Peristaltic rotation pump with exact, especially mechanically linear dosage

Abstract

The peristaltic rotation pump includes the pump segment extending along the working path, which is transversely grooved at the place of contact with the compressed pump segment, and is adjacent along all its length to an elevated circular supporting occlusal path, for rolling of pressure rollers. The working path includes a lead-in path, occlusal path and releasing path. Mechanical linearity of dosing is ensured by a circular occlusal path and the nearly circular releasing path, adjacent along all its length to the elevated supporting occlusal path for rolling of at least three pressure rollers. The angle length of the releasing path corresponding to the distance from the point of the beginning of releasing the pump segment to the point of complete release of the pump segment by the pressure roller is identical with that of the occlusal path.

Description

RELATED U.S. APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO MICROFICHE APPENDIX

Not applicable.

FIELD OF THE INVENTION

The invention deals with a peristaltic rotation pump with exact, mechanically linear dosage, designed particularly for use in medicine, half-operation medicine production and laboratories involved in any sphere.

BACKGROUND OF THE INVENTION

The peristaltic effect is based on the principle of gradual repeated ejection of the dosed media from a flexible container.

Gradual and repeated ejection of the media from the flexible container happens on a circular occlusal path by pressing a pressure roller onto a flexible pump segment and simultaneous shifting of the roller in the direction of the longitudinal axe of the pump segment on the occlusal path pumps the media.

From the existing approach of all known designs of rotating peristaltic rotation pumps in their history it is obvious that the manufacturers only wanted to reach the pumping effect. All other objective criteria of pump quality as e.g. accuracy and linearity of dosage were less important as the so far known designs could not meet these qualities in principle as they were not able to fix the pump segment on the pump occlusal path and could not suppress the negative influence of the pressure roller when leaving the pump segment at the output of the pump.

The microprocessor regulation of movement of the pressing element on the pump segment and/or location of the pump segment in line with the gradual pressing by cams perpendicularly on the longitudinal axe of the pump segment represented some kind of improvement. The pump segment placed this way is well fixed on the linear occlusal path. As movement of the pressing roller in the direction of the pump segment longitudinal axe is not applied here, its pre-stressing cannot happen and thus changes of cross section cannot occur.

Significant reduction of the negative influence of the pressing element when leaving the pump segment on the output of the pump is not technically solved by this design solution either.

The most progressive known design so far solves the mechanical drawback of lack of dosing linearity and accuracy by microprocessor regulation of non linear movement of pressure rollers (pressure elements in general) both in one pumping cycle and more pumping cycles. Higher dosage accuracy and linearity can be achieved this way when the smallest dose of the pump (which is usually an integer multiple of the smallest volume ejected by one cycle) is specified, but only for bigger dosage volumes.

Non linear regulation in this instance means different speed of the pressure roller (pressure element in general) in different sections of the pump segment of one pumping cycle, the aim of which is to compensate mechanical non linearity of the chosen pump design by its opposite influence.

Mechanical non-linearity of pumping in one pumping cycle is primarily caused by cyclical constriction (pressing) of the pump segment at the beginning of the occlusal path, which ejects a non-zero volume from the pump segment, and secondarily by cyclical release of the pump segment after the end of the occlusal path, which causes expansion of the flexible pumping segment and thus reception of the above mentioned non-zero disturbing volume (V_DISTURBING), causing pulsing of the pumped media and one-revolution non linearity of the dosed media at the pump output.

BRIEF SUMMARY OF THE INVENTION

The principal drawbacks of peristaltic rotation pumps, i.e. overall substantial inaccuracy of pumping and pulsing of the pumped media on the pump output during one revolution of the pump rotor are removed by the peristaltic rotation pump for exact dosing comprising of a pump segment located on a working path, and a rotor with pressure rollers, which is according to the invention based on the fact that the pump segment is extended to the working path, which is transversely grooved at the place of touch with the pressed pump segment, and is adjacent within its all length to an elevated circular supporting occlusal path for rolling at least two pressure rollers which are sliding mounted in pressing blocks located in the arms of at least double-arm rotor connected with a shaft of a stepping motor, while the supporting occlusal path is elevated in the central direction over the transversally grooved working path, which consists of a lead-in path, occlusal path and releasing path.

The pump segment is extended in the working path and both the ends of the pump segment are leant outside the working path on a supporting surface, and the pump segment forms angle a 90° with the working path radius at the point of the pump segment diversion from the working path.

Mechanical linearity of dosing is ensured by the circular occlusal path and approximately circular releasing path adjacent within all its length with an elevated circular supporting occlusal path for rolling of at least of three pressure rollers. The angular length of the releasing path, corresponding with the distance from the beginning of releasing of the pump segment to the point of complete release—it means nothing force by the pressure roller on the pump segment, is the same as the angular length of the occlusal path and the supporting occlusal path is elevated above the occlusal path by the distance d<double of thickness of the pump segment wall and at the point of complete release of the pump segment the supporting occlusal path is elevated above the releasing path by the distance k, which is maximum the same as the external diameter of the pump segment.

The rotor is made of at least double-arm hollow profile in which the whole inside space of each hollow profiled arm contains a pressure block, each of them is divided by a longitudinal partition into two parts, a spring is located in each of the parts, the pressure blocks are secured in each arm of the hollow profile of the rotor within the length of their strokes by a pin placed in the lengthwise partition of the pressure block and moves in the first groove made in the arm of the hollow profile, the springs inside the pressure block are leant against the back wall of the sliding mounting, in which a roller is freely located from the other side, the springs are pre-stressed at the other end against the body located in the center of the hollow profile, the body is fixed with a locking close to the stepping motor shaft, the body is at least a trilateral prism.

For a double-arm rotor the body is a quadrilateral prism.

For a three-arm rotor the body is a trilateral prism the rounded vertexes of which mesh into the second socket at the place of connection of the hollow profile arms. The body is fitted with a protrusion on the front side, in which a locking spring is located, a locking groove and an inlet groove for the locking pin placed on the shaft are on the back side of the body, the width of locking groove in the most distant position is narrower, that the diameter of the locking pin.

The pin of the pressure block fits into the first groove symmetrically located in the front part of the hollow profile of the rotor, the pin locks at the same time into the appropriate second groove of the control element designed for handling the pressure block when locating to rotor to the working path, into which the pump segment is pressed by expansion. The control element is connected to a cylindrical extrusion by thread.

The minimum length of the occlusal path is defined by the size of the central angle of the pump rotor rotation and is calculated as 360°/number of rotor arms.

The pressure block is equipped with guiding grooves for transversal guiding of the pump segment on the grooved working path.

The pressure roller is a roller from a roller bearing, which slides with the whole cylindrical surface in the sliding mounting of the pressure block.

The sliding mounting is finished with wiping blades for removing of possible dirt in both directions of rotation, there are sockets in the head of the pressure block at the level of the wiping blades.

The stroke length of the pressure block moves between 1.1 to 2.0 multiple of the pump segment external diameter.

The pressure roller is an electric conductor and when it touched the speed contact or the position contact located on the supporting occlusal path at the point of the change from the lead-in path into the occlusal path, and with a common contact located against them on the edge of the occlusal path, is under electric current of very low voltage.

The pressure roller may also be magnetized.

By expansion of the pump segment and its leading on an arch of radius of about three to four times the radius of the occlusal path and by leaning of the ends of the pump segment against the supporting surfaces the basic radial pressure of the pump segment against the transversally grooved working path of the pump is into being. The pump segment length has to be by 2-5 percent longer than the distance between the supporting surfaces of the pump segment in the pump box case measured on the working path perimeter. The rate of “compression” of the length is adequate to the pump segment diameter and the thickness of its wall. The pump segment has to be in the plane perpendicular to the main rotation axe of the pump even after pre-stressing of its length. The pre-stressing causes the basic forces pressing the pump segment to the occlusal path.

Lengthwise shifting of the pump segment on the working path of the pump in the direction of the rotor rotation is prevented by transversal grooving of the working path. The basic pressure forces the soft surface of the pump segment into the transversal grooves even when the pump is switched off, and then, when it is on the pressure roller moving on the pump section in longitudinal direction even increases this impression in the contact point.

The transversal cross section through the grooving has an advantageous shape of isosceles triangle of height between approx. 0.15 and 0.50 mm, depending on the pump segment radius and thickness of its wall.

Transfer of the excessive compressing force of the pressure roller to the supporting occlusal path prevents crushing and occurrence of undesirable or even harmful force causing through the movement of the pressure roller lengthwise movement of the pump segment, when the grooved occlusal path is smooth or worn out.

The pressure roller leaning also on the supporting occlusal path then cannot crush the pump segment by excessive force. It either cannot sink deeply in the soft pump segment by excessive force and thus generate an undesirable shifting force applied on the pump segment in the direction of its longitudinal axe (length).

The level of the pressure force of the pressure roller is adjusted automatically for variable working conditions of the pump by redistribution of the total pressure force between the grooved working path with inserted pump segment and the supporting occlusal path. The distance between the occlusal path and the supporting path has to be shorter by the manufacturing tolerance of the pumping segment than the double thickness of the wall of the pump segment.

The fixed distance of the supporting occlusal path from the transversally grooved working path defines the extent of clasp of the pump segment on the occlusal path and the releasing path for releasing of the pump segment from the occlusal path and thus also the volume ejected by the pressure roller from the pump segment only as a result of its radial application on the pump segment.

The source of pulsing (i.e. repeated releases of the compressed flexible container) cannot be removed, the consequences, i.e. the cyclical drop and increase of the ejected medium (pulsing) at the pump outlet in one cycle period can be removed mechanically, if the mutually correct correlation of geometrical dimensions is observed, i.e.

• • equal lengths of the occlusal path and the releasing path for the guiding of the pump segment from the occlusal path; and
  • constant increment of the pump segment volume at gradual release of the pressure of the pressure roller on the releasing path related to any unit of its length regardless the chosen way of mechanical clasp of the pump segment.

Mechanical linearity of the peristaltic rotation pump according to the invention is ensured by the equal angle lengths of the occlusal and the releasing paths. This condition can only be met with a three-or more-arm pump rotor.

The pump rotor arms have to be symmetrically situated in a circle, i.e. in the angle of 360°. The minimum length of the main occlusal path of the pump in angle degrees is defined from the formula 360°/number of the pump rotor arms. FIG. 1A shows location of the of the decisive parts of the pump in the pump case for three-arm rotor. The minimum length of the main occlusal path of the three-arm pump rotor is thus defined by the central angle 120°, which can be extended by angle β at the sucking part of the pump. The length of guiding the pump segment from the occlusal path has to be exactly 120° of central angle of the pump rotor swing for a three-arm rotor, as it ensures mutually continuous linkage of each pump rotor arm cycle to the next one.

For a four arm rotor the basic central angle of the arms is 90°, for a five-arm rotor 72° and, for six arms it is 60°, etc.

With zero back pressure at the pump output only minimum pressure of the pressure roller is sufficient for closing the pump segment cross section and the excessive force of the pressing springs is compensated by reaction of the supporting occlusal path on which the pressure roller also rolls. When the back pressure increases the need to increase the pressing force of the pressure roller increases. This happens automatically by reduction of the force applied by the same pressure roller on the supporting occlusal path.

The pressure roller of any of the pump rotor arms rolls on the supporting occlusal path and at the place of concurrence also on the pump segment placed in the working path. The pressing force of the roller is carried out by the sliding mounting of its surface in the pressure block. It is thus a unique combination of rolling and sliding friction of the pressure roller of the peristaltic rotation pump out of the rotation axe of the pressure roller. This holds the reaction of pressing force of the pressure roller in the sliding mounting in the pressure block of the pump rotor.

Positioning of the pump rotor in the pump case without dislocation of the pump segment on the working path is a substantive condition for reaching high pumping accuracy. The design of the hollow profile of the pump rotor, in the arms of which the pressure blocks move, enables to use the design space thus created for the biggest possible diameter, length and number of threads of spiral pressing springs. This ensures high stroke of the pressure roller and the softest possible characteristic of the pressing force, i.e. condition closest to the requirement, that the change of the pressing force of the pressure roller is approximately constant for the pressure block stroke.

When putting the pump rotor into the pump case with the pump segment already fitted it is necessary to avoid wrong displacement of the pump segment from the working path to the supporting occlusal path. It is ensured by simultaneous high stroke of all pressure rollers when putting the rotor in and by groove guiding of the pump segment in transverse direction in all the pressure blocks for both direction of the pump rotor rotation.

Easily disconnectable fixing of the pump rotor on the propulsive shaft of the step motor with self-adjusting clearance of the angle deviation in both directions of the rotor rotation is ensured by a locking close.

You turn the pump rotor placed on the beginning of the shaft so as the input groove for the locking pin is parallel with the locking pin on the shaft. You get over the back pressure of the locking spring located inside the body of the rotor hollow profile and after pressing to the limit position you turn the rotor by specific angle of approx. 30°-45°. When you release the pressing force gradually the locking pin locks into the groove. To dismantle the rotor proceed in reverse mode.

The locking groove has the same or less width in the limit position than the diameter of the locking pin is. This ensures permanent definition of the clearance by permanent pressing the locking pin into the groove by the pressing spring force during operation and even when the unit is worn out.

The torque of the step motor is transferred via the locking pin on the shaft and via the locking groove in the pump rotor body.

The peristaltic rotation pump is usually located in a case and the motor operation is controlled by a microprocessor or by a computer.

Accuracy of the peristaltic pump according to the invention achieves, and in numerous applications even outmatches accuracy and linearity of so far known alternative means of discrete and continuous dosage, and is determined by:

• • 1) Long-term and stable fixation of the pump segment on the working path of the pump.
  • 2) exactly defined distance between the pressure roller and the pump segment at each point of the pump working path.
  • 3) Mechanical split of the working path of the pump into two paths of identical length, i.e.
  • a) occlusal path of the pump; and
  • b) releasing path for guiding the pump segment out of the occlusal path of the pump, and lead-in path of any length for guiding the pump segment into the occlusal path of the pump. These three paths form the working path of the pump segment of each pump.
  • 4) Mechanically provided constant increment of the pump segment volume by gradual releasing of the pressure roller from the pump segment located by the release path for leading the pump segment out of the occlusal path.

Pumping linearity is ensured by removal of negative influence of that particular pressure roller, which is moving on the pump segment at the output from the occlusal path of the pump. Accuracy and long-term stability of the pump mechanical function then enables further substantial increase of dosage accuracy by microprocessor calibration for individually used pump segment.

The peristaltic rotation pump according to the invention is a series manufacturable product with tiny and also definite (i.e. not random) dispersion of functional parameters of one particular pump. It has an exact linear dependence of dosed volume on the number of steps (the angle of the rotor movement) of the pump.

This applies until occurrence of irreversible deformation of the pump segment not replaced by the user despite highlighted manufacturer's warning in the operation manual.

The linear dependence of the dosing volume on the number of steps (rotor movement angle) obtainable in practice enables usage of software correction of the accuracy of the dosed volume for any chosen dose within individual calibration of a particular pump segment used, and thus increase substantially the accuracy range of the whole unit for a declared pumping dose.

The peristaltic rotation pump with exact dosage has the following advantages against the previous solutions:

• • A) The pump is exact and mechanically linear from the design principle and these features are not substantially dependent on manufacturing tolerances of the individual mechanical components.
  • B) Linear dependence of the dosed volume on the number of steps (angle of rotor rotation) of the pump is an indisputable advantage.
  • C) The pump is also cheap to manufacture and does not require specialist installation and mechanical calibration in manufacturing, non-observance of which might cause later accuracy of the unit.
  • D) It is a maintenance free device for the whole life period and the operation is simple. It only requires a few-minute training how to put the pump segment and the rotor into the pump case.
  • E) the wide range of pumping parameters ranging from microliters to tens or hundreds of liters may be covered by just one or two design variations of the pump.
  • F) It may be switched during operation by a control to both directions of rotation with no change in accuracy and linearity of pumping, i.e. it can be used as a compressing or suction pump. It is similar to sucking of medicine by an injection syringe and subsequent injection of the medicine into a patient's body.
  • G) Liquids as well as gases may be pumped and dosed with the same accuracy.
  • H) The dosage accuracy achieved with low costs may also be used in highly pure environment by using sterile sets, e.g. dosage of medicine by infusion pumps, dosage pumps operating in laminate boxes, laboratory distributors for small-series production, half operating medicine production etc.
  • I) The low manufacturing costs with reaching the declared accuracy enable the pumps to be also used where the accuracy is not the decisive parameter (supplying nutrition in the digestion system, endoscopic operation of nee arthritis, sucking liquids from operation wounds, dialyse monitors etc.).

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A shows schematically the rotation pump case with the pump segment and the rotor inside.

FIG. 1b shows a detail of the occlusal path start

FIG. 2 shows an axonometric view of the dismantled pump

FIG. 3a shows an axonometric view of the rotor from the front.

FIG. 3b shows an axonometric view of the rotor from the rear.

FIG. 4 shows dismantled rotor system.

FIG. 5a shows the rotor three lateral from the front.

FIG. 5b shows the rotor three lateral from the rear.

FIG. 6a shows the pressure block from the front.

FIG. 6b shows the pressure block from the rear.

DETAILED DESCRIPTION OF THE INVENTION

The peristaltic pump for exact dosing consists of the pump segment 1 of external diameter 3.9 mm placed on the working path 24 of diameter approx. 65 mm and three-arm rotor 6 with pressure rollers 4. The pump segment 1 is from an infusion set normally available in medicine. The working path 2 is transversally grooved at the place of contact with the compressed pump segment 1, and is adjacent and is adjacent along the whole perimeter to the elevated supporting occlusal path 3, on which three pressure rollers 4 roll, sliding mounted in pressure blocks 5 fitted in arms 23 of the rotor 6. The pressure roller 4 is a roll from a rolling bearing of diameter 9 mm, made of hardened and lapped steel. The rotor 6 is made of a three-arm hollow profile 7, in which the whole hollow of the arms 23 is filled with three symmetrically located pressure blocks 5, in each of which springs 8 are located, separated by a longitudinal partition 13. The springs are pre-stressed against the body 22 placed in the hollow profile 7. The body 22 is a three lateral prism the rounded corners 35 of which fit into the second socket 34 at the place of connection of the arms 23 of the hollow profile 7, the body 22 has a cylindrical protrusion 29 at the front, on which a securing spring 17 is placed, a securing groove 19 is made in the back side of the body 22 and input groove 20 for securing pin 21 placed on the shaft 9 of the motor 10. The width of the securing groove 19 at the most distant position is narrower than the diameter of the securing pin 21 is.

The pump segment 1 is mechanically compressed to the working path 24, which consists of the lead-in path 15, occlusal path 2 and releasing path 16.

Both ends of the pump segment 1 lean against the supporting surface 18.

The supporting occlusal path 3 is elevated above the grooved occlusal path 2 by the distance d=1.0 mm.

The pressure block 5 is provided with a guiding groove 111 for transversal guiding of the pump segment 1 on the grooved working path 24.

The stroke of the pressure block 5 is 7 mm, which is in the range of 1.1 to 2.0 multiple of the external diameter of the pump segment 1.

The pressure blocks 5 are secured inside the rotor 6 within the range of the stroke with a pin 12 placed in the front on the longitudinal partition 13 placed in the pressure block 5. The pin 12 locks into the first grooves 14 symmetrically located inside the hollow profile 7 of the rotor 6 and at the same time into the appropriate second groove 33 of the control element 32 designed for handling the pressure blocks 5 when the rotor 6 is being mounted to the working path 24 into which the pump segment 1 is pressed by expansion, the control element 32 is connected to the cylindrical protrusion 29 by thread.

The length of the grooves 14 is 7 mm+0.8 mm for the securing pin 12. The rotor 6 is connected by the body 22 to the shaft 9 of the step motor 10 by a locking close secured by a securing spring 17.

The pressure roller (4) is an electric conductor and when it touches the speed contact (25) or the position contact (26) located on the supporting occlusal path (3) at the point of the change from the lead-in path (15) into the occlusal path (2), and with a common contact (27) located against them on the edge of the occlusal path (2), is under electric current of very low voltage.

To prevent unintentional rotation of the control element 32 during operation of the pump, there are depressions 30 to which protrusions 31 placed on the front side of the hollow profile lock 7.

Description of the Function

1) Before Commissioning

You shift the pump segment 1 with its solid ends into the holders of the pump case equipped with supporting surfaces 18. After that you press the rest of the pump segment 1 to the grooved working path so as the pump segment 1 covers the lead-in path 15, the occlusal path 2 and the releasing path 16 at the same distance from the edge of the supporting occlusal path 3.

You shift the pressure blocks 5 into the arms 23 of the hollow profile 7 by means of the control element 32 and the rotor 6 is ready for free sliding into the pump case. You turn the input groove 20 in the body 22 of the rotor 6 parallel with the locking pin 21 placed on the shaft 9 of the step motor 10 and slide the rotor 6 on the shaft 9, you press it against the securing spring 17, turn right by 30°; after that you release the pressure against the rotor 6. The pin 21 of the shaft 9 of the stepping motor 10 then locks in the securing groove 19 in the body 22 and the motor 10 is connected to the rotor 6 without any play.

When you turn the control element 32 back, the pressure blocks 5 slide out of the rotor 6 hollow profiles 7 arms 23, and the pressure rollers 4 lean against the supporting occlusal path 3 and also against the pump segment 1 located on the working path 24. At the same time the guiding grooves 11 of the pressure blocks 5 are ready to guide the pump segment 1 transversally on the working path 24.

With each switching on and without using the pumped medium the unit carries out an automatic functionality self-check via the electric position contact 26, which senses position of the pump rotor 6. By rotation of the rotor 6 with the pump segment 1 inserted any of the pressure rollers 4 rolls on the electric position contact 26 and the common contact 27 and causes their conductive connection. The electronic system immediately and with high angle accuracy determines the number of steps of the stepping motor necessary to repeated turn of the rotor 6. To switching the same electric contact by the pressure roller of any further arm in any direction, and the electronic system carries out the test. The unit thus tests correct operation plays of all moving parts of the pump rotor 6 as well as accuracy of adjustment of the pressing force of the pressing springs 8.

The pump is thus able to determine the condition when it can or cannot ensure the correctness and accuracy of pumping.

2) Pumping

You place the input hose fitted to the pump segment 1 into a vessel with the pumped medium, and the output hose, also fitted to the pump segment 1 into the vessel you want to dose the medium into.

After switching the unit on you fill the pump system (the hoses) completely by electric rotation of the rotor 6. Then you adjust the volume to be dosed, which will be automatically calculated into the necessary number of steps of the stepping motor 10. After pressing the Start button the rotor 6 of the pump starts turning and the programmed exact and linear pumping starts.

The pressure roller 4 of one of the rotor 6 arms 23, which moves on the supporting occlusal path 3 between the input and output hoses, when the rotor 6 turns, starts to press the pump segment 1 and thus reduce its cross section. Complete compression of the pump segment 1 by the pressure roller 4 always occurs at the most distant point 28 of the prolongation of minimum length of the main occlusal path, when the rotor 6 turns slowly.

When the rotor 6 rotation velocity increases, with higher viscosity of the pumped medium or with pumping against back pressure the right compression of the pressure roller 4 occurs, later in the direction of the pump rotor 6 rotation. At the rotor 6 speed, when the pressure roller does not connect the electric speed contact 25 with the common contact 27, the electronic system interprets the speed as too high and slows down the rotation speed accordingly. Then the connection of the position contact 26 (located by approx. 4° in the direction of the rotor 6 rotation in relation to the contact 25) with the common contact 27 has to occur, which defines the beginning of the occlusal path 2 and reliability of the compression of the pressure roller for any rotation speed of the rotor 6, and thus pumping correctness and liability. The pump in this operation mode of maximum pumping speeds then guarantees correct compression of the pump segment 1 at the beginning of the occlusal path 2 and thus also the accuracy of pumping. Reading of rotation speed and also the position of the rotor 6 happens 3 times per revolution for a three-arm rotor, and so the regulation loop is quite stable at this speed range.

The pump is thus able to determine and not to exceed the maximum pumping speed, at which it still can guarantee correctness and accuracy of pumping even under variable operation conditions.

At the moment of compression of one of the pressure rollers 4 on the pump segment 1 and also on the electric position contact 26 the preceding pressure roller 4 is at the end of the occlusal path 2 and at the beginning of the releasing path 16.

Further slight turn of the rotor 6 shifts the above mentioned preceding pressure roller 4 to the releasing path 16, which causes opening the pump segment 1, tightly closed before that, by constant volume. Each further movement of the rotor 6 causes progressive release of the pressure roller 4 from the pump segment 1 by constant volume, which is supported by the transversally grooved releasing path 16. A relation geometrically unequivocally and repeatably defined between the supporting occlusal path 3 and the releasing path 16 by a constant volume increment of the pump segment 1 being released, related to the unitary angle of rotation of the pump rotor 6.

The pumped medium is forced out of the pump segment 1 and thus also out of the pump output by the pressure roller 4, which is moving at that moment on the part of the pump segment 1 adjacent to the occlusal path 2. The preceding pressure roller 4, which is moving on the pumping segment I adjacent to the releasing path 16, does not influence the pressure force of the pump, as the space inside pump segment 1 before and after this roller 4 is then connected and gradually filled with the medium forced by the next roller 4 moving on the pump segment I on the occlusal path 2. The above algorithm still repeating after each 120° of the three-arm pump rotor turn (or each 90° with 4-arm rotor, 72° with 5-arm rotor, 60° with 6-arm pump rotor etc.) really compensates the influence of the pressure roller moving on the pump output.

3) After Pumping

The unit switches off.

By turning the control element 32 of the rotor 6 the pressure blocks 5 slide inside the arms 23 of the hollow profile 7 of the rotor 6. Axial pressure on the rotor 6 causes higher compression of the spring 17 fitted in the hollow cylindrical protrusion 29 of the body 22 against the shaft (9) of the motor 10, and the securing pin 21 gets out of the securing groove 19. By turning the rotor to the left the securing pin 21 moves opposite the output groove 20 and the rotor 6 may be pulled of the shaft 9 of the motor 10. By turning the control element 32 in the opposite direction the pressure blocks 5 slide out and their pressing springs 8 get partly released.

You pull the pump segment 1 out of the space of the working path 24 and then out of the other space. Finally you remove the ends of the pump segment supported by the supporting surfaces 18.

Industrial Application

The peristaltic pump according to the invention is applicable anywhere, where accuracy of dosage of liquids or gases is required. It is especially designed for application in medicine and in chemical, physical or biological laboratories.

Claims

1. A peristaltic rotation pump with exact, especially mechanically linear dosing, comprises:

a pump segment placed on a working path, is said path being adjacent to an elevated circular supporting occlusal path and a rotor with pressure rollers, characteristic by the fact, said pump segment extending along the working path, both ends of said pump segment leaning against a supporting surface outside the working path, the working path being transversally grooved at the place of contact with the compressed pump segment and being adjacent within all its length to an elevated circular supporting occlusal path on which at least two pressure rollers roll, the rollers being freely sliding mounted with their outside surface in a hollow slide mounting of the pressure blocks placed flexibly in the hollow arms of at least double-arm rotor, the rotor being connected to a shaft of the step motor, while the supporting occlusal path is elevated in the direction to the rotor rotation center above the transversally grooved working path comprised of the lead-in path, occlusal path and releasing path.

2. The peristaltic pump according to claim 1 the wherein said pump segment forms angle α=90° with the radius of said working path at the point of diversion of the pump segment from the working path.

3. The peristaltic pump according to claim 1, wherein the circular occlusal path and nearly circular releasing path are adjacent to an elevated circular supporting occlusal path along a whole length thereof, for rolling of at least three pressure rollers, and elevating the supporting occlusal path above the occlusal path by distance d<than twice the width of the pump segment wall, and at the point of absolute release of the pump segment, the supporting occlusal path being elevated above the releasing path by a distance less or equal to the external diameter of the pump segment, while the angle length of the occlusal path equals to the angle length of the releasing path corresponding to the distance from the point where the pressure roller starts releasing the pump segment to the point of complete release of the pump segment by the pressure roller, where the pressing force of the pressing roller to the pump segment is zero.

4. The peristaltic pump according to claim 1, wherein the rotor comprising:

at least a two-arm hollow profiles an inside space of each arm of each hollow profile being filled with a pressure block, each profile being split by a longitudinal partition into two parts;

a spring placed in each part, the pressure blocks being secured in each arm of each hollow profile within an extent of stroke thereof by a pin located in a longitudinal groove of the pressure block and going through the first groove made in the arm of the hollow profile, each spring being leant inside the pressure block against the back wall of the slide mounting; and

a freely located a roller, each spring being pre-stressed at the other end against the body located in the hollow profile, the body being fixed by a bayonet close to the shaft of the step motor, the body being at least trilateral prism.

5. The peristaltic pump according to claim 1, wherein the rotor has two arms and wherein the body is a tetralateral prism.

6. The peristaltic pump according to claim 1 wherein the rotor has three arms, wherein the body is a trilateral prism, the rounded corners thereof fitting into the second socket at the place of connection of the arms of the hollow profile, the front of the body being fitted with a cylindrical protrusions, in which a securing spring is placed, wherein the back of the body has a securing groove and an input groove for a securing pin placed on the shaft, the width of the securing groove at its most distant point from the cylindrical protrusion axis being less than the diameter of the securing pin, and wherein a pin of the pressure block fits into the first groove symmetrically placed at the front of the rotor and hollow profile, the pin locking at the same time into the appropriate second groove of the control element handling the pressure blocks when the rotor is inserted into the working path, into which the pump segment is pressed by expansion, the control element being connected by thread with the cylindrical protrusion.

7. The peristaltic pump according to claim 1, wherein a minimum length of the occlusal path is defined by size of a central angle of the rotor rotation and is calculated from the formula 360°/number of arms of the rotor.

8. The peristaltic pump according to claim 1, wherein said pressure block is comprised of guiding grooves for transversal guiding of the pump segment for the grooved occlusal path.

9. The peristaltic pump according to claim 1, wherein the pressure roller is a roll from a rolling bearing which slides by all cylindrical surfaces thereof in sliding mounting of the pressure block.

10. The peristaltic pump according to claim 1, wherein the sliding mounting is finished with wiper blades for removing possible dirt in both direction of rotation of the rotor, and wherein sockets are made on the head of the pressure block at the level of the blades.

11. The peristaltic pump according to claim 1, wherein a length of stroke of the pressing block moves in the range of 1.1 to 2.0 multiple of the external diameter of the pump segment.

12. The peristaltic pump according to claim 1, wherein the pressure roller is an electric conductor and when it gets to touching a speed contact or the position contact located on the supporting occlusal path where the lead-in path changes into the occlusal path and with common contact placed opposite to them on the edge of the occlusal path, the conductor is under electric current of very low voltage.

13. The peristaltic pump according to claim 1, wherein the pressure roller is magnetized.