U.S. patent number 3,636,945 [Application Number 05/040,953] was granted by the patent office on 1972-01-25 for electrical massage instrument.
This patent grant is currently assigned to Hoshidenki-Seizo Kabushiki-Kaisha, Matsushita Electric Works, Ltd.. Invention is credited to Sanro Sato.
United States Patent |
3,636,945 |
Sato |
January 25, 1972 |
ELECTRICAL MASSAGE INSTRUMENT
Abstract
An electrical massage instrument is provided which comprises a
main body, 8-shaped in section, having connected at its opposite
ends a pair of flexible strings each tying a plurality of spherical
members in a row. The main body houses an electrically energized
source of vibration such as an electric motor having eccentric
weights mounted on the motor shaft. One of the tying strings
include lead wires for supplying electric power to the source. The
free ends of the tying strings are attached with grip members.
Inventors: |
Sato; Sanro (Yao,
JA) |
Assignee: |
Matsushita Electric Works, Ltd.
(Osaka-hu, JA)
Hoshidenki-Seizo Kabushiki-Kaisha (Osaka-hu,
JA)
|
Family
ID: |
26399327 |
Appl.
No.: |
05/040,953 |
Filed: |
May 27, 1970 |
Foreign Application Priority Data
|
|
|
|
|
Jun 19, 1969 [JA] |
|
|
44/58273 |
Nov 1, 1969 [JA] |
|
|
44/103924 |
|
Current U.S.
Class: |
601/71; 601/132;
601/144 |
Current CPC
Class: |
A61H
23/0263 (20130101); A61H 2015/0007 (20130101); A61H
2015/0071 (20130101); A61H 2023/0281 (20130101) |
Current International
Class: |
A61H
23/02 (20060101); A61H 15/00 (20060101); A61h
001/00 () |
Field of
Search: |
;128/24.3,36,57,58 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Trapp; L. W.
Claims
What is claimed is:
1. An electrical massage instrument comprising a main body having a
hollow space, a pair of flexible strings connected at one end with
the opposite ends of the main body and each tying a plurality of
spherical members in a row, a pair of grip members connected with
the free end of each tying string, a source of vibration housed
within the space of the main body and adapted to produce mechanical
vibrations upon energization with electric power, and lead wire
means extending through at least one of the tying strings and
electrically connected with the source of vibration for supplying
electric power thereto.
2. An electrical massage instrument according to claim 1, further
including switch means mounted on one of the grip members which is
connected with the lead wire means electrically connected with the
source of vibration for controlling the supply of electric power
thereto, and a power supply cord taken out of said one grip
member.
3. An electrical massage instrument according to claim 2 in which
said switch means includes means for turning the supply of power on
and off, and means to vary the level of power supplied.
4. An electrical massage instrument according to claim 1 in which
the source of vibration comprises an electric motor and an weight
mounted on the motor shaft.
5. An electrical massage instrument according to claim 4 in which
the motor includes a cooling fan mounted on the motor shaft and
said weight is located eccentrically of the fan.
6. An electrical massage instrument according to claim 4 in which a
pair of weights are mounted on the opposite ends of the motor shaft
at substantially the same angular position with respect
thereto.
7. An electrical massage instrument according to claim 1, further
including a pair of retention means carried on the tying strings at
the opposite outer extremities of the series of the spherical
members, and urging means for urging the retention means towards
the main body.
8. An electrical massage instrument according to claim 7 in which
the urging means is located within each retention means and
comprises a coiled spring wound around the tying string, and an
auxiliary string extending through the spherical members and
engaging with the end of the coiled spring nearer the associated
grip member at one end and with the main body at the other.
9. An electrical massage instrument according to claim 7 in which
the retention means is in the form of a sleeve through which the
associated tying string extends, the end of the sleeve nearer the
grip member being formed with a flange.
10. An electrical massage instrument according to claim 1, further
including a plurality of buffering rings interposed between
adjacent elements on the tying strings.
11. An electrical massage instrument according to claim 1, in which
the length of the instrument between the both grip members when the
strings are pulled straight is shorter than the distance between
the extremities of both hands of an average man opening the arms,
but is greater than the breadth of the shoulders.
12. An electrical massage instrument according to claim 1 in which
each of the tying strings is connected with an intermediate portion
of the associated grip member at right angles thereto.
13. An electrical massage instrument according to claim 1 in which
the main body has a transverse dimension which is greater than the
diameter of any spherical member, and the spherical members have
decreasing diameters as they are located further away from the main
body.
14. An electrical massage instrument according to claim 1, in which
the main body is provided with a spongelike, elastic cushioning
layer at a portion thereof designed for contact with the human
body.
15. An electrical massage instrument according to claim 1, in which
the main body is substantially 8-shaped in section.
16. An electrical massage instrument according to claim 15 in which
the separation between two sphere portions of the main body is
chosen nearly equal to the distance between muscular tissues
extending vertically on the opposite sides of the spinal column of
the human body.
17. An electrical massage instrument according to claim 1 in which
each of the tying strings comprises a plurality of yarns of
polyester resin, a greater number of cotton yarns, and a coating
layer of flexible synthetic resin which surrounds the both yarns.
Description
The invention relates to an electrical massage instrument which is
adapted to be energized with electric power to produce mechanical
vibrations.
The prior art electrical massage instrument has been of such
construction that a user holds the grip of the instrument with one
hand to apply the vibrating body to which the grip is attached onto
part of a human body, for example, shoulder, to be massaged, where
it is desired to apply the instrument to the back of a human body
and to move thereacross, the user could not operate it himself, but
needed another's help. Even when the shoulder is to be massaged,
the instrument has to be held in place against the shoulder, by the
user's continued effort, causing undesirable fatigue of the hand
strained. To provide the massaging of the back conveniently, there
has been a proposal to mount a mechanical vibrator on the lazy back
of a chair. However, the resulting apparatus becomes large-sized,
requiring a wide space for its installation, accompanies handling
inconveniences and is expensive.
Therefore, it is an object of the invention to provide a compact
and easily operable electrical massage instrument.
It is another object of the invention to provide an electrical
massage instrument capable of being manipulated by a user himself
all over the human body.
It is a further object of the invention to provide an efficient
electrical massage instrument.
It is still another object of the invention to provide an
electrical massage instrument which is adapted to conform well or
adjusts itself to the human body.
It is a still further object of the invention to provide an
electrical massage instrument which can be applied to both the back
and one arm of the human body.
It is yet another object of the invention to provide an electrical
massage instrument having a control to adjust the intensity of the
massaging.
It is an yet further object of the invention to provide a rigid and
durable electrical massage instrument.
In accordance with the invention, the electrical massage instrument
comprises a main body and a plurality of spherical members which
are tied in a row on opposite sides of the main body by means of a
pair of strings which are each connected at one end to the opposite
ends of the main body. The free end of each string is attached to a
grip member. The main body houses a source of vibration which is
energized with electric power to produce mechanical vibrations, and
lead wires extend through one of the strings to be connected with
the source for power supply.
The length of the strings as measured between their attached grip
members is shorter than a fathom or the distance between the
extremities of both hands of an average man when opening his arms,
but is greater than the breadth of the shoulders, so that it is a
simple matter for a user, holding the grip members with both hands,
to apply the main body against his back. The main body is
substantially 8-shaped in section, with the axial separation
between the two circles being chosen nearly equal to the distance
between the muscular tissues which run vertically on opposite sides
of the spinal column. The spherical members have gradually
decreasing diameters as they are spaced further away from the main
body, thereby rendering the whole spherical members more conforming
to the human body or part thereof where the instrument is
applied.
The drive source may comprise a small motor, for example, with an
eccentric weight or weights attached to the motor shaft. The weight
or weights may be mounted on a part of a cooling fan. Where the
weights are mounted on the opposite ends of the motor shaft, they
are located at an identical angular position with respect to the
motor shaft.
The strings for tying the spherical members in rows must be
sufficiently flexible and capable of withstanding high tensions. A
string capable of withstanding the tension of 100 kilograms and
100,000 times of bending can be obtained, for example, by using
several yarns of a polyester resin and a greater number of cotton
yarns together with a coating layer of a suitable synthetic resin
such as vinyl resin which encloses the both yarns as well as the
lead wires extending to the source of vibration.
The spherical members are resiliently urged towards the main body
so that the string can be flexible without causing their movement
along the string. At this end, there is provided at each outer
extremity of the series of spherical members a retention means in
the form of a sleeve through which the string extends.
Loosely wound around each string within the retention means is a
coiled spring, of which end nearer the grip member is engaged by
one end of an auxiliary string which extends through the series of
spherical members to be secured to the main body at its other end.
In this way, the retention means and also the spherical members are
urged by the coiled spring towards the main body.
Interposed between the main body and adjacent spherical members,
between successive spherical members as well as between the
outermost spherical members and associated retention means are
buffer rings which reduce the collision between any adjacent
members. The main body carries a buffer layer formed of, for
example, polyethylene foam at its part preselected for contact with
the human body.
The grip member at each end of the instrument is generally T-shaped
in section, through the vertical bar of which extends the string to
be anchored therein, the T-shape providing means for preventing
slippage of a hand on the grip when the grips are held by both
hands and pulled apart.
Similar means is provided in the form of a flange at the end of the
retention means nearer the grip member so that these retention
means may be gripped by both hands to use the instrument with a
reduced length for massaging the neck, for example.
One of the grip members is provided with a control switch at one
end of the horizontal bar of the T-shape, and to the other end is
connected an electric supply cord. The switch controls on-off and
the power level of the source of vibration contained within the
main body. This may be achieved by having several positions of the
switch in which the source is connected through either a full-wave
or half-wave rectifier to the commercial supply or by connecting a
resistor in the current path to the source. The power level may, if
desired, be controlled continuously by means of an adjustable
resistor.
With the electrical massage instrument mentioned above, it is
possible to massage any part of the human body, by holding either
the grip members, the retention means or the main body directly.
Nevertheless the instrument is compact as a whole and can be stored
in a relatively small space by bending or folding the flexible
string.
Further features and details of the invention will become apparent
from the following description with reference to the drawings, in
which:
FIG. 1 is a plan view of the electrical massage instrument
according to the invention,
FIG. 2 is a longitudinal section of the main body,
FIG. 3 is a longitudinal section in a plane at right angles to the
plane of FIG. 2,
FIG. 4 is a cross section along the line A--A shown in FIG. 3,
FIG. 5 is a section showing one of the grip members and its linkage
with the main body,
FIG. 6 is a section showing the other grip member and its linkage
with the main body,
FIG. 7 is a perspective view showing one end of the string, and
FIG. 8 is a wiring diagram of the electrical circuit.
Referring to the drawings, the electrical massage instrument shown
comprises a main body 1 formed of synthetic resin or hard rubber.
In the example shown, the body 1 is 8-shaped in section along an
axis, and has a hollow cylindrical inner space 3 which is defined
by a pair of opposite semispherical parts 4 and 5 and an
intermediate part 6, these parts being secured by a plurality of
bolts 7 which extend from the part 5 to the part 4 through the
space 3 adjacent the part 6 and are clamped in place by nuts 8.
Buffering materials 9 and 10 which may comprise rubber rings may be
interposed between the part 6 on one hand and the parts 4 and 5,
respectively, on the other to provide antivibration effect. In the
end face of each semispherical part 4 or 5 is formed an annular
groove 11 or 12, respectively, which is concentric with the axis.
It is within the bottom of these annular grooves 11 and 12 that the
buffering material 9 and 10 are fitted, and the intermediate part 6
has its opposite end portions 13 and 14 of reduced thickness
engaged with the annular grooves 11 and 12, respectively. The end
faces of the end portions resiliently bear against the buffering
materials 9 and 10. The main body 1 is formed with a pair of
axially spaced, annular grooves 15 and 16 in coaxial relationship
with the axis in the regions of its two spheres. In the grooves 15
and 16 are mounted elastic cushioning layers 17 and 18,
respectively, each of which may comprise a layer of polyethylene
foam 19 and its surrounding vinyl cover 20.
These cushioning layers project slightly beyond the outer periphery
of the main body 1 for direct contact with the human body. The
distance (l.sub.1) between the both cushioning layers 17 and 18 is
nearly equal to the separation between the muscular tissues on
opposite sides of the spinal column of an average man, and
typically measures 57 mm. for a main body 1 having the axial length
(l.sub.2) of about 130 mm.
Coaxially mounted within the inner space 3 of the main body 1 is an
electric motor 21 which serves as the source of vibration. As shown
in FIGS. 3 and 4, the motor 21 is provided with a plurality of
projections 22 on the outer periphery of its one end, each
projection 22 having a threaded hole formed therein. The main body
1 integrally carries a plurality of inward projections 23 in
alignment with the projections 22 on the motor 21. Each projection
23 of the main body has a through hole, and a set screw 24 inserted
through the hole in each projection 23 threadably engages the
threaded hole in the projection 22 of the motor 21 for securing the
motor 21 to the main body 1. A buffering piece 25 is interposed
each pair of projections 22 and 23. To stabilize the mounting of
the motor 21, a plurality of elastomers 26 are arranged at a
suitable interval circumferentially around the opposite end of the
motor 21 so as to be interposed between the outer periphery of the
motor 21 and the inner periphery of the main body 1.
Referring to FIGS. 2 and 4, it will be seen that a pair of cooling
fans 27 and 28 are mounted on the opposite ends of the motor shaft.
These fans function as weights at the same time, and are
constructed substantially in the form of discs such that one-half
of the disc comprises iron or lead of substantial thickness to
thereby provide a weight 29, while the other half comprises a
plurality of segmental blades 30 which are arranged equiangularly
and at a given angle with respect to the plane which is
perpendicular to the axis. These blades 30 are formed so that upon
rotation of the motor shaft, one of the fans 27 draws air into the
motor 21 from outside the main body 1 and the other 28 withdraws
air from the interior of the motor 21 for discharge externally. At
this end, each of the semispherical parts 4 and 5 of the main body
1 is formed with a plurality of small apertures 31, 32,
respectively, for the passage of air.
A pair of strings 33 and 34 have their one end attached to the
opposite ends of the main body 1, as by making knots 33a and 34a,
at said one end, of a size greater than the diameter of holes 35
and 36 which are formed in the semispherical parts 4 and 5 in
alignment with the axis, thereby preventing the withdrawal or
disengagement of the strings from the main body 1. In order to
prevent the knots 33a and 34a from contact with the weights and
fans 27 and 28 to interfere with the rotation thereof, partition
plates 37 and 38 are located within the main body 1 between the
weights and fans 27 and 28 and the knots 33a and 34a, respectively.
The partition plates 37 and 38 are held sandwiched between the
opposite end faces of the intermediate part 6 and the semispherical
parts 4 and 5, respectively, and are formed with small holes 39 for
allowing the air to pass therethrough.
The strings 33 and 34 have the same construction. In an example
shown in FIG. 7, a string comprises a pair of parallel lead wires
40 and 41, each including 36 copper wires of 0.08 mm. in diameter
twisted together, separated by a pair of groups of tough yarns of
polyester resin such as tetron (trademark), each group including 10
such yarns, and a bundle of, say, 200 cotton yarns 44 enclosing the
lead wires and the strands therein and surrounded by a coating
layer 45 of a flexible synthetic resin, for example, a pipe formed
of vinyl chloride. The string thus formed may have a thickness on
the order of 8 mm., and withstand the tension of 100 kilograms and
100,000 times of bending.
Returning to FIG. 2, the lead wires 40 and 41 within one of the
strings, 34, are electrically connected with the terminals 46 and
47 of the motor 21. In order to provide such connection, one end
portion having a reduced thickness of the intermediate part 6 is
provided with contact pieces 48a and 49a, respectively, with which
the motor terminals 46 and 47 are connected by means of
through-type capacitors 50 and 51, respectively. Mating contact
pieces 48b and 49b are nestedly received within the annular groove
12 of the semispherical part 5 at positions corresponding to the
contact pieces 48a and 49a. The contact pieces 48b and 49b are
directly connected with the lead wires 40 and 41, respectively. The
arrangement is such that upon assembling the semispherical parts 4
and 5 and the intermediate part 6 together, an electrical
connection is automatically made between the contact pieces 48a,
49a and the contact pieces 48b, 49b, respectively, so that the lead
wires 40 and 41 are electrically connected with the motor terminals
46 and 47, respectively.
Each of the strings 33 and 34 serves tying a plurality of spherical
members in a row. Thus, the string 33 ties spherical members 52, 53
and 54 and retention means 55 in a row, in the sequence named from
inside towards the outside. The other string 34 similarly ties
spherical members 56, 57 and 58 and retention means 59 in a row
successively. These spherical members may be formed of similar
material as the main body, such as synthetic resin, hard rubber or
the like, and are made hollow and shaped to be substantially
precise spheres of decreasing diameters as they are located further
away from the main body 1. In addition, diametrically aligned holes
are formed in each spherical member so that the string can extend
therethrough. In the example shown, the main body 1 has the maximum
transverse dimension or diameter of 62 mm., and the spherical
members 52 and 56, 53 and 57, and 54 and 58 have the diameters of
50 mm., 40 mm. and 32 mm., respectively.
Annular members 60 which may comprise vinyl resin, for example, are
interposed between the main body and the adjacent spherical members
and between successive spherical members as well as between the
outermost spherical members and the retention means. These annular
members 60 serve as buffering material, not only diminishing the
collision between any adjacent elements, but also preventing
damages to the strings 33 and 34 caused by the edges of holes in
the spherical members upon bending these strings in use.
Furthermore, they extend partly into adjacent elements so that the
string portions between them can be hidden from view. These effects
are achieved by having the form of the annular member 60 shown
which comprises a short cylinder 61 having an outer flange 62
intermediate its ends.
The retention means 55 and 59 are shaped for gripping convenience,
and in the present example are in the form of a sleeve through
which the string extends. The end of the sleeve remote from the
main body 1 is peripherally formed with an integral, outwardly
extending flange 63 or 64, which prevents slippage of hand out of
the retention means when both of the retention means 55 and 59 are
held by hands and pulled apart. In the example shown, the retention
means 55 or 59 has an outer diameter of 24 mm.
Loosely wound around the strings 33 and 34 within the respective
retention means 55 and 59 are coiled springs 65 and 66,
respectively, the inner ends of which or the ends nearer the main
body 1, abut against shoulders 67 and 68, respectively, which are
formed on the inner periphery of the sleeves 55 and 59,
respectively. The other end of the coiled spring 65 or 66 is
engaged by an auxiliary string 69 or 70, respectively. These
auxiliary strings 69 and 70 extend through the respective coiled
springs 65 and 66 along with the tying strings 33 and 34 and extend
through the spherical members into the main body 1 to be tied with
the knots 33a and 34a of the tying strings 33 and 34, respectively.
The auxiliary strings 69 and 70 compress their associated springs
65 and 66, respectively, thereby causing the retention means 55 and
59 to resiliently urge the spherical members towards the main
body.
Attached to the free ends of the tying strings 33 and 34 are grip
members 71 and 72, respectively, which are generally in the form of
hollow cylinders each having a guide tube 73 or 74 integrally
formed therewith so as to extend at right angles thereto from a
position intermediate the ends thereof. The tying strings 33 and 34
are passed through the guide tubes 73 and 74, respectively, to the
interior of the grip members 71 and 72 in which their ends make
knots 33b and 34b of a size greater than the inner diameter of the
guide tubes 73 and 74. The grip members 71 and 72 each comprise two
portions axially, that is, a semicylindrical portion 71a or 72a
having the guide tube 73 or 74 respectively, and a semicylindrical
portion 71b or 72b, these semicylindrical portions being secured
together by means of threaded bolts 75. At this end,
semicylindrical portions 71a and 72a or 71b and 72b of each pair
are formed with aligned bosses 76 and 77. One of the bosses, 76, is
formed an axially extending bore through which the bolt 7 is
inserted and engages a threaded bore formed in the other
semicylindrical portion 77 for clamping the portions 76 and 77
together.
The length of the instrument including the both strings and the
main body, as measured between the grip members 71 and 72, is
chosen shorter than the distance between the extremities of hands
of an average man, when spread out, but greater than the breadth of
the shoulders. Typically the length may be 120 cm. One of the grip
members, 72, to which the string 34 including the lead wires 40 and
41 connected to the motor 21 is fastened is provided with a switch
78 at one end, and from the other end of the grip member 72 is
taken out a power supply cord 79 having an attachment plug 80 at
its free end.
In the example shown, the switch 78 is of pushbutton-type and is
mounted substantially coaxially with the axis of the grip member 72
between an end plate 81 and its adjacent bosses 76 and 77. The
switch 78 has an actuator button 82 which extends externally of the
end plate 81 through a central hole therein, and a large diameter
portion 78a of the switch housing is snapped in the space defined
between a flange 83 and a projection 84, both formed on the inner
wall of the housing, thereby holding the switch 78 in place within
the grip member 72.
The switch 78 is constructed so that each time the actuator button
82 is pushed, a movable contact 85m is repeatedly moved into
contact with stationary contacts 85a, 85b and 85c in turn, as is
shown in the electrical wiring diagram of FIG. 8. As shown, the
switch 78 is electrically connected with the power supply cord 79
and the motor 21. Thus the movable contact 85m is connected with a
lead wire 79a which constitutes the cord 79 together with another
lead wire 79b. The stationary contact 85a remains without
electrical connection, which represents the off-position of the
switch. The stationary contact 85b represents a low level position
in which the lead wire 79a is connected with one of the input
terminals of a full ware rectifier circuit 88, through a diode 86
and a protective resistor 87. The circuit 88 comprises four diodes
connected in a bridge configuration, and the other input terminal
is connected with the lead wire 79b directly. The stationary
contact 85c represents a high-level position and is connected with
a junction between the diode 86 and the resistor 87. The output
terminals of the rectifier circuit 88 are connected with the lead
wires 40 and 41, respectively, through choke coils 89 and 90 which
suppress brush noises. Numeral 91 denotes a capacitor connected
across the input terminals of the rectifier circuit 88 for
minimizing the noise interferences. The lead wires 79a and 79b of
the cord 79 may be connected with the commercial supply line by
means of the plug 80.
When the movable contact 85m of the switch 78 is in its
off-position or connected with the stationary contact 85a, the
motor 21 is not fed with electric power and hence remains still.
With the movable contact 85m connected with the contact 85b, the
power is fed from the commercial supply line through the diode 86
and the circuit 88 to the motor 21. It is to be noted that at this
time, the circuit 88 functions as a half-wave rectifier owing to
the presence of the diode 86 in the supply path, so that the motor
21 rotates at a relatively low speed. However, when the movable
contact 85m is connected with the contact 85c, a full-wave
rectified output is supplied to the motor 21, which therefore
rotates at a higher speed.
Referring to FIG. 6, the full-wave rectifier circuit 88 including
the capacitor 91 is mounted on a common wiring substrate 93, which
is formed with a central hole, the periphery of the this hole being
clamped between those bosses 76 and 77 which are positioned away
from the switch 78, upon assembling the grip member 72, thereby
holding the substrate 93 in place within the grip member 72. The
diode 86 is secured to the terminals of the switch 78 directly, the
protective resistor 87 is located as extending between the switch
78 and the substrate 93, and the choke coils 89 and 90 are arranged
on opposite sides of the bosses 76 and 77 which serve to secure the
substrate 93. The cord 79 is admitted into the grip member 72
through a hole in the end plate that is opposite to the switch 78,
the cord 79 being protected in this region by a coiled spring 94 as
is conventional.
In use, the grip members 71 and 72 of the electrical massage
instrument are held by both hands after the plug 80 has been
inserted into a receptacle, and the main body 1 is applied to the
body part to be massaged, for example, to the back. By operating
the pushbutton 82 of the switch 78, the motor 21 is rotated,
whereupon the weights 27 and 28 which are eccentrically mounted on
the motor shaft rotate to produce vibrations which are transmitted
to the body part through the cushioning layers 17 and 18. The
switch 78 can be operated to control the intensity of the
vibrations imparted through the main body 1, or to interrupt the
operation of the instrument.
The main body 1 can also be carried across the shoulder with the
saddle portion between the two spherical parts thereof located on
the shoulder. By pulling the grip members 71 and 72 downwardly, a
strong massaging effect is provided. Similarly, the main body 1 may
be applied around the neck. When it is desired to massage a thigh,
the retention means 55 and 59 can be held by both hands to apply
the main body 1 against the thigh and the switch operated.
Massaging an arm is also possible by holding the main body 1
directly with the other hand to apply the saddle portion of the
main body 1 around said arm.
In this way, the electrical massage instrument of the invention can
be operated by a user himself to massage every part of his body,
without requiring another's help, and the switch operation can be
made while holding the grip members 71 and 72. It will be
appreciated that as compared with the prior art massage unit which
is held by one hand, the massaging effect given by the instrument
of the invention is more powerful while avoiding the fatigue of the
strained hand. In addition, the whole construction is compact,
without the need for a large-sized chair.
Because of the 8-shaped construction of the main body 1, when it is
applied to the back, the two sphere portions can bear against the
muscular tissues on opposite sides of the spinal column
simultaneously. Decreasing diameters of the spherical members away
from the main body permit good conformability of the instrument to
the profile of the human body. Where the instrument is applied to a
broad area such as the back, the vibrations of the main body 1 are
also transmitted through adjacent spherical members. The vibrations
from the main body 1 are transmitted in a direction perpendicular
to the surface of contact with the human body, but if the grip
members 71 and 72 are moved along said surface either vertically or
transversely while keeping the strings 33 and 34 tensioned, the
massaging effect is improved by addition of frictional
massaging.
During the use, the tying strings may be bent sharply as required
by forcing the spherical members to conform to the body part where
the main body 1 is applied, thereby forcing the spherical members
apart against the urging force of the coiled springs 65 and 66 so
that the spacing between adjacent elements is greater on the
outside of the curvature than on the inside thereof. The T-shaped
construction of the grip members 71 and 72 facilitates the handling
in that they act as stops for the hands when pulling the tying
strings outwardly. It will be seen that depending upon the body
part to be massaged, the grip members 71 and 72 or the retention
means 55 and 59 may be held by hands to use the instrument with an
increased or short length, respectively, or the main body 1 may be
directly held by hand or hands.
In the above arrangement, mounting the both weights 27 and 28 at
the same angular position with respect to the motor shaft is
effective to provide powerful vibrations. By constructing these
weights 27 and 28 integrally with the cooling fans, the overall
size can be reduced. While in the above description, the source of
vibration comprises an electric motor associated with weights, it
may comprise an electromagnet to produce vibrations. Furthermore,
the auxiliary strings 57 and 58 may be tubular so as to enclose the
tying strings therein.
* * * * *