US1338905A - Anesthetic apparatus - Google Patents

Description

A. c. CLARK.

ANESTHETIC APPARATUS.

APPL1cAT1oN HLED 11111118.1914.

Patented May 4, 1920.

2 SHEETS-SHEET l.

A. c. CLARK.

ANESTHETICVAPPABATUS. APPLICATION FILED MAY Is. 1914.

y 2 SHEETS-SHEET 2.

Ez ven for Z6 NITED OFFICE.

ALBERT CHARLES CLARK, or CHICAGO, ILLINOIS, A'ssIeNOR To A. C. CLARK a oo., OF CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.

ANESTHETIC APPARATUS.

Specification of Letters Patent.

Patented May 4:, 1920.

Application filed May 18, 1914. Serial No. 839,228.

To @ZZ lw/wm it may concern.'

Be it known that I, ALBERT CHARLES CLARK, a citizen of the United States, residing at Chicago, in the county of Cook and State Oi" lllinois, have invented certain new and useful Improvements in Anesthetic Apparatus, of which the following is a specilication.

My invention relates to apparatus for administering a mixture of nitrous' oxid and oxygen gases for producing analgesia and anesthesia, as widely practised in dentistry, and also to some extent in surgery, and particularly concerns the provision of e'liicient and sensitive means for reducing and regulating the pressure of the gases which pass from the compressed gas cylinders to the gas bags of apparatus of a well known type, in general similar to that shown and described in my pending application for Patent No. 686,252, so that a uniform pressure may be maintained in each bag and the proper proportion of each gas may pass to and through the mixing passages of the apparatus to the breathing or inhaling devices. Prior to my invention pressure-reducing and regulating devices have been employe/d which have employed a diaphragm acted upon by the gas admitted under high pressure to an expansion chamber and controlling the reducing valve opening; but the use of a diaphragm, which l have avoided in my present invention, is objectionable because of the danger of rupturing the diaphragm or of distorting it beyond usefulness, and because the irregular and sudden expansive action of the compressed gas entering the expansion chamber is liable to cause a chattering of the valve which strains the diaphragm and impairs the uniformity of action of the valve, and because such valves, as heretofore constructed, are peculiarly liable to freezing, as a result of the cold produced by the sudden expansion of the gases adjacent the restricted passage leading into the diaphragm chamber. j

The object of my invention is to provide j nessure-reducing and regulating means free from the objections'to prior apparatus above mentioned, and which shall have various advantages and features of novelty and utility which will beapparent from the description hereinafter given, and the essential elements of which are pointed out in the appended claims.

In the drawings, Figure 1 is a top plan -view of an anesthetic apparatus in which my invention is embodied; Fig. 2 is a section on the line 2-2 of Fig. l; Fig. 3 is a section on the line 3-3 in Fig. l;l and Fig. 4 is a section of the reducing valve, in the same plane as Fig. 2 but on a larger scale; and Fig. 5 a detail showing the scale for the adjusting collar.

rlhe same letters of reference indicate the same parts in the several figures of the drawings. Y

In order to make clear the present invention it will be necessary to briefly describe anl anesthetic apparatus to which it may be applied, or in which it may be` embodied. From the base of the apparatus (not shown) rises a post l, upon the top of which is mounted a casing 2 having two extensions 2. with two passages 3 and 4, communicating one with the supply of nitrous oxid and one with the supply of oxygen, and communieating respectively with ports 5, 6, both or either of which are adapted to be placed in V communication with a large port 7 in one side of a hollow plug valve 8, the other side being provided with a port 9 communicating with mixing passages 10 on the inside of the casing, tl e mixed gas passing from the casing'through` the gas administering hose ll to a suitable inhaling device. The handle l2 of the mixing valve is provided with a lsuitable indicating device and dial marked to indicate the different positions of the valve, and the relative proportions of the 'different gases admitted at such positions.

In the form of apparatus shown, .each of the extensions 2u of the casing supports at its sides a pair of opposite tubes or arms 13, 13, each of the Outer ends of which terminates in a closed yoke 14- adapted to receive the head of a gas cylinder 15. The arms of one extension are designed to receive cylinders containing nitrous oxid, and the other cylinders containing oxygen, under the usual high degree of compression Of from about nine hundred to fifteen hundred pounds to the square inch. Transversely arranged with respect to the arms, 13, 13 and extending in opposite directions from what may be termed the outer ends of the extensions 2a, are arranged two tubes or arms, 16, 16 to the outer ends of which the gas bags 28, 28 for nitrous oxid and oxygen, respectively, are secured. The ports and passages for controlling and supplying the two O'ases may be, and are in the apparatus described, alike, and for convenience of description and illustration, similar parts are numbered alike, excepting that the parts relating-sto the distribution of one gas, as oxygen, are marked with prime, while the parts relating to the distribution of nitrous oXid are not so marked.

One feature of my present invention re-A lates to a provision for supplying each of 'the different gases either' through throttled,

thoughk unregulated passages, or through the regulating and reducing valve which is the principal feature of my invention. The passages for the direct flow of gas-will-therefore now be described.

rlhe head 17 of each gas cylinder is formed in the usual manner with an outlet passage governed by an outlet valve and permitting a throttled flow of gas through a supply passage extending at right angles to the outletpassage. The outer end of each tubular arm 13 is formed with a horizontal bore within which is arranged a valve bushing 18 communicating with a block 19 arranged. to rest against the inner face of the yoke 14 and which is formed with a passage communicating with the supply passage of the gas cylinder. A nut 20 is provided to clamp thev valve bushing in place in the bore in the arm 13. A rotary or plug valve 21, in the present instance, though not necessarily,

- tapered in shape, 1s seated in the bushing 18 and is equipped with a handle 22 by means of which it may be turned to admit the gas into the interior passage of the arm or tube 13.

The inner ends ofthe passages in the pair' of tubes 13 communicate with an annular passage 23, such passage lying between the tube 16 associated with thev tubes 13 and an inner tube 24, this latter tube being in communication with the passage 3 (or the passage 4, as the case may be) of the casing. The outer end of the annular passage Q3 is in communication, through the passage 25, and connecting open passages through the casing of the reducing and regulating valve which will later be described, with the gas bag 23, and also with the passage through the inner tube 24, the result of this arrangement being that under the direct, though throttled flow of gas thus far described, the gas bag will act as an elastic reservoir for gases passing through the direct flow valve 21 to and through the mixing valve 8. 1n the passage through which flows the oxygen gas, a check valve 27 is provided intermediate the gas bag and inner tube 24', to prevent a back flow of gas, but in the present instance the passage for the nitrous oxid gas is left wholly unobstructed.

The casing of the reducing and regulatydrical portion having screw-threaded engagement with the approximately cylindrical upper member and a depending irregular gooseneck portion to which the nozzle of the gas bag 2S is secured. The interior of the tube 16 andthe inner tube 24 are bothin communication with the gas bag through a series of ducts 31, a chamber 32, and a passage 33 in the depending gooseneck portion of the casing. Through passages in the block 19 and a pipe 34, communication is provided for the passage of gas from the cylinder 15 to a passage 35 formed in the casing member 29. The lower end of surh passage terminates in a'coned inlet nozzle 36 secured' in said casing member and hav-A ing a restricted or contracted gas port.

The lower part of the chamber 32st the casing is formed with a screw-threaded opening for the reception of an eXteriorly threaded bushing 37 which has at its outer end au interior coned surface adapted to receive packing 37a and a cylindricalr bore forthe reception of a plunger 38. A packing nut 39, perforatedto receive the plunger 33, is provided to inclose and compress the packing. The upper end of the plunger is equipped with a valve seat 40, which is preferably formed of a fiber composition or material having similar characteristics, and the plunger is pressed downward to normally open communication through the valve by a compression spring 41interposed between the valve casing and a shoulder on the plunger. The lower end of the plunger is bored to receive a sliding plug 42 formed with a shoulder near its lower end and a coned bearing below such shoulder, which plug normally is yieldingly pressed' downwardly by a relief spring 43 so that the shoulder will contact with a cap 44011 the plunger constituting a stop for the plug. The spring 43 is-of suiiicient strength to force the plunger 328 upward against the stress of the spring 41 and maintain the valve seat 40 in closed position aga-inst the valve nozzle 36 in the normal operation ofthe reducing valve mechanism, but when the plug 42 is forced to a still more elevated position', as hereinafter explained, the spring will be compressed, andinjury which would other'- wise be done to the' valve seat is avoided.

The plunger 38 is raised and lowered, to eil'ect a regulated supply of gas through the valve 36, throughthe expansion of the gas bag 218. To this end a frame 45 is provided, this frame having at its lower central portion a seat arranged toV receive and coperate with the coned lower endof the plunger, and being provided with upwardly extending arms 4G formed with bearings in which are pivoted levers 47 having long downwardly extendingl arms 48 terminating in disks 49 which are arranged tobe .acted upon by the gas bag. The gas bag 1s '1nclosed in a net 50 in the practical operation of the device, and this net is important 1n producing an effective contact with the arms. The upper ends of the levers 47 are fulcrumed upon the flange 5l of an adjustable collar 52, which has a screw threaded engagement with the casing member 29 so that by turning the collar and flange may be raised or lowered to vary the fulcrum point of the lever arms.

It will be understood that the pressure in the gas bag is but slight when the bag is nearly deflated, but increases regularly as the bag is more and more distended. In the apparatus illustrated and described, the pitch of the screw threads of the collar, the elasticity of the bag, and the arrangement and adjustment of the parts is such that a turning of the collar through approximately three-fourths of a revolution will effect a change in the position at which the gas bag will act on the arms 48 to shift the plunger 38 and valve seat 40 corresponding to a variation from zero pressure to a pressure of ten ounces per square inch. A dial indicating such variation is therefore provided, the graduations being formed on the casing member 29 and read by reference to a pointer 53 carried by a handle 54 formed on a ring which is secured to the adjusting collar. To provide for the adjustment of the parts when the apparatus is assembled or a readjustment when some of the parts, as the valve seat 40, have become worn, the handle 54 is made angularly adjustable on the collar. In the present instance this adjustment is effected by means of a pair of screws passing through the handle ring and adapted to engage any pair of a plurality of pairs of screw sockets in the collar 52.

In the ordinary use of my apparatus, the collar 52 of the nitrous oXid and the oxygen gas bags will be set to corresponding degrees of pressure, and the ination and deflation of the gas bags, as the gases are used, will open and close the regulating valves to maintain a substantially constant degree of pressurevin the bags. If, how

-ever, as may under some conditions be desired, a direct flow of either gas be desired the handle 22 of the direct flow valve for that gas may be turned to admit such gas through the tube or arm 13 to the gas bag. In such case the bag will be inflated beyond the indicated setting of the regulating valve, or even beyond the capacity of regulation of the arms 48. The relief spring 43 will nevertheless permit an excessive spreading of the arms 48 without causing any injury to the mechanism of the regulating and reducing valve I claim: y

l. In anesthetic apparatus arranged to be equipped with a compressed gas cylinder, a regulating valve in communication with the gas supply from such cylinder, an expansible elastic gas bag constituting a variable-pressure reservoir for a relatively large volume of gas at a relatively low pressure in free communication with the gas-administering passages of the apparatus, a pivoted lever arranged to be rocked by said bag as it is inflated, and a connection operated by said' lever for opening and closing said valve.

2. In an anesthetic apparatus arranged to be equipped with a compressed gas cylinder, a regulating valve, in communication with the gas supply from such cylinder, an expansible elastic gas bag constituting a variable pressure reservoir for a relatively large volume of gas at a relatively low pressure in free communication with the gas-administering passages of the apparatus, a pivoted lever arranged to be rocked by said bag as it is inflated, and a connection operated by said lever for opening and closing said valve, said connection including provision for varying its adjustment with respect to said pivoted lever.

3. In anesthetic apparatus arranged to be equipped with a compressed gas cylinder, a regulating valve in communication with the gas supply from such cylinder, a gas bag, a plurality of levers spaced around said bag and arranged to be rocked thereby as the bag is inflated, and a connection operated by said levers for-opening and closing said valve.

4. In anesthetic apparatus arranged to be equipped with a compressed gas cylinder, a regulating valve in communication with the gas supply from such cylinder, a gas bag, a plurality of levers spaced around said bag and arranged to be rocked thereby as the bag is inflated, and a yielding connection operated by said levers for opening and closing said valve.

5. In anesthetic apparatus arranged to be equipped with a compressed gas cylinder, a regulating valve in communication with the gas supply from such cylinder, a gas bag, a plurality of levers spaced around said bag and arranged to be rocked thereby as the bag is inflated, a connection operated by said levers for opening and closing said valve, and means for varying the adjustment of throw of said levers with respect to the opening and closing of the valve.

6. In anesthetic apparatus arranged to be equipped with a compressed gas cylinder, a gas bag, a regulating valve in communication with the gas supply from such cylinder, a plunger equipped with a valve seat, a

series of levers spaced around said bag and arranged to be rocked thereby as the bag is inflated, and a frame pivoted to said levers and operatively connected with said plunger.

7. In anesthetic apparatus arranged to be equipped With a compressed gas cylinder, a gas bag, a regulating valve in communication with the gas supply from such cylinder, a plunger equipped with a valve seat, an adjusting ring on said casing, a series of levers each fulcrumed at one end on said ring and having its other end arranged to be rocked by said gas bag as it is inflated, and a frame having branches pivoted to intermediate portions of said levers and operatively conv nected with said plunger.

8. In anesthetic apparatus arranged to be equipped With a compressed gas cylinder, a gas bag, a regulating valve in communica*- tion vvith the gas supply from such cylinder, a plunger equipped With a valve seat, a spring-pressed bearing plug slidingly arranged in the lower end of said plunger, a pivoted lever arranged to be rocked by the inflation of said gas bag, and a connection intermediate said lever and bearing plug for operating said plunger and opening and closing the valve.

9. In apparatus of the character described, and including a gas cylinder, an eX- pansible gas bag, and an inhaling device, a passage for the direct floiv of gas from said cylinder to said gas bag, a direct flow valve for opening and closing said passage, a second passage for the flow of gas from said cylinder to said gas bag, an automatic regulating and reducing valve governed by the expansion of the gas bag'` and arranged to control said last mentioned passage, and a passage for the outflow of gas from said gas bag to said inhaling device.

10. In apparatus of'v the character described, and including a gas cylinder, a gas bag, and an inhaling device, a passage for the direct iiovv of gas fromsaid cylinderv to said gas bag, a directl flow valve for opening and closing said passage,. a second pas'- sage for the flow of gas from said cylinder to said gas bag, an automatic regulating and reducing valve in said last-mentioned passage, means operated by a relatively slight expansion of said gas bag for controlling said reducing valve When the direct flow valve is closed and for closing the reducing valve and permitting a relatively large expansion of the bag when the direct fioiv valve is open, and passages for. the outflow of gas from said gas bag to said inhaling device. 4

1l. In. anesthetic apparatus arranged to be equipped With a compressed gas cylinder, a gas bag, a regulating valve in communication with the gas supply from such cylinder, a plunger equipped with a valve seat, a series of levers spaced Varound said bagk and arranged to be rocked thereby as the bag is inflated, a frame pivoted te said levers, and a universal connection intermediate said frame and said plunger.

ALBERT CHARLES CLARK.

lVitne'sses CHARLES H. W'ARREN, J. V. HAnBERG.

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