U.S. patent number 3,640,272 [Application Number 04/844,581] was granted by the patent office on 1972-02-08 for therapy table.
This patent grant is currently assigned to Pete J. Bonin. Invention is credited to Joseph L. Hussey.
United States Patent |
3,640,272 |
Hussey |
February 8, 1972 |
THERAPY TABLE
Abstract
A therapy table for massaging the spinal column of a patient
while the person is under traction applied to the cranial and pedal
extremities. Identical and therefore interchangeable movable
carriages are provided for connection to those body extremities.
The carriages are separately provided with identical locomotion
means for positively moving them to and fro longitudinally of the
table, supplemented by means for controlling and limiting and
cyclically varying the traction forces applied. Intermediate its
ends the table is provided with still another carriage having
locomotion means for moving it to and fro longitudinally of the
table. This carriage has a vibratory support for rollers that may
be brought with variable pressure against the back of a patient
lying supine on the table, for massaging the spinal area.
Inventors: |
Hussey; Joseph L. (Costa Mesa,
CA) |
Assignee: |
Bonin; Pete J. (Newport Beach,
CA)
|
Family
ID: |
25293126 |
Appl.
No.: |
04/844,581 |
Filed: |
July 24, 1969 |
Current U.S.
Class: |
601/99;
601/116 |
Current CPC
Class: |
A61H
1/0222 (20130101); A61H 15/00 (20130101) |
Current International
Class: |
A61H
1/02 (20060101); A61H 15/00 (20060101); A61h
011/00 () |
Field of
Search: |
;128/33,70,71,57,24.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Trapp; L. W.
Claims
What is claimed is:
1. Apparatus for applying multidirectional therapeutic traction to
the human body which comprises:
a table for supporting a human body in an outstretched
position;
rails extending longitudinally of the table beneath the body
supporting surface thereof;
at least two carriages supported by the rails for to-and-fro
movement longitudinally of the table;
means for connecting the two carriages to the extremities of the
body;
means for imparting movement to the carriages in opposite
directions to apply tensioning forces to the body, and
progressively reactive means on each carriage adapted to react to
changing amounts of tensioning forces and effective upon reacting
to a predetermined extent to cause arrestment of its carriage.
2. Apparatus in accordance with claim 1 in which the progressively
reactive means comprises;
a movable element biased in opposition to reactive response to
increasing tensioning force applied to the body, and
a stop for limiting the movement of the movable element.
3. Apparatus in accordance with claim 2 including means operable
incident to engagement of the movable element with the stop for
disabling the carriage movement imparting means and thereby
limiting the amount of traction applied to the body.
4. Apparatus in accordance with claim 1 in which the progressively
reactive means comprises:
a movable element biased in opposition to reactive response to
increasing tensioning force applied to the body and having a
predetermined rest position upon the carriage in the absence of a
tensioned connection to the body, and
an adjustable stop affording selectively variable extents of
movement of the movable element from its rest position to cause
arrestment of the carriage upon engagement of the movable element
with the adjustable stop and thereby to limit to selectively
predetermined amounts the traction applied to the body.
5. Apparatus in accordance with claim 4 in which the means for
imparting movement to the carriages includes facilities for
positively moving the carriages in both directions of their
to-and-fro movement, and in which the progressively reactive means
further comprises:
a second stop for determining the rest position of the movable
element, and
means operable incident to movement of the movable member into
engagement with the second stop for disabling the carriage movement
imparting means.
6. Apparatus for applying therapeutic treatment to the human body
which comprises:
a table for supporting a human body in a supine position;
rail members extending longitudinally of the table beneath the
body-supporting surface thereof;
a wheeled body treatment carriage supported by the rail members for
to and fro movement longitudinally of the table;
a rotatable member supported by the carriage with its axis
extending transversely to the carriage;
means for imparting rotation to the rotatable member in either
direction, and
an elongated flexible member having a plurality of turns around and
in engagement with the rotatable member and having its ends secured
to structural elements of the table at points spaced from one
another longitudinally of the table whereby rotation of the
rotatable member in engagement with the flexible member causes
movement of the carriage along the supporting rails.
7. Apparatus in accordance with claim 6 in which the flexible
member extends in opposite directions from the point of engagement
with the rotatable member to its secured ends.
8. Apparatus in accordance with claim 6 in which the flexible
member is secured at at least one point on its length to the
rotatable member and has a sufficient number of turns around the
rotatable member to accommodate to and fro travel of the carriage
along the rails for the intended operational distance.
9. Apparatus in accordance with claim 6 in which the flexible
member is a cord.
10. Apparatus in accordance with claim 6 including means yieldably
engaging the flexible means between one of its ends and the
rotatable member for variably offsetting that portion of the
flexible member from conformity to a direct path and for thereby
diminishing the extent of movement of the carriage relative to the
amount of peripheral motion of the rotatable member in engagement
with flexible member during rotation of the rotatable member.
11. Apparatus in accordance with claim 10 including means
associated with the yieldably engaging means for resisting
diminution in the amount of the offset in the path of the flexible
member.
12. Apparatus in accordance with claim 11 in which the resisting
means comprises a spring biasing the yieldably engaging means in a
direction of increase in the amount of the offset.
13. Apparatus in accordance with claim 10 including adjustable
means for limiting the extent of movement of the yieldably engaging
means in the direction of dimunition in the amount of the offset in
the path of the flexible member.
14. Apparatus in accordance with claim 13 in which the yieldingly
engageable means is a pivotally mounted member supporting at a
distance from its pivot a rotatable member engaging the flexible
member and the adjustable limiting means is a rotatably mounted
eccentric disposed in the path of pivotal movement of the
yieldingly engageable means.
15. Apparatus in accordance with claim 14 including means operable
jointly by the pivotally mounted means and the adjustable limiting
means to suspend operation of the rotation imparting means.
16. Apparatus in accordance with claim 15 including timing means
operable upon timing a predetermined interval to reactivate the
rotation imparting means in the direction of enlargement of the
amount of the offset in the path of the flexible member.
17. Apparatus in accordance with claim 14 including a fixed
limiting means on the opposite side of the pivotally mounted member
from the adjustable limiting means for limiting movement of the
pivotally mounted member in the direction of enlargement of the
amount of the offset in the path of the flexible member.
18. Apparatus in accordance with claim 17 including means operable
conjointly by the pivotally mounted member and the fixed limiting
means to suspend operation of the rotation imparting means.
19. Apparatus in accordance with claim 18 including timing means
operable upon timing a predetermined interval for reactivating the
rotation imparting means in the direction of diminution of the
amount of the offset in the path of the flexible member.
20. Apparatus in accordance with claim 17 including oscillatory
timing means for activating the rotation imparting means to move
the carriage in either direction a predetermined interval after the
activation of the rotation imparting means to move the carriage in
the other direction.
21. Apparatus in accordance with claim 20 including master timing
means operable upon timing a predetermined interval for
deactivating the oscillatory timing means and thereby causing
cessation of the to-and-fro movement of the carriage.
22. Apparatus in accordance with claim 20 in which the oscillatory
timing means is a multivibrator having one of its output terminals
connected to cause activation of the rotation imparting means to
move the carriage in one direction and having its other output
terminal connected to cause activation of the rotation imparting
means to move the carriage in the other direction.
23. Apparatus in accordance with claim 22 including adjustable
means associated with the multivibrator for independently setting
the duration of each of the alternate half-cycles of the
multivibrator within a predetermined range of durations.
24. Apparatus in accordance with claim 22 including selectively
operable means for causing activation of the rotation imparting
means in the direction to apply a tensioning force to the human
body and for overriding operational control of the rotation
imparting means by the multivibrator.
25. Apparatus in accordance with claim 18 including a second
carriage duplicating the other carriage.
26. Apparatus in accordance with claim 25 including an elongated
flexible member having a plurality of turns around and in
engagement with the rotatable member of the second carriage and
having its ends secured to structural elements of the table at
points spaced from one another longitudinally of the table.
27. Apparatus in accordance with claim 25 including oscillatory
timing means common to the two carriages for activating the
rotation imparting means of one carriage to move that carriage in
either direction a predetermined interval after the actuation of
its rotation imparting means to move it in the other direction, and
for activating the rotation imparting means of the other carriage
to cause simultaneously initiated movements of said other carriage
in directions opposite to those of said one carriage.
28. Apparatus in accordance with claim 27 including selectively
operable means individual to each of the two carriages for causing
activation of the rotation imparting means of the carriage in the
direction to apply a tensioning force to the human body and for
overriding operational control of the rotation imparting means of
that carriage by the oscillatory timing means.
29. Apparatus in accordance with claim 14 including a support for
the eccentric comprising:
a rotatable shaft, and
motor means for rotating the shaft.
30. Apparatus in accordance with claim 29 including:
a control panel, and
means on the control panel for starting, stopping and reversing the
motor means.
31. Apparatus in accordance with claim 29 including indicator means
associated with the rotatable shaft for assuming positions
indicative of the orientation of the eccentric relative to the
pivotally mounted member.
32. Apparatus in accordance with claim 31 including:
a control panel, and
display means on the control panel for representing analogically
the positions assumed by the indicator means.
33. Apparatus in accordance with claim 14 including:
a potentiometer comprised of contactor means and resistive means
engaged by the contactor means and having one of said means
connected to the rotatably mounted eccentric and the other of said
means stationarily mounted;
a potential difference source connected to the potentiometer,
and
an electrical meter connected to the potentiometer to register the
potential difference across a portion of the potentiometer and
thereby represent analogically the orientation of the eccentric
relative to the pivotally mounted member.
34. Apparatus for applying therapeutic treatment to the human body
which comprises:
a table for supporting a human body in a supine position;
rails extending longitudinally of the table beneath the body
supporting surface thereof;
a carriage supported by the rails for to-and-fro movement
longitudinally of the table;
means for imparting movement to the carriage in opposite
directions;
a cradle having trunnion pivots midway between its ends;
a pair of links connecting the trunnion pivots to the carriage;
a rocker shaft supported by the carriage;
an arm having one end secured to the shaft;
a post having one end pivotally associated with said arm and the
other end engaging one of the trunnion pivots of the cradle;
means for rocking the shaft to cause raising or lowering of the
post and correspondingly raising or lowering of the cradle; and
a pair of spaced rollers at each end of the cradle for applying
pressure against the back of a human body supported by the
table.
35. Apparatus for applying therapeutic treatment to the human body
which comprises:
a table for supporting a human body in a supine position;
rails extending longitudinally of the table beneath the body
supporting surface thereof;
a carriage supported by the rails for to-and-fro movement
longitudinally of the table;
a rotatable member supported by the carriage with its axis
extending transversely of the carriage;
means for imparting rotation to the rotatable member in either
direction;
an elongated flexible member having a plurality of turns around and
in engagement with the rotatable member and having its ends secured
to structural elements of the table at points spaced from one
another longitudinally of the table whereby rotation of the
rotatable member in engagement with the flexible member causes
movement of the carriage along the supporting rails;
a cradle having trunnion pivots midway between its ends;
a pair of links connecting the trunnion pivots to the carriage;
means for supporting trunnion pivots of the cradle, and
a pair of spaced rollers at each end of the cradle for applying
pressure against the back of a human body supported by the
table.
36. Apparatus for applying therapeutic treatment to the human body
which comprises:
a table for supporting a human body in a supine position;
rails extending longitudinally of the table beneath the body
supporting surface thereof;
a carriage supported by the rails for to and fro movement
longitudinally of the table;
means for imparting movement to the carriage in opposite
directions;
a cradle having trunnion pivots midway between its ends;
a pair of links connecting the trunnion pivots to the carriage;
a telescopic post for supporting the trunnion pivots of the cradle
comprising a first support member and a hollow tubular second
support member slidably receiving internally the first support
member;
means for connecting one of the support members to a trunnion pivot
of the cradle;
means for connecting the other support member to the carriage;
a compression spring confined within the tubular support member and
engaging the other support member to accommodate vertical movement
of the cradle relative to the carriage; and
a pair of spaced rollers at each end of the cradle for applying
pressure against the back of a human body supported by the
table.
37. Apparatus in accordance with claim 34 including:
motor means for rocking the shaft;
a control panel, and
motor control means on the control panel for starting, stopping and
reversing the motor.
38. Apparatus in accordance with claim 37 including indicator means
associated with the rocker shaft for assuming positions indicative
of the orientation, the arm interconnecting the shaft and the
post.
39. Apparatus in accordance with claim 38 including display means
on the control panel controlled by the indicator means for
representing analogically the positions assumed by the indicator
means.
40. Apparatus in accordance with claim 39 including:
a potentiometer comprised of contactor means and resistive means
engaged by the contactor means and having one of said means
connected to the rocker shaft and the other of said means
stationarily mounted;
a potential difference source connected to the potentiometer,
and
an electrical meter connected to the potentiometer to register the
potential difference across a portion of the potentiometer and
thereby represent analogically the orientation of arm on the
shaft.
41. Apparatus for applying multidirectional therapeutic traction to
the human body which comprises:
a table for supporting a human body in an outstretched
position;
rails extending longitudinally of the table beneath the body
supporting surface thereof;
a wheeled carriage supported by the rails at one end of the table
for movement to and fro longitudinally of the table;
means including a vertically adjustable fixture mounted on the
carriage and a traction harness connected to the fixture and
engageable with the cranial extremity of the body whereby the angle
of application of traction to the cranial extremity of the body
relative to the plane of the body supporting surface of the table
may be varied;
a second wheeled carriage supported by the rails at the other end
of the table for movement to and fro longitudinally of the
table;
a fixture mounted on the second carriage having means for engaging
the pedal extremity of the body;
means for imparting movement to and fro to the carriages
individually to apply and relieve tensioning forces to the
extremities of the body;
reactive means on each carriage adapted to react to changing
amounts of tensioning forces and effective upon reacting to a
selectably predetermined extent to cause arrestment of its carriage
and thereby to limit to selectively predetermined amounts the
traction applied to each extremity of the body;
a third wheeled carriage supported by the rails intermediate the
other two carriages for movement to-and-fro longitudinally of the
table;
reversible means for driving the third carriage to-and-fro;
adjustably positionable means for determining the extent of
movement of the third carriage in each direction and for effecting
reversal of the reversible driving means, and
vertically adjustable yieldable means mounted on the third carriage
for exerting pressure against the body while traversing the body
to-and-fro.
Description
BACKGROUND OF THE INVENTION
The human anatomy is subject to many discomforts, one of the most
common being manifestations of pain in the back, along the spinal
column from shoulders to hips. A type of therapeutic treatment that
has been found to be beneficial to relieve discomfort in that area
is the application of massage, with or without vibration, and with
or without heat, along or on both sides of the spinal column. This
type of treatment has been found to be generally more effective if
some of the vertebrae of the spinal column are somewhat separated
by the application of traction to the body of the patient.
Various types of equipment have been proposed and some used for
this type of treatment. Usually the equipment takes the form of a
table upon which the patient lies and which has movable attachment
devices at the opposite ends of the table for connection to the
head and the ankles of the patient for applying traction. Such
tables are also equipped with a carriage that is movable
longitudinally of the table a sufficient distance to traverse the
spinal column of a patient and is provided with rollers that are
pressed against the back of the patient. It has been the custom to
equip such tables with dissimilar mechanisms for varying the
traction applied to the two extremities of the body and further to
provide means for moving the massaging carriage which has no
similarity whatsoever to either of the traction applying
mechanisms. Dissimilarity of the movable mechanisms that engage the
body of the patient in one way or another brings about a complexity
in the manufacture, maintenance and repair of the tables, resulting
in structures which are expensive to produce and expensive to
maintain and repair.
SUMMARY OF THE INVENTION
In accordance with the present invention a table for giving
therapeutic treatment along the spinal column of a human being is
provided with three movable carriages equipped with rollers
supported on rails that extend longitudinally of the table from end
to end. Power means are provided for moving the carriages to and
fro longitudinally of the table. Not only are the carriages
basically identical but the means for applying power to produce
locomotion are identical. In addition the two carriages located at
opposite ends of the table, used to apply traction to the body, are
provided with identical means for controlling the amount of
traction that will be applied at the two extremities of the body.
Each of these two carriages is adapted to receive and support a
fitting that extends above the surface of the table, one to be
connected to a chin strap harness for applying traction to the
cranial extremity of the body and the other provided with a member
with recesses and straps for fitting to the ankles of the patient.
Since these fixtures are removable from the carriages and may be
fitted to the carriages by identical supporting means, the
carriages may be identical and interchangeable, and one spare
carriage may be used for replacement at either end of the table as
needed. The intermediate carriage is, of course, differently
equipped from the other two, in that it adjustably supports a
roller structure for pressing against the back of the patient as it
is moved to-and-fro. As previously stated, however, the means of
locomotion of this carriage may be the same as that of the other
two carriages.
The table is provided with a control panel including all of the
controls needed for the variables of the table. The principal ones
are the setting of limits to the amount of traction to be applied
by the two end carriages of the table, and the setting of the
amount of pressure that will be exerted by the massage rollers
against the back of the patient. In accordance with the preferred
embodiment of the invention these adjustments are controlled and
varied by means of small electric motors individual to and mounted
on the carriages. Electrical switches mounted on the control panel
are included in the circuits of these motors and the panel is
provided with meters that are direct-reading in appropriate values
such as pounds of traction or pressure, and that are controlled by
variable electrical devices, such as potentiometers, associated
with the motor control adjustment means on the carriages. With this
arrangement there are no mechanical linkages between the control
panel and the carriages and the result is a simple and
straightforward association of components.
DESCRIPTION OF THE DRAWINGS
For a complete understanding of the invention reference may be had
to the following detailed description to be interpreted in the
light of the accompanying drawings in which:
FIG. 1 is a perspective view of a therapy table in accordance with
the present invention;
FIG. 2 is a plan view of the table with top removed to show the
interior of the table;
FIG. 3 is a vertical sectional view taken along the line 3--3 of
FIG. 2;
FIG. 4 is a horizontal sectional view of one of the traction
carriages taken on the line 4--4 of FIG. 3;
FIGS. 5 and 6 are vertical sectional views through a traction
carriage taken substantially on the lines 5--5 and 6--6
respectively of FIG. 4;
FIG. 7 is an end elevational view of the middle carriage of the
table, which is the back-massaging carriage;
FIG. 8 is a vertical sectional view taken on the line 8--8 of FIG.
7;
FIGS. 9 to 11 are electrical circuit schematics of portions of the
control and operating circuitry; and
FIG. 12 is a diagrammatic representation of the mechanical
arrangement for controlling the travel of the back-massaging
carriage.
Referring now to the drawings and particularly to FIG. 1 the
reference numeral 15 designates a table, generally enclosed to
conceal the internal mechanisms and resting on feet 16. The top 14
of the table 15, which is preferably removable, and on which a
person to receive a treatment will rest, generally in a supine
position, is provided with a cover 17 of durable flexible material,
such as woven cloth or a synthetic leatherlike material, which also
conceals the internal mechanisms of the table. The table may have,
loosely resting thereon, comfort devices such as the convex bolster
member 18 to be placed under the neck of the patient, and a
supporting member 19 for the legs, as at the hollow of the
knees.
At each end of the top of the table there is a longitudinally
extending slot, designated 21 and 22, the former providing a
clearance for movement of traction applying fixture 23 particularly
intended for applying traction at the cranial extremity of the body
and the other providing a clearance path for the ankle traction
fixture 24 which has recesses or depressions 26 to support the
ankles, and straps 27 for securing the ankles in the fixture. FIG.
1 also includes a showing of the control panel 28, the details of
which will be set forth hereinafter.
When the top of table 15, which is the body support portion of the
table, is removed the interior of the table is revealed as shown in
FIG. 2. The table has a framework consisting of side rails 31 and
end rails 32 secured to leg members 33. Secured to the leg members
and extending longitudinally of the table from end to end are
U-shaped channel iron members 34 mounted with their web portions
vertical and their flanges extending inwardly toward a centerline
of the table. The lower flanges are preferably wider than the upper
ones, and have their edge portions turned upwardly parallel to web
portions of the members 34, as shown in FIG. 7. The channel members
34 serve as rails for supporting and guiding the traction and
massaging carriages and are spaced apart a suitable distance to
accommodate the carriages. At the left-hand end of the table as
viewed in FIGS. 1 and 2 the rails 34 support the traction carriage
36 to which is fitted traction fixture 23 for applying traction to
the cranial extremity of the patient. At the opposite end of the
table the rails support the traction carriage 37 for applying
traction to the pedal extremity of the body, and intermediate the
ends the rails 34 support the back-massaging carriage 38.
The details of the traction carriage 37 are shown in FIGS. 4, 5 and
6. Referring first to FIG. 4 it will be seen that the carriage 37
is provided at its opposite ends, near the top of the carriage,
with pairs of rollers 40 and 41 rotatably supported on spindles 42
and 43 respectively. Intermediate its ends the carriage 37 is
provided with a pair of rollers 44 freely rotatable on a spindle
46. The vertical spacing between the rollers 44 and the rollers 40
and 41 is not less than the thickness of the lower flange of the
rail 34 but only slightly greater than the thickness of that flange
so that as the rollers 40 and 41 rest on the upper surface of the
lower flange of the rail the rollers 44 engage, or so nearly
engage, the lower surface of the flange that upward movement of
either end of the carriage relative to the lower flange of the
rails is negligible.
At a distance from the right-hand end of the table, as viewed in
FIGS. 2 and 3, that is beyond the normal operational travel of the
carriage 37, the lower flange of each of the rails 34 is provided
with a cutout 47 of sufficient size to permit passage of the
rollers 40 and 41 therethrough. The sides of the carriage 37 have
no outside attachments extending above any part of the rollers 40
and 41. With this construction the carriage 37 may be installed in
operative position relative to the rails 34 that are permanently
secured to the table. This is accomplished by bringing the carriage
37 into position below the apertures 47, passing the rollers 41
through the apertures and into engagement with the upper surface of
the lower flanges of the rails 34, moving the carriage rightwardly
as viewed in FIG. 3, with the rollers 40 beneath the lower flanges
of the rails 34, and then lifting the left-hand end of the carriage
to pass the rollers 40 through the apertures and into supported
relationship to the lower flange of the rail 34, thereby bringing
the rollers 44 into position immediately beneath the flanges. After
the carriage has been mounted on the rails a rod 48 is fitted into
apertures in the web portions of the two rails directly above the
apertures 47 and retained by any suitable means such as nuts
fitting threaded ends of the rod to prevent the rollers 40 from
falling through the apertures in the event that the carriage should
move that far to the left.
As shown in FIGS. 4 and 5 the carriage 37 rotatably supports, on a
shaft 51, a cylindrical body or arbor 52. A cable 53 has one end
securely connected to rod 48 and extends from the rod right, an
idler or tensioning pulley 54, supported as will be described
hereinafter, a plurality of turns around and in frictional
engagement with the arbor 52, thence over idler pulleys 56 and 57
and a rod 58, supported as will be described hereinafter, and to a
frame member 59 of the table, to which the other end of the cable
is secured. The spindle 51 is connected through reduction gearing
(not shown) to the drive shaft of a reversible electric motor
structure designated by the reference numeral 61, and the arbor 52
is secured to the shaft 51. Disregarding for the moment the several
idler pulleys 54, 56 and 57 it will be apparent that if arbor 52 is
driven by the motor 61 in clockwise direction as viewed in FIG. 5
it will take up on the portion of cable 53 that extends to the
right and yield cable to the portion that extends to the left and
will, therefore, propel the carriage to the right and as seen in
FIG. 3 this is in the direction to apply traction to the ankle
support fixture 24 of the table.
The idler pulley 54 is rotatably supported in a fork 62 carried at
one end of a tensioning structure comprising spaced disks 64 and 66
between which a compression spring 67 is retained by a U-shaped
wire 68 that engages the fork 62, and has its arms extending
through disks 64 and 66 where the free ends of the arms have
reverse bends. A similar U-shaped wire 69 is mounted on the spindle
43 and has its arms extending through apertures in disks 66 and 64
where it has reverse bends. The U-shaped wires 68 and 69 are in
quadrature to one another.
Below and parallel to the spindle 43 the carriage 37 supports a
spindle 71. This spindle rotatably supports the idler pulley 57 and
pivotally supports a lever structure 72 comprised of complementary
members 70 and 75 spaced apart by the pulley 57. This lever has
arms 73 extending obliquely upwardly to the left as viewed in FIG.
5 and the idler pulley 56 is rotatably supported between the free
ends of the arms 73. Below and to the left of spindle 71, as viewed
in FIG. 5, tension springs 74 have one end hooked into ears 80 of
the complementary members 70 and 75 of the lever 72 and the other
end retained in apertures in a block 76 that is held by a hook 77
retained in a bracket 78 by a nut 79 threaded on the shank of the
hook 77. It will be apparent that the springs 74 bias the lever 72
in clockwise direction as viewed in FIG. 5.
Consideration will now be given to the components of the carriage
37 thus far described when the motor 61 is set in operation to
rotate the arbor 52 in clockwise direction after the ankles of a
patient have been clamped in the ankle traction fixture 24. It will
be supposed first that the ankle traction fixture 24 were to be
connected to an immovable object on the table. The carriage 37
would thus be prevented from moving to the right, and with arbor 52
being rotated clockwise to take up the cable 53 the lever 72 would
of necessity be rocked in counterclockwise direction, against the
resistive tension of the springs 74 to yield cable to the arbor 52.
The slack in the cable yielded by the arbor 52 would be taken up by
the tensioning support for the idler pulley 54. Counterclockwise
movement of the lever 72, as viewed in FIG. 5, would continue until
the offset in the path of travel of the cable 53, established by
the idler pulley 56 between the arbor 52 and the idler pulley 57
had been reduced to zero, or the tension of the spring 74 had
become substantially equal to the tractive force of arbor 52 under
the driving influence of the motor 61.
Since the patient's ankles are not immovable objects, however, a
different series of events will occur. The carriage 37 will move to
the right without appreciable rotation of the lever 72 on its
pivotal mounting while any slack in its connection to the patient
is being taken up. As traction begins to build in the lower
extremity of the patient, the rightward movement of the carriage 37
will be resisted and the lever 72 will begin to rotate in
counterclockwise direction about its pivot, the springs 74
distending to accommodate this movement. It follows from this that
the clockwise rotation of the arbor 52 by the motor 61 should be
stopped when the desired traction has been applied to the pedal
extremity of the patient.
Referring to FIG. 6 in which the opposite side of the lever 72 is
viewed, as compared with FIG. 5, the reference numeral 81
designates a miniature electrical switch having an operating
plunger 82. The switch 81 is carried by the lever 72. Actually,
there are two such switches, the other, designated by the reference
numeral 83, is shown in FIG. 4 but is behind the switch 81 in FIG.
6 and can not be seen. The operating plunger for the switch 83 is
designated 84 in FIG. 6.
One wall of the carriage 37 is provided with a bracket 86 into
which is threaded an adjustable stop 87 which is in the path of
movement of the operating plunger 82 of the switch 81 and is
adapted to serve as a limit stop for the lever 72 in its
counterclockwise movement as viewed in FIG. 6, and which is its
clockwise movement as viewed in FIG. 5. The position of the lever
72 in which the operating plunger 82 of the switch 81 is in
engagement with the adjustable stop 87 may be considered as the
normal or idle position of the lever 72 relative to the carriage
37, since, with no restraint upon the carriage, the springs 74 will
move the lever 72 to that position.
Below and in the path of the operating plunger 84 of the switch 83
an eccentrically mounted adjustable stop member 91 is fixed to a
shaft 92 that is supported by the carriage 37. The shaft is
connected through gears 93 and 94 to an electric motor 96 secured
on the outside of one of the sidewalls of the carriage. If
eccentrically mounted stop member 91 is in the position shown in
FIG. 6 the lever 72 may move into the dotted line position before
engagement of the operating plunger 84 of switch 83 with the stop
member 91. If the adjustable stop member 91 is rotated in
counterclockwise direction the lever 72 will be permitted to travel
only a lesser distance in a clockwise direction as viewed in FIG. 6
before the operating plunger 84 of the switch 83 engages the
adjustable stop member 91. As will be set forth more fully
hereinafter, the switches 81 and 83 are a part of the control
circuitry for the reversible motor 61 that moves the carriage 37
to-and-fro.
When the motor 61 drives the carriage in the direction to apply
tension to the pedal extremity of a patient the operating plunger
84 of the switch 83, upon coming into engagement with adjustable
stop member 91 causes the opening of the operating circuit for the
motor 61 and therefore limits the amount of traction that is
applied to the patient. The greater the distance of the surface of
adjustable stop member 91 from the operating plunger of switch 84
when the lever 72 is in its normal position, the greater will be
the amount of traction applied to the patient. Because the motor 61
is reversible a positive drive is provided for moving the carriage
37 to the left as viewed in FIGS. 3 and 5 to diminish the traction
applied to the patient. The switch 81, when operated as the lever
72 returns to its normal position, opens the operating circuit of
the motor 61 to suspend the driving of the carriage to the left as
viewed in FIGS. 3 and 5. In the event that the coefficient of
friction between the arbor and the cable is insufficient to prevent
slippage between them, the cable may be clamped to the arbor at a
point on the cable that is not yielded by the arbor to the left or
the right as the carriage 37 is moved to-and-fro on the table.
In order that it shall not be necessary to maintain the reversible
motor 61 under torque when traction is being held on the patient, a
brake mechanism is provided. The brake mechanism is comprised of a
disk 101 which is secured to the shaft 51 of the carriage driving
arbor 52, and a braking band 102. The disk 101 has a flat
peripheral surface, and the braking band 102 has one end secured to
the frame of the carriage by any convenient securing means 103,
which might be a machine screw or a rivet, and the other end
connected to the armature of a solenoid 104 which is also secured
to the framework of the carriage. The braking band 102 extends
around the periphery of the disk 101 for a distance preferably
approaching 90.degree. of the disk 101.
In one embodiment of the invention the braking band 103 is a length
of thin spring steel, and the disk 101 is of composition material
such as fiber; or, if it is of metal, it may have a rim of material
having a relatively high coefficient of friction by comparison with
the braking band 102. When the solenoid is in the released
condition the braking band is not engaged at any point with the
disk 101, or engages the disk so lightly that the shaft 51 is free
to turn. When the solenoid 104 becomes energized it draws the
braking band 102 into engagement with the periphery of the disk
101, and the shaft 51 will be held stationary to hold the patient
under traction when the circuit of the motor 61 is opened. As will
be set forth hereinafter, the circuit of the solenoid 104 is
established when the switch 83 operates under the control of
eccentrically mounted stop 91 to open the driving circuit for the
motor 61 and suspend the building-up of traction.
When the interval in which steady traction is to be held has
terminated and the motor 61 is actuated in the reverse direction,
the solenoid 104 is released to permit the carriage 37 to move to
the left as viewed in FIG. 3. The energy stored in the body of the
patient due to the stretching caused by the application of traction
may be sufficient to move the carriage 37 leftwardly, before the
motor 61 takes effect, particularly if the brake releases a moment
before the circuit of the motor 61 is completed. If there if a
significant delay in the activation of the motor, the natural
contraction of the body of the patient might be sufficient to move
the carriage back to its initial position with the operating
plunger 82 of the switch 81 in engagement with the adjustable stop
screw 87. In any event, whether by motor power or without it, the
traction will be diminished to zero. The reversibility of the motor
provides for movement of the carriage in either direction
appreciable distances to provide different starting positions for
the application of traction to patients of different heights.
The carriage 37 is provided with vertically mounted, oppositely
faced identical channel members 98 and 99 which form a well to
receive the arm 25 that mounts the ankle fixture 24.
As previously stated, the carriage 36 is used for applying traction
at the cranial extremity of the patient and may be identical with
the carriage 37. It is mounted on the rails 34 in an orientation of
180.degree. relative to that of the carriage 37 so that whereas the
reversible driving motor 61 for the carriage 37 is seen in front of
the carriage in FIG. 3, the motor 96 for adjusting the
eccentrically mounted adjustable stop member of the carriage 36 is
seen in front of that carriage in the same figure. The cable 106 by
which the carriage 36 is moved to-and-fro longitudinally of the
table has one end connected to the bar 107 corresponding to the bar
48, and the other end connected to the frame member 108 which
corresponds to the frame member 59. The carriage 36 may be
installed on the rails 34 through the same apertures 48 through
which the carriage 37 was installed in which case the carriage 36
must be installed before the carriage 38 is installed, or a set of
apertures corresponding to the apertures 48 could be provided below
the rod 107.
The fixture 23 for applying traction to the cranial extremity of
the body of the patient is carried on an arm 111 that fits into the
well in the carriage and extends into the slot 21 in the top of the
table. At its free end the arm 111 carries a hollow tube 112 of
rectangular cross section which slidably receives a supporting post
113 for the traction fixture 23. Post 113 is provided with a
plurality of holes extending transversely therethrough, any one of
which may be aligned with a hole 114 in the tubular support for the
post. The apertures in the post 113 provide for adjustment of the
height of the fixture 23 relative to the table and a pin may be
inserted into the hole in the tubular member and through any hole
in the post 113 to hold the fixture 23 in the desired position. The
fixture 23 has a row of holes 116 on its opposite sides, and these
are adapted to receive hooks of a traction harness 117 that engages
the head of the patient and that usually includes a strap that
passes under the chin of the patient.
The massage carriage 38 is generally similar to the carriages 36
and 37. It is provided with rollers 121 and 122 at its opposite
ends, corresponding to the rollers 41 and 40 respectively of the
carriage 37, which ride on the rails 34. It does not require
rollers below the rails, corresponding to the rollers 44 of the
carriage 37 because its sole purpose is to thrust a set of
massaging rollers upwardly against the patient. In the case of the
traction carriages, the traction forces have a component that may
tend to lift the carriages relative to the table, and the lifting
component is resisted by the rollers 44 disposed below the rails
34.
FIG. 7 shows the carriage 38 viewed from the left-hand end as it
appears in FIG. 3. The carriage has a driving arbor 126 that is
secured to a shaft 127 extending transversely of the carriage. A
reversible motor 128, which may be identical with the motor 61, is
mounted on one side of the carriage 38 and drives the arbor 126
through reduction gearing (not shown). A cable 129 has a plurality
of turns wrapped around the arbor 126 and is stretched taut between
and secured to the transverse rods 48 and 107, to which the cables
53 and 106 for the carriages 37 and 36 respectively are connected.
As the motor 128 is energized to drive in one direction or the
other, it will move the carriage 38 to and fro longitudinally of
the table. As with the other carriages, the cable 129 may be
clamped to the arbor 126 to assure that there will be no
slippage.
At one of its ends, the carriage 38 supports, extending
transversely thereof, a bracket 131 which pivotally supports, on
the opposite sides of the carriage, the arms 132. At their free
ends, the arms 132 provide pivotal support for trunnions 134 of a
cradle 133. The trunnions are located midway between the ends of
the cradle. At its ends, the cradle 133 has transversely extending
rods 136 which support freely rotatable spaced rollers 137. The
cradle 133 is supported by a telescoping rod comprising a solid rod
141 pivotally mounted at the end of a supporting arm 142 and a
hollow sleeve 143 suspended from one of the trunnions 134 of the
cradle 133. A compression spring 144 is contained in the sleeve
portion 143 of the telescoping rod and serves as a yieldable
support for the cradle 133 relative to the solid rod 141 and its
supporting arm 142.
The arm 142 that mounts the telescoping support for the cradle 133
is secured to a shaft 146 which is connected by reduction gearing,
shown in FIG. 8 as a worm wheel 147 and worm 148, to a reversible
motor 149. The motor 149 may be similar to the motors 96 that
position the traction limit stops on the carriages 36 and 37. When
the motor 149 drives in one direction, it rocks the arm 142 carried
by the shaft 146 in clockwise direction as viewed in FIG. 8 to
raise the cradle 133 relative to the table. The top of the table is
provided with an elongated opening in which the cradle 133 travels
to-and-fro and when the cradle 133 is lifted, it presses upwardly
against the flexible covering 17 for the top of table and applies
pressure to the back of the patient lying supine upon the table.
The normal position of the patient will be with the spine aligned
with the middle of the table longitudinally, so that the rollers
137 will engage the patient's back on opposite sides of the spinal
column. The balanced pivotal mounting of the cradle 133 permits the
cradle to rock about its point of pivotal mounting and accommodate
itself to irregularities in the patient's back. The spring 144
permits vertical accommodation of the rollers 137 to the patient's
back.
As stated hereinbefore the motors 96 and 149 are provided for
adjusting the shafts 92 and 146 respectively in order to avoid
direct mechanical control of those shafts from the control panel.
It is necessary, of course, that the technician operating the table
be able to know, in meaningful terms, the positions of these shafts
when traction and massaging pressure are being applied to a
patient. As a means for generating an indication of the position of
the shaft, potentiometers are employed. As shown in FIG. 4 a
potentiometer 151 mounted on a bracket 152 has its contactor
mounted on a control shaft which, externally of the potentiometer,
is a hollow sleeve 153. One end of the shaft 92 that supports the
eccentrically mounted adjustable stop member 91 enters the sleeve
153 and connection to the sleeve is established as by means of a
setscrew 154. As the motor 96 drives the eccentrically mounted stop
member 91 in one direction or the other the contactor of the
potentiometer 151 will traverse the resistive element of the
potentiometer. The shaft 146 that mounts the supporting arm 142 for
the massaging cradle 133 similarly has a potentiometer associated
with it.
As shown in FIG. 1 the control panel 28 mounts electrical meters
171, 172 and 173. The electrical circuitry for these meters is
shown in FIG. 9. The potentiometer 151 which is associated with the
pedal extremity traction carriage 37 is connected across a source
of direct current voltage. The meter 171, which may be a moving
coil type of instrument, is connected through a variable resistor
157, which serves as a multiplier, to the contactor of the
potentiometer 151. The variable multiplier 157 permits adjustment
of the meter for full scale deflection at different settings of the
potentiometer 151 and permits calibration of the potentiometer and
meter combination to traction in terms of pounds, which is the unit
of measurement displayed on the meter scale.
Below the meter 171 on the control panel 28 is a control switch 174
having a central normal position and operating positions in
opposite directions (FIG. 10) for driving the reversible motor 96
in one direction or the other. When the lever 72 on the carriage 37
is in its rest or extreme counterclockwise position, as viewed in
FIG. 6, and if in this position of the lever the eccentrically
mounted adjustable stop 91 is in a position where the operating
plunger 84 of the switch 83 engages and has been operated by the
stop, the meter 171 should have a "zero" scale reading. As motor 96
moves the adjustable stop 91 in clockwise direction, as viewed in
FIG. 6, under the control of switch 174, the meter 171, responding
to the movement of the contactor of potentiometer 151, advances its
pointer along its scale to register pounds of traction that the
carriage will apply to the patient.
Similarly, the meter 173 is associated through a variable
multiplier resistor 158 with the contactor of the potentiometer 159
which is associated with the carriage 36 that applies traction to
the cranial extremity of the patient's body. A meter 172 is
connected through a variable multiplier resistor 161 to the
contactor of the potentiometer 162 which is associated with the
shaft 146 of the massaging carriage 38. The meter 172 also
registers in pounds, this being pressure applied to the patient's
back. Switch 176, movable in either direction from a central
position, controls the energization of the reversible motor 96 for
the establishment of a traction limit for the carriage 36 and
switch 177, operable to either of two positions, controls the
application of pressure to the patient's back by the carriage
38.
FIG. 11 shows in simplified schematic form the control circuitry
for the traction motors of the carriages 36 and 37. The schematic
has been called simplified because not all biasing circuits for
solid-state devices and not all dropping resistors have been shown,
the circuitry being confined to paths over which controls are
actually effected.
The motors 61 have been shown as being operative by alternating
current. They may, in fact, be two motors having their rotors
coupled, each arranged to drive in the direction opposite to the
other. They could, however, be reversible single motors.
The switches 81 and 83 previously identified in the description of
FIGS. 4 and 6, are shown in each of the carriages 36 and 37 in FIG.
11. It will be remembered that the switch 81 brings its operating
plunger 82 into engagement with the stop 87 when the carriage is in
the starting position, in which no traction is applied to the
patient, and in this condition of the operating plunger 82 the
switch 81 is open. When, incident to the application of traction,
the lever 72 begins to move from its rest position the switch 81
closes. Similarly, the switch 83 is closed until its operating
plunger 84 comes into engagement with the adjustable eccentrically
mounted stop 91 to limit the amount of traction applied to the
patient.
Any suitable form of switch may be employed for closing the
operating circuits of the motor 61. Since one or the other of the
switches 81 and 83 are closed when the carriage is in one or the
other of its operational "rest" positions, these switches are used
only to control other switches through which the operating circuits
of the motor 61 are completed. Solid-state switching devices known
as triacs have been shown in FIG. 11 in association with the
operating circuits of the motors 61. These are gate controlled
devices equivalent to a pair of diodes connected in opposite
directions so that they will pass alternating current when a proper
DC potential is applied to the gate. Accordingly, the gates are
connected to control circuits through the switches 81 and 83, a
triac 181 being associated with the switch 81 to supply current for
driving the motor 61 in the direction to relieve traction and the
triac 183 being associated with switch 83 to drive motor 61 in the
direction to apply traction. The switches 81 of the two carriages
36 and 37 are connected over paths 184 and 185 to the anodes of
silicon controlled rectifiers 186 and 187 respectively. Similarly
the switches 83 of the carriages 36 and 37 are connected over paths
188 and 189 to the anodes of silicon controlled rectifiers 191 and
192 respectively. The gates of the silicon-controlled rectifiers
186 and 187 are connected in parallel to one of the output
terminals 193 of a multivibrator 195, which may have transistors as
its commutating elements and is of conventional configuration. For
this reason the circuit details have not been shown. The gates of
the two silicon-controlled rectifiers 191 and 192 are connected to
the output terminal 194 of the multivibrator 195.
With the anodes of the silicon controlled rectifiers 186 and 187
connectable through the switches 81 to the gates of the triacs 181
as their source of current the silicon controlled rectifiers will
be conductive when the multivibrator 195 is in one of its operative
conditions, and nonconductive in the other if its operative
conditions, and upon the establishment of conductivity in the
silicon controlled rectifiers 186 and 187 by their gates the triacs
181 will be activated to drive the carriages to the position in
which traction is relieved. When the switches 81 open the
conductivity through triacs 181 will be cut off and the carriages
will be stopped. Correspondingly, when the carriages are in the
position of relieving traction the switches 83 are closed and upon
a reversal of the multivibrator 195 the triacs 183 will be rendered
operative by the silicon controlled rectifiers 191 and 192 to move
the carriages in the direction to apply traction.
The two sides of the multivibrator 195 receive their biasing
potentials through variable resistors 196 and 197 which are
resistive components of the resistive-capacitative cross-couplings
that control the duration of the half-cycles of the multivibrator
195. These variable resistors are represented by the corresponding
numerals applied to control knobs on the control panel 28 in FIG.
1.
Mounted on the control panel and shown also in FIG. 11 is a
single-pole, three-position switch 201 for controlling the mode of
operation of the carriage 36. The switch has three positions, the
center position establishing an "off" condition for the carriage,
the lower providing a static condition in which the carriage will
be driven to a position to apply traction without interruption, and
the upper position placing the carriage under the control of the
multivibrator 195, for alternate application and relief of
traction. A similar switch 202 provides for the same type of
control of the carriage 37. The switches 201 and 202 appear on
control panel 28.
A single-pole, double-throw master switch, identified by reference
number 203, is associated with a conventional mechanical timer
which, when set in operation by means of a control knob, runs for a
period of time dependent upon the extent of advancement of a
control knob, the knob returning during its timing period, to the
initial position. The switch 203 is so associated with the timer
that it goes off normal when the timer is activated and returns to
normal at the end of the timing interval.
With the switch 203 in the normal position a path is traced from
negative battery through two diodes in the cathode-to-anode
direction to the paths 184 and 185 for controlling the triacs 181.
Since an idle condition is assumed to exist the switches 81 will be
open and the negative potential will not be applied to the gates of
the triacs 181. The anodes of the two diodes are also connected to
the center or "off" terminals of the switches 201 and 202 but the
paths of contactors of those switches include diodes in the
anode-to-cathode direction which block those paths to negative
potential.
In order that the table shall accommodate patients of varying
heights without providing harness straps of different lengths for
attachment to the carriage 36 it is desirable to be able to move
one of the carriages to an optimum starting point for each patient.
The carriages 37 which has the ankle engaging fixture 24 has been
adapted to this operation. As seen in FIG. 11 a single-pole, three
position switch 204 has its contactor connected to the triac
control path 185, one of its terminals to the gate of triac 181,
and the other terminal to the path 189 over which the triac 183 is
controllable. With the master switch 203 in the normal position
negative battery is connected to path 185 through the diode in the
forward direction for that polarity. Thus, if switch 204 should be
closed to its upper contact, as shown in FIG. 11, a shunt will be
established across the open switch 81 and triac 181 will be
rendered conductive while the switch remains operated to cause the
motor to drive the carriage to the left as viewed in FIGS. 2 and 3,
thereby positioning the carriage for applying traction to a short
patient. If, instead, switch 204 is closed to its lower contact the
battery connection will be extended through the closed switch 83 to
render triac 183 conductive and move carriage to the right as
viewed in FIGS. 2 and 3 to accommodate it to a taller patient. The
switch 204 is preferably spring-biased to be self-returning to its
off position.
After the carriage 37 has been correctly positioned and the
traction connections have been established from extremities of the
patient to the carriages the mode switches must be adjusted for the
desired type of traction. It will be assumed that switch 201 is
moved to the upper position for intermittent traction and that
switch 202 is moved to the lower position for static traction. This
having been done the mechanical timer is adjusted to the time
interval during which treatment is to be given to the patient, and
this causes an operation of switch 203 to its off-normal condition.
With the switch 203 thus operated the negative battery connection
on its swinger is extended through diode 211 in the forward
direction, the right-hand armature and back contact of the relay
212 and to the contactors of the mode switches 201 and 202 through
individual diodes in the forward direction. Because it has been
assumed that the switch 201 has been placed in the intermittent
mode the connection is extended to the cathodes of the silicon
controlled rectifiers 186 and 191 and through diode 213 in the
forward direction to multivibrator 195, thereby activating that
circuit. The negative battery connection is also extended through
the diode in the forward direction and the swinger of switch 202
and its static contact to the path 189. The connection is extended
over this path and through the switch 83 to render the triac 183
conductive and apply traction to the pedal extremity by moving
carriage 37 to the right as viewed in FIGS. 2 and 3. No return path
for the cathodes of the silicon controlled diodes 187 and 192 is
provided at switch 202 in the static condition so that these diodes
will remain nonconductive and the triac 181 can not become
conductive to cause the traction applied by carriage 37 to be
released. However, as the multivibrator 195 proceeds with its
oscillatory activity the silicon controlled rectifiers 186 and 191
will be rendered conductive and nonconductive in alternation to
cause the carriage 36 to move to-and-fro, applying and relieving
the traction. When the switch 83 opens as the carriage 36 moves to
the left, applying traction, it opens the path for gate current in
the triac 183 and that device becomes nonconductive, stopping the
motor 61. The carriage is held in the leftward position by the
brake controlled by the solenoid 104, the operation of which will
be described hereinafter. When, following the stopping and holding
of the carriage 36 in the position of applying traction, the
multivibrator 195 reverses, it activates the triac 181 to cause the
carriage to move to the right, to relieve the traction, and
incident to that action the carriage brake is released. As
previously stated the contraction of the body of the patient upon
the release of the brake may return the carriage 36 rightwardly to
the point where the switch 81 opens almost before the motor 61 has
an opportunity to move the carriage to the right. However, the
motor 61 assures movement of the carriage until the traction has
been relieved and switch 81 opens.
As shown in FIG. 11 a shunt path across the two primary terminals
of the triac 183 includes a resistor 206, the winding of the
solenoid 104 shunted by a capacitor 207, and a silicon controlled
rectifier 208. The triac 181 has a shunt path across its primary
terminals, including a resistor 214, a diode 215 and a resistor 216
with a connection from the junction of resistor 216 and the cathode
of diode 215 to the gate of the silicon-controlled rectifier 208.
Any time that triac 181 is nonconductive a small amount of current
will flow through the motor and be rectified by the diode 215. The
current is insufficient to have any effect on the motor but
provides a positive bias on the gate of silicon-controlled
rectifier 208. The path including the silicon controlled rectifier
208 will draw a small amount of current through the other winding
of the motor 61 when it is forward biased at its gate and this
rectified current will energize the solenoid 104, the capacitor 207
preventing the release of the solenoid during the negative
half-cycles. The brake will thus be applied providing the triac 183
is not conductive because when it does conduct to operate the motor
61 to apply traction it becomes a short circuit across the solenoid
operating path and causes the release of the brake. Similarly when
the triac 181 is conductive to cause the motor 61 to operate to
relieve the traction it short circuits the path including the diode
215 and removes the forward bias from silicon-controlled rectifier
208. In this way the brake operates only when the carriage is in
either of its stop positions.
When the mechanical timing unit times out the interval for which it
was set it returns the switch 203 to its normal condition. This
removes operating potentials for the multivibrator and its
associated silicon-controlled rectifiers, eliminating further
control of the operating motors 61 of the carriages 36 and 37 by
the timing circuitry. If at the time of restoration of the switch
203 to normal the carriages are in the condition of applying
traction the switches 81 will be closed. As previously stated the
control paths 184 and 185 are connected through diodes to the
normal terminal of the switch 203 and the polarity applied to the
normal contact is in the forward direction so that the triacs 181
will be rendered conductive to relieve the traction. Since it had
been assumed that the static mode of control had been applied to
the carriage 37 the switch 81 will be closed and the carriage will
be operated to relieve traction.
The table is provided with a control operable by the patient to
relieve traction if it produces an intolerable discomfort. The
control is in the form of a manually operable pushbutton switch 221
which is on the end of a flexible cable and may be held by the
patient during the treatment. Upon operation of switch 221 it
completes the energizing circuit for the relay 212 through the
off-normal contact and contactor of the timer controlled switch
203. The switch 221 also completes the circuit of an alarm bell
222. The relay 212 locks through its left-hand armature and front
contact, its winding and the off-normal contact of the switch 203.
The front contact associated with the right-hand armature of the
relay 212 is connected to the same paths as the normal contact
switch 203, so that the circuitry returns to the same negatively
terminated condition that it does when the switch 203 returns to
normal except that the relay 212 remains locked up. Thus the
traction is relieved and the intermittent reapplication of traction
is suspended. A blocking diode in the energizing circuit of the
relay 212 prevents continuous operation of alarm bell 222 through
the left-hand armature and front contact that provide the locking
circuit. The patient can, however, repeat the operation of the
alarm bell 222 by repetitious closure of the pushbutton switch 221.
In order for normal operation of the table to be restored it is
necessary for an attendant to operate the timer control knob to the
zero position, thereby restoring the switch 203 to normal and
opening the locking circuit for the relay 212.
As shown in FIG. 11 the motor 128 for the carriage 38 is
energizable over either of two paths. The motor 128 has its common
terminal connected to one side of a source of alternating current,
as is the case with motors 61, and its reversing terminals
connected to the terminals of a single-pole, double-throw switch
218. The contactor of the switch 218 is connected to the "on"
terminal of an "on-off" switch 219 which is located on the control
panel 28. The contactor of the "on-off" switch 219 is connected to
one of the two principal terminals of a triac 223 which has its
other principal terminal connected to the opposite side of the
source of alternating current. The gate of the triac 223 is
connected to the back contact associated with the right-hand
armature of the relay 212 through path 224 and diode 225, the
connection of which is in the forward direction for the negative
polarity that is applied to the path through the diode 211 when the
timer switch 203 is operated to activate the table. When the switch
203 is thus operated the negative potential applied to the gate of
the triac 223 renders the triac conductive, but the motor 128 will
not be rendered operative unless and until the switch 219 is
operated to the "on" position. It follows from this that traction
may be applied to a patient without massaging of the back by means
of the carriage 38, merely by leaving the switch 219 unoperated.
The inclusion of the triac 223 under the control of the timer
switch 203 and also under the control of the relay 212 places the
carriage 38 under the control of the patient's pushbutton switch
221 so that the motor 128 for driving the carriage 38 will be shut
down along with the motors 61 if the patient operates the switch
221. The triac 223 also serves as a switch for a vibrator motor
231, the circuit including variable resistor 232. The motor 231 is
mounted on the underside of the massaging roller cradle 133 of the
carriage 38, and when the motor is running it imparts vibration to
the carriage because the rotor is intentionally unbalanced. The
variable resistor 232 provides for control of the intensity of
vibration and the resistor 232 appears on the panel 28 of the
table.
As shown in FIG. 12 the switch 218 that controls the direction of
movement of the carriage 38 is mounted on the outer surface of the
wall of the carriage that faces the front of the table and is a
toggle type switch with the operating lever extending vertically
from the switch case. Bars 227 that are slidably positionable along
a slot 229 in the panel 28, an are provided with locking knobs 228,
have their inner ends presented on opposite sides of and in the
path of the operating lever of the switch 218, so as to be able to
effect reversals of the switch. Since the slidable bars 227 are
adjustable along the slot 229 each may be positioned selectively to
determine the location and extent of travel of the carriage.
The table may be provided with means for applying heat to a
patient, in the form of resistance wire, beneath the flexible
covering of the table on which the patient lies, and distributed
principally over an area on which the patient's back will be
resting. The intensity of the heat may be varied by means of a
rheostat, and the control knob 236 on the panel 28 represents such
a heat intensity control.
* * * * *