Pipette for operating a syringe

Abstract

Pipette for operating a syringe with a bar-shaped housing, a fixture with an opening at the lower end of the housing for putting in a syringe with a fastening portion on the upper edge of a cylinder, a fixture body with a further fixture and a further opening on the lower end of the housing, for putting in a further fastening portion of a piston of the syringe, means for detachably holding the fastening portion in the fixture and the further fastening portion in the further fixture, means for displacing the fixture body within the housing in the longitudinal direction of the housing, which have a draw-up lever activated from the outside of the housing, which is connected to the fixture body via a connection element which grips through a straight slit extending in the longitudinal direction of the housing, wherein below the slit in the housing, a cover stripe covering the slit is held in the housing at two positions spaced apart from each other in the longitudinal direction of the slit, and wherein the connection element has a channel through which the cover stripe extends.

Claims

1. Pipette for actuating a syringe, comprising: a bar-shaped housing (2), having housing walls accommodation means (20) located at a lower end of the housing, for the accommodation of a syringe (3), the syringe (3) having a cylinder (11) and a fastening portion (16) on the upper end of the cylinder (11), an accommodation body (25) with further accommodation means (24) for the accommodation of a further fastening portion (19) of a piston (12) within the syringe (3), spring fasteners for detachably holding (23, 26) the fastening portion (16) in the accommodation means (20) and means (26) for detachably holding the further fastening portion (19) in the further accommodation means (24), means for displacing (5, 8, 34, 37, 27) the accommodation body (25) within the housing (2) in the longitudinal direction of housing (2), the means for displacing having a draw-up key (5) actuated from the outside of the housing (2), and being connected to the accommodation body (25) via a connection element (62) which extends through a straight slit (4) extending in a longitudinal direction of a wall of the housing (2), characterised in that a cover stripe (45) is fixedly held within the housing (2) at two spaced apart positions (48, 49) and extends in the longitudinal direction of the slit (4) and covers the slit (4) from below, the stripe (45) extends through a channel (50) of a portion of the connection element (62) located within housing (2), so that slit (4) is covered from below independent from the position of the draw up key (5) and the connection element (62).

2. The pipette according to claim 1, wherein the friction between the means for displacing (5, 8, 34, 37, 27) the accommodation body (25) and/or other components movable in the housing, which are fixedly connected to the means for displacing, and components fixedly arranged in the housing is dimensioned such that the draw-up key (5) does not move along the slit (4) automatically when the pipette is in vertical orientation.

3. The pipette according to claim 2, wherein the friction between connection element (62) and covering stripe (45) is dimensioned such that the draw-up key (5) does not move along the slit (4) automatically when the pipette is in vertical orientation, or is correspondingly dimensioned together with the friction between another pair of components movable in the housing (2) and fixedly arranged in the housing (2).

4. A pipette according to claim 1, characterised in that the cover stripe (45) is flexible.

5. The pipette according to claim 4, characterised in that the channel (50) in the connection element (62) has a flatly U-shaped course in the longitudinal direction of the cover stripe (45), so that the cover stripe (45) in the channel (50) is deflected from a plane in which it runs contiguously to the connection element (62).

6. A pipette according to claim 1, characterised in that the channel (50) in the connection element (62) runs out curvedly with its mouths into the plane through the deflected portions of the cover stripe (45).

7. A pipette according to claim 1, characterised in that the accommodation body (25) is fixedly connected to at least one support element (63, 64), which is supported on a support rally (65, 66) in the housing (2) that is oriented parallel to the plane across the portions of the cover stripe (45) outside of the connection element (62).

8. The pipette according to claim 7, characterised in that the support elements (63, 64) are wings which project on different sides of the accommodation body (25) in a plane that is parallel to the plane in which the cover stripe (45) is disposed contiguously to the connection element (62), and which engage in parallel grooves (65, 66) on the inner side of opposing walls of the housing (2).

9. A pipette according to claim 1, characterised in that the connection element (62) has a groove stone engaging into the slit (4).

10. A pipette according to claim 9, characterised in that the draw-up key carrier (29) has the groove stone.

11. A pipette according to claim 1, characterised in that the connection element (62) has a draw-up key mount (28) fixedly connected to the accommodation body (25) and disposed in the housing (2), as well as a draw-up key carrier (29), extending through the slit and connected to the draw-up key (5), wherein the channel (50) is formed between the draw-up key mount (28) and the draw-up key carrier (29).

12. The pipette according to claim 11, characterised in that one wall of the channel (50) is a lateral surface (51) of the draw-up key mount (28) and an opposing wall of the channel is a further lateral surface (52) of the draw-up key carrier (29).

13. The pipette according to claim 12, characterised in that the draw-up key mount (28) and the draw-up key carrier (29) are joined components.

14. A pipette according to claim 1, characterised in that the cover stripe (45) is held at two spaced apart positions (48, 49) on the two ends and/or outside of the two ends of the slit (4).

15. A pipette according to claim 1, characterised in that the cover stripe (45) is fastened on the housing (2) beyond the two ends of the slit (4) in one or plural of the following ways: positive fit, adhesive joining or non-positive fit.

16. The pipette according to claim 15, characterised in that the cover stripe is fastened on eyes (46, 47) or ears on pins (48, 49) which project from the inner side of the housing (2).

17. A pipette according to claim 1, characterised in that the cover stripe (45) is elastic in the longitudinal direction and/or tensioned in the longitudinal direction by means of a spring.

18. A pipette according to claim 1, characterised in that the housing (2) and the cover stripe (45) are made of the same plastic material or of different plastic materials.

19. Pipette for actuating a syringe, comprising: a bar-shaped housing (2), having housing walls accommodation means (20) located at a lower end of the housing, for the accommodation of a syringe (3), the syringe (3) having a cylinder (11) and a fastening portion (16) on the upper end of the cylinder (11), an accommodation body (25) with a further accommodation means (24) for the accommodation of a further fastening portion (19) of a piston (12) within the syringe (3), spring fasteners for detachably holding (23, 26) the fastening portion (16) in the accommodation means (20) and means (26) for detachably holding the further fastening portion (19) in the further accommodation means (24), displacement mechanism (5, 8, 34, 37, 27) for displacing the accommodation body (25) within the housing (2) in the longitudinal direction of the housing (2), the displacement mechanism having a draw-up key (5) actuated from the outside of the housing (2), and being connected to the accommodation body (25) via a connection element (62) which extends through a straight slit (4) extending in the longitudinal direction of the housing (2), wherein that below the slit (4) in the housing (2), a cover stripe (45) covering the slit is held in the housing (2) at two positions (48, 49) spaced apart from each other in the longitudinal direction of the slit (4), and that the connection element (62) has a channel (50) through which the cover stripe (45) extends.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) The present invention will be explained in more detail in the following by way of the attached drawings of exemplary embodiments. The drawings show:

(2) FIG. 1 a pipette of the present invention with syringe held therein, in a perspective view from the side;

(3) FIG. 2 the same pipette in a longitudinal section;

(4) FIG. 3 fixture body with tooth bar, connection element, draw-up lever and cover tape of the same pipette in a magnified partial section in the longitudinal direction;

(5) FIG. 4 the same configuration in a perspective partial view from the side;

(6) FIG. 5 the same configuration in a housing half of the pipette in a perspective partial view from another side;

(7) FIG. 6 the draw-up lever mount in a perspective view from the side;

(8) FIG. 7 the draw-up lever carrier in a perspective view from the other side;

(9) FIG. 8 the draw-up lever carrier with inserted cover tape in a perspective view from the side;

(10) FIG. 9 the draw-up lever carrier with inserted cover tape in a further perspective view.

(11) In the present application, the designations up and down refer to the orientation of the pipette in which the bar-shaped housing is oriented vertically, and the fixture for the syringe is disposed at the downside.

DETAILED DESCRIPTION OF THE INVENTION

(12) While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated.

(13) According to FIG. 1, a pipette 1 has a bar-shaped housing 2, in which a syringe 3 is held at the downside. From a side wall of the housing 2, a draw-up lever 5 (also referred to as a draw-up key 5) projects from the housing 2 above a straight slit 4. An actuation button 8 of a tooth bar pawl control projects from the same side wall of the housing above two further slits 6, 7. Above it, a LCD display 9 is countersunk into the same side wall of the housing 2. Segments of a dial 10 project from openings in the neighbouring side wall.

(14) According to FIG. 2, the syringe 3 has a cylinder 11 and a piston 12 movably arranged therein. The cylinder 11 has a conical portion 13 with a hole 14 for the passage of liquids at the downside, and above it a cylindrical portion 15 in which the piston 12 can be displaced. At the upside, the cylinder 11 has a fastening portion 16 with a circumferential flange 17. A piston rod 18 projects towards the upside from the piston 12, which has a further fastening portion 19 with several circumferential bulges (not shown).

(15) The syringe 3 is arranged with its flange 17 in a fixture 20 at the lower end of the housing 2, which has an axially directed opening 21.1 for insertion and withdrawing of the syringe 3 at the lower end of the housing 2. With its topside, the syringe 3 pushes against a pressure-sensitive ring sensor 22, which scans projections on the upper edge of the flange 17. The flange 17 is kept in the housing 2 in this position by means of spring fasteners 23.

(16) The further fastening portion 19 of the piston 12 is disposed in a further fixture 24 in a hollow-cylindrical fixture body 25. The latter has a further axially oriented opening 21.2 for inserting the fastening portion 19. The further fastening portion 19 is held with further gripping levers 26, which engage between the bulges of the further fastening portion 19 or clamp it in.

(17) The fixture body 25 is fixedly connected to a tooth bar 27, which extends below the slit 4 in the longitudinal direction of the housing 2.

(18) A draw-up lever mount 28 (also referred to as a draw-up key mount 28) is fixed on the fixture body 25 and on a lower part of the tooth bar 27.

(19) Further, there is a draw-up lever carrier 29 (also referred to as a draw-up key carrier 29), which bears against the lower side of the edges of the slit 4 with a sliding board 30. The draw-up lever carrier 29 has an upward-projecting post 31 which grips through the slit 4. Outside of the housing 2, the draw-up lever 5 is fixed on the post.

(20) In the upper half of the housing 2, a metering lever 34 is pivotally mounted in a hinge bearing 32 in a bulge 33 of the side wall of the housing 2 opposite to the slit 4. The metering lever 34 has two spaced apart legs 35, 36, which stand out of the two slits 6, 7 on the opposite side wall of the housing 2. The actuation button 8 is fixed there on the projecting ends of the legs 35, 36.

(21) Between the two legs 35, 36 of the metering lever 34, a pawl 37 is pivotally mounted. The pawl 37 is arranged above the toothing 39 of the tooth bar 27 with a pawl tooth 38. The metering lever 34 is pressed into the position of FIG. 2 by a not shown spring device. Against the action of the spring device, the metering lever 34 can be swung towards the downside by actuating the actuation button 8. The pawl 37 is pushed towards the toothing 39 of the tooth bar 27 by a not shown further spring device.

(22) A movable covering 40 is arranged between pawl 37 and tooth bar 27. The covering 40 can be moved by turning the dial 10 which projects laterally out of the housing 2, so that it covers the toothing 39 of the tooth bar 27 more or less.

(23) Further, a circuit board 41 with electronics is arranged in the upper half of the housing 2. Here is also situated a power supply in the form of batteries or accumulators 42.

(24) A further sensor 43 is assigned to the dial 10, which acquires the position of the dial 10. The measurement values determined by the ring sensor 22 and the further sensor 43 are forwarded to the electronics via cable.

(25) The code indicated on the flange 17 designates the size of the respective syringe 3. From the measurement signals provided by the ring sensor 22, the electronics determines the respective syringe size, and from the setting of the dial 10 the respective step width. From these it calculates the set metering volume and displays it on the display 9.

(26) At the inside, the slits 6, 7 are covered by a diaphragm 44 connected to the metering lever 34.

(27) According to FIGS. 3 to 5, a flexible cover stripe 45 exists in the housing 2 below slit 4 in order to cover up the slit 4. The cover stripe 45 is made of polypropylene. According to FIG. 8, the cover stripe 45 has eyes 46, 47 at its ends, which are fixed on pins 48, 49 according to FIG. 2, which project from the inner side of that side wall of the housing 2 which has the slit 4.

(28) According to FIGS. 3 to 5, the cover stripe 45 runs through a channel 50 between draw-up lever mount 28 and draw-up lever carrier 29. According to FIGS. 6 and 7, the channel 50 is limited on opposing sides by a lateral surface 51 with a radius of the draw-up lever mount 28 and by a further lateral surface 52 with corresponding radius of the draw-up lever carrier 29. The two lateral limits of the channel 50 are formed by two stripe-shaped side walls 53, 54 of the draw-up lever carrier 29. These are connected to each other by a cross member 55 in a distance from the lateral surface 52 that has the radius. Between the further lateral surface 52 having the radius and the cross member 55, the draw-up lever carrier has a breakthrough 56. From one side of the cross member 55 project two projections 57, 58, which can be put into corresponding pockets 59, 60 of the draw-up lever mount 28. The two stripe-shaped side walls 53, 54 are bridged by a front wall 61, which has the further lateral surface 52 with the radius at the downside, and from which the post 31 projects at the upside.

(29) According to FIGS. 8 and 9, the draw-up lever carrier 29 can be pre-assembled with the cover stripe 45 by guiding the cover stripe 45 along the further lateral surface 52 and across the breakthrough 56, so that it runs on the topside of the cross member 55 between the two stripe-shaped side walls 53, 54. In this configuration, the draw-up lever carrier 29 can be connected to the draw-up lever mount 28 by putting the projections 57, 58 into the pockets 59, 60 and draw-up lever carrier 29 and draw-up lever mount 28 are glued together or snapped together by suitable snapping means. The cover stripe 45 is then arranged in the channel 50 between lateral surface 51, further lateral surface 52 and side walls 53, 54. At one side next to the draw-up lever carrier 29, the cover stripe 45 rests on a projecting rib 51.1 of the draw-up lever mount 28 that extends in the longitudinal direction of the slit 4 (compare FIGS. 4 to 6).

(30) Draw-up lever mount 28 and draw-up lever carrier 29 form together a connection element 62 between fixture body 25 and draw-up lever 5 (compare FIG. 2, 3, 4).

(31) According to FIGS. 4 and 5, the draw-up lever mount 28 has wings 63, 64 which project from both sides. In the example, the wings 63, 64 have a cylindrical shape. They engage into grooves 65, 66 on two opposing side walls of the housing 2. The grooves 65, 66 are limited by an edge of a housing half at one side, and on the other side by a ledge of a chassis in which parts of the drive mechanics of the pipette 1 are mounted.

(32) According to FIG. 2, on the eyes 46, 47, the cover stripe 45 is held stretched at the inner side of the slit 4 by the two pins 48, 49 according to FIG. 8, 9.

(33) According to FIG. 3, it is vaulted on the plane in which it extends on both sides of the channel 50 due to the radii of the lateral surfaces 51, 52 of the channel 50. Close bearing of the cover stripe 45 against the edges of the slit 4 is obtained through this.

(34) In order to draw up liquid through the opening 14 of the syringe 3, the draw-up lever 5 is pushed upward from the position of FIGS. 1 and 2. The liquid drawn up can be discharged in small steps by repeatedly pushing the actuation button 8 downward against the action of the spring device. In this, the further spring device pushes the pawl 37 with the pawl tooth 38 against the covering 40, until the pawl tooth 38 reaches the lower end of the covering 40. Thereafter, the pawl 37 falls into the toothing 39 of the tooth bar 27 with its pawl tooth 38, and takes the tooth bar 27 somewhat along when the metering lever 34 is further swung downward. In this, the displacement of the tooth bar 27 in each swinging of the metering lever 34 till the arrival at a lower stop depends on a position of the covering 40 that is set by means of the dial 10. After unloading the actuation button 8, it is pushed upward by the spring device, and a further metering step can be performed. This is possible for so long until the residual amount of liquid remaining in the syringe 3 is smaller than the set metering amount. A residual stroke lock provides that the covering 40 is swung against the lower side of the pawl 37, so that the pawl tooth 38 can no more fall into the toothing 39.

(35) When the draw-up lever 5 is displaced, the cover stripe 45 is guided across the channel 50. The slit 4 remains always covered up. Unintended displacement of the fixture body 25 and of the connection element with the draw-up lever 5 as well, is counter-acted by the friction between cover stripe 45 and connection element.

(36) The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term comprising means including, but not limited to. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.

(37) Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.

(38) This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.

LIST OF REFERENCE SIGNS

(39) 1 pipette 2 housing 3 syringe 4 slit 5 draw-up lever 6 slit 7 slit 8 actuation button 9 display 10 dial 11 cylinder 12 piston 13 portion 14 hole 15 portion 16 fastening portion 17 flange 18 piston rod 19 fastening portion 20 fixture 21.1 opening 21.2 opening 22 ring sensor 23 gripping lever 24 fixture 25 fixture body 26 gripping lever 27 tooth bar 28 draw-up lever mount 29 draw-up lever carrier 30 sliding board 31 post 32 hinge bearing 33 bulge 34 metering lever 35 leg 36 leg 37 pawl 38 pawl tooth 39 toothing 40 covering 41 circuit board 42 accumulator 43 sensor 44 diaphragm 45 cover stripe 46 eye 47 eye 48 pin 49 pin 50 channel 51 lateral surface 51.1 rib 52 lateral surface 53 side wall 54 side wall 55 cross member 56 breakthrough 57 projection 58 projection 59 pocket 60 pocket 61 wall 62 connection element 63 wing 64 wing 65 groove 66 groove