. One common shape for tool holder 10 is cylindrical,
although, a rectangular or polygonal shape may be used.
It is understood that the requirement for substantial area at
output end 10A of tool holder 10 is dictated by the desirability of
having tool members in desired number and spacing carried at such
end. Tool holder 10 is preferably proportioned so as to avoid
change in vibration amplitude from the input end 10B of tool holder
10 to the output end 10A. End 10B of tool holder 10 is adapted to
be coupled to one or more sources of sonic energy. This is most
simply accomplished by having tapped recess 10C for each source
extending into the tool holder and preferably symmetrically
disposed with respect to the tool holder axis. In order to attach a
source of sonic energy, a steel stud may be screwed into recess
10C, the steel stud being strong enough to withstand the various
stresses and strains to which it may be subjected. For example, a
sonic generator of the piezoelectric or magnetostrictive type may
be used, the output being directly coupled to tool holder 10 or
through an intermediate resonant coupling member.
One or more tool members 11; 11A; 11B etc. may be coupled to tool
holder 10 at output face 10A. Referring to tool member 11, as an
example, this consists of input portion 13 and reduced tool member
portion 14 as an extension thereof. In the particular example
given, tool member 11 as a whole will have an overall length of
one-half wavelength with input portion 13 and tool member portion
14 being respectively one-quarter wavelength each. It is understood
that the physical length of the entire tool member may be different
from the physical length of tool holder 10 depending, of course,
upon the nature and contour of the material used.
The designation of one-half wavelength for the overall tool member
11 is exemplary. It is understood that either the tool holder or
the tool member, or both, may have one or more integral number of
acoustical half wavelengths. In particular, the possibility of
using tool members longer than one-half wavelength may be
desirable. There is no particular arrangement or number of tool
members necessary for use at the output part 10A of the tool
holder.
Referring to FIG. 1A, it will be observed that a symmetrical
arrangement of four tool members is provided. Each tool member is
rigidly secured to tool holder 10 by means of threaded steel stud
16. It is important that stud 16 be of a sufficiently strong
material and properly dimensioned to withstand the vibratory
stresses. Stud 16 may be integral with a tool member, if the tool
is of sufficiently strong metal, such as titanium. The stud will in
all cases extend into tapped recesses or holes in bottom face 10A
of tool holder 10.
While four tool members are shown, it is not necessary that all
tool members be used or be positioned in the tool holder. In fact,
there is nothing magic about the number of tool members and the
number may be as desired. This is also true of the pattern in which
the tool member accommodating recesses are disposed. While the
number and spacing of tool member accommodating recesses in face
10A of tool holder 10 may vary within wide limits, it is essential
that the volume of metal removed from all the recesses be small
enough in comparison to the mass of the entire tool holder so that
the general transmission characteristics of tool holder 10 for
conducting sonic energy from face 10B to face 10A be unimpaired.
Thus, if an excessively large number of tapped recesses is to be
provided, it may be necessary to compensate a change in
transmission characteristics by adjusting the length of the tool
holder or the transverse dimensions of the tool holder or both.
No attempt is made to show the detailed structure of tool member
portion 14 at the tip thereof since such details are well known,
depending upon the work effect to be created. It should be noted
that the various tool members extending downwardly from tool holder
10 are rigid members and that the entire assembly of tool holder
and tool members together with the source of sonic energy, such as
transducer, may be handled in conventional fashion by supporting in
a press so that one or more tool members have their working ends
pressed against the work piece to be treated. The actual support of
the entire assembly of transducer, tool holder 10 and the tool
members, may be on the transducer, or on tool holder 10 or both. If
the tool holder is to be supported, then a supporting nodal mount
around the middle of tool holder 10 can be provided. At this region
of the tool holder, the longitudinal amplitude of the sonic energy
is substantially zero. The same is true for transducers so that
mounts for the nodal regions of transducers and tool holders may be
joined.
Referring now to FIG. 2, the tool member is substantially similar
to that illustrated in FIG. 1 except that tools 11A' are shown as
being of greater transverse area than 11 and 11B. Such an
arrangement permits greater amplitude to be delivered at the
working end of the tool member as may be required in certain
instances.
Referring now to FIG. 3, output face 10A has slotted portion 10A'
for accommodating tool members 11A so long as the offset of slotted
portion 10A with respect to 10A is small in terms of wavelength (as
for example in the assumed case a difference of about one-quarter
of an inch may be tolerated), the rigid horn assembly will function
generally satisfactorily. Such an arrangement may be desirable
where material to be worked upon requires a stepped arrangement of
tool member working faces. As is illustrated in FIG. 3A, slotted
portion 10A' extends straight across the end face of tool holder
10. It is not necessary that slot 10A' extend all the way across
and instead only one of the face members 11A may be thus
longitudinally offset.
Referring now to FIG. 4, a different arrangement of tool member
attachment to tool holder 10' is illustrated. In this instance,
instead of tapped recesses in the tool holder, there may be a
pattern of passages or holes longitudinally of the tool holder and
generally parallel to the axis but laterally offset therefrom. Such
passages have enlarged bore portions 20 having shoulders 21 and
reduced bore portions 22 extending longitudinally of tool holder
10'. Bolts 23 having enlarged heads 23A can extend as illustrated
with threaded portions 24 extending into and cooperating with
threaded recesses in tool member 26. Tool member 26 may have a
suitable workable shape. As shown here, enlarged head 23A of bolt
23 is provided with a suitably shaped hex recess for engagement by
a hex shaped rod to be used as a wrench. The diameters of bores 20
and 22 and shoulder 21 are all relatively proportioned so that each
tool member retaining bolt will not be excessively stressed. Again
as with tapped recesses or holes in the tool holder previously
described, it is essential that the number of passages or holes 20
and 22 in a tool holder be such that the transmission
characteristics of the entire tool holder remain constant. In this
particular modification, it is clear that the volume of metal
removed for each tool member position is much greater than in the
previous instances where only a blind tapped recess is used.
However, the compensation for the removal of metal may be readily
provided by controlling the lateral and longitudinal dimensions of
the tool holder. The arrangement of bolts as illustrated here in
FIG. 4 is such that access to the top face 10B of tool holder 10'
is required. In some instances, the mounting of the rigid horn
assembly, transducer accessories various accefories may make access
difficult. It is understood, therefrom, that while the two
arrangements illustrated in FIG. 4 and FIGS. 1 to 3 for example
with regard to tool member attachment to a tool holder are
equivalent, one may for certain purposes be more convenient than
the other.
Referring to FIG. 4A, it will be noted that tool member 26 has the
top portion of rectangular shape. Either one or two bolts 23 may be
used for each tool member, depending upon requirements for a
particular job. The arrangement of tool members in this particular
tool holder may vary so that more or less than two tool members are
used.
Referring to FIG. 5, a modified tool member arrangement, each of
which may have a tapered shape, is illustrated. In this particular
modification, as illustrated in FIG. 5A, two lines of tool members
at right angles to each other are illustrated. It is not necessary
that every tool member position be filled with a tool member and it
is not even necessary that each tool member be of the tapered
type.
Referring now to FIG. 6, an arrangement of recesses in a tool
holder is shown wherein such recesses which are tapped are aligned
along lines which extend in various directions making possible a
large number of possible tool member arrangements. It is understood
that this particular arrangement of recesses or holes may be
replaced by through passages or holes in a tool holder similar to
FIG. 4.
Referring now to FIG. 7, a tool holder is illustrated wherein tool
members have their axes disposed at a slight angle to the tool
holder axis. Thus, two or more tool members may be arranged in this
fashion, it being understood that the various angles at the output
faces of the tool holder must be small.
By having the tool member axes inclined to be nonparallel to the
tool holder axis, the totality of all work area patterns may be
made smaller or larger than the entire work area of parallel tool
member arrangements.
In FIG. 7, the rigid horn tool members diverge. In FIG. 7A, the
tool members converge. In both cases, the opposing tool holder and
tool member surfaces must be flat and true. Where the entire tool
holder face is conical, it is necessary to machine flat areas
against which a tool member may fit, as suggested in FIG. 7B. The
tool members may be bolted, brazed or welded in place.
In FIG. 7A, the convergence of the tool members tips may require
machining after tool members have been set in place on a tool
holder. This may involve shaping the tool member tips to straighten
out the working axis normal to the work.
Referring now to FIG. 8, an arrangement is shown wherein two
differently dimensioned tool members are utilized, one tool member
being thicker and longer than the other. This arrangement can be
obtained by controlling the nature of the contour for the tool. It
is understood, of course, that in each case each tool must have a
length equal to one or more integral half wavelengths.
In a broad sense, a tool holder and tool member may each be
considered as a horn so that an entire assembly may be designated
as a rigid horn assembly.
An entire assembly of tool holder and tool member horns embodying
the present invention is substantially rigid at the tool member
ends even though resilient nodal mounting means for tool holder
and/or transducer means are provided. Resilient mounts are
desirable because of their efficiency.
* * * * *