US 2235138 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Matth 18, 1941.' j 1 H, A BILLETTER l 2,235,138
'runnAPnu'rIcAL APPARA'rusl K -Fi-led April 28, 19sa 2 sheets-sheet 2 f// 95 sv i s Fg 8- F127 HAum AxLLErrrER @the output shaft of the above mentioned d.speed reducing mechanism, the input shai't of which valve 8| opposite the stem 82 is open and when the valve is positioned in the body 40, this open is driven by pulley 4| which in turn is conveniently driven from the double pulley 34 (Figure 1) by the connecting belt 42. The speed of rotation of the valve 8| may be'varied by utilizing different grooves in the stepped pulleys 11 and I6 asis well understood in the art. It should also be understoodl that various meansto vary the speed of rotation of the valve, other than that shown, may be used for the purpose with equal results. Inasmuch as the motor 8l rotates at a substantially constant speed, and a continuous mechanical driving connection exists between the motor and the valve, the valve will rotate at a uniform constant speed, the rate of which is determined by the diameter ratios be- ,tween the power transmitting pulleys 38, 34 and 4|, the ratio of the reductiongear housed in 'l5 and the selected diameter ratio between the pulleys 'I6 and 11, and the speed of rotationof the valve will be uniform regardless of the load imposed onthe assembled machine. Thus the frequency of the pressure-suction cycle is positively maintained at the prescribed rate thereby elimihating-any danger of harm to the patient due to variations in the frequency. Also the smooth, uninterrupted Vmovement of the valve results in quiet operation of the device and freedom from mechanical breakdowns.
Valve 8| is provided with a pair of axially spaced circumferential slots 84 and 83 adapted to register with the ports in the sidewall of the valve body 40 which ports are\connected with the inlet and outlet. respectively, of the pump i0. The slots 83 and 84 are diametrically opposed. as shown in Figures 6 and '1, to alternately uncover the said ports thereby alternately connecting the inlet' and outlet of pump I8 with the space within the valve 8i. The end of the end is substantially in the plane of the open end of the body. A cover plate 88, having the conduit 43 extending therethrough, is secured to the open end of the body 4l, as by the machine screws 88, thereby providing communication between conduit 43 and the space within valve 8|. i The proportion of time within each cycle allotted tothe pressure phase and to the vacuum phase is determined, of course, by the relative lengths of the circumferential slots 83 and 84. By lengthening slot 84 and correspondingly shortening slot 83 a greater portion of each cycle will be devoted to the suction or negative pressure phase and a lesser portion to the positive pressure phase. The features of construction of the valve described enblean adjustment of this nature to be quickly made. Itis only necessary to remove cover 88 and pulley 'I'l to enable the valve 8| to be removed. A second valve having vdiii'erent relative lengths of slots may then be inserted and the pulley 11 and cover 88 replaced.
This change may be accomplished in a very short time and by one not particularly skilled in mechanical work. A
In order to prevent the lapse of a considerable interval of time between the termination of the negative phase and the attainment of proper pressure in the boot 50 for the positive phase, I provide a third port inlthe side wall of the valve body 40 axially spaced from the two ports above mentioned and in this third port I secure the member shown in Figures 8 yand l9 which member consists of a body 35 having a bore 95 therethrough with tapered seat against which a check ball 98 is adapted to. abut. Valve body 3| is provided with an aperture 85 axially aligned with the third bore of the valve body and positioned circumferentally between the negative phase termination end of the slot 84 and the positive phase beginning end of the slot 83. Now as the slot 84 moves past the suction port of the valve body and the port is closed the partial vacuum remains in the boot, conduits and valve, and if the pressure phase of the cycle were relied on to both bring up the pressure to atmospheric value and to the positive pressure desired for the positivephase a considerable volume of air would be required and the time allotted to the positive phase would be considerably advanced before the proper pressure is reached. Upon the closing of the suction port in the valve body the third port therein isy opened by the aperture 85 in the valve 8| and air is drawn into the valve and boot past the check valve 96 to restore the pressure to atmospheric value before the beginning of the measured positive phase of the cycle.
Interposed between the pump outlet I2 and the pressure port in the valve body 40 are the pres- I sure relief valve Ill-wand the manually controlled valve 2|. As shown, the pressure relief valve consists of a body 4 having an internally threaded bore therein with an inwardly tapering shoulder forming a seat for the ball I5. Ball l5 is urged inwardly by the spring I8 the outer end of which abuts against the adjusting member Il screw-threaded into the bore of body |38. Member il is provided with a passage therethrough to communicate with the bore through body iti and is provided with an enlarged outer exposed end for the purpose of providing a grip and to serve as a container for fibrous material i8 which muiiies the sound oi' the outmoving air. The pressure required to unseatyalve l5 is determind by the pressure exerted by the spring i6 and this pressure may be varied by adjusting the position of the member il as will be apparent. Thus the upper limit vof the pressure produced by the pump may readily be varied.
Interposed between the suction port of valve body El and the pump inlet I3 are the suction relief valve 25-29 and the manually operated valve 3|. The suction relief valve consists of a body 25 having an internally threaded bore extending therethrough and a shoulder against which the inner end of a spring 29 is adapted `to seat. A member 28 having a bore extending therethrough is threaded into the bore of body 25 and is provided on its inner end with a seat against which the spring pressed ball 28 is adapted to rest. Member 28 is formed with an enlarged outer end to provide a grip and a container for suitable filtering and noise muiiling material 2l. The negative pressure at which valve 28 will unseat may be varied by screwing in and out the member 26 and consequently the lower limit of negative pressure produced by the machine may be controlled.
It should be obvious from the above description that the settings of the controllable relief valves |4|8 and 25-29 determine the negative and positive pressures produced by the pump I0 and since these sources of pressures are alternately connected with the boot 50 through valve 40 the settings determine the negative and positive pressures applied to the extremity within the boot. The settings may be readily altered by rotation of the members and 26 and in practice suitable pressure indicating devices are utilized to indicate the pressures developed so that adlit dit
iustments may be'made in reference to such data.
To prevent/excessive negative or positive pressures from accidentally building up in the boot, suitable pressure and suction relief valves 54-59 and [9E- 10, respectively, are inserted in the conn duit 43 leading from the timing valve to the boot. These are conveniently supported on the pipe l"s 44 and 45, respectively, and the first consista oi a body 64 having a bore extending therethrough with an inwardly tapering seat I to receive the check ball 5G, the bore being internally threaded to receive the screw member 59 which is provided with a bore 59 in communication with the bore of the body 54. The outer end of screw bd is diametrically slotted to receive a tool i'or turning the screw. A spring 51 is interposed between the inner end of screw B9 and the ball itt and urges the latter against the seat 55. By
adjusting the position of screw 59 the pressure at which the valve will unseat may be regulated.
The negative pressure safety valve consists oi a body 65 provided with a bore in communica tion with the conduit 43 having a shoulder against which the inner end of a spring 69 is adapted to rest. A hollow screw member 96 havine,r a valve seat 61 on its inner end is threaded into the body t5 and a ball B8 is interposed between the seat and the outer end of the spring til. Excessive negative pressure in the line 43 and boot 50 will cause ball 61 to move inwardly in opposition to the outward force exerted by the spring and bring the pressure within the boot to the desired value. The pressure at which the valve t'l-EB will open may be altered by adjusting the position of the screw E6 as will be wel] understood.
lin operation, the boot 50 is connected with the machine by means of the flexible tube 49 and conduits 4d, 49 and 43 and if two or more` boots are 'used simultaneously the other boots may be connested to the connector 46 by removing plug 41,
ior example, and inserting a second pipe corre dit to start the machine.
spending to member 48. The frequency of the cycle and the pressure phase distribution within the cycle having been determined and taken care oi by the proper selection of a valve 8| and grooves oi the pulleys 16 and 11, the motor 31 is energized The prescribed positive and negative pressure values are then attained by manipulation of the members I1 and 26 of the pressureand suction relief valves adjacent the pump or by manipulation of the valves 2| and 3| in case the members I1 and 26 have previously been adjusted for maximum positive and negative pump pressure capacity. The rotating valve BI alternately connects the boot or boots with the inlet i3 and outlet l2 of the pump I9 in rhythmical sequence to provide the manner of treatment prescribed. When the inlet is so connected, the port in the side wall of valve body 40 is covered and conduit is consequently closed. The air which is being exhausted from the boot is discharged through relief valve I4-l8 as the pressure builds up in line 20. When the outlet of the pump is connected with the space within valve 8l and consequently with the boot, the suction line --32 is closed and air required to be taken into the pump to produce the required pressure in line 20 and the boot is taken into the pump through suction relief valve 25-29. It can thus be seen that the relief valves i4-I8 and 25--29 perform two functions-regulating the pressures generated by the machine and providing an inlet and outlet for the air required for the operation of the machine. The design and arrangement of the parts enable these complex functions to be satisfactorily accomplished by the simple, inexpensive and durable means shown.
It can thus be seen that I have provided a simple and inexpensive apparatus for carrying out the treating method stated and that the ob jects are accomplished by the use of simply' de signed and rugged parts which are operable with a minimum of noise and vibration and which are unlikely to get out of order. The apparatus can be used with any number ci boots to simultaneously serve a number oi patients and the irequency oi the cycles and the pressures produced will not vary because oi the addition or removal oi any of the boots since the timing and presm sure regulation is not dependent in any way on the pressures existing in any of the boots. lit is also possible to position part oi the apparatus, as the motor and pump in a separate room leaving the pressure adjusting and timing mechanisms in the patients room.
It should be observed that none of the air exhaunted from the boots is reintroduced back into the boots and consequently the boots are well ventilated by substantially a complete change oi air every cycle and ii a plurality of boots on different patients are used at the same time no objectionable intermingling of the air in the various boots takes place. By placing a suitable filter in the bore 91 oi' member 95 (Figure 9) all air inlets to the system will be provided with iilters and consequently any air coming into the boots by reason of operation of the apparatus will be filtered. The ilters perform the added function oi mailling the sound oi the moving air.
The above specifically described embodiment oi my inventionshould be considered as illustrative only as obviously many changes may be made therein without departing from the spirit or scope oi my invention as deiined in the appended claims.
Having thus fully described my invention what I claim is:
1. In an apparatus of the character described having a sealed chamber for the reception of an `extremity of the human body, means to rhyth- 4Jmically vary the pressure within said chamber comprising means to produce positive and negative fluid pressures, means to alternately connect said positive and negative pressures with said chamber comprising a valve body having a cylindrical bore with a pair of ports in its side wall connected with said sources of positive and negative pressures, a hollow valve rotatable within said bore and being provided with circumferentially extending slots in its side Wall adapted to alternately register with said ports, means to connect the space within said valve with said chamber, means to continuously rotate said valve, and means supporting said valve for quick removal from said bore whereby valves having slots of different lengths may be readily interchanged to vary the relative time allotted to said positive and negative pressures.
2. In an apparatus of the character described having a sealed chamber for the reception of an extremity of the human body, means to rhythmically vary the pressure within said chamber compricing a fluid pump for producing positive and negative fluid pressures at its outlet and inlet, respectively, a valve assembly having a first port connected with said outlet, a second port connected with said inlet, and a third port connected with said chamber, means to simultaneously cover said rst and second ports,means to alternately uncover said first and second ports whereby said ports are alternately connected with said third port and said chamber, a pressure relief valve connected with Said pump outlet, and a suction relief valve connected with said pump inlet.
3. A structure according to claim 2 in which said two last mentioned means consist of a continuously moving member having closed spaces to cover said ports and open spaces to uncover said ports.
4. In an apparatus of the character described having a sealed chamber for the reception of an extremity of the human body, means to rhythmically vary the pressure within said chamber comprising sources of positive and negative uid pressure; a valve assembly having a port connected with said source of positive pressure, a port connected with said source of negative pressure, a port connected with said chamber and a port connected with the atmosphere; said valve including means to iirst connect said second port with said third port, then to connect said fourth port with said third port and then to connect said first port with said third port in sequence, and means to operate said valve in predetermined time sequence.
5. In an apparatus of the character described having a pressure member adapted to be applied about a member of the human body, means to supply controlled and intermittentpressure to said member comprising a source of positive fluid pressure, means to intermittently connect said source with said member comprising a valve body having a cylindrical bore with a port in its side wall connected with said source, a hollow valve rotatable within said bore and Abeing provided with a circumferentially extending slot in its side YWall adapted to register with said port for a length of time determined by the length of said slot and the speed of rotation of said valve. means to continuously rotate said valve at a uniform rate, means to connect the space within said valve with said member, means supporting said valve for quick removal from said bore wherebyvalves having slots of diierent lengths may be readily interchanged to vary said length of time, and an adjustable pressure relief valve in the means connecting the space within the valve with said member.
6; In an apparatus of the character described having a pressure member adapted to be applied about a member of the human body, means to supply controlled and intermittent pressure to said member comprising a source of positive fluid pressure, means to intermittently connect said source with said member comprising a valve body having a cylindrical bore with a port in its side Wall connected with said source, a second port in the side wall of said body circumferentially spaced from said irst mentioned port, a hollow valve rotatable Within said bore and being provided with a circumferentially extending slot in its side Wall adapted to alternately register with said ports for lengths of time determined by the length of said slot and the speed of rotation of said valve, means to continuously rotate said valve at a uniform rate, means to connect the space Within said valve with said member, means supporting said valve for quick removal from said bore whereby valves having slots of different lengths may be readily interchanged to vary said lengths of time, and an adjustable pressure relief valve in the means connecting the space with- Tin the valve with said member.
HALTON A. BHLET'I'ER.