JPH02136665A - Thermoelectric device quickly changing temperature of pour - Google Patents

Abstract

PURPOSE: To provide an inexpensive efficient, and easily disposable unit being used in combination with a thermoelectric cooling means for a matter to be injected by providing a heat conduction means, on the other side thereof, with a fluid passage defining a snaking passage in order to sustain a tight heat exchanging relation between a bolus and the heat conduction means. CONSTITUTION: A heat exchanging cassette 35 comprises a heat conduction plate 36 formed of a stainless steel sheet bonded, through an adhesive, to a thermally formed plastic labyrinth 37 having respetitive S-shaped part. A connector 38 having a spacial shape terminating at the open end is provided at the end of the labyrinth 37. The labyrinth 37 is made of a channel 39 having U-shaped cross-section and extending below the plate 36 while traversing longitudinally to form a circulation passage comprising parallel passages inverted at each end in hair pin state. The plate 36 is held against a thermoelectric refrigerating plane 46a and the temperature of fluid flowing through the labyrinth 37 is lowered to that of the plate 36.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for delivering cold medicinal fluids to a thermodilution cardiac ejection metering catheter.

BACKGROUND OF THE INVENTION Thermodilution catheters have been used to determine cardiac output, and these catheters are typically small diameter balloon-shaped catheters that include a distal temperature sensing means and a portion slightly proximal to the temperature sensing means. A lumen opening is provided in the bloodstream for introducing cold liquid infusate into the blood stream. Changes in temperature due to the introduction of cold liquid injectate are detected by temperature sensing means, usually a thermistor. Such devices are equipped with a suitable sterile injectate, usually 5% Dextrose in water or saline, and a multi-lumen catheter, with at least one of the lumens being A thermistor is provided, another lumen is for the injectate, and yet another lumen is for the balloon. The injectate lumen has a proximal opening or port approximately 28 cm from the tip through which the injectate is injected. A thermistor is provided at the distal end of the port, a balloon is provided at the distal end, and a distal lumen is provided at the distal end.

The amount and interval of temperature change over time is used to calculate the blood flow rate for metering the patient's cardiac output. U.S. Pat. No. 3,995,623 discloses a typical thermodilution catheter.

Blood flow rate is calculated from changes in blood temperature according to the Stewart-Hamilton dilution equation for silent indicators described in US Pat. No. 3,987,788. As described in this patent, numerical values are used for the calculation constants, blood temperature and infusate temperature.

The calculation constant is due to the nature of the injectate, the volume of the injectate, and a correction factor for the temperature increase of the injectate as it passes through the lumen of the catheter toward the injection orifice.

American in Santa Ana, California, USA
Co-3et®, provided by Edwards Laboratories, requires the injection to be delivered from a syringe filled from a coiled tube placed in a container filled with crushed ice. Ice covers the coiled cooling tube and water is used to facilitate heat transfer between the tube and the ice. The container is thermally insulated by Styrofoam. Difficulties that arise when monitoring thermodilution cardiac output include the time it takes to fill the syringe, the infusate temperature being unclear despite the provision of a thermistor, and the risk of user misuse or device misuse. erroneous operation may occur due to unfamiliarity with the device, and air bubbles may form within the device during filling of the syringe and subsequent injection.

Fluid Cooling Appa
No. 3, issued December 27, 1966, to F. A. Gonzxlez entitled
, 293,868 discloses a device having a flat plate with undulating fins. The fins form channels for holding the flexible tube through which blood or the like passes for heating or cooling. The plate is in contact with a number of spaced apart thermocouples which act to heat or cool the plate due to thermoelectric effects depending on the direction in which the current flows through the thermocouples. A rotary blower can also be used to remove heat from the fluid. The device is designed to be used in a generally horizontal position, and blood or other fluid is passed through the tube by a pump or other device. This device did not have a mechanism for automatically and accurately injecting fluids, nor did it have an easily disposable heat exchanger.

U.S. Pat. No. 4,532,414 to Shah et al. discloses an in-system fluid heater for heating mother liquors such as blood.

The heater includes an enclosure having a heating plate having an undulating groove shaped to receive and hold a supply tube in thermal transfer relationship with the plate. Appropriate temperature control is provided to regulate the heating and to maintain the blood at the desired level of heating. A good heat exchanger in a disposable heat exchanger is not taught.

Variations in injection technique, such as injection temperature and injection rate, ie, surgeon dexterity, can cause erroneous cardiac ejection measurements. Such measurements could potentially lead to inadvertent diagnosis and potentially fatal treatment. Also, injection of air bubbles into the lungworm ductal system can cause other fatal conditions due to the possibility of pulmonary embolism.

Further improved syringes are disclosed, for example in U.S. Patent No. 3.3.
36,925.3,156,236.3,335.72
4.2,896,621.2.457 977.3,3
13,29112,602,446.2°498.67
2, and 3,584,623. However, none of the devices disclosed in these US patents provides a mechanism for accurately and easily adjusting the amount injected.

PROBLEM TO BE SOLVED BY THE INVENTION It is therefore an object of the invention to provide a device with sub-dynamic syringe functionality that allows the volume of cold infusion to be easily and standardly varied.

Another object of the invention is to provide a thermoelectric cooling device capable of providing refrigerated infusions.

Yet another object of the present invention is to provide an efficient, easily disposable, and inexpensive device for use in conjunction with thermoelectric cooling means for the injectate.

E Means for Solving Problems] In order to solve the problems with conventional devices, we provide a solid, reliable, simple and inexpensive device that can be used regardless of the skill level of the user. An automatically cooled infusion mechanism is disclosed for use with a cardiac output computer to provide a device with all the necessary elements to perform the following steps. The device is equipped with an automatic drive for a thermally insulated syringe with a disposable cassette heat exchanger. Syringes and cassettes can be easily exchanged within the basic device. Because the cassette and syringe are disposable, the basic mechanism of the device can be used repeatedly on different patients without concern for contamination or transmission of germs or the like.

More particularly, the disposable portion of the device is designed to be inexpensive and to be effective and easy to use in conjunction with the basic mechanism of the device. The basic device disclosed herein includes an auto-injector drive mechanism that can provide various volume strokes without complex adjustments by simply changing the connecting rod. In addition to this,
The device includes an infusion cooling system with a thermoelectric platen to which disposable cassettes can be easily attached. The thermoelectric device is brought into intimate contact with the heat transfer portion of the disposable heat exchange cassette, thereby achieving uniform, rapid and efficient cooling of the injectate. The temperature of the thermoelectrically refrigerated surface can be measured and used as an input to the cardiac output computer, which controls the temperature of the injectate appropriately.

The device is simple, lightweight and portable and requires no ice or water replenishment. The basic mechanism is adapted to hold the conductive part of the heat exchanger cassette against the refrigerated surface of the thermoelectric tarp, providing maximum area contact and ensuring that the heat exchanger cassette is disposable and easy to use. Heat exchange can be performed despite the fact that it is possible to exchange heat. The retention mechanism is a door with a flexible, non-conductive pad that not only acts as an insulator, but also acts as a clamping mechanism to hold the cassette against the thermoelectric refrigeration surface.

The injectate auto-injector drive has a gear reduction motor combined with a slider-crank mechanism, and the connecting rod for this motor can be easily replaced to easily increase or decrease the stroke to reduce the amount of injectate. It can be changed. In a preferred embodiment, connecting rods of various lengths can be provided and selected to drive the syringe plunger according to the desired stroke amount.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an automatic syringe drive device 10 that supports an insulated syringe 11 .

The syringe 11 has a double-walled insulated body and a plunger 13, and the plunger 13 slides on the inner wall of the body 12 of the syringe 11 to transfer fluid to a Luhe connector 12a provided at the tip of the syringe 11. Push out through. As used herein, the term "tip" refers to the direction toward the roux-echo ink, and the term "base" refers to the direction toward the opposite direction. Extending from the proximal end of the thermally insulated syringe 11 is a pair of finger handles 14 which are designed to fit the fingers of a user in normal or manual use. In an automatic syringe drive application, the syringe is held in a platform 15, which is a heavy metal plate and has specially shaped openings to support the components of the device 1o.

In particular, it has a recess 16 adapted to support the barrel 12 against lateral or axial movement.

A lateral recess 17 is formed in the proximal direction of the recess 16 and extends outwardly from the recess 16 to form a T-shaped opening for receiving the handle 14. . Parallel to and spaced apart from each side of the recess 16 is an adjustable tab 18.
B extends into the handle recess 17 and supports the finger joint portion of the handle 14. The tabs 18 are movable towards or away from the handles, forcing each handle 18 more proximally into the recess 17.

To drive the plunger 13, a slider 19 is provided, which is driven by a connecting rod 20j, which is rotated by a crank 21 provided at the proximal end of the connecting rod.

A slider/crank mechanism constituted by connecting rod 20, crank 21, and slider 19 converts rotational movement of crank 21 into linear movement of slider 19. The reciprocating movement of the slider 19 is controlled by a guide 22 provided within the platform 15.

In particular, the guide 22 has grooves for controlling the movement of the tongues on each side of the slider 19. The particular arrangement of tongues and grooves is located parallel to the slider 19 and the pedestal mount supported in the pedestal 15 consists of a channel 23. The guide 22 is the insulated syringe 11. It is accommodated and supported by the operating surfaces of the slider 19 and the crank 21, thereby allowing the reciprocating motion of the slider 19 to
Matches the A axis. For installation, channel 23 is guide 22
is held in place to support the slider 19. A groove 24 is provided on each side of the guide 22 and the groove 22 controls the reciprocating sliding movement of the slider 19 along the A--A axis of the plunger 13.

Each 924 is formed by a pair of seven flange 25 extending into the respective guide 22, the pair of seven flange 25 including a tongue 26 extending laterally outwardly from each side of the piston 19. are made to be supportive between them. As a result, when the slider 9 reciprocates in response to the force transmitted through the connecting rod 20, the slider 19
A tongue 26 on each side of moves within its corresponding groove 24. The movement of the slider 19 is thus maintained in the plane and axially relative to the plunger 13.

A T-shaped opening 27 is formed at the tip of the slider 19, and this opening 27 is connected to the end 13a of the plunger 13.
is accommodated so that the plunger 13 can move in the distal direction and the proximal direction by the reciprocating movement of the slider 19. A pin 28 is provided at the proximal end of the slider 19, which allows pivoting between the tip of the connecting rod 20 and the slider 19 in a manner known in the art.

A crank 21 is supported by a shaft in a known manner and rotates about a crank center 29 in the direction indicated by arrow B in FIG. Platform 15 is stepped in wall 15a to provide clearance for movement of sections 19, 20 and 21. Although the motor is shown schematically in FIG. 1, it is actually located under the platform 15 and drives the crank 21 about its center 29. The crank 21 has a series of screw holes 21a located along a radial line.
, and these holes work with connecting rods having varying lengths. The long connecting rod 20 used with the configuration shown in FIG. 1 provides a short stroke of the plunger. A replaceable pin 20a connects the proximal end of the connecting rod 20 to the crank 21. The pin 20a is a shoulder screw and can be easily removed from the hole 21a and connected to the connecting rod 2o.
can be replaced with one of other lengths.

The tip of the connecting rod 20 is designed to be able to pass over the pin 28. Slider 1 due to tongue and groove configuration
Since the movement of 9 is maintained in the plane of reciprocation, no forces act on the connection of pin 28 to disengage it.

The crank 21 also has a cam flat 21b that controls the start and stop points for the syringe drive 10. The schematically illustrated switch 30 has a contact 31 which is movable by cam action.
1 is responsive to cam flat 21b and manually movable contact 32 so that switch 30 is normally open except when contact 31 is in contact with flat 21b. When the contact point 31 is in contact with the flat part 21b,
Switch 30 is opened and the circuit to auto-injector drive 10 is cut off. Manually operable contacts 32 can be used to close switch 30 and initiate operation of device 10. The actuation circuit comprises a power supply 33 connected at one end to contacts 32 and at the other end to a motor 34, as shown schematically in FIG. The other input to the motor 34 is connected to a movable contact 31.

Motor 34 is disconnected from power supply 33 when crank 21 is in the position shown in FIG. 1 and cam flat 21b releases movable contact 31 from contact with manually operated contact 32. Eventually, switch 30 will move excessively, activating device 10. The switch 30 is designed to control the position at which the slider 19 starts and stops reciprocating.

With this configuration, the auto-injector drive mechanism is manually started and automatically stopped to provide one complete stroke. Plunger 13 starts and stops at the same location, ie, at the most distal end of the stroke depending on the particular length of connecting rod used. The stroke of plunger 13 can be varied easily and accurately. The injection volume can be set completely automatically, easily and accurately.

FIG. 2 is a perspective view of a heat exchange cassette 35 for use with auto-injector drive 10. Heat exchange cassette 35
The thickness is 0.254mm and the length is 70 to 111m.
It consists of a thermally conductive plate 36 made of m stainless steel sheet. These dimensions can vary depending on the intended application and the stainless steel will be of medical quality and finish. Plate 36 is adhesively connected to a thermoformed brass labyrinth 37 having repeated S-shaped sections. The end of the labyrinth 37 is provided with a specially shaped connector 38 which is adapted to terminate at the open end of the labyrinth 37.

The labyrinth 37 has a U-shaped cross section and extends from a channel 39 forming a circulation path consisting of parallel passages extending back and forth under the plate 36 and inverted in a hairpin manner at each end. It is configured. channel 39
The open ends of the tubes are filled with connectors 38 which replace the generally U-shaped cross-section of the channel with a circular cross-section extending into a male tube expansion 40. U-shaped portions 38a on each side of connector 38 are adhesively sealed to the open ends of channels 39 by extension joint portions 40. Passing through the extension joint portion 41 is a passageway (not specifically shown) which allows fluid to flow from the U-shaped channel 39 to the circular cross-section of the male Rouhe tube extension 40. It is shaped like pouring water.

Between each U-shaped channel 39 there is a flat butd-shaped area 39a which sits on one of the large surfaces of the conductive plate 36. Area 39a
A hot melt adhesive 42 is placed between the plate 36 and the labyrinth 37 to seal the labyrinth 37 to the plate 36 to form a liquid-tight, circulating conductive path through the channel 39. In particular, the ends of the channels 39 are provided with connectors 38 that allow fluid to flow from one side of the heat exchange device 35 to the other. As will be explained in detail below, fluid passing through labyrinth 37 formed by channels 39 undergoes heat exchange. The amount of fluid retained in the preferred heat exchanger 35 is at least three times the stroke capacity of the device 10. Heat exchanger 35 is efficient because conductive plate 36 is metal and labyrinth is plastic. This combination is easy to construct and efficient in operation. It is also cheap and can be disposed of. Another safety feature is the use of a non-rupture hot melt adhesive 42. Sterilization must be done with radiation or ethylene oxide gas.

In operation, the conductive plate 36 is held against a thermoelectric refrigeration surface such that the fluid flowing through the labyrinth 37 is reduced in temperature to the temperature of the conductive plate 36 (third
figure). In a preferred embodiment, thermoelectric refrigeration device 44
includes a finned heat exchanger 45 having a series of joints made of different metals to change the temperature of the heat exchanger 45 as fluid passes through the joints. FIG. 3 is a top view of thermoelectric refrigeration device 44. FIG. More specifically, disposable heat exchange cassette 35 is shown in contact with the refrigeration surface of thermoelectric refrigeration device 44 . The finned heat exchanger 45 is made of aluminum extrusion and is adapted to support a refrigeration surface containing a thermoelectric device 46a that receives electrical current. Refrigerated surface 46 may include a thin electrically insulating coating, such as ceramic, for safety. Depending on the direction of current flow through device 46a, the temperature increases or decreases. In the preferred application, temperature reduction is used to refrigerate surface 46. Opposite the cold side of the device 46a is a hot side connected to a heat exchanger 45 for removing heat. A fan device 47 is provided for blowing air through the heat exchanger 45, thereby raising the temperature of the heat exchanger 45 to ambient temperature.

A door 48 supported on hinges 49 is held above the housing 50 of the heat exchanger 45 reservoir. door 48
, hinge 49 and housing 50 facilitate replacement of the disposable heat exchange cassette 35. The door 48 supports a flexible insulating foam pad 51 which is attached to the labyrinth 3 of the heat exchange cassette 35.
7 and is also designed to touch the refrigerated surface 4
6, the conductive plate 36 is held. Heat exchange device 35
is a disposable medical device and therefore it is necessary to be able to easily use a new cassette for each operation. This is important in order to prevent the transmission of pathogenic bacteria and the like. Connector 38 has a male tubing extension 40 which connects on the one hand to the administration set and on the other hand to auto-injector drive 10 at Rouet connection 12a. For this purpose, a special tube is provided which fits the extension 40 and fits into the Rouhe connection.

A housing latch 52 is provided which cooperates with the door 48 to hold the insulating foam pad 51 against the heat exchange cassette 35. In operation, the refrigeration device 44 combined with the cassette 35 as shown in FIG.
n Works to replace the ice bath used in the Edvxrds Co-5et® device. 4, except for the auto-injector drive 10, the refrigeration system 44 and the disposable cassette 35, are well known to medical personnel. The coil and ice bath have been replaced by the apparatus of FIG. All tubing, including valves and fittings, is identical to that familiar to medical personnel, and the tubing is arranged according to conventional techniques. The device of the invention has porous (bo)
lus) can be repeatedly and controllably refrigerated, and the device is accurate, easy and convenient to use. In operation, the device of the invention is capable of accurately metering a porous set to a desired temperature, and both its volume and temperature can be automatically and easily controlled.

FIG. 4 shows the automatic syringe drive device 10. 1 is a block diagram of an autoinjector 53 for the purpose of illustrating how a disposable heat exchanger 35 and thermoelectric refrigeration device 44 are used.

The infusion is transferred from the infusion set 54 to an assembly 5 comprising a thermoelectric refrigeration device 44 and a disposable heat exchange cassette 35.
5 is inhaled. Operation of the device 10 is automatically controlled by a cardiac ejection computer 56, which is connected to an assembly 55 of auto-injector drive 10, heat exchanger 35, and refrigeration system 44. Once the temperature of the injectate inhaled from the infusion set 54 reaches the proper temperature, a signal is communicated from the assembly 55 to the computer 56 and in response the device 10 is connected to the computer 56. To operate.

The flow of injectate sent by device IO is controlled by check valve 5.
Controlled by 7. Check valve 57 allows flow to first fill assembly 55 from infusion set 54 and then from there to thermodilution catheter 58.

More specifically, the device 10 is first filled from the infusion set 54 and then the syringe plunger 13 directs the injectate back through the check valve 57 and into the thermodilution catheter 58.

Check valves 57 are simply two one-way valves that pass through assembly 55 from infusion set 54 (filled with disposable heat exchanger cassette 35 and syringe).
, and then allows flow from auto-injector 10 and assembly 55 to thermodilution catheter 58.

A thermodilution catheter 58 is placed within the patient.

A thermistor is provided at the end of the thermodilution catheter 58 within the patient, and this thermistor is connected to the computer 56.
The temperature of this section of the catheter can therefore be monitored by the computer 56.

To operate assembly 55, it is electrically actuated by periodic syringe drive 10 and filled with injectate. The apparatus 10 is operated for one cycle until the apparatus consisting of the injectate overflow infusion set 54 is purged away. During the purge, the surrounding infusate within the device is injected into the patient.

The volume of the disposable heat exchanger cassette 35 is at least three times the volume of one stroke of the plunger 13. Therefore, the purge cycle is optimal for ambient temperature infusate to be delivered entirely into the patient and for the device to be completely filled with refrigerated infusate.

The device operates completely automatically because:
This is because assembly 55 and computer 56 are electrically connected, and device 10 and computer 56 are electrically connected. Once the computer 56 receives a signal from the thermistor of the thermodilution catheter 58 (i.e., once the patient end temperature of the thermodilution catheter 58 has stabilized), a signal to inject a first refrigerated bolus is sent to the cardiac output. It is sent by computer 56 to auto-injector drive mechanism 10.

As explained in connection with FIG. 1, the switch 30 for actuating the drive IO can be operated manually. Power supply 33 and motor 34 for fully automatic operation
The cassette between the switch connections from
t) ie switching of the circuit initiates operation of the auto-injector 10. This shunt is provided by computer 56 just enough time for the motor to advance past cam flat 21b, and switch 30 then completes the circuit and causes motor 34 to run one complete cycle of plunger 13.

Automatic plunger operation is determined by the temperature of the refrigerated injectate, which is measured at the refrigerated surface 46 of the thermoelectric refrigeration device. Once the refrigeration surface 46 is at its operating temperature, the computer 56 begins cycling the device 10. The injection is completed at the point where the movable contact 31 of the switch 30 reaches the cam flat 21b again. The device can also be operated manually. Once the thermoelectric refrigeration and cassettes have reached operating temperature, the medical technician manually starts computer 56 and then starts drive mechanism 10. When operated automatically or manually, the device repeatedly delivers precise volumes of carefully chilled infusion.

Although a preferred embodiment has been described in connection with an automatic injection device for predetermined volume boluses, those skilled in the art will no doubt recognize that changes and modifications may be made thereto.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the preferred embodiment slider/crank automatic injection drive mechanism. FIG. 2 is a partially cutaway perspective view of a preferred embodiment disposable heat exchange cassette. FIG. 3 is a plan view of the housing in section showing the arrangement of the disposable heat exchange cassette and the thermoelectric device used to change the temperature of the injection porous. FIG. 4 is a block diagram showing the relationship of components in the automatic injection device of the present invention. 10: Automatic syringe drive 11: Syringe 13: Plunger 15: Base 19: Slider 20: Connecting rod 21: Crank 21b = Cam flat portion 30: Switch 31: Movable contact 35: Heat exchanger cassette 56: Computer. (4 other people)

Claims (1)

Claims: 1. A thermoelectric device for rapidly changing the temperature of an infusate in a cardiac ejection thermodilution catheter of the type in which the infusate ball passes through a heat exchanger, the one being an energy heating device; or a heat transfer means having a pair of major surfaces adapted to exchange energy when placed in intimate contact with the source to be cooled; a fluid path defining a tortuous passageway for contacting the preceding flowing bowl and for maintaining the bowl in intimate heat exchange relationship with the heat transfer means;
Thermoelectric device, characterized in that the combination of said tortuous path and said heat transfer means is sufficient to vary the temperature of the injection bolus. 2. The thermoelectric device according to claim 1, wherein the fluid path is bonded to the other surface with a hot melt adhesive, and the fluid path is a thermoformed circulation path. Thermoelectric device. 3. The thermoelectric device of claim 1, wherein the tortuous passageway begins and terminates with a connector configured to seal and terminate the passageway defining a fluid passageway therein. A thermoelectric device characterized by comprising: 4. The thermoelectric device according to claim 1, wherein the one surface is in contact with a heating or cooling surface, and the thermoformed circulation passage is connected to the heating or cooling surface by an elastic insulating member. A thermoelectric device characterized in that it is retained. 5. An automatic injection device for a syringe having a barrel and a plunger, characterized in that it is equipped with the following components (a) to (d): (a) rotational movement to reciprocating movement; pedestal means for supporting a mechanism for converting into a motor; the pedestal means having a motor for the crank and a linear guide for the plunger, said linear guides forming parallel spaced guideways; It has a pair of slides. (b) a lock provided on said platform for retaining the end of the barrel of the syringe in said spaced guideway; (c) a slider for the end of the plunger; said slider being connected to said linear guideway; It is adapted to fit between the slides to define reciprocating motion coincident with the axis of the plunger. (d) connecting rod means having one end positioned between said cranks and the other end reciprocating within said linear guideway; said connecting rod means having a variable length; At the same time, the plunger can be positioned in various positions, thereby varying the distance of linear movement of the plunger. 6. Apparatus as claimed in claim 5, in which the connecting rod means are connecting rods of varying lengths, and depending on the connecting rod used, different plunger stroke lengths are provided as a result of a given bolus of injectate. Further, these rods are connected to the crank and the holder, so that rods having various lengths can be easily exchanged to adjust the ball amount. Device. 7. A conversion mechanism for converting rotational motion into linear motion to drive the syringe plunger and inject a predetermined amount of injection bolus, the conversion mechanism for supporting the axially aligned thermally insulated syringe barrel; 1st
a second means provided together with the first means for guiding a slider that drives the plunger of the syringe so that it aligns with the axis of the barrel; third means for providing rotational movement in a plane and provided on a center of rotation perpendicular to the axis; fourth means for converting rotational motion in the means into linear motion in the second means to drive the plunger; and a fifth predetermined amount for adjusting the stroke of the plunger to a preselected value to obtain a preselected amount of bolus injectate. 8. A conversion mechanism as claimed in claim 7, wherein said fifth means cooperates with said fourth means, said fourth means having different lengths each adapted to provide a desired plunger stroke. and each connecting rod is separated from said third means to said second means for easy replacement.
A transformation mechanism characterized in that it is adapted to stretch different areas up to a means of. 9. A conversion mechanism as claimed in claim 8, in which the extensions extending from the different regions are adapted to be easily replaceable, and a threaded journal provided on the third means allows the extensions extending from the different regions to extend along their radii and from the third A conversion mechanism characterized in that it has a crank arm having lengths defined at different distances with respect to the center of rotation of the means. 10. The conversion mechanism according to claim 9, wherein the third means is combined with a switch motor to start the plunger for one rotation of the third means.