Traction device

A portable traction device includes a frame which has an upper surface to support the individual to be subjected to traction. The frame has at least one mounting point at one end of the upper surface. At least one tension member emanates from the frame and has a free end passing through the mounting point and back toward the upper surface of the frame. The free end of the tension member is secured to the individual who is to be subjected to traction. A takeup mechanism for applying tension to the tension member is located on the frame. The takeup mechanism is activated, usually by the patient. The activation mechanism is adapted to disengage when the applied tension reaches a preselected value, while maintaining the preselected tension on the tension member.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to traction devices, and in particular to a 
portable traction device which can be operated by the individual being 
subjected to traction. 
In most modern hospitals, traction is applied to a patient using an 
electrically controlled winch system. The system includes a mechanism for 
setting the winch force needed to obtain the desired tension, and the 
system automatically maintains that tension on the patient. 
While practical in most hospital environments, electric traction systems 
are impractical in many other situations where the application of traction 
is desired. For example, it is often desirable to provide traction in a 
home environment so that persons under traction, but otherwise not needing 
hospital attention, can receive treatment at home. In addition, it is 
often desirable to provide traction in an emergency at a location remote 
from a hospital, or to have traction equipment available in a hospital 
emergency room. In both of these latter situations, it is desirable to 
have traction equipment which is readily portable. 
2. Description of the Prior Art 
The patent literature contains a wide variety of traction devices, some of 
which are portable. Applicant is aware of the following patents which show 
traction devices: French Pat. No. 92,349; British Pat. No. 826,277; U.S. 
Pat. Nos. 951,515; 1,605,578; 1,642,158; 1,915,841; 2,798,481; 2,861,565; 
3,276,444; 3,420,229; 3,554,189; and 3,856,003. French Pat. No. 92,349 
illustrates a traction device operable by the patient. However, these 
devices in general are inefficient, cumbersome and complex, and do not 
satisfy modern medical standards as to the application of traction. 
Specifically, these devices do not provide precise control over the amount 
of traction applied, and they are not failsafe in the sense of preventing 
the application of excess forces which can harm the patient. 
SUMMARY OF THE INVENTION 
The present invention provides a traction device including a frame which 
has an upper surface to support the individual to be subjected to 
traction. The frame has at least one mounting point at one end of the 
upper surface. At least one tension member emanates from the frame and has 
a free end passing through the mounting point and back toward the upper 
surface of the frame. The free end of the tension member is secured to the 
individual who is to be subjected to traction. A takeup mechanism for 
applying tension to the tension member is mounted on the frame. The takeup 
mechanism is manually activated, usually by the patient. A 
tension-adjustment system is provided for automatically preventing the 
takeup mechanism from exceeding a preselected value of applied tension, 
while maintaining such preselected tension on the tension member until the 
patient releases it. 
In the preferred embodiment of the present invention, the activating means 
comprises a manually-operated hydraulic pump mounted on the frame within 
reach of the patient. The takeup means comprises a hydraulic piston and 
cylinder assembly wherein the piston is driven by hydraulic pressure from 
the manually-operated pump and connected to the tension member, typically 
a flexible cable. Thus, the patient can increase the applied tension by 
continuing to operate the manual pump. To allow precise adjustment of the 
applied tension, a device (typically an adjustable relief valve) is 
provided to automatically relieve the pressure on the cylinder once a 
predetermined set point has been reached. Typically, the device will 
return the hydraulic fluid to the fluid reservoir. The range of operation 
of the pressure relief device is chosen so that the tension applied to the 
patient cannot exceed what is considered a safe level, even at its highest 
setting. A dump valve is provided to immediately relieve all pressure on 
the hydraulic cylinder when the patient desires to terminate treatment. 
The present invention thus provides a very simple and convenient traction 
system which can easily be constructed so as to be portable. The entire 
system can be operated by the patient, thus facilitating its use in a home 
environment. Moreover, the device contains a failsale tension-adjustment 
system so that excess traction forces cannot be applied by mistake. 
The novel features which are characteristic of the invention, as to 
organization and method of operation, together with further objects and 
advantages thereof will be better understood from the following 
description considered in connection with the accompanying drawings in 
which a preferred embodiment of the invention is illustrated by way of 
example. It is to be expressly understood, however, that the drawings are 
for the purpose of illustration and description only and are not intended 
as a definition of the limits of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The traction device 10 of the present invention is illustrated generally in 
FIGS. 1-3. FIG. 1 illustrates a patient 12 being subjected to pelvic 
traction, while FIG. 2 illustrates the traction device 10 being used for 
cervical traction. Generally, a patient will be subjected only to one or 
the other kind of traction, but not to both simultaneously. 
The traction device 10 includes a frame 14 which in turn comprises a padded 
board 16, folding legs 18 which may be retracted for transportation and 
storage, and a channel 20 secured axially along the middle of the 
underside of the board 16. 
A pelvic traction post 22 is inserted into a bracket 24 at the foot of the 
frame 14 (to the right as viewed in FIG. 1). A foot bracket 26 is 
detachably secured at its lower end to legs 18 and at its upper end to the 
traction post 22. The foot bracket 26 acts both as a footrest for the 
patient during traction and as a structural member in helping support the 
traction post 22. 
Referring now particularly to FIG. 2, a cervical traction post 30 is 
detachably inserted into a bracket 32 at the head of the frame 14 (to the 
left as viewed in FIGS. 1 and 2). The cervical traction bracket 30 is 
L-shaped and, when inserted in bracket 32, extends outward and upward from 
the frame 14. When using the traction device 10, the patient 12 lies on 
top of the board 16 and is held in place by a counter-traction belt 36 
which is secured around the waist. 
Referring now in particular to FIG. 3, a hydraulic cylinder 40 is mounted 
axially within the channel 20 on the underside of the frame 14. The 
cylinder 40 includes a rod 42 terminating in a block 44 at its distal end. 
As will be described more fully hereafter, the patient may manually 
actuate the cylinder 40 to draw the rod inward (to the left in FIG. 3) as 
a source of tension for the traction device 10. 
A cervical traction cable 46 acts as a tension member and may be secured to 
the block 44 and drawn over an idler pulley 48, as illustrated in FIGS. 3 
and 4. The cable 46 runs along channel 20 toward the head of frame 14 and 
into the cervical traction post 30 until reaching idler pulley 50 (FIG. 2) 
at the junction between the two legs thereof. Cable 46 then runs upward, 
around idler pulley 52 which defines a first mounting point and exits from 
post 30, as shown. The elevation of idler pulley 52 within the vertical 
leg of the cervical traction post 30 is adjustable to vary the angle at 
which the cervical traction is applied. The free end of the cable 46 
connects to a spreader 54 which in turn is attached to a cervical halter 
56 for the application of cervical traction to the patient 12. 
In the case of pelvic traction, a pelvic traction cable 60 (similar to 
cervical traction cable 46 but having a different length) is attached at 
one end to block 44, as illustrated in FIGS. 3 and 4. The pelvic traction 
cable bypasses idler pulley 48 and extends to the foot of the frame 14 
where it enters the hollow pelvic traction post 22. The cable 60 extends 
to the end of post 22 and reverses direction around idler pulleys 62 (FIG. 
1) which defines a second mounting point. The cable 60 extends back toward 
(and generally underneath) the patient 12 where it is secured to a waist 
belt 64 which is wrapped around the patient's lower waist. 
Using the cables 46,60 as described hereinabove, the single hydraulic 
cylinder 40 may be used selectively to apply either cervical or pelvic 
traction. The remaining systems of the present invention are common to 
both types of traction and are designed to apply a preselected pressure to 
the hydraulic cylinder, which, in turn, applies a corresponding tension to 
the patient 12. 
Referring now to FIGS. 3 and 4, the hydraulic system of the present 
invention comprises the hydraulic cylinder 40, a pump and control block 
80, a dump valve 82, and a hydraulic oil reservoir 84. The pump and 
control block 80 includes a pump handle 86 and a micrometer adjustment 
dial 88. Oil from the reservoir 84 enters the pump and control block 80 
where the patient 12, or anyone else, may pump the oil up to a pressure 
which is set by adjustment of dial 88. Hydraulic line 90 connects the 
output of block 80 with the hydraulic cylinder 40 so that the piston 
therein realizes the full output pressure. The normally-closed dump valve 
82 allows the user to relieve pressure from the cylinder to the oil 
reservoir when it is desired to terminate treatment. 
Referring now to FIG. 5, the pump and control block 80 includes an inlet 
port 96 which is connected to the oil reservoir 84. Oil is able to flow 
through port 96 and passed an inlet check valve 98 into a pump cylinder 
100 formed integrally in the block 80. A pump piston 102 is operatively 
connected to the pump handle 86 (as best illustrated in FIG. 4) so that 
the user may reciprocate the piston to pressurize the oil and cylinder 
100. The pressurized oil will pass outward through T-shaped passage 106 
where it may flow past an outlet check valve 108, through an outlet port 
110 and to hydraulic cylinder 40 (see FIG. 4). Alternatively, the oil in 
passage 106 may flow past the adjustable relief valve 112, depending on 
its set point and the pressure in the hydraulic line, as described 
hereinbelow. 
The relief valve 112 is a spring-loaded check valve (defined by seating of 
ball 113 within the passage 106) where the tension on a spring 118 may be 
adjusted by the micrometer adjustment dial 88. Dial 88 is secured to a 
threaded shaft 114 which terminates in seal plug 115 within the valve 
housing. Thus, the seal plug 115 may be moved axially within the housing 
by rotating the adjustment dial 88. Such motion, in turn, adjusts the 
pressure applied on a ball pressure pad 116 by the spring 118. The ball 
113 will remain seated in passage 106 until the pressure in the passage 
exceeds the force applied by spring 118 multiplied by the exposed area of 
the ball. When this occurs, the oil will flow past the ball 113 until the 
pressure is equalized. The adjustment dial 88 will typically be calibrated 
in pounds force applied by the cylinder 40 on the patient 12. 
The pressure in the hydraulic cylinder 40 is a direct function of the 
tension on the associated cable 46 or 60. The tension on the cable (46 or 
60) is, of course, determined by the traction force being experienced by 
the patient 12. Thus, until both the patient 12 and the traction cable are 
under tension, the cylinder 40 will not be pressurized. As soon as a cable 
begins to pull on the patient, however, the pressure in the cylinder 40 
immediately begins to rise. The tension, and the pressure in the cylinder, 
will continue to rise as the user reciprocates handle 86 until the 
pressure in cylinder 40 exceeds the set point of the adjustable relief 
valve 112. 
The relief valve 112 will be calibrated in pounds tension applied by the 
cylinder to the patient, typically in the range from 0 to 200 pounds. Such 
a range provides for both gentle cervical traction and the necessary 
heavier pull for pelvic traction. Once reached, the desired traction force 
will be maintained by the hydraulic system. After a time, however, the 
patient may relax and by so doing relieve pressure from the system. Should 
this occur, the patient need merely work the pump a little bit more to 
restore the desired pressure to the system. The patient need not worry 
that excess traction will be applied since the relief valve 112 prevents 
such overstressing. 
The traction device 10 can be readily carried from one place to another 
until needed. Both pelvic traction post 22 and cervical traction post 30 
may be removed from the frame 14 and secured to the underside thereof. 
Similarly, foot bracket 26 may be removed and stored on the underside of 
frame 14, while legs 18 fold up. Traction device 10 is then ready for 
transportation or storage. 
While a preferred embodiment of the present invention has been illustrated 
in detail, it is apparent that modifications and adaptations of that 
embodiment will occur to those skilled in the art. However, it is to be 
expressly understood that such modifications and adaptations are within 
the spirit and scope of the present invention, as set forth in the 
following claims.