Heater for hypodermic solutions and the like

July 20, 1937.

F. TISHMAN

2,087,586

HEATER FOR HYPODERMIC SOLUTIONS AND THE LIKE

Filed Feb. 28, 1935

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Patented July 20, 1937

2,087,586

UNITED STATES PATENT OFFICE

2,087,586

HEATER FOB HYPODERMIC SOLUTIONS AND THE LIKE

Paul Tishman, Scarsdale, N. Y.

Application February 28, 1S35, Serial No. 8,681

Claims.

This invention relates to a heating device and more particularly to a thermostatically controlled heater for flowing liquids, such as hypodermic solutions and the like.

An object of the invention is to provide a sensitive temperature control for liquids of the above type.

Another object is to maintain a hypodermic solution at a substantially constant temperature 10 during the injection period.

Another object is to control the temperature of a hypodermic solution at the point of injection, regardless of any variations in temperature of the ampoule or container.

A further object is to· provide a simple, convenient and dependable means to accomplish the above purposes.

Although the novel features which are believed to be characteristic of this invention will be 20 pointed out more particularly in the claims appended hereto, the invention itself, as to its objects and advantages and the manner of its operation, will be better understood by referring to the following description taken in connection with 25 the accompanying drawing in which one embodiment thereof is disclosed for purposes of illustration.

In the drawing,

Figure 1 is a side elevation showing the heater 30 assembled with an ampoule and an injection needle;

Figure 2 is a broken side elevation of the heater;

Figure 3 is a top plan view thereof; and 35 Figure 4 is a side elevation of the heater showing the flexible tubes arranged for sterilization.

In the following description and in the claims, various details will be identified by specific names for convenience, but they are intended to be as 40 generic in their application as the art will permit.

Referring to the drawing, there is shown in | Figure 1 a heater 10 which is mounted in a spring clamp 11 slidably secured to a suitable stand 12 45 and connected by a flexible tube 13 to a container for hypodermic solutions, such as an ampoule i 4, which is likewise supported from the stand 12, as by a hook 15 engaging the stem 16 of the ampoule. The heater 10 is also connected by a 50 flexible tube 20 to a thermometer well 21 carrying a thermometer 22. The thermometer well 21 is connected by a flexible tube 23 to an injection device, such as an injection needle 24.

The ampoule 14 may be of the type disclosed in 55 the patent to Blaivas No. 1,905,362, dated April (CI. 219—39)

25, 1933, in which the stem 16 provides a vent for the liquid within the ampoule and forms a physical support to engage the hook 15 of the stand. The lower portion of the ampoule is elongated to form a stem 25 adapted to receive 5 the tube 13 for discharge purposes. It is to be understood, however, that this type of ampoule is referred to only for purposes of illustration and that any other suitable container for hypodermic solutions may be employed. It is also to be un- 10 derstood that the thermometer well 21 may be omitted, provided it is not necessary to ascertain the temperature during the injection period, in which case the tube 20 is connected directly to the injection needle 24 so as to discharge the 15 liquid directly from the heater 10 thereto. A suitable clip 26 may also be provided to regulate the flow of liquid from the ampoule to the injection needle.

The heater 10 is shown more in detail in ₂₀Figures 2 and 3 as comprising a container or jar 30, preferably of glass or the like, having a plurality of fins 31 formed as a helix on the outer surface thereof and providing channels 32 therebetween adapted to receive the coiled tubes 13 ₂₅and 20 for the purposes to be described. A plurality of spring clips 33 are positioned in said channels 32 at spaced points so as to grip the coiled tubes for holding the same in position. Said clips 33 may be mounted by wires 34 ex- 3θ tending around the container 30 and located in suitable recesses 35 formed therein.

A pipe 36, preferably formed of glass, is mounted in thermal contact with the liquid within the container 30. This pipe may be of any conven- 35 ient shape, such as an open loop, as shown in Figure 2, and may be supported in any convenient manner. It may, for example, be sealed to the walls of the container 30 and may extend therethrough to form nipples 38 and 39 to which 40 the flexible tubes 13 and 20, respectively, may be connected. The arrangement is such that the hypodermic solution may be passed through the pipe 36 and may be heated in its passage therethrough by heat transfer from the liquid within 45 the container 30. Obviously, the pipe 3G may be of any convenient length which is adapted to give the required heat transfer. The pipe may, for example, include a coil of one or more turns, if desired. 50

The container 30 is provided with a cover 40, preferably of insulating material such as bakelite or the like, which carries the heating unit and thermostatic control device, to be described. The cover 40 may be secured to the container 30 in 55

2,087,586 any convenient manner, as by a partial thread 4 i formed on the container and cooperating with lugs 42 formed on the cover. A suitable sealing ring 43 may also be used to effect a tight seal.

The cover 4G carries a housing 50 which may be secured thereto, as by a pin Si and a nut 52. A tube 53 may be mounted on the housing 50 and extends through the top 40 into the container 30. A second tube 54 is rotatably mounted within the 10 tube 53 and carries at its upper end a worm gear 55, which may be secured thereto as by a screw 55, and is adapted to be rotated by a cooperating worm 57, mounted on a rod 58 and carrying control knob 59. The control knob 59 may be pro15 vided with a suitable index 5S' graduated to indicate the condition of adjustment of the tube 54 and the associated elements.

The tube 54 carries at its lower end a block 60 to which is secured one end of a bi-metallic heli20 cal thermostat 61, the other end of which is secured to a rod 62 extending through the helical thermostat 61 and through the tube 54 and carrying at its upper end a block S5 of insulating material, which may be secured thereto as by a screvz 25 56. The block 65 carries a contact arm 67 having secured thereto a contact 68 which is adapted, to engage a stationary contact 69 connected, to a binding post 7Q. Electrical connection may be made to the contact arm 67 from a second bindto ing post 73 by means of a flexible conductor 74 having a loop 75 adapted to provide the necessary flexibility. Bolts 76 may extend through the block 65 to secure and make electrical connection between the flexible conductor’ 74 and the con35 tact arm 67.

It is to be understood that the binding posts 70 and 73 and the contact elements above described are supported by and suitably insulated from the housing 50. It is also to be understood 40 that the type and construction of the switch and thermostat may be varied as desired. A specific form has been shown merely as an illustration of a particular embodiment of the invention.

A condenser 80 may also be mounted on the 45 cover 40 and may be provided with a pair of terminals 81 which are connected, to the binding posts 70 and 73. The condenser may be of appropriate size to prevent sparking at the contacts 63 and. 69 when the contacts are separated 50 during normal operation.

The cover 40 may also carry a connector block 90 having an electrical heating unit 91 depending therefrom and extending through the cover into the liquid within the container 30. The unit 91 55 may be connected to the binding posts 70 and 73, as by leads 92, and may be connected to suitable spring fingers 93 which are adapted to make contact with the prongs Sfl of a standard plug connector 95, the connection being such that GO the contacts 68 and 69 control the flow of current through the heating unit 9 ί.

In order to prevent accidental insertion of the connector 95 when the cover 40 is not mounted in position on the container 30, a. lever SOO is procs vided which is pivoted to the connector block 90, as at ! 91, and is bent at its upper end to form a pin. (02 which is caused by a spring 183 to project forwardly from the connector block 90 so as to prevent the connector 95 from being in70 serted therein. The lever 100 is provided at its lower end with an arm 164 which is adapted to contact with the outer surfaces of the container 30 so as to cause movement of the lever 100 for retracting the pin 102 when the cover 40 is in 75 position on the container 30 and thereby to per mit the connector 95 to be attached to the connector block 90. The cover 40 may also be provided with a filler opening 110, closed by a cap 111 and a gasket 112. A vent 114 may be provided in the container 30 and may have a nipple 115 5 associated therewith to facilitate attachment of a flexible tube for the purpose to be described.

In operation, the container 30 is filled with a suitable heat-transfer liquid, such as water. The cover 40 is locked in position thereon and suitable 10 electrical connection is made by the connector 95. The current flowing through the heating unit 9! serves to heat the liquid within the container and actuates the thermostat 61 in accordance with the temperature thereof. Suitable adjust- 15 ment is made of the thermostat 61, as by manipulation of the knob 59, to cause the thermostat to separate the contacts 68 and 69 when the proper temperature has been reached. Thereafter, the thermostat serves to maintain the liquid at about 20 said temperature. The required temperature of the liquid will depend upon the initial temperature and rate of flow of the solution to be heated within the pipe 36 and the effective length of said pipe in heat-transfer relationship with the liq- 25 uid. It is obvious that by suitable adjustment of the knob 59 the heat may be so controlled that the solution can be discharged from the heater at any predetermined temperature.

As applied to the heating of a hypodermic solu- 30 tion, the heater 19 may be mounted upon the stand 12, as illustrated in Figure 1, and the pipe 36 thereof may be connected to the flexible tubes 13 and 20, leading respectively to the ampoule !4 and the thermometer well 2! or to the injec- 35 tion needle 24. Using a given hypodermic solution, experience will determine the initial setting of the knob 59 to produce the desired temperature at the needle 24. While the injection is being carried out, the thermometer 22 may be noted 40 and any variations in temperature may be compensated for by suitable adjustment of the knob 59. It is obvious that the temperature of the hypodermic solution may thus be maintained substantially constant during the entire period of 45 injection and may be accurately controlled at the point of injection. If a temperature indication is not required in any particular case, the thermometer well 21 may be omitted and the tube 20 may be connected directly to the injection needle 50 24, the device operating otherwise as above indicated.

The pipe 36 and the flexible tubes 13 and 20 may be sterilized prior to use by the method illustrated in Figure 4. For this purpose the tubes 55 13 and 20 are disconnected from the ampoule and the thermometer well 21, respectively, and are wrapped around the container 30 within the grooves 32 which are provided for this purpose, the clips 33 securing the tubes in position. The GO free end of tube 13 may be connected to the nipple 115, while the free end of the tube 20 may be left open. Heating current is then applied and suitable adjustment is made of the thermostat 61 to permit the liquid to boil, thus producing steam G5 which passes from the vent 114 through the nipple 115, through the tube 13, thence through the pipe 36, and through the flexible tube 20 from which it is discharged. Steam may be applied for a sufficient length of time for sterilization pur- 70 poses.

It is to be noted that the process and apparatus above set forth provide a dependable, practical and efficient means for accomplishing the purposes specified. The device maintains the tern- 75

2,087,586 perature of flowing liquids at predetermined values without requiring frequent or skilled manipulation. This feature is of special importance in connection with hypodermic solutions or the 5 like which are to be applied to body tissues, particularly if the solutions are being injected over an extended period of time. The invention is not limited to such use, however.

It is to be understood, that the details above 10 described constitute only a single embodiment of the mechanical features of the invention. Various changes may be made as desired in the thermostatic control and in the heating unit, as well as in the manner of mounting the same. The 15 pipe 36 may also be variously located or mounted, as from the cover 40, if desired. The fins 3i may be omitted if the flexible tubes are otherwise supported for the sterilization step or if sterilization is otherwise effected.

A specific embodiment of the invention has been shown and described for purposes of illustration only. Various changes and modifications may be made therein and it may be applied to various other uses as will be readily apparent to a person skilled in the art. The invention is accordingly to be limited only in accordance with the following claims when interpreted in view of the prior art.