JP6033628B2 - Manual weighing device - Google Patents

Description

  The present invention relates to a manual metering device for metering a liquid.

  The manual metering device is a liquid metering device that can detachably hold a syringe or pipette tip. The syringe has a syringe cylinder with a syringe plunger that moves within it and has an opening that connects to an environment for aspirating and discharging liquid. The opening is usually aligned with the tip at the bottom of the syringe cylinder. A pipette tip is a small tube that generally narrows downward, and has a bottom opening for sucking and discharging liquid and an upper opening to which a gas displacement device is connected. The manual metering device is held in one hand by the user during administration so that a syringe or pipette tip held in the manual metering device can align the liquid to be aspirated or discharged with a container or other object. The user can operate the suction and discharge of the liquid but cannot operate additional functions with the same hand holding the manual metering device. Manual metering devices are used in the laboratory, especially for the administration of liquids.

  Manual weighing devices are designed as air cushion weighing devices and positive displacement weighing devices. The air cushion type weighing device has a seat part that detachably holds the pipette tip at the upper end opening. The air displacement device is built in the manual weighing device, communicates with the flow path, and is connected to the hole of the seat portion. The air cushion is displaced by the displacement device so that the liquid is sucked or discharged from the lower end opening according to the displacement direction of the air cushion. The displacement device is usually a cylinder having a plunger displaceable therein. The plunger is moved by the drive unit. A manual weighing device that functions with an air cushion is called a “pipette”.

  The positive displacement device moves with the syringe. The syringe can be connected to or released from the volume displacement device. The syringe cylinder is held by a positive displacement metering device, and the syringe plunger is held by a seat body that can be displaced by a drive unit. The syringe plunger moves back and forth so that liquid is aspirated or ejected from the opening of the syringe by the drive unit. A direct displacement device that works with a small syringe having the same size and shape as a pipette tip is also referred to as a “direct displacement pipette”.

  Direct displacement metering devices that work with large syringes that are typically emptied in several steps are also referred to as “dispensers”.

  The pipette tip and syringe are preferably made of plastic and can be discarded after they have been used and replaced with a new pipette tip or syringe.

  Known manual metering devices comprise a mechanical drive unit or an electromechanical drive unit. In addition, manual metering devices with manual drive units with electromechanical supports (“servo drive units”) are well known. In addition, there are constant dose manual metering devices and adjustable dose manual metering devices. Furthermore, there are manual metering devices with only one channel for a single syringe or pipette tip and manual metering devices with multiple channels for simultaneous use with multiple syringes or pipette tips. The present invention relates to all manual weighing devices of the above type.

  Conventional manual weighing devices include a housing formed as a hard plastic handle. These are means for holding the syringe or pipette tip, drive means, transmission means for causing movement of the drive device relative to the plunger or syringe, or displacement devices for air cushion displacement, movable elements and possibly display elements or others Of components. In the case of an electrically driven manual weighing device, an electrically driven motor, an electronic control device and a battery or a rechargeable battery are arranged in the housing. Thus, the plurality of components are housed in a very small space in the manual metering device housing. The housing is formed simultaneously with a well-known manual weighing device support structure.

  EP 2 033 712 A2 describes a dispenser having a seat in the lower end region of the housing for the syringe flange of the syringe. The syringe flange is held by a syringe grip lever attached to a pivot shaft in the lower region of the housing. The plurality of leaf springs are disposed on the inner jacket of the housing, and their upper ends are fixed to the lower region of the housing. The lower end of the leaf spring presses the pretension against the inside of the syringe grip lever toward the position where the syringe flange is gripped rearward.

  The spring-biased thrust bearing is disposed in a seat that can press the upper side of the syringe flange. The thrust bearing includes a sensor that scans the code on the upper side of the syringe flange.

  The seat part main body which has a plunger seat is arrange | positioned at the housing which can insert the edge part which protruded upward of the syringe plunger of a syringe. The plunger gripping lever is attached to a seat body that can be gripped behind the collar of the plunger at the outer end of the syringe plunger. Plunger grip levers are pre-tensioned by a plurality of legs springs that head toward the position where they are gripped behind the plunger collar.

The seat body is driven by a mechanical plunger positioning element. These consist of a lifting unit connected to a seat body extending from the housing. Furthermore, the plunger positioning element includes a screw spindle or rack that is also securely attached to the seat body. The adjusting sleeve is seated on the screw spindle, and its axial position is adjustable with the screw spindle by means of an adjusting knob. An actuating unit with a pivot actuating lever, which can be moved from the outside by means of an actuating button, is arranged in the upper region of the housing. A pawl is pivotally disposed on the actuation lever.
The actuating lever is pressed upwards by a spring and the pawl is pretensioned by a spring towards the screw spindle.

  The actuating unit, adjustment knob and spindle are attached to a holder such as a plate having a laterally protruding bearing bracket that fits into the housing.

  When the syringe is inserted into the syringe seat and the housing is held by the syringe gripping lever and the plunger gripping lever, the liquid can be sucked upward by moving the lifting unit. The injection volume is adjusted using the adjustment knob. By actuating the actuation unit, the syringe plunger moves downward and the desired amount of liquid is released. For each actuation stroke, when the pawl reaches the lower end of the adjusting sleeve, the pawl enters the screw thread. The amount of injection to be discharged is set by adjusting the adjustment sleeve using the adjustment knob.

European Patent Publication EP 2 033 712 A2 European Patent Application Publication No. EP2 033 7121 A1 German Application DE 10 2009 034897 A European Application Publication EP 0 656 229 B1 US Application Publication US 5,620,660A European Application Publication EP 0 657 216 B1 US Application Publication US 5,620,661A European Application Publication EP 2 033 712 A1 US Application Publication US2009 / 139351 A1

  However, in the case of the above-mentioned patent document 1, before the holder is inserted into the housing, the operation unit, the adjustment knob, and the spindle can be pre-mounted on the holder. The additional elements are attached to the holder, not the holder part. In particular, the holder for the syringe flange is part of the housing. The thrust bearing, syringe grip lever and leaf spring pulled by the spring are attached to the housing. The syringe holding means must be attached separately by a holder in the housing. Therefore, since the suction of the liquid into the syringe and the discharge of the liquid from the syringe exert a strong force on the syringe holding means, the housing must be very strong. This limits the choice of materials that can be used.

  The disadvantages of known manual metering devices are that the housing does not fit well and is difficult to get dirty and easy to clean.

  In view of this situation, the present invention, against this background, is to produce a manual weighing device with improved tactile sensation.

  This object is achieved by a manual injection device having the features of claim 1. Advantageous embodiments of the manual metering device are described in the dependent claims.

The manual weighing device according to the present invention comprises:
An elongated frame as a support structure;
Holding means for detaching the syringe or pipette tip disposed at the lower end of the frame;
Drive means mounted on the holding means removable from the frame;
At least one displacement means for displacing fluid in a syringe or pipette tip that is drivable by the drive means and connected to the removable holding means;
A housing covering the frame ;
The frame (1) comprises longitudinal members (5.1, 5.2, 6.1, 6.2) parallel and spaced apart;
The parallel longitudinal members (5.1, 5.2, 6.1, 6.2) are connected to the holding means (8, 30.1, 30.2, 31.1-31) removable at their lower ends. .4) is connected with a syringe or pipette tip,
The parallel longitudinal members (5.1, 5.2, 6.1, 6.2) are connected to the support plate (8, 50) at their lower ends.

  The support structure of the manual weighing device according to the present invention is an elongated frame. The holding means from which the syringe or pipette tip can be removed is arranged on the frame. They are either part of the frame or attached to the frame. The driving means is attached to the frame. The removable holding means and the driving means are connected to each other by a displacement means. In one version, the displacement means is a transmission means for transmitting the movement generated by the drive means to the syringe plunger of the syringe. For this purpose, the displacement means is detachably connected to the holding means to which the syringe plunger can be attached and detached. When the drive means generates linear motion, the transmission means is a rod that is actuable by the drive means, connects the syringe plunger to the removable holding means and is guided in the axial direction of the frame. A positive displacement injection device is thereby achieved. In another version, the displacement means is a displacement device for displacing the air column. The displacement device is preferably a cylinder and a plunger displaceable therein. When the removable holding means holds the pipette tip, the cylinder is connected to the removable holding means via a flow path communicating with the upper end opening of the pipette tip. The displacement device is fixed to the frame. When designed as a cylinder with a plunger that is interchangeable with the frame, the cylinder is secured to the frame. Thus, the air cushion type weighing device is realized. The amount of liquid sucked and discharged is set by the amount by which the plunger or air column is displaced by the displacement means. In an air cushion metering device having therein a cylinder and a replaceable plunger, the displacement means preferably has a rod connected to the plunger and is at the upper end against the push button and frame, or the plunger or push button And a return spring that presses against. By actuating the push button against the action of the return spring, the return spring presses the plunger toward the home position where air can be discharged from the displacement device.

  When the drive means moves the displacement means, a force is applied to the frame. When the displacing means is a transmitting means for transmitting motion to the syringe plunger, these forces are transmitted by a holding means that can attach and detach the driving means and the syringe flange to the frame. When the displacement means is a displacement device, these forces act between the drive means and the frame as well as between the displacement device and the frame. These forces depend in particular on the amount and viscosity of the liquid to be injected. The frame is designed so that it does not deform significantly under the force exerted. This ensures that the operating element of the displacement means moves reproducibly with the desired accuracy. The desired injection accuracy is thereby achieved. The force when the syringe or pipette tip is connected to the manual metering device is also absorbed by the frame. The frame is preferably formed by polyether ketone (PEEK) characterized by its great stability. The housing is preferably attached to the frame at a few points to relieve stress on the housing. The housing is guided in the longitudinal direction of the frame so that the frame can be extended and contracted longitudinally relative to the housing without transmission of excessive force to the housing and several points (simply one or two). It is preferable to be fixed at a location). Thus, the forces generated during use are substantially absorbed by the frame, thereby reducing the stress on the housing.

  The specific characteristics of the frame make the choice of housing material, design and dimensions quite free for the designer. Soft housing materials, designs and housing dimensions can be used in particular so that the feel of the manual metering device is particularly good. The frame design thus makes it possible to use a particularly soft housing with an improved tactile feel. The frame only partially supports the housing. In particular, areas of the unsupported housing that are designed to be particularly easily moldable are recognized as being tactile by holding such a manual metering device in the user's hand. The special properties of the frame are special chemical resistance and / or resistance to soiling and / or can be easily cleaned and / or more easily processable and / or particularly economical It is also possible to use a housing material that is suitable. In particular, when actuating the control elements of the manual metering device, the force on the housing, brought about by the user's hand, is absorbed over a large area and transmitted to the frame so that the housing is not loaded. Another advantage is that the frame is used as a support structure that allows pre-mounting of the components of the manual metering device in the frame and testing the manual metering device before mounting the housing. Furthermore, the design based on the manual weighing device of the present invention facilitates the use of common parts (COPs) of different manual weighing devices. In particular, different manual weighing devices can provide the same frame with different components depending on the product. Different products can be arbitrarily distinguished from different housings.

  According to one embodiment, the frame is connected and comprises a plurality of frame parts that are securely connected to each other. Dividing the frame into a plurality of frame parts allows components to be individually pre-attached to different frame parts, thereby allowing individual assemblies to be prepared. Furthermore, manually prepared manual weighing devices can each be composed of an equivalent frame and partially different frames. According to a preferred embodiment, the frame has a lower part and an upper part. The lower part of the frame preferably comprises holding means from which the syringe or pipette tip can be removed, and the upper part preferably comprises drive means and displacement means.

  According to another embodiment, the lower part and the upper part connect connecting structures, which are provided with fixing means for connecting to each other. The connection structure is, for example, an eye connected to different frame parts, and overlaps each other and is connected by a pin.

  According to a preferred embodiment, the frame comprises longitudinal members spaced apart in parallel. When the driving means operates, an axial force mainly acts. These are transmitted to the longitudinal member. The longitudinal member can also absorb forces exerted by the user's hand on the housing side. Furthermore, the effects of the longitudinal members can be accommodated in the housing in such a way that they do not take up space. The manual weighing device according to the invention can therefore be designed in a particularly compact manner. The plurality of frame parts of the frame can have parallel longitudinal members.

  According to a preferred embodiment, the manual metering device comprises only two parallel longitudinal members.

  According to a preferred embodiment, the longitudinal members are in the lower and / or upper part of the frame.

  According to another embodiment, the longitudinal member is connected to the lower end of the holding means from which the syringe or pipette tip can be removed. According to another embodiment, the load carrier is connected to a lower end having a support plate. The support plate is one of the components of the holding means to which the syringe or pipette tip can be attached and detached. The support plate can form a stopper for the syringe flange of the syringe or a carrier for the seat of the pipette tip. If the support plate is a syringe flange stop, it is designed approximately in the shape of an annular disk in one embodiment.

  According to one embodiment, the support plate is connected to the lower end of the longitudinal member via a fork-shaped connection region. The fork-shaped connection area prevents chipping of the support plate due to uneven load.

  According to another embodiment, the parallel longitudinal members are connected to each other at the upper end of one bearing plate. According to another embodiment, the operating means or display means for the manual weighing device are fixed to the bearing plate.

  According to another embodiment, the parallel longitudinal members are bridged between the lower end and the upper end by a cross-shaped brace. According to another embodiment, the slideway is integrated into a cruciform brace for rod-shaped displacement means.

  According to another embodiment, the cross-shaped brace is arranged at the lower end of the upper parallel load carrier.

  According to another embodiment, the frame comprises two bearing blocks projecting to one side and the housing houses a laterally convex bearing block. In particular, when the manual metering device is designed as a dispenser, the bearing block serves to support the actuating lever of the manual metering device that is mechanically or electrically driven. When the actuating lever is actuated by the thumb, the convex surface of the housing can also be used as a hand rest because the manual weighing device rests at the index finger or the upper end of the adjacent palm. In the convex area, the housing is supported by bearing blocks that prevent overloading.

  According to one embodiment, the bearing block projects from two parallel longitudinal members at the top of the frame.

  According to one embodiment, the housing is divided in the longitudinal direction of the frame and the frame parts have snap joints. According to a preferred embodiment, the housing is divided in two. According to a preferred embodiment, the housing is divided in a plane extending parallel to the two longitudinal members and / or perpendicular to the bearing block.

  According to another embodiment, the housing is guided in the longitudinal frame of the elongated frame. This allows correction of housing deformation from longitudinal expansion of the frame. According to another embodiment, the frame is screwed to the housing at the lower or upper end. The receiving parts are preferably snapped together, and the frame is screwed to the housing.

  According to a further embodiment, the housing is made of polypropylene or other polyolefin.

  According to an embodiment, the manual metering device is rod-shaped. The manual metering device therefore has the shape of a rod. This manual weighing device can be held by the user with just one hand and is sized to be operated by the same hand.

  The invention is described in more detail below on the basis of the drawings of exemplary embodiments.

The perspective view is an exploded perspective view of a frame portion of the manual weighing device of the present invention. FIG. 2 is a perspective view from above of the assembled frame part of FIG. 1. It is a vertical perspective view of the housing in which the frame of FIG. 2 was inserted. FIG. 3 shows the frame of FIG. 2 with components. FIG. 5 is a longitudinal perspective view of a housing in which the frame of FIG. 4 provided with components is inserted. It is detail drawing from the left side provided with the flame | frame of FIG. It is a longitudinal cross-sectional view of another manual weighing device of the present invention. FIG. 8 is a cross-sectional view of the same manual metering device along line VIII-VIII in FIG. 7.

  In this example, the terms “lower” and “upper” are suitable for a manual metering device when the elongated housing is vertically aligned and a syringe or pipette tip is deployed under the housing for metering. Indicates placement.

  The manual metering device shown in FIGS. 1-6 is a positive displacement metering device in which the dispenser, ie the syringe, can be emptied in multiple steps.

  According to FIG. 1, the frame 1 is composed of a lower part 2 and an upper part 3. The upper part 3 is assigned to a cover 4 that holds a dial.

  The lower part is composed of two parallel strip-shaped longitudinal members 5.1, 6.1. These are connected to the lower end portion of the annular disk-shaped support plate 8 via fork-shaped connection regions 7.1 and 7.2. Bearing sleeves 9.1, 9.2, 9.3, 9.4 protrude from the support plate 8. Each longitudinal member 5.1, 6.1 is connected at its upper end to an annular disk shaped eyelet 10.1, 10.2.

  On the other hand, the two longitudinal members support parallel gate guides 11.1, 11.2 which can guide the center release slider, as described in detail in EP2 033 7121 A1.

  The upper part 3 has two parallel strip-shaped longitudinal members 5.2, 6.2. They are provided with a pair of concentric annular disk shaped eyelets 12.1, 12.2 at the bottom. They are also bridged at the bottom by cross braces 13. In the middle, the cross brace 13 has a sliding groove 14 with a passage that functions as a sliding groove for the rack in parallel with the other longitudinal members 5.2, 6.2. At the upper end of the upper part 3, the distance between the two longitudinal members 5.2, 6.2 is bridged by the bearing plate 15.

  Between the cross brace 13 and the bearing plate 15, bearing blocks 16.1, 16.2 like plates project from one side of the other longitudinal members 5.2, 6.2 to the other side, stable To make it easier, the outer bone is attached. At the lower end, the bearing block is provided with bearing eyes 17.1, 17.2 that are inwardly facing and flush with each other.

  On the side of the bearing plate 15, further bearing sleeves 18.1, 18.2 are integrally formed with the longitudinal members 5.2, 6.2 for fixing the cover 4.

  On the upper side of the bearing plate 15 are formed recesses 20.1, 20.2 for receiving guide shapes of spring bearings and dials (to adjust the dose).

  The bearing pins 21.1 projecting from the sides of the other longitudinal members 5.2, 6.2 are 21.2, 21.3, 21.4 on the opposite side of the bearing blocks 16.1, 16.2. It is in.

  According to FIG. 2, the upper part 3 and the lower part 2 are arranged at the lower ends of the other longitudinal members 5.2, 6.2 between the pair of eyelets 12.1, 12.3. 1 and 6.1 are inserted into the tops 10.1, 10.2 of the upper ends, and the screws 22.1, 22.2 to the tops 10.1, 10.2, 12.1, and 12.2. Are joined in a clear relationship. Further, the cover 4 is fixed to the upper part 3 by screwing screws 22.3 and 22.4 into the bearing sleeves 18.1 and 18.2 and the holding plates 23.1 and 23.2 of the cover 4. .

  The long, elongate frame 1 formed in this way is fitted into a two-part housing 24, shown in FIG. 3, made of a thin and soft material (eg polypropylene). The housing is formed by joining two shell-shaped accommodation parts 24.1 and 24.2. The lower shell-shaped receiving part 24.1 in FIG. 3 is below the upper shell-shaped receiving part 24.2. The receiving parts have snap coupling means at their ends for joining together so that they can be fitted. Furthermore, the frame 1 is screwed to the two housings 24.1, 24.2 by fastening the upper part 3 and the lower part 2 of the frame together with screws 22.1, 22.2.

  On the front end face, the two receiving parts 24.1, 24.2 are screwed onto the support plate 8 of the frame 1 by means of screws 22.5, 22.6, 22.7, 22.8 aligned in the axial direction. It has been stopped.

  In FIG. 3, the lower housing part 24.1 has a convex surface 25 that receives the bearing blocks 16.1, 16.2. This formation simultaneously forms a finger rest.

  The slot-like opening 26 is between the receiving parts 24.1, 24.2 so that the end area of the dial can protrude outwards.

  In addition, the upper housing part 24.2 of FIG. 3 has a liquid crystal display window 27 (eg for displaying the dose, number of steps and / or tip or syringe type used) and a slot 28 for the lifting and actuating levers. , 29.

  According to FIG. 4, the frame 1 is attached to the bearing sleeves 9.1, 9.2, 9.3 9.4 by four pins (only two are shown (31.1, 31.2)). The plunger grip levers 30.1 and 30.2 are provided. In other embodiments, only two pins are used. Further, an annular disk-shaped sensor plate 32 is disposed on the support plate 8 for scanning the code at the upper end of the syringe flange. The sensor plate 32 surrounds a centering ring 33 that engages a cylinder of a syringe that is fixed to the sensor plate 32 by syringe grip levers 30.1 and 30.2. The centering ring corresponds to the centering ring disclosed in DE 10 2009 034897 A.

  The rack 34 includes a bell-shaped seat main body 35 at the lower end that is inserted into the slide path 14 and receives the upper end of the syringe plunger or plunger rod connected to the syringe plunger. The plunger gripping lever is attached to the seat body 35. The preferred embodiment has screw threads instead of the rack 34.

  Details of this syringe fastener are described in EP 0 656 229 B1 and US 5,620,660A. Details regarding scanning the code on the syringe flange of the syringe are described in EP 0 657 216 B1 and US 5,620,661A. These descriptions are included in the present application as cited documents. The actuating lever 36 is attached to the bearing blocks 16.1, 16.2. The actuating lever 36 has two arms and slots 37.1, 37.2 for guiding the shaft 38 in two parallel arms 36.1, 36.2, which shaft 38 is connected to the bearing block 16 .1 and 16.2 are inserted into the bearing eyes 17.1 and 17.2. The actuating lever 36 is guided on both sides via guide rollers 39.1, 39.2 to straight guides 40.1, 40.2 at the upper ends of the other longitudinal members 5.2, 6.2 at the top. Is done. The activation button can be located at the end of the activation lever 36 shown above in FIG.

  The actuating lever 36 is provided with a pawl 41 that is pivotably mounted between its two arms 36.1, 36.2.

  A dial 43 is rotatably attached to the other shaft 42 between the bearing plate 15 and the cover 4.

  The dial 43 is provided with an adjustment sleeve 43.1 (or cover strip) (see FIG. 6) that covers the upper side of the rack 34 with teeth in FIG. The position of the adjustment sleeve is made adjustable by the dial 43 within the range in which the pawl 41 moves when the actuating lever 36 swings within the limits defined by the slide paths 40.1, 40.2. . By adjusting the dial 43, the position of the adjustment sleeve 43.1 can be determined behind the slipway 14 towards the stop and subsequently into the teeth.

  In addition, the frame 1 includes spring means for pressing the cylinder gripping lever and the plunger gripping levers 30.1 and 30.2 at the pivot position for holding the syringe. The further spring means pushes the actuating lever 36 to the pivot position shown in FIG. 4 and pushes the pawl 41 against the teeth of the rack 34.

  The lower end of the rack 34 is a connection means that can connect the rack and the lifting button.

  The actuating lever 36, the rack 34, the adjusting sleeve 43.1 and the lifting button forming the plunger positioning element are described, for example, in EP 2 033 712 A1 or US 2009/139351 A1. The above contents are included in the present application as prior documents.

  A frame 1 comprising the components described in FIG. 4 can be subjected to functional tests and calibration during manufacture. Furthermore, the presetting of the manual weighing device can be performed at the assembly stage. At this time, there is an effect that the defect of the housing that can be confirmed at this stage can be removed from the product (at this stage). This reduces the consumption of housing material. Furthermore, this is effective depending on the type of problem. That is, the parts attached to the frame can be removed and replaced with other things to create a perfect product, or the components that are perfect for replacement are already provided in the frame, and they are It can be used to manufacture a manual weighing device.

  In FIG. 5, the equipped frame 1 is fitted into the housing 24 shown in FIG. 3 having the unequipped frame 1. The operation button 44 and the lift button 45 are attached. The operating units 44, 45 and the dial protrude from the housing 24.

  When the syringe is attached, the axial force is guided through the support plate 8 to the frame 1 that contacts the wide area of the housing 24. When the lift button 45 and the activation button 44 are actuated, the axial force is absorbed by the frame 1. The manual weighing device is familiar to the user's hand and has a good tactile sensation so that fatigue due to long-term use can be delayed. When polypropylene is used, there is also very good chemical resistance, and the manual metering device housing 24 is free of dust and can be easily cleaned.

  The manual metering device shown in FIGS. 7 and 8 is a pipette, i.e., an air cushion displacement device, which uses a pipette tip to aspirate and dispense a specific amount of liquid into the pipette tip. Can be provided.

  The metering device of FIGS. 7 and 8 includes a frame 46 having longitudinal members 47, 48 spaced apart and parallel. The parallel longitudinal members 47, 48 are connected to each other at the upper part by a disk-shaped support plate 49 aligned perpendicularly to the longitudinal members, and at the lower part, they are connected to each other by a disk-shaped support plate 50. . Furthermore, the longitudinal members 47, 48 are bridged at their ends by a cross-shaped brace 51.

  The cylinder 52 in which the plunger 53 is arranged fixes the upper part of the support plate so as to be movable along the longitudinal members 47 and 48 and to be sealed around the cylinder 52.

  A conical (or alternatively cylindrical) pin 54 projects from the bottom of the support plate 50 in the longitudinal direction of the longitudinal member 47, and the pipette tip can be fixed there.

  The inside of the cylinder 52 is connected to the hole at the lower end of the pin 54 through a flow path 56 extending through the support plate 50 and the pin 54.

The plunger 53 is connected at the top of a lifting rod 57 disposed in the center between the two longitudinal members 47, 48. The lifting rod 57 extends upward from the hole in the bearing plate 49.
The lifting rod 57 has an operation button 58 at the upper end.

  At its center, the cruciform brace 51 has a slideway 59 in which the lifting rod 57 is movably guided relative to the longitudinal members 47, 48.

  A thrust bearing 60 fixes the lifting rod 57 below the bearing plate 49. The return spring 61 in the form of a helical spring abuts against the cross-shaped brace 51 at the bottom and abuts against the thrust bearing 60 at the top.

  In addition, one or more protrusions of different designs that define the peripheral bead 62 or the top stop of the lifting rod 57 are located under the cross-shaped brace 51 on the lifting rod 57. The return spring 61 is initially loaded so that it pushes the lifting rod 57 upward until the bead 62 leans against the lower side of the cross-shaped brace 51. The manual weighing device shown in FIGS. 7 and 8 is in this home position.

  In addition, the manual metering device includes a housing 63 that covers a frame 46 formed from longitudinal members 47, 48, a bearing plate 49, a support plate 50 and a cross-shaped brace 51. The housing 63 is fixed to the center of the longitudinal members 47 and 48 by approximately two screws 64 and 65.

  In addition, small guide protrusions 66, 67, 68, 69 extend from the inside of the housing 63 to the front side and the rear side of each longitudinal member 47, 48. The guide protrusions 66 to 69 guide the screws 64 and 65 of the longitudinal members 47 and 48 up and down to the housing 63.

  The housing 63 includes frames 47, 48, 49, 50, 51 such as sleeves. In this embodiment, the housing 63 is cylindrical. Other sleeve shapes are possible.

  The housing 63 includes, for example, a cylindrical portion composed of a first section pushing the frame upward and two sections pushing the frame downward, and these sections overlapping each other in the region near the screws 63 and 65 are 64 and 65 are fixed to the frame 46. Alternatively, the housing 63 is divided into two equal planes extending through the longitudinal members 47, 48, and each half of the housing is fixed to the frame 46 by two screws 64, 65.

  The housing 63 has an upper wall covered with the bearing plate 49 by the upper wall 70 and a lower wall covered with the support plate 50 by the bottom wall 71. The top wall 70 is at a short distance from the bearing plate 49, and the bottom wall 71 is at a short distance from the support wall 50 to allow the length to be adjusted.

  The frames 47, 48, 49, 50, 51 are made of a rigid or hard material (preferably plastic). The housing 63 is made of a thin and soft material (preferably plastic (for example, polypropylene)).

  This manual weighing device is used by first fixing the pipette tip 55 to the pin 54. In order to suck the liquid through the pipette tip 55, the operation button 58 is pressed downward until the plunger 53 is positioned at the lower end of the cylinder 52. Next, the lower opening of the pipette tip 55 is immersed in the liquid. The actuating button 58 is then released and the return spring 61 returns the lifting rod 57 with the plunger 53 to the home position of FIGS. Thereby, the liquid is sucked into the pipette tip 55 through the lower opening.

  The pipette tip 55 is then lifted with a manual metering device and directed to a different container that is to be discharged of liquid. When the operation button 58 is pressed downward, the plunger 53 displaces the air column and presses the liquid 55 sucked into the pipette tip 55.

  The downward movement of the lifting rod 57 is limited by the contact member element 72. And the bead 62 contacts the contact member element by the downward movement of the lifting rod. The contact member element 72 of FIG. 7 and the spring element 73 of the frame 46 are shown in broken lines. After the bead 62 abuts the contact member element 72, the lifting rod 57 can be overstroked by applying increased force to the actuation button 58. The overstroke helps to eject the remaining liquid from the pipette tip 55.

  According to this manual weighing device, the force is exerted when the pipette tip 55 is attached, and is absorbed by the frame 46 when the activation button 58 is activated. The housing 63 disposed on the frame 46 allows the manual weighing device to become familiar to the user's hand and feel good so that fatigue due to long-term use can be delayed. In addition, the housing 63 can be made of a chemical resistant material such as polypropylene and a resistant material that does not attract dust.

  The manual metering device of FIGS. 7 and 8 is a fixed volume pipette that can fix the dose when the bead 62 contacts the cross-shaped brace 51 and the piston stop 53 leans against the bottom of the cylinder 52. The present invention relates to a pipette whose dosage can be adjusted. By utilizing these pipettes, the position of the upper stopper for the lifting rod can be adjusted by means of a setting device for changing the dose.

Claims (17)

A manual weighing device,
An elongated frame (1) as a support structure;
Holding means (8, 30.1, 30.2, 35) capable of detaching a syringe or pipette tip disposed at the lower end of the frame (1);
Drive means (36, 41) mounted on the holding means (8, 30.1, 30.2) removable to the frame (1);
A syringe or pipette tip driven by the drive means (36, 41) and connected to the removable holding means (8, 30.1, 30.2, 31.1-31.4, 35); At least one displacement means (34) for displacing the liquid;
A housing (24) covering the frame (1) ;
The frame (1) comprises longitudinal members (5.1, 5.2, 6.1, 6.2) parallel and spaced apart;
The parallel longitudinal members (5.1, 5.2, 6.1, 6.2) are connected to the holding means (8, 30.1, 30.2, 31.1-31) removable at their lower ends. .4) is connected with a syringe or pipette tip,
The parallel longitudinal members (5.1, 5.2, 6.1, 6.2) are connected to the support plate (8, 50) at their lower ends. The manual weighing device according to claim 1, wherein
The frame (1) is configured by connecting and fixing a plurality of frame parts (2, 3) to each other. The manual weighing device according to claim 2,
The frame consists of a lower part (2) and an upper part (3). The manual weighing device according to claim 2 or claim 3,
The different frame parts (2, 3) comprise connecting structures (10.1, 10.2, 12),
The connection structure (10.1, 10.2, 12) includes fixing means (22.1, 22.2) connected to each other. The manual weighing device according to any one of claims 1 to 4,
The frame (1) comprises longitudinal members (5.1, 5.2, 6.1, 6.2) which are parallel and spaced apart. The manual weighing device according to any one of claims 2 to 5,
The plurality of frame portions (2, 3) are composed of parallel longitudinal members (5.1, 6.1; 5.2, 6.2). The manual weighing device according to claim 6, wherein
Said frame (1) comprises two parallel longitudinal members (5.1, 5.2, 6.1, 6.2). The manual weighing device according to any one of claims 5 to 7,
The parallel longitudinal members (5.1, 5.2, 6.1, 6.2) are connected to the holding means (8, 30.1, 30.2, 31.1-31) removable at their lower ends. 4. Syringe or pipette tip is connected by 4). The manual weighing device according to claim 8, wherein
The parallel longitudinal members (5.1, 5.2, 6.1, 6.2) are connected at their lower ends to the support plate (8). The manual weighing device according to claim 9,
The support plate (8) is connected via a fork-shaped connection area (7.1, 7.2) at the lower end of the longitudinal member (5.1, 5.2, 6.1, 6.2). Is done. The manual weighing device according to any one of claims 1 to 10,
The parallel longitudinal members (5.1, 5.2, 6.1, 6.2) are connected to each other at the top by means of bearing plates (15). The manual weighing device according to any one of claims 1 to 11,
The parallel longitudinal members (5, 6) are bridged between their ends by cruciform braces (13). The manual weighing device according to claim 12,
A slideway (14) is incorporated in the cruciform brace (13) for the rod-shaped transmission means (34). The manual weighing device according to any one of claims 1 to 13,
The frame (1) comprises two bearing blocks (16.1, 16.2) protruding from the side surface,
The housing (24) accommodates the bearing block (16.1, 16.2) on the convex surface (25) in the lateral direction. The manual weighing device according to any one of claims 1 to 13,
The housing (24) is divided in the longitudinal direction of the frame (1), and the frame portions (24.1, 24.2) are snap-engaged with each other. The manual weighing device according to any one of claims 1 to 15,
The housing (24) guides the frame (1) in the longitudinal direction of the elongated frame (1). The manual weighing device according to any one of claims 1 to 16,
The housing (24) is made of polypropylene or other polyolefin.

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