AU663793B2

AU663793B2 - Driving shaft for peristaltique pump and fabrication method

Info

Publication number: AU663793B2
Application number: AU42635/93A
Authority: AU
Inventors: Bernard Bouvier; Frederic Neftel
Original assignee: Debiotech SA
Current assignee: Debiotech SA
Priority date: 1992-04-24
Filing date: 1993-04-22
Publication date: 1995-10-19
Anticipated expiration: 2013-04-22
Also published as: EP0604604B1; JPH06508669A; FR2690484A1; WO1993022559A1; AU4263593A; FR2690484B1; DE69304502T2; ES2092308T3; DE69304502D1; EP0604604A1; ATE142311T1; CA2110981A1

Abstract

The driveshaft (1) driving at least one rotary roller (2) is characterized in that the external part (6) of said driveshaft (1) presents surfaces (7, 7') which have been treated by projecting particles in order to provide the shaft with controlled roughness appropriate for providing slip-free driving of the roller (2) with respect to the shaft (1).

Description

OPI DATE 29/11/93 APPLN. ID 42635/93 li 111lll~l IIIIIIIl I AOJP DATE 10/02/94 PCT NUMBER PCT/FR93/00396 IIiIIliiiii IIII hIIIIi AUJ9342635 DEMANDE INTERNATIONALE PUBLIEE EN VERTU DU TRAITE DE COOPERATION EN MATIERE DE BREVETS (PCT) (51) Classification internationale des brevets 5 (11) Num~ro de publication internationale: WVO 93/22559 F04B 43/12 Al (43) Date de publication internationale: I I novembre 1993 (11.11.93) (21) Numi~ro de la demande internationale: PCT/FR93/00396 (74) Mandataire: PHELIP, Bruno; Cabinet HarIl Ph~Iip, 21, rue de La Rochefoucauld, F-75009 Paris (FR).

Date de dip6t international: 22 avril 1993 (22.04.93) (81) Etats disign~s: AU, BB, BG, BR, CA, CZ, Fl, HU, JP, (3G) Donnees relatives i la priorit6: KR, LK, MG, MN, MW, NO, PL, RO, RU, SK, US, 92/05114 24 avril 1992 (24.04.92) FR brevet europ~en (AT, BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), brevet OAPI (BF, 13., CF, CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, (71) D~posant (pour tous les Etats d~sign~s sauf US): DEBLO- TG).

TECH [CH/CH]; 17, rue des Terreaux, C.P. 82, CH-l1000 Lausanne 9 (CR).

Publie (72) Inventeurs; et Ai'ec rapport de recherche internationale.

Inventeurs/fleposants (US seulemtent) NEFTEL, Fr~d~ric [FR/FR]; 1, rue des Ecouffes, F-75004 Paris BOU- VIER, Bernard [FR/FR]; 17, rue de la Marne, F-95 160 Eragny-sur-Oise (FR).D

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(54) Title: DRIVING SHAFT FOR PERISTALTIQUE PUMP AND FABRICATION METHOD (54)Titre: AXE D'ENTRAINEMENT POUR POMPE PERISTAILTIQUE ET SON PROCEDE DE FABRICATION (57) Abstract The driveshaft 8! driving at least one rotary 31 roller is characterized in3 that the external part of said driveshaft presents/ surfaces which have 6 been treated by projecting particles in order to provide 7 the shaft with controlled roughness appropriate for 'Z J 16 14 providing slip-free driving of the roller with respect to 1 the shaft I 1 (57) Abrige L'axe d'entrainement 13 d'au momns un galet rotatif est caract~ris6 en ce que la partie externe dudit axe d'entrainement pr~sente des surfaces trait~es nar projection de particules pour lui donner une rugosit6 contr6lee apte di permettre un entrainement sans glissement du galet par rapport A l'axe

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c~ Drive shaft for a peristaltic pump and its process of manufacture Field of the invention The present invention concerns a drive shaft for a peristaltic pump and its process of manufacture.

Background of the art In peristaltic pumps, drive shafts are used to rotate rollers, which compress deformable tubes containing the liquid to be conveyed.

These shafts are connected by all suitable linkages to a driving motor. The driving motor rotates the drive shaft, which acts on at least one roller which is contiguous to it.

Usually, drive shafts are metallic, and are specifically made of stainless steel, whereas the rollers are made of various plastics.

The drive shafts in the prior art are generally satisfactory.

However, it has been found that, after a certain period of use, wear occurs, both of the drive shaft and of the roller, accompanied by slippage between the shaft and the roller, which leads to faulty rotation and to unsatisfactory drive.

The faulty drive of a roller by a shaft prevents the uniform and appropriate compression of the deformable tube, with which a roller comes into contact, and, consequently, prevents proper conveyance of the liquid t1

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to be transported.

Many attempts were made in the past to try to avoid this slippage, but, to the best of the applicant knowledge, they have all proved fruitless because, in fact, it has been necessary to compress the rollers to obtain a satisfactory drive.

In US Patent No.2.899.904, it is proposed to make the drive shaft rough by knurling. The result obtained is unstable in time and liable to cause rapid wear of the rollers.

US Patent No.3.249.059 proposes to equip the drive shaft with rings of an elastic material. The added parts are a potential source of failure. Furthermore, they fail to correct all the drive defects, and they are rapidly worn.

US Patent No.5.037.274 also proposes the use of a drive shaft having a tapered upper end.

Summary of the invention The present invention corrects the aforementioned drawbacks, and proposes a drive shaft for rotating rollers, with which slip-free drive of a roller by the shaft is obtained.

In the present invention, the drive is obtained without compressing ~d t the rollers and with a very low drive torque.

T 2 IV p.- The present invention also has for object the process of manufacture of such a shaft.

The present invention thus creates a drive shaft for at least one rotating roller, wherein the external part of said drive shaft has surfaces treated by the projection of particles, to impart a controlled roughness to it, designed to enable slip-free drive of the roller by the shaft.

The present invention also has for object a process of manufacture of a drive shaft of a peristaltic pump with rotating rollers, from a cylindrical metal shaft, in which the zone intended to come into contact with a rotating roller is cropped, and then ground, to obtain a controlled uniform surface state, wherein a portion at least of said zone designed to come into contact with a roller is surface-treated by the projection of a material to impart a controlled roughness to it.

The present invention also concerns the following characteristics, considered separately or in all technically possible combinations: S the treated surfaces are provided over the entire external Ii portion of the drive shaft, S the treated surfaces are made selectively on one or more zones of the drive shaft, S only the external parts of the drive shaft, intended to come 3 t4 into contact with at least one roller, are treated, the surface treatment is made by the projection of solid particles, S the surface treatment is a shot-blasting, in which glass beads, particles of tungsten, sand, or similar, are projected against the external surface of the drive shaft, S the upper portion of the shaft has a rounded tapered shape, S the radius of curvature of the cone of the shaft is approximately equal to half the diameter of the shaft at the level of the rollers, S the treated parts designed to come into contact with the rollers correspond to the upper part and to the lower part of a roller, which causes the squeezing of the tube by its median portion, S the treated part of the drive shaft is subsequently polished.

Brief description of the drawing The above and other objects and advantages of the invention will be apparent from the following description taken in conjunction with the i accompanying drawing wherein: S Figure 1 is a plan view of a portion of a peristaltic pump, S Figure 2 is a cross-section along line II-II of Figure 1, 4 0 Figure 2A is detail A of Figure 2, Figure 3 is a partial schematic section of a shaft and a rotating roller.

Figure 1 illustrates schematically and partially a peristaltic pump 4, with which three rollers 2 are rotated by a drive shaft 1 actuated by a motor, not shown.

With reference to Figure 2, the drive shaft 1 has many different zones on its external surface coming into contact with at least one roller 2 housed in the peristaltic pump 4.

The drive shaft 1 is integral with a shoulder 12 which ensures its maintenance in the body of the peristaltic pump.

The driving motor 5 of the drive shaft 1 is connected to said shaft by a link 13, which may be of any appropriate shape.

Tihe external surface 6 of the drive shaft 1, coming into contact with at least one roller 2, comprises treated surfaces 7,7' cooperating with selective portions of tht. roller 2.

The method of obtaining the treated surfaces 7,7' is described below.

Figure 2A shows detail A of the upper end of the drive shaft 1. The upper portion 8 of the drive shaft 1 has a rounded tapered n .T 7 A J"'4^ r -7 1 shape.

The radius of curvature 9 of the cone is approximately equal to half the diameter 10 of the drive shaft 1 at the level of the rollers 2.

Figure 3 shows the cooperation between an example of a drive shaft 1 according to the present invention, and a particular example of a roller having a bulge configuration.

In the implementing of the invention according to Figure 3, only zones 7,7' coming into contact with the portions 15,16 of the roller 2 are treated, while the other external portions 6 of the drive shaft 1 are not treated.

During the rotation of the roller 2 by the drive shaft 1, the tube 3 is compressed by the median portion 11 of the rotating roller 2.

The treatment of the external surface of the drive shaft 1 will now be described.

The surface treatment of the drive shaft 1 of the rollers 2 is what is commonly referred to as shot-blasting or abrasive blasting.

According to this shot-blasting or abrasive blasting treatment, particles are projected, generally solid particles, at a certain angle and under a predetermined pressure, to obtain a controlled roughness of the selective portions of the drive shaft which have received the projections of I- rf solid particles.

These projections of solid particles may, for example, be projections of glass beads, tungsten particles, or particles of various hard materials such as diamond. Naturally, they may also be projections of various sand particles.

Brief description of an embodiment of the invention In an embodiment of the present invention, the drive shaft is manufactured in the following conditions.

The shaft is made in a mateial that is, for example, stainless steel.

It is ground in order to give it a precise diameter, for example 2.48 +0.001 mm.

It is then shot-blasted on at least selective portions For this purpose, the shaft is held by a rotary head and is subjected to the projections of an adjustable nozzle, approximately perpendicular to the shaft, and actuated with a reciprocating movement parallel to the shaft.

The nozzle thus sweeps the selective portions 7,7' of the shaft to be shotblasted.

The abrasive shot consists of glass beads or diamond crystals with an average size of 65 micrometers The projection time was 5 s, at a distance of 100 mm, at a 90 degree shot angle.

The pressure of the machine projecting the abrasive was 2 bars.

I In certain cases, after se.ective shot-blasting treatment over an extended zone, to obtain the portion 7,7' shown in the drawing, the drive shaft 1 was ground again in the portions 14 which did not receive the shotblasting or abrasive blasting treatment.

The shaft is then subjected to heat treatment accompanied by a deposition of titanium nitride, in a thickness of 2 micrometers for example. This treatment serves to enhance the superficial hardness of the shaft without changing its surface state.

During the intensive use of the drive shaft 1 according to the present invention, having treated selective portions 7,7' to have a controlled roughness during contact with the upper part 15 and lower part 16 of the rotating roller 2, it was found that the shot-blasting or abrasive blasting treatment, applied to the drive shaft 1 of the present invention, ensures a proper drive of the roller or rollers 2, without wear or abrasion of said roller or rollers 2. Nor is there any transfer of plastic particles to the shaft, which could lead to clogging of the craters created by the shot-blasting or abrasive blasting.

The drive shaft 1 of stainless steel with the treated portions 7,7' as

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indicated above had a diameter of about 2.5 mm, while the diameter of the rotating rollers 2 was about 12 mm.

The portion of the drive shaft is polished entirely before abrasive blasting and, after the abrasive blasting operations, the dimensions of the drive shaft 1 are unchanged, making it possible to obtain excellent dimensional accuracy of the diameter of the drive shaft 1.

The invention is not limited to the embodiment represented and described in detail, and various modifications can be made to it without departing from its scope.

What is claimed is: 1 A drive shaft for at least one rotating roller, where' e external part of said drive shaft has surfaces treated by thepr jection'of particles, to impart a controlled roughness to it, desig to enable slip-free drive of ihe roller by the ?'haft.

2 The drive shaft accoi g to Claim 1, wherein the ,reated surfaces are provided over ti entire external portion of the drive shaft.

3 The e shaft according to Claim 1, wherein the treated surfaces are ade selectively on one or more zones of the drive shaft.

4 The drive shaft according to Claim 1 or Claim 3, wherein only extemalparts-of the drive shaft -tended4-to-eOme into coentact--

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Claims

1. A process for manufacturing a drive shaft for a peristaltic pump comprising at least one rotating roller, wherein surfaces of the external part of said drive shaft are treated by tine projection of particles to impart a controlled roughness to said external part.

2. The process according to claim 1, wherein the treated surfaces are provided over the entire external portion of the drive shaft. oO 3. The process according to claim 1, wherein the treated surfaces are made go o *o selectively on one or more zones of the drive shaft. 0 00 .000 *0 4. The process according to claim 3, wherein only the external parts of the dr;re shaft, intended to come into contact with at least one roller, are treated. 00 1 The process according to any one of claims 1 to 4, wherein the external parts of the drive shaft, intended to come into contact with at least one roller, are cropped, then ground, in order to obtain a controlled uniform surface state, before being treated by the projection of particles.

6. The process according to any one of claims 1 to 5, wherein the treated surfaces are subsequently polished. ,000

7. The process according to any one of claims 1 to 6, wherein the surface treatment is made by the projection of solid particles.

8. The process according to claim 7, wherein the surface treatment is a shot- blasting, in which glass beads, tungsten particles or sand particles are projected. 4U .ir:ii i -l l-.i -ill j o°° 0 0 00 *000 11

9. The process according to any one of claims 1 to 8, wherein the drive shaft is manufactured from a metallic shaft. The process according to any one of claims 1 to 9, wherein the drive shaft has an upper portion with a rounded tapered shape.

11. The process according to claim 10, wherein the radius of curvature of the upper portion of the shaft is approximately equal to half the diameter of the shaft at the level of the rollers.

12. The product obtained by the process according to any one of claims 1 to 11.

13. The product according to claim 12, wherein the drive shaft belongs to a peristaltic pump, in which at least one roller compresses a deformable tube.

14. The product according to claim 13, wherein each roller having an upper, a median and a lower part and said median part being designed to be in contact with the tube, said treated surfaces intended to come into contact with the rollers correspond to said upper part and to said lower part, which causes the squeezing of the tube by said median part. DATED this 7th day of August, 1995. DEBIOTECH S.A. WATERMARK PATENT TRADEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA 0 0( SKP:KWB:ML VAX doc 03 AU4263593.WPC In I. ABSTRACT OF THE DISCLOSURE 'Drive shaft for peristaltic pump, and its process of manufacture' DEBIOTECH SA Invention of: Bernard Bouvier Fr6deric Neftel A drive shaft for at least a rotating roller wherein the external portion of said drive shaft has surfaces treated by projection of particles to impart to it a controlled roughness designed to enable slip-free drive of the roller by the shaft Figure 3. 912 x