Cervically adjustable chiropractic treatment table

A headpiece and headpiece coupling arrangement to be used in conjunction with a chiropractic treatment table, allowing the practitioner to select any one or more of six different modes of movement of the headrest relative to the main portion of the treatment table is disclosed. In addition to the somewhat conventional pivotal motion about a horizotal axis, the present invention provides the practitioner with pivotal motion about a vertical axis, linear extensin or traction, rotation of the headpiece about a longitudinal axis coinciding with the patient's spinal column, auxiliary flexion of the headpiece about a horizontal axis, and an abrupt limited motion for bringing a patient's head forward and downwardly, imparting a snapping action to the cervical spine. The latter two modes of movement are mechanically linked to the rotation of the headpiece.

BACKGROUND OF THE INVENTION 
The present invention relates generally to chiropractic treatment tables of 
the type for generally horizontally supporting a patient in a face-down 
position and, more particularly, to such tables having a wide latitude of 
variability in orienting and moving the cervical portion of the patient's 
spine. With such an arrangement, a chiropractor or other practitioner can 
select appropriate positions and motions tailored to the particular 
patient's disorder of the cervical curve of the spinal column. 
The treatment of various maladies of the human body by means of the 
manipulation of the muscles and skeletal structure thereof, commonly 
referred to as "chiropracty," has become a widely used and accepted art. 
Various apparatuses have been developed to facilitate this type of 
treatment, one such apparatus being an articulated treatment table. Such 
tables, such as, for example, the "Barnes Flexion-Distraction" 
manufactured by Custom Tool, Inc., Fort Wayne, Ind. typically include an 
elongated, padded platform or table on which a patient can recline. The 
table is further provided with means for securing the patient's 
extremities, e.g., the patient's ankles, and includes an articulated lower 
anterior body section which underlies the patient adjacent the lower back. 
The table provides means for tiltably raising and lowering (extension and 
flexion, respectively), laterally bending, rotating and extending the 
anterior body section with respect to the upper body or support section. 
Such treatment tables have proven to be valuable aids to the practitioner 
of chiropractic medicine and various treatments for patients suffering 
from spinal and related nerve, muscle, and skeletal maladies have been 
devised using such tables. Among the many options available on the tables 
manufactured by the assignee of the present invention have been 
power-driven or automated arrangements for moving the anterior body 
section with respect to the upper body support as illustrated in U.S. Pat. 
No. 4,489,714, and arrangements for tilting about a transverse horizontal 
axis and a headrest segment of the upper body support section of the 
table. Such tilting of a headrest about a transverse horizontal axis is 
also illustrated in U.S. Pat. No. 1,938,006. 
Each of the aforementioned arrangements for tilting or pivoting the 
headrest portion of a chiropractic table relative to the main support 
arrangement of that table have been limited to a single degree of freedom, 
namely, pivotal motion of the headrest about a transverse horizontal axis, 
generally separating that headrest portion from the main body of the 
table. Such a pivotal motion is highly desirable in treating certain 
disorders of the cervical portion of the spine; however, it is frequently 
desirable for the practitioner to be able to move the cervical portion of 
the spinal column in other than a simple forward tipping motion. With 
these prior treatment tables, such other motions could only be 
accomplished by the doctor physically moving the patient's head relative 
to the head support portion of the table. It is therefore highly desirable 
for the practitioner to have a wider variety of table support motions 
available to him. 
U.S. Pat. No. 4,649,905 provides such a variety. According to that 
application, a patient having a disorder of the cervical curve portion of 
the spinal column may be treated by supporting the patient in a generally 
horizontal, face-down attitude on a chiropractic treatment table, with the 
patient's body resting on a first table portion such as a body support 
section, and the patient's head resting on a second table portion such as 
a headpiece, which is selectively movable relative to the first table 
portion, the practitioner thereafter simultaneously moving the patient's 
head and the table headpiece relative to the patient's body and the first 
table in a manner so that the head and body continuously remain in contact 
with the respective table portion and with that movement including one or 
more of the following motions: 
rotation or pivotal motion about a horizontal, longitudinal axis passing 
lengthwise along the patient and through a cervical portion of the 
patient's spine, thus allowing a twisting motion from side-to-side to be 
imparted to the patient's head; 
rotation or pivotal motion about a generally vertical axis extending 
generally perpendicular to and through a cervical portion of the patient's 
spine, thus allowing a lateral flexion or side-to-side head motion in a 
generally horizontal plane; 
a tilting forward and backward or vertical flexion of the patient's head by 
pivotal motion of the head support about a generally horizontal transverse 
axis which was, prior to the present invention, the motion available with 
the above-noted prior art devices; 
a linear translation to stretch a cervical portion of the patient's spine 
to induce a traction in the cervical spine portion; and 
a snap action or drop wherein the headpiece executes an abrupt oblique 
linear translation downward and away from the main body support section of 
the table, imparting a stretching and forward snapping action to a 
cervical portion of the patent's spine. 
According to applicant's U.S. Pat. No. 4,649,905, rotation or pivotal 
motion about a horizontal, longitudinal axis passing lengthwise along the 
patient and through the cervical portion of the patient's spine is 
accomplished by an improved mechanical coupling which includes an 
elongated support bar articulately coupled near one end thereof to the 
body support section of the table and a pair of arcuate rails fixed to the 
head support section and relatively movable along a pair of rail-receiving 
fixtures on the support bar. The rails are formed in the general 
configuration of portions of circles, the centers of which coincide with 
the longitudinal axis. The rail-receiving fixtures may include a plurality 
of rail-engaging rollers along with a manually actuable clamp for 
selectively securing the rail section to the fixture at a preferred 
rotational orientation of the head support section relative to the body 
support section. The head support, arcuate rails, and fixtures may be 
longitudinally movable along the support bar and the support bar 
articulately coupled to the body support section to provide desired 
traction, vertical flexion, and lateral flexion of a patient's spine 
portion. 
SUMMARY OF THE INVENTION 
While all of the above-described features result in a wider variety of 
positions of the patient's body and enable the practitioner to maintain a 
greater degree of control over those positions, the present invention 
provides a treatment table having even greater flexibility and body 
control. According to that copending application, the head support section 
may be abruptly translated through a limited distance obliquely downward 
and away from the body support section due to the presence of a sliding 
interconnection forming part of the articulate coupling. This arrangement 
enables the practitioner to perform the snap action or drop while the 
patient's head is in a rotated position relative to the spinal column. 
However, since the mechanism permitting the drop is formed as part of the 
articulate coupling between the headpiece and the body support sections of 
the treatment table, the drop is always downwardly in a fixed path 
independent of any rotated position of the headrest, since practitioners 
customarily perform the snap or drop motion downwardly and in a plane 
perpendicular to the main body support. They, therefore, may tend to avoid 
a drop when the headpiece is in a rotated position, since the drop would 
exert a displacing motion with respect to the natural curvature of the 
spine. 
As was previously noted, the tilting and backward or vertical flexion of 
the patient's head is also about a generally horizontal, transverse axis 
which passes through the articulate coupling. This axis is substantially 
displaced downwardly from the surface of the body support section of the 
table, and tends to displace the entire headpiece downwardly or upwardly 
relative to the surface of the main support portion of the table. 
According to the present invention, a chiropractic table is provided having 
the aforementioned five degrees of freedom provided by the table set forth 
in U.S. Pat. No. 4,649,905 and provides an improved mechanism for 
providing a drop or snap action in a direction which is fixed with respect 
to the headpiece for all rotated positions of the headpiece, thus 
providing a more natural and controlled movement for the practitioner. 
Furthermore, according to this invention, the degree or length of travel 
of the drop may be adjustably selected by the practitioner. A mechanism is 
provided which will releasably lock the headpiece in a first or raised 
position and which will be released as a function of applied pressure. The 
practitioner may establish a reference point for a particular patient by 
adjusting the release mechanism and permitting the patient's head to drop 
without applying external pressure and then setting the release mechanism 
to a desired predetermined release pressure beyond that pressure exerted 
by the patient's head. 
An additional degree of freedom is provided by pivoting the headpiece 
relative to a carriage which may be rotated in an arcuate track, so that 
by adjusting the pivoted attitude of the headpiece in conjunction with a 
pivoted attitude of the articulate coupling, a more precise control is 
maintained over the flexion or extension of the patient's spine in the 
neck area of the patent. 
These functions are obtained by a mechanism which provides arcuate movement 
of the headpiece about a cervical axis spaced above the plane of the table 
and parallel to a longitudinal axis of the treatment table. A locking 
mechanism is provided which locks the headrest in any one of a 
multiplicity of positions along an arc. The mechanism provides at least 
one additional degree of freedom for the headpiece in a direction located 
in a plane normal to the headpiece and passing through the cervical axis 
when the headpice is in any one of its rotated positions. According to 
narrower aspects of this invention, two additional degrees of freedom are 
provided, with one of the degrees of freedom being arcuate about an axis 
passing through the headpiece and the other one of the degrees of freedom 
being rectilinear and mechanically linked to the rotated carriage carrying 
the headpiece.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to the drawings, and in particular to FIG. 1, there is 
illustrated a chiropractic treatment table incorporating a presently 
preferred embodiment of the present invention. Generally speaking, the 
treatment table of FIG. 1 is of the type having a support pedestal 11 
resting on a floor-engaging base 13 and having an upper body support 
section 15 resting on the pedestal 11. An anterior body support portion 17 
extends from the main body support portion and the pedestal 11 toward the 
right as viewed, while a headpiece or head support portion 19 extends from 
the upper body support section 15 toward the left as viewed. The upper 
body support section 15 and the anterior portion 17 for supporting a lower 
portion of the patient's body, as well as the relationship between those 
two sections, and the support pedestal 11 are largely conventional and 
may, for example, be constructed such as in the aforementioned copending 
applications for the aforementioned known devices. 
Briefly, the uppermost portions of the upper body support section and the 
anterior support section 17 comprise cushions 21 and 23 upon which a 
patient may rest in a prone or face-down, generally horizontal position 
during treatment. Examination and treatment of numerous lubar and lower 
thoracic spinal column disorders are facilitated by the numerous relative 
motions between the upper body support section 15 and the anterior support 
section 17, which are selectively available to the practitioner. For 
example, traction in the general direction of elongation of a patient's 
spinal column, with the patient's ankle secured in stirrups 25, may be 
induced by rotation of a crank handle 27. Lateral flexion, i.e., moving 
the lower support section 23 pivotally about the support pedestal 11 in a 
horizontal plane, is achieved by releasing a locking handle (not shown). 
Flexion, i.e., pivotal motion of the lower body support section 17 about a 
horizontal axis, is facilitated by a pair of tension springs 31 which tend 
to oppose or counterbalance the weight of the patient's lower body section 
on section 23, with spring tension being under the control of the handle 
33 and selectable to match the weight of a particular patient. The lower 
body support section may also be rotated about a generally longitudinal, 
horizontal axis passing approximately through the elevation of the pivot 
35. The relative motions between the main body 15 and the lower body or 
anterior support sections 17, as thus far discussed, are conventional and, 
while present in both the applicant's presently preferred embodiment of 
the present invention and in the known prior art, are optional to any 
particular embodiment of the present invention. 
In the known prior art chiropractic treatment tables, the headpiece 19, 
including an upper headrest cushion, was formed either with the cushions 
37 and 21 as an integral one-piece cushion or, in some cases, as two 
separate cushion portions, the headrest of which was pivotable only about 
a horizontal axis relative to the main body support section 15. 
Applicant's U.S. Pat. No. 4,649,905 and the present invention provide a 
wide variety of relative motions or degrees of freedom to the headpiece 19 
relative to the main body support section 15. These motions, of course, 
may be employed in any practitioner-selected combination but will, for 
clarity, be discussed individually. 
Cervical spine flexion in the form of an up-and-down headpiece pivotal 
motion about the horizontal axis 39 is best seen in FIG. 11, with certain 
details thereof illustrated in FIG. 12. The horizontal axis 39 is coaxial 
with that of a pin 41 which is slidably and rotatably received in a bore 
43 provided in one end of a headpiece support bar 45. The end of the 
support bar 45 through which the pin 41 passes is formed as a gear 47 
which meshes with a toothed link 49 that is pivoted about a pin 51. The 
headpiece support bar 45 is counterbalanced in a clockwise direction as 
viewed in FIG. 11 by a compression spring 53 mounted in a cylinder 55 
which exerts a downward force on a piston 57 which is pinned to the link 
49 by a pin 59. 
The bar 45 may be locked in any one of a number of preselected, rotated 
positions about the axis 39 by a clamping mechanism which includes a 
plurality of hinged leaf plates 65 which are provided on the sides of the 
support bar 45 and fixed thereto by bolts 67. The bolts 67 are threaded 
into the support bar 45, but permit axial movement of the plates 65 
relative thereto and axial movement of side-retaining plates 69 relative 
thereto. The pin 41 passes through apertures 71 in the plates 65, and also 
through apertures 73 in the retaining plates 69. A plurality of hinge 
plates 75 are loosely mounted on a cross pin 77 for axial movement 
relative to the pin and are interleaved with the plates 65 and, like the 
plates 65, slidably receive the pin 41. 
The pin 41 is provided with an end cap 78 which bears against a thrust 
receiving cap 80. The other end of the pin 41 projects outwardly and has 
cam lock mechanism 82 pivoted thereto by a pin 84. The cam lock mechanism 
82 includes a cam roller 86 which, upon movement of a flexion lock handle 
88 in a counterclockwise direction, is adapted to bear against an end cap 
90 and draw the pin 41 downwardly, as viewed in FIG. 12, to thereby cause 
the thrust plate 80 and a thrust plate 92 to clamp the interleaved plates 
65 and 75 together to securely lock the support bar 45 in a preselected 
position. 
The articulate coupling between the headpiece 19 and the main body support 
section 15, in addition to providing the above-discussed vertical traction 
of the headpiece, also provides a lateral traction or side-to-side motion 
for the headpiece 19, generally about a vertical axis of a mounting plate 
94. The mounting plate 94 has a projection 96 to which a lateral bend lock 
handle 98 is pivoted by a pin 100. The lock handle 98 carries a cam 
locking mechanism 102 which includes a cam roller 104 which, upon 
counterclockwise movement of the handle 98, draws the supporting base 94 
downwardly toward a support shelf 106 fixed to the main body support 
section 15 by a pin 108. The base 94 rests on a plurality of washers 110 
which permit the bar 45 to be rotated in a horizontal plane and which will 
lock the bar 45 in a preselected position upon movement of the handle 98 
in a counterclockwise direction. 
The headpiece support bar 45 projects through the headpiece 19 and is 
provided with a handle 112 to enable the doctor to position the headpiece 
19 relative to the main body support section 15. A traction mode of motion 
is also available to the practitioner in which the headpiece 19 is movable 
linearly and generally horizontally along the headpiece support bar 45. As 
may be seen in FIG. 5, the support bar 45 extends between a traction lock 
housing 114 and a front end plate carriage 116. The mounting bar 45 also 
is slidably received by a rear end plate carriage 118. The end plate 
carriages 116 and 118, and therefore the headpiece 19, may be positioned 
along the support bar 45 and then locked thereto by a tapered wedge block 
120 (FIG. 6) which coacts between the traction lock housing 114 and the 
bar 45 by sliding along an upwardly tapered floor 122 in the housing 114. 
The upper surface 124 of the block 120 has a similar taper so that upon 
movement of the block 120 along the floor, the surface 124 will remain 
parallel to the surface of the bar 45 and will apply an interference to 
movement of the headpiece 19 along the bar 45 to lock the headpiece 19 in 
a preselected position. The block 120 is moved by an eccentric pin 126 
which engages a recess 128 in the block 120 and the pin 126 projects from 
a traction block handle 130. 
During chiropractic treatment of cervical problems, it is frequently 
desirable to impart a twisting or rotational motion to the patient's head. 
Such twisting motion should be generally about an axis corresponding 
generally to the axis of the patient's spinal column. Thus, in effect, a 
pure rotational movement is effected between adjacent vertebra of the 
cervical spine portion. The arrangement for achieving this rotation about 
the spinal cord will now be described. 
A patient's head faces downwardly and rests on the cushions 37, and the 
patient's spinal cord axis is generally indicated at 132. 
The headpiece, and in particular the cushions 37, are connected to the 
support bar 45 by an arrangement which allows limited arcuate movement of 
the headpiece about the axis 132, but without, of course, any direct 
coupling between the headpiece and the axis 132. This coupling arrangement 
includes a carriage 134, which comprises a rectangular box. The carriage 
134 is fixed to front and rear end plates 136 and 138, respectively. The 
end plates 136 and 138 are rotatably mounted on the front and rear end 
plate carriages 116 and 118 by means of rollers 140. An auxiliary roller 
142 is provided on a rotational lock housing 144 to coact with an arcuate 
slot 146 in the end plate 136. 
The end plates 136 and 138, and therefore the headpiece 19, may be rotated 
to a preselected position and locked in that position by means of a 
locking device. The locking device includes a rotation lock clamp 148 
loosely mounted on a rotation lock bolt 150, which projects as a portion 
of a rotational lock body 152 between the end plate 136 and the end 
carriage 116. The body 152 has a bore 154 therein, which carries a cam 
lock bar 156 associated with a rotation lock handle 158. The bar 156 has a 
relieved portion 160. The locking arrangement shown in FIG. 5 is in a 
locking condition, with the lock clamp 148 drawn against the end plate 
136. When the handle 158 is rotated upwardly in a counterclockwise 
direction, the relieved portion 160 permits movement of the block 152 to 
the right, as viewed in FIG. 5, to release the pressure exerted by the 
clamp 148 on the end plate 136. The rotated position in degrees may be 
provided on the end plate as visible indicia 162 and a pointer 164 which 
is an extension of the block 148. 
An additional degree of freedom is provided in the headpiece which supplies 
auxiliary flexion to the headpiece. Referring to FIG. 7, the cushions 37 
are pivoted to a carriage 166 at a pivot connection 168. A camp 170 is 
fixed to a cushion support frame 172 and rests on a roller assembly 174. A 
tension spring 176 biases the ramp 170 into contact with the roller 
assembly 174. The cushions 37 may be adjusted upwardly from a horizontal 
position by moving the roller assembly 174 to the left as viewed in FIG. 
7. The roller assembly 174 is threadedly mounted on an auxiliary flexion 
adjustment shaft 178 having an adjusting knob 180. 
A further degree of freedom of headpiece movement is made available to the 
practitioner in the form of a so-called drop or abrupt downward 
translation of the headpiece away from the main body support portion 15 by 
employing a triggered detent arrangement. 
Referring particularly to FIGS. 7 and 10, it may be noted that the carriage 
166 is carried by the carriage 134, and that the carrige 166 is provided 
with oblique slots 182 which coact with rollers 184 fixed to the carriage 
134, so that the carriage 166 is movable in an oblique path relative to 
the carriage 134 between the raised position illustrated in FIG. 7 and a 
lowered or dropped position wherein the carriage 166 abuts an adjustable 
stop 186. 
The carriage 166 is held in its raised or cocked position by a roller 188 
which engages a ramp 190 fixed to the bottom of the carriage 166. The 
roller 188 is adapted to release the carriage 166 from its raised position 
upon the application of a predetermined pressure thereto exerted on the 
roller 188 by pressure on the cushion 37. To this end, and referring to 
FIG. 8, it may be noted that the roller 188 is fixed to a shaft 192 at one 
end thereof and the other end of the shaft 192 has a driven clutch 194 
fixed thereto. Rotatably mounted on the shaft 192 is a combination driven 
pinion gear 196 and drive clutch 198 which is formed as a unitary 
assembly. A drive gear 200 meshes with the spur gear 196 and is fixed to a 
shaft 202 to be driven thereby and is biased by a plunger 204 (FIG. 10) 
and a compression spring 206 in a direction of rotation which will 
disengage the drive clutch 198 from driving engagement with the driven 
clutch 194. Rotation of the shaft 202 is accomplished by a cocking lever 
bracket 205 which is associated with a cocking lever handle 206. 
A downward movement of the cocking lever handle 206, as viewed in FIGS. 1 
through 3, causes the drive gear 200 to rotate the driven gear 196 and its 
associated drive clutch 198 in a direction which drives the driven clutch 
194, and therefore the shaft 192 and the roller 188, to lift the carriage 
166 to the position illustrated in FIG. 7. When the carriage 166 reaches 
its raised position, a ball detent 208 (FIG. 9) registers with a recess 
210 in the surface of the driven clutch 194. The force exerted by the 
detent 208 is determined by a tension adjustment spring 212 which is 
adjustably compressed by a threaded shaft 214 having an adjusting knob 216 
at its end. 
When the detent 208 engages the recess 210 and the operator releases the 
handle 206, the plunger 204 causes the drive clutch 198, the gear 196, and 
the handle 206 to back off out of driving engagement with the nowlocked, 
driven clutch 194. The pressure on the roller 188, which is sufficient to 
overcome the force of the spring 212, is therefore fully dependent on the 
pressure of the engagement of the detent 208 independent of the cocking 
mechanism. 
The practitioner may "pre-tune" the drop to the force applied by him 
independent of the weight of the patient's head by cocking the headpiece 
19 in the foregoing manner, with the patient's head resting naturally on 
the cushions 37. The practitioner would then relieve the tension of the 
adjusting spring 212 by turning the knob 216 until the weight of the 
patient's head released the detent 208. The practitioner would then 
increase the tension on the spring 212 by turning the knob 216 a 
predetermined number of turns, e.g., two turns. The practitioner would 
then be assured that the detent would release to perform the drop 
independent of the weight of the individual patient's head and the 
function of his own exertion. It should further be noted that the drop may 
be accomplished while the headpiece is in a rotated position and in a 
direction corresponding to the direction that the patient's head is 
facing. 
The extent of the drop may be varied by adjusting the adjustable stop 
inwardly or outwardly to control the amount of travel of the carriage 166 
obliquely downwardly along the rollers 184. 
From the foregoing, it is now apparent that a novel, articulate coupling 
between a headpiece and a main body support section of a chiropractic 
treatment table, allowing a wide variety of practitioner-induced 
movements, has been disclosed, meeting the objects and advantageous 
features set out hereinbefore, as well as others, and that modifications 
as to the precise configuration, shape, and details may be made by those 
having ordinary skill in the art without departing from the spirit of the 
invention or the scope thereof as set out by the claims which follow.