Note: Descriptions are shown in the official language in which they were submitted.
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FORCE-MULTIPLYING PERCUSSOR AND SELF-APPLICATOR
SYSTEM FOR AIRWAY CLEARANCE
DESCRIPTION
FIELD OF THE INVENTION
[Para 1] The invention relates to airway clearance treatments.
Specifically,
the present invention is directed to a force-multiplying percussor and self-
applicator system for airway clearance. A percussor is a medical device for
supplying impulse forces to a patient's back or chest for the purpose of
loosening and dislodging bronchial secretions in the lungs. A self-applicator
is
a strap that holds a percussor in a secure manner such that an individual can
apply the percussor to their back without assistance from another person.
BACKGROUND OF THE INVENTION
[Para 2] A percussor is a medical device for supplying impulse forces to a
patient's back or chest for the purpose of loosening and dislodging bronchial
secretions in the lungs. The present invention is of a system of straps to
allow
a person to properly apply a percussor against his or her own back.
[Para 3] The type of percussor is based on the use of a solenoid in
developing impulse forces for application to a patient's back or chest. A
"solenoid", as defined in the McGRAW-HILL DICTIONARY OF SCIENTIFIC AND
TECHNICAL TERMS, Fourth Edition, Sybil P. Parker, Editor in Chief, McGraw-Hill
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_
=
Book Company, New York, N.Y., 1989, is "a coil that surrounds a movable iron
core which is pulled to a central position with respect to the coil when the
coil
is energized by sending current through it."
[Para 4] An example of this type of percussor is described in U.S. Patent
4,512,339 as a device which energizes a coil to develop an impulse force for
application to a patient and utilizes a compressed spring to return the
movable
iron core to its rest position. The designs of percussors of this type are
unnecessarily complicated and inflexible with respect to their use in treating
patients and the adjustment of the operating parameters of the devices.
[Para 5] The present invention avoids the complexities and inflexibilities
of
the prior art by utilizing a solenoid in a new and different way in generating
impulse forces. The present invention utilizes the solenoid only for returning
the movable iron core to its rest position. The patient-experienced impulse
forces that result from the present invention are multiplied versions of the
continuing force applied by a technician in using the invention.
[Para 61 By the nature of such a percussor and human physiology, it is
extremely difficult for individual to self-apply a percussor to their own
back.
The present invention makes it possible for an individual to hold a percussor
against his or her own back so as to properly apply the impacting force for
the
purpose of loosening and dislodging bronchial secretions in the lungs. The
person can self-apply the percussor so as to not require the services of a
technician in using the percussor.
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[Para 7] Accordingly, there is a need for a self-applicator for an airway
clearance device that addresses these needs. The present invention fulfills
these needs and provides other related advantages.
SUMMARY OF THE INVENTION
[Para 8] The present invention is directed broadly to a medical device for
supplying impulse forces to a patient's back or chest for the purpose of
loosening and dislodging bronchial secretions in the lungs. More particularly,
the invention is a force-multiplying percussor and self-applicator system for
airway clearance. The force-multiplying percussor comprises an anvil, a
hammer, a coil, and a pulse generator. The self-applicator comprises first and
second straps joined at their respective ends. The first strap overlays and is
substantially co-extensive with the second strap. A pouch for holding the
percussor is disposed between the first and second straps. The self-applicator
also comprises a pair of handles with one each attached to one of the
respective ends of the first and second straps.
[Para 9] In the percussor, the anvil is equipped with a force-receiving
surface and a force-delivering surface which are rigidly connected together,
the
force-delivering surface being intended for contact with a patient's body. The
hammer is also equipped with a force-receiving surface and a force-delivering
surface, the hammer being oriented with respect to the anvil in such a way
that
the force-delivering surface of the hammer and the force receiving surface of
the anvil are mechanically free to come together or move apart.
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[Para 10] The coil forces the force-delivering surface of the hammer and the
force-receiving surface of the anvil to separate when the solenoid is
energized
with an electrical current. The pulse generator supplies repeated electrical
current pulses to the coil which causes repeated force-multiplied impulse
forces to be applied to a patient's body via the force-delivering surface of
the
anvil whenever the technician applies a continuing force to the force-
receiving
surface of the hammer.
[Para 11] In the self-applicator, the first strap is preferably longer than
the
second strap so as to define an open region between the two straps. The
second strap has an application surface on one side. The application surface
comprises a padded material and is configured so as to make physical contact
with a user's back. The pouch is disposed in the open region. The pouch is
attached to at least one and preferably both of the straps.
[Para 12] The pouch comprises a closure mechanism. The closure
mechanism is configured so as to securely hold the percussor. The closure
mechanism comprises adjustable hook and loop straps configured so as to
accommodate percussors of varying sizes.
[Para 13] At least one of the pair of handles is attached to one of the ends
of
the first and second straps by an adjustable length harness. The other of the
pair of handles is attached to the other of the ends of the first and second
straps by a fixed length harness.
[Para 14] A method for using the force-multiplying percussor and self-
applicator system begins with the step of inserting the percussor into the
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pouch. The percussor is positioned in the pouch such that an anvil is oriented
toward the second strap. A user then grasps each of the pair of handles in
his/her hands. The user then self-applies the application surface of the
second
strap to his/her back. The percussor is turned on such that a force delivering
surface of the anvil contacts the user's back through the application surface.
[Para 1 5] The method further comprises the step of closing the closure
mechanism on the pouch so as to securely hold the percussor in the pouch.
The method also comprises the step of adjusting the length of the adjustable
length harness on one of the pair of handles so that the user can comfortably
perform the self-applying step.
[Para 1 6] Other features and advantages of the present invention will become
apparent from the following more detailed description, taken in conjunction
with the accompanying drawings, which illustrate, by way of example, the
principles of the invention.
BRIEF DESCRIPTION OF DRAWINGS
[Para 1 7] The accompanying drawings illustrate the invention. In such
drawings:
[Para 1 8] FIGURE 1 is a perspective view of a first embodiment of the
percussor of the present invention;
[Para 1 9]
FIGURE 2 is a sectional view taken along line 2-2 of FIG. 1 with the
hammer shown in a neutral position relative to the anvil;
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[Para 20] FIGURE 3 is a sectional view taken along line 2-2 of FIG. 1 with the
hammer shown fully-withdrawn from contact with the anvil;
[Para 21] FIGURE 4 is a perspective view of a second embodiment of the
percussor of the present invention;
[Para 22] FIGURE 5 is a sectional view taken along line 5-5 of FIG. 4 with the
hammer shown in a neutral position relative to the anvil;
[Para 23] FIGURE 6 is a sectional view taken along line 5-5 of FIG. 4 with the
hammer shown in contact with the anvil;
[Para 24] FIGURE 7 is a schematic drawing illustrating the inputs and outputs
of the pulse generator which supplies the driving current for the percussor;
[Para 25] FIGURE 8 is an elevated perspective view of the self-applicator of
the present invention;
[Para 26] FIGURE 9 is an elevated perspective view of the self-applicator of
the present invention illustrating insertion of a percussor;
[Para 27] FIGURE 10 is an exploded perspective view of the self-applicator of
the present invention;
[Para 28] FIGURE 11 is an environmental view of the force multiplying
percussor and self-applicator system of the present invention being self-
applied by a user;
[Para 29] FIGURE 12 is a close-up cut-away view of the force multiplying
percussor and self-applicator system of the present invention being self-
applied by a user;
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[Para 30] FIGURE 13 is a perspective view of a particularly preferred
embodiment of a percussor of the present invention;
[Para 311 FIGURE 14 is a cut-away view of the particularly preferred
embodiment of the percussor depicted in FIG 13;
[Para 32] FIGURE 15 is a partially dis-assembled view of the particularly
preferred embodiment of the percussor of FIG. 14;
[Para 331 FIGURE 16 is a cross-sectional view of the front wall of the
particularly preferred embodiment of the percussor of FIG. 14;
[Para 341 FIGURE 16a is an end view of the front wall of the particularly
preferred embodiment of the percussor of FIG. 14;
[Para 35] FIGURE 17 is a side view of the shaft and plunger of the
particularly
preferred embodiment of the percussor of FIG. 14; and
[Para 36] FIGURE 18 is a cross-sectional view of the rear support bearing of
the particularly preferred embodiment of the percussor of FIG. 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[Para 371 The present invention is directed to a force-multiplying percussor
= and self-applicator system for airway clearance, the system being
referred to
generally by reference numeral 20. The system 20 comprises a percussor 22
and a self-applicator 24, all of which are illustrated in FIGS. 1-12.
[Para 38] A first embodiment of the percussor 22 is shown in FIGS. 1-3. The
percussor 22 of the present invention consists of a hammer 26 and an anvil 28
oriented with respect to one another such that the hammer 28 may impact the
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anvil 28. The percussor 22 is configured to be placed on the back or chest of
a
patient with the anvil 28 in contact with the patient's body. Typically, a
user
holds the percussor 22 in place by gripping the hammer 26 with one hand,
palm on top, and then turns on the power. The force continually applied by the
user to the hammer 26 is converted by the percussor 22 into repeated force-
multiplied impulses in which the force associated with each impulse is
significantly greater than the force being applied by the user on a continuing
basis.
[Para 39] The details of the percussor 22 design are shown in the sectional
views of FIGS. 2 and 3. The hammer 26 consists of a plastic structural member
30 attached to guiding member 32. Guiding member 32 may be either metal or
plastic and attaches to structural member 30 utilizing mating threaded regions
(not shown). Coil 34 is embedded in structural member 30 as shown (assuming
structural member 30 is a plastic material).
[Para 40] The anvil 28 consists of ring 36 and platen 38 connected together
by cylindrical guiding member 40. Ring 36 has a rectangular cross-section and
is made of a magnetic material such as iron. Guiding member 40 attaches to
ring 36 by a press fit. Platen 38 is attached to guiding member 40 by means of
a machine screw (not shown). The hammer 26 has a force receiving surface 42
and a force delivering surface 44. The anvil 28 also has a force receiving
surface 46 and a force delivering surface 48.
[Para 41] If there is no current flowing through coil 34, hammer 26 is free to
slide back and forth along guiding member 40 subject only to the constraints
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imposed by the combination of structural member 30 and guiding member 32.
Current flowing through coil 34 generates a magnetic field which exerts a
force
on ring 36 causing hammer 26 and anvil 28 to assume an extended position,
i.e., the relative positions shown in FIG. 3.
[Para 42] In operation, a user places the force delivering surface 48 of the
anvil 28 against a patient's chest or back in the gentlest possible way and
coil
34 is energized by a series of current pulses. When the coil 34 is energized,
hammer 26 and anvil 28 will assume the extended position shown in FIG. 3 and
remain in that extended position for as long as the coil 34 is energized and
the
user does not apply a force to force-receiving surface 42 of the hammer 26.
[Para 43] Now assume that the user begins to apply a force (with their hand)
to force-receiving surface 42 of the hammer 26 while the coil 34 is energized
with a current pulse. Nothing happens because the magnetic force from the
energized coil 34 holding hammer 26 and anvil 28 in the extended position is
greater than the force applied by the user.
[Para 44] When the current pulse to the coil 34 ends, the magnetic force
holding the hammer 26 and anvil 28 in the extended position ends and any
opposition to the force applied by the user to the force receiving surface 42
of
the hammer 26 disappears. The force-delivering surface 44 of the hammer 26
.
then strikes the force-receiving surface 46 of the anvil 28 thereby delivering
a
considerably greater force to platen 38 than simply the force applied by the
user's hand alone. The force delivering surface 48 of the anvil 28 translates
the
impact from the hammer 26 against the anvil 28 to the patient's chest or back
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with which it is in contact. The process repeats with each current pulse
supplied to coil 34.
[Para 451 The work expended by the user is the product Fick, of the force Fi
applied by the user to the force receiving surface 42 of the hammer 26 and the
distance dr, traveled by the hammer 26 before striking the anvil 28. The
user's
work is converted into kinetic energy of the hammer 26. This kinetic energy is
dissipated when the hammer 26 strikes the anvil 28 and the anvil 28 depresses
the patient's flesh. The kinetic energy is converted into potential energy
associated with the depression of the patient's flesh and heat. The user's
work
is balanced by the work Fpdp expended by the patient's body which resists the
anvil 28 with a force Fp over a distance dp. Thus, the effective force applied
by
the anvil 28 to the patient's body is given by Fp = (dh/dp) Fi.
[Para 46] The ratio (dh/dp) of the distance traveled by the hammer (c1h) to
the
distance traveled by the patient's flesh (do) is typically greater than three
and
consequently the percussor 22 described herein typically has a force-
multiplying effect. For example, a user's force of 10 lbs is typically
experienced
as a force of 30 lbs or more by a patient.
[Para 47] A second embodiment of the percussor 22 is shown in FIGS. 4-6.
It also consists of a hammer 26 and an anvil 28. The design details for the
second embodiment are shown in the sectional views of FIGS. 5 and 6. The
hammer 26 consists of a plastic structural body 50 in which is embedded a core
52 made of a magnetic material such as iron. The anvil 28 consists of a
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body 54 in which is embedded coil 34 which surrounds core 52 when the
hammer 26 is inserted into the anvil 28.
[Para 48] As in the first embodiment, the hammer 26 has a force receiving
surface 42 and a force delivering surface 44, and the anvil 28 also has a
force
receiving surface 46 and a force delivering surface 48. If there is no current
flowing through the coil 34, the hammer 26 is free to slide back and forth
within the anvil 28 but limited in range by three pins (not shown) anchored
into
the curved wall of the anvil 28 and terminating in three vertical grooves (not
shown) spaced 120 degrees apart in hammer 26. When a current flows through
the coil 34 it generates a magnetic field which exerts a force on core 52
causing hammer 26 and anvil 28 to assume the positions shown in Fig. 5.
[Para 49] In operation, the percussor 22 is placed against the back or chest
of a patient with the force delivering surface 48 of the anvil 28 in contact
with
the patient's body. The user holds the percussor 22 in place by gripping the
force receiving surface 42 of the hammer 26 with one hand, palm on top, and
then turns on the power. As described above, the force continually applied by
the user to the force receiving surface 42 of the hammer 26 is converted into
repeated impacts of force on the patient's body through the force delivering
surface 48 of the anvil 28 as current impulses pass through the coil 34. Each
time the current impulse through the coil 34 is ceased, the force delivering
surface 44 of the hammer 26 impacts the force receiving surface 46 of the
anvil
28. Each such impact delivers the force through the anvil 28 to the force
delivering surface 48. The force associated with each impulse is significantly
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greater than the force being applied by the user to the force receiving
surface
42 of the hammer 26 on a continuing basis.
[Para 50] Let us again assume that a user places the percussor 22 against a
patient's back in the gentlest possible way and coil 34 is energized by a
series
of current pulses. Hammer 26 and anvil 28 will assume the positions shown in
FIG. 5 and remain in those positions for as long as the technician does not
apply a force to force-receiving surface 42. Again assume that the technician
begins to apply a force to force-receiving surface 42 while the coil 34 is
energized with a current pulse. Nothing happens because the magnetic force
holding hammer 26 and anvil 28 in the relative positions of FIG. 5 is
typically
greater than any force that can be manually applied by a user.
[Para 51] When the current pulse ends, the magnetic force opposing the
force applied by the user disappears and the force-delivering surface 44 of
the
hammer 26 strikes the force-receiving surface 46 of the anvil 28 as shown in
FIG. 6. The hammer 26 thereby delivers a considerably greater force to the
patient's back with which the anvil 28 it is in contact, as discussed above.
As
long as the user maintains a force on the hammer 26, the impacting process
repeats with each current pulse supplied to coil 34.
[Para 52] A schematic of the pulse generator required to drive the coil 34 is
shown in FIG. 7. It preferably operates with standard 120 V AC input power and
has means for controlling the frequency and amplitude, i.e., widths and rate
of
repetition, of the output pulses.
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[Para 53] The self-applicator 24 consists of two substantially co-extensive
straps having a pouch configured to accept and securely retain the percussor
22. FIGURES 8 through 10 illustrate the self-applicator 24 along with its
various components.
[Para 54] The self-applicator 24 has a pair of straps 56, 58 being
substantially co-extensive with one overlaying the other. The respective ends
of the straps 56a, 58a and 56b, 58b are stitched 60 together or joined by any
securing means know to those skilled in the art. One of the straps 56 is
preferably slightly longer that the other strap 58 such that when the ends of
the
first strap 56a, 56b are joined to'the ends of the second strap 58a, 58b,
there
is an open area 62 between the two straps 56, 58. Preferably, the stitching 60
or other securing means is applied a second time 60a for added securement.
[Para 55] A pouch 64 is disposed in the open area 62 between the straps 56,
58. The pouch 64 may be in the form of a U-shaped pocket having a bottom
66, upright sides 68a, 68b and an open top 70. The pouch 64 in configured
and designed to accept the percussor 22 through the open top 70 and securely
retain the percussor 22 therein. Front and back edges 72a, 72b of the pouch
64 are in contact with inside surfaces 56c, 58c of the straps 56, 58. At least
one of the front and back edges 72a, 72b are attached to the inside surfaces
56c, 58c so as to securely retain the pouch 64 in the open area 62.
Preferably,
both front and back edges 72a, 72b are attached to the inside surfaces 56c,
58c.
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[Para 561 The pouch 64 also includes a closure mechanism 74 designed to
cover the open top 70. The closure mechanism 74 preferably comprises a pair
of adjustable hook and loop straps 74a, 74b. The straps 74a, 74b preferably
have essentially their entire mating surfaces covered by hook and loop
material,
i.e., VELCRO , whereby the respective straps 74a, 74b can be adhered to each
other at any point along their length. The closure mechanism 74 can also
comprise snaps, buttons, a zipper, or other commonly known methods of
closure.
[Para 57] A pair of handles 76, 78 are secured to the respective ends
56a/58a, 56b/58b of the straps 56, 58. The ends 76a, 78a of the handles 76,
78 are preferably secured between the ends 56a/58a, 56b/58b of the straps
56, 58 when they are stitched 60 together. At least one of the straps 78
includes an adjustable length harness 80 so that the length of the handle 78
may be changed to accommodate users of different sizes. Each of the handles
76, 78 include respective grips 76b, 78b for a user 82 to grasp in each of
his/her hands 84.
[Para 58] The second strap 58 includes an applicator surface 58d that is
configured to contact the back 86 of a user 82 when the self-applicator system
20 is being applied. The application surface 58d is aligned with the inside
surface 58c at the point where the pouch 64 is disposed or secured. The
applicator surface 58d preferably comprises a soft, comfortable material that
will not irritate a user's skin and can easily and smoothly move during use.
The
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applicator surface 58d may even include padding to provide comfort to the
user.
[Para 591 The method of using the system 20 begins with arranging the self-
applicator 24 on a surface such that the pouch 64 is oriented with the open
top
70 pointing upwards. A user then inserts the percussor 22 into the open top
70 of the pouch 64. The percussor 22 is positioned in the pouch 64 such that
the anvil 28 on the percussor 22 is pointed toward the inside surface 58c of
the
second strap 58. The closure mechanism 74 is secured around the percussor
22 so as to securely retain the percussor 22 in the pouch 64 in a manner that
does not allow rotation, revolution or other similar movements during use.
[Para 601 If necessary, the user 82 can adjust the length of the adjustable
length harness 80 to make the system 20 more comfortable to use. The user
82 then grasps each of the handles 76, 78 in his or her hands 84 and self-
applies the application surface 58d to his/her back 86. As illustrated in
FIGS.
11 and 12, the self-applicator 24 spans the user's back 86 with the user's
hand
84 in front of his/her body, pulling the handles 76, 78 forward to apply force
to
the force receiving surface 42 of the hammer 26 and resultant pressure to the
back 86. The user 82 then turns on the percussor 22 with the results as
described above.
[Para 61] By moving ones hand 84 up/down and side/side, the user 82 can
self-apply the percussor 22 to almost any area of his/her back 86. By aligning
the anvil 28 of the percussor 22 with the application surface 58d, the user is
able to keep the anvil 28 in contact with the user's back 86 without the need
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for a treatment technician or the aid of any other person. The user can also
more easily self-apply the percussor 22 to those parts of his/her back 86 that
are most beneficial for the loosening or dislodging of bronchial secretions in
the lungs, rather than try and describe to another person where to apply the
percussor 22.
[Para 62] Except for the applicator surface 58d, described above, the self-
applicator 24 and its various components are made from a sturdy, durable
material such as nylon or similar polymer material. The goal in selecting a
material is to make sure that the self-applicator 24 is comfortable for the
user
while still being durable enough to withstand the stresses of self-application
and the movement of the percussor 22. The grips 76b, 78b preferably
comprise a soft, durable polymer material such as polyurethane, latex, or
similar materials, molded to form hand grips 76b, 78b.
[Para 63] FIGURES 13 through 18 illustrate a particularly preferred
embodiment of the percussor 90 of the present invention. From the outside,
the percussor 90 consists of a rear cover or hand hold 92, an anvil 94 and an
intervening thermal shell 96. Inside of the thermal shell 96 is a housing 98,
which encloses a solenoid 100. The solenoid 100 comprises an internal shell
102 containing a central shaft 104 upon which is mounted a plunger 106. The
plunger 106 may be shaped as a cylinder with recessed cavities at its upper
106a and lower 106b ends. The plunger 106 may also be presented in other
shapes so as to conform to adjacent parts as described below. The plunger
106 is made from magnetic material as the ring 36 or core 52 described above.
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A coil 108 surrounds the shaft 104 and plunger 106 and exerts magnetic forces
thereon when energized.
[Para 64] The bottom of the shell 102 contains a front wall 110 that includes
an upward extending base 112 that generally matches the shape of the recess
in the lower end 106b of the plunger 106. The front wall 110 also includes a
central opening 114 through which the shaft 104 extends. One end 104b of
the shaft 104 protrudes through the front wall 110 and is connected to the
anvil 94 by a screw 116 or similar securement mechanism. As the shaft 104
slides through the shell 102, the anvil 94 follows.
[Para 65] The top of the shell 102 contains a rear support bearing 118
secured thereto. The rear support bearing 118 has a lower surface that
generally conforms to the shape of the recess of the upper end 106a of the
plunger 106. The rear support bearing 118 also includes a central opening 120
through which the shaft 104 extends. The central opening 114 of the front wall
110 and the central opening 120 of the rear support bearing 118 cooperate to
keep the shaft 104 in straight line, oscillating movement through the shell
102.
[Para 66] The rear cover 92 provides a hand hold for a user to grasp the
percussor 90. In the terms of the previously described embodiment, the upper
surface of the rear cover 92 provides a force receiving surface 122 of the
hammer 124. The force delivering surface 126 of the hammer 124 is located at
the bottom of the housing 98. The anvil 94 includes a force receiving surface
128 that receive impacts from the force delivering surface 126 of the hammer
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124. The anvil 94 also includes a force delivering surface 130. These surfaces
122, 126, 128 and 130 interact as described above in the earlier embodiment.
[Para 67] As shown in FIG. 16a, the front wall 110 includes set screw
openings 132 around its perimeter. These set screw openings 132 are
configured to receive set screws through the wall of the shell 102 so as to
secure the front wall 110 thereto. The upper surface of the upward extending
base 112 includes bumpers 134. The bumpers 134 are configured to cushion
the impact between the plunger 106 and the base 112 when the coil 108 is
energized. This cushioning is only intended to make the impact less jarring or
noise generating - it does not lessen the force of any impact.
[Para 681 The thermal shell 96 is configured to insulate the user against heat
generating by the oscillations of the solenoid 100 when the percussor 90 is in
use. The thermal shell 96 provides an air gap 136 between the thermal shell 96
and the housing 98. In addition, the rear cover 92 houses the pulse generator
138 as discussed above, as well as a cooling fan 140. The pulse generator 138
is connected to the coil 108. As the pulse generator 138 energizes the coil
108, electricity is also supplied to the cooling fan 140, which draws air
through
the housing 98 and out the exhaust vents 142 to provide additional cooling.
[Para 69] The percussor 90 of this alternate embodiment may also be used
with the self-applicator 24. The percussor 90 may fit within the pouch 64 as
described above.
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