JP2007171350A - Sample stage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toothed rack having both of flexibility and accuracy and the design of a drive array of the rack. <P>SOLUTION: A sample stage comprises a supporting body and a long and narrow guide part formed on the supporting body and having a first length. At least one movable plate is mounted on the supporting body to be guided by the guide part. The drive array for moving the plate comprises at least one rotatable shaft, an actuator coupled with the shaft to rotate the shaft, a pinion interlocking and coupled with the shaft to transmit the rotation, and a toothed rack having a second length; where the teeth of the rack are engaged with teeth of the pinion and the rotational motion of the pinion is converted into the linear motion of the rack. The rack is flexible, so that a linear portion is suitably guided at least to one bent portion. To provide the rack with some rigid properties in spite of flexibility, the teeth of the rack is mechanically worked on an ethylene halide body. The pinion is suitably engaged with the rack on the outer surface of a bent part in the radius direction. The shaft can be coupled with the pinion in a freely opened state so as to be easily replaced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a sample stage for a microscope, in particular, comprising a support plate and a movable plate arranged on the support plate, guided by an elongated guide arrangement of a first length. This guide arrangement consists of guide surfaces. A drive mechanism is provided for moving the movable plate: the drive mechanism comprises a rotating shaft and an actuator coupled to the shaft for rotating the actuator to move the movable plate. Further, the drive mechanism is composed of a transmission mechanism that transmits the motion of the actuator to the plate. The transmission mechanism includes (at least one) pinion coupled to a shaft for transmitting rotation from the drive mechanism and a second length toothed rack. The rack comprises teeth that engage the pinion and are connected to the movable plate to move the movable plate. There are connectors that connect the toothed rack to the movable plate. In this arrangement, the guide arrangement is a guide connection with the toothed rack, and the first length of the guide arrangement is longer than the second length of the rack. The guide arrangement consists of at least one curved part and suitably at least one straight part so that the rack is flexible.
Although these types of sample stages are typically used in microscopes, these sample stages can be used in a variety of applications.

  The microscope sample stage according to WO 97/26576 (Patent Document 1) consists of a stationary support plate, and in the embodiment, the sample stage is formed as a cross slide, and two slides connected to the cross slide. It consists of a plate. These sliding plates are movable in the x and y coordinate directions. A drive arrangement is provided for moving the sliding plate. Two coaxial pivot knobs are used as actuators.

  Each of these coaxial swivel knobs is securely connected to the pinion via a rotating shaft so that the pinion meshes with the teeth of a sturdy toothed rack. Since each rack of a sturdy toothed rack is securely connected to an interlocking sliding plate, any pivoting movement of the corresponding pivoting knob is securely transmitted to the interlocking sliding plate.

  Often there is a requirement to observe an object where a moving process as large as possible is effective, and the known design comprises a toothed rack that is distinguishably longer than an interlocking sliding plate. However, this structure not only provides higher space requirements for, for example, the microscope sample stage, but also the sample stage in some cases necessary to observe the object, since the toothed rack significantly exceeds the length of the sliding plate. Turning has the disadvantage that it can no longer be done or is only limited.

  In order to avoid such disadvantages, DE 226091 suggests cable pulling as a driving means for the sliding plate, the cable being guided around two deflection pulleys. Has been. The sliding plates are connected in a non-positive manner. The deflection pulley is located within the limits of the support plate and is driven by the rotating shaft. Such a structure is expensive due to the number of components and requires considerable maintenance and service work as the cable is subject to high wear and tear. Another disadvantage is that it results in vibrations that affect the accuracy required for adjustment.

  A flexible toothed rack that cooperates with a pinion is known in conveyors according to US Pat. No. 3,822,606 as a transmission unit for converting rotational movement into linear movement. The flexible toothed rack has such elasticity that it can be bent freely in all parts of the part.

  German Patent Application No. 4414384 (Patent Document 4) discloses a vacuum cleaner having a slider as a component for controlling the rotational speed of a fan motor. In this construction, the toothed rack associated with the slider is guided in a straight and curved area of the instrument housing. The length of the toothed rack is independent of the dimensions of the housing, and the slider can be moved to the outer edge of the housing.

  Although flexible toothed racks can be space-saving structures, one of those problems is in some applications and must be operated under completely different temperature conditions reaching from minus 20 ° C or at room temperature. Must be lowered or higher. However, German Offenlegungsschrift 102004007306 has suggested the use of polyoxymethylene which lacks flexibility under extreme conditions.

  A further problem is the conflicting requirement that the toothed rack is flexible (over time and / or temperature range) while the teeth and their distance are relatively rugged and provide the required accuracy.

  Yet another problem in the flexibility / stiffness relationship is that some limited flexibility toothed racks tend to move away from the radially inner guide surface after bending. However, according to the German document, this affects the engagement of pinions located on the radially inner surface by the teeth of the toothed rack until the situation where both teeth are separated from each other.

Another problem of the prior art is that each pinion must be connected to a length of rotating shaft. However, it must be applied to sample stages and / or microscopes with different axial lengths. This was not possible with prior art structures.
International Patent Application Publication No. 97/26576 German Democratic Republic Patent No. 226091 US Pat. No. 3,822,606 German Patent Application No. 4413884 German patent application 10200407306

  The object of the present invention is to find a design of a toothed rack and its drive arrangement which overcomes the disadvantages and in particular gives both flexibility and accuracy.

  Another object is to provide a drive arrangement that can be adapted to the respective application.

In a first aspect of the present invention, flexibility / accuracy is solved by providing an elongated toothed rack of halogenated ethylene material with a maximum static pressure load of 1 N / mm ² or less and substantially unchanged. This halogenated material is preferably a polytetrafluoroethylene material.

Because the halogenated ethylene and especially polytetrafluoroethylene are formed into an elongated toothed rack, they can usually be sintered, and then the necessary toothing to provide the necessary flexibility and at the same time the required accuracy. Because it did not have rigidity, molding would have to be done in two steps:
1. Extruding material to obtain long polymer chains in a substantially parallel configuration to give some flexibility. For this purpose, materials with a permissible pressure of 1 N / mm ² or less, preferably about 0.7 N / mm ² , have proven to be ideal since the materials tend to have higher stiffness. The term “allowable pressure” is customarily used in tables on polytetrafluoroethylene content, for example by suppliers of Kaindle in Vienna or Faigle in Austria (Austria).
2. In the second step, the outer surface of the extruded elongated rod is heated slightly, preferably by simply machining or cutting teeth into the material. This has a surprising effect: although halogenated ethylenes such as polytetrafluoroethylene are known to be hardly affected by temperature, relatively low temperatures above room temperature have higher stiffness. Without wishing to be found in theory, it is most probable that an increase in temperature affects a plasticizer that reduces its content. Thus, by locally heating the surface during machining of the teeth, each face area becomes harder or more robust. It has been found that locally applied heat (during a short time of machining) of at least 40 ° C., for example 50 ° C., is sufficient to provide the desired stiffness.

  In order to avoid affecting the flexibility of the body where this surface hardening is further required, it is advisable to cool the machined toothed rack immediately, preferably to room temperature or lower in the third step. .

  Thus, it can be seen that the present invention relates to a method of manufacturing a toothed rack having both a flexible body and a hard toothed surface.

  In the second aspect of the invention, each pinion can be exchanged and connected to an interlocked shaft by a releasable coupler that can assemble the sample stage to a different sized microscope or instrument that requires a different length of the shaft. Has been provided.

  Further details and advantages will become apparent from the following description with reference to the accompanying drawings.

  FIG. 1 displays a sample stage that is suitably used for a microscope (not shown). The sample stage consists of at least two horizontal plates 2 and 3 supported by a suitable support arrangement such as a console 3a. The plate 2 can move linearly, for example in the direction of the x-coordinate, i.e. in one direction substantially parallel to one of its sides, while the plate 3 supporting the plate 2 in the case of a cross-slide in turn As will be described later, it can be moved in a direction corresponding to the y-coordinate, ie perpendicular to the direction of displacement of the plate 2. In some examples, one of the x or y coordinates is sufficient. The support console 3a can be connected to the foot portion or the holding portion of the microscope.

  In order to move the horizontal plates 2 and 3, there are suitably coaxially rotatable shafts 4 and 5 which are actuated by turning the knobs 6 and 7 (if both plates 2 and 3 can be moved). Suitably, the swivel knob 7 is connected to the inner shaft 5 while the swivel knob 6 is connected to the shaft 4 and the arrangement could be further reversed. Said displacement of the plates 2 and 3 is useful in order to be able to observe various details of the object arranged approximately in the center of the sample stage. Each axis 4 and 5 is associated with one different movement of the plates 2 and 3. Therefore, although the coaxial arrangement of shafts 4 and 5 saves space and facilitates manual actuation with knobs 6 and 7, it was possible to have two separate shafts (and knobs). .

  In FIG. 2, the plates 2 and 3 are represented upside down from FIG. 1, and the rotational movement of the shaft 5 actuated by the swivel knob 7 (FIG. 1) is the movable plate 2 below the plate 3 in this figure. A drive mechanism and a transmission mechanism are illustrated in order to convert the linear displacement into a linear displacement.

  The plate 3 has a groove 9 that includes a first straight portion 9a, a bent portion 9b, and another straight portion 9c that extends substantially (but not necessarily) perpendicular to the portion 9a, for example. In this groove 9, a flexible toothed rack 8 represented by the large dimensions in FIGS. 4 and 5 is formed and extended. In order to be able to move the toothed rack 8 in the groove 9, the rack 8 has a length shorter than the length of the groove 9.

  The pinion 10 connected to the shaft 5 engages with the teeth 17 (FIG. 4) of the toothed rack 8 to give a sliding motion to the toothed rack 8. In the embodiment shown in FIG. 2, the pinion 10 is positioned within the bent portion 9b but is positioned at the direct coupling portion of the straight portion 9c. Accordingly, the teeth 17 (FIG. 4) of the toothed rack 8 are at least approximately on the radially inner surface with respect to the bent portion 9b (see FIG. 3). The pinion is rotatably supported by the plate 3. This detail is represented in large dimensions in FIG. 3 and the toothed rack is omitted for the sake of simplicity.

  There is a connecting plate 12 that moves with the toothed rack 8 to convert the rotational movement of the pinion 10 into the linear movement of the plate 2. Furthermore, the connecting plate 12 is not shown, but is connected to the plate 2 in a known manner. The connecting plate 12 is frictionally connected to the rack 8 and the plate 2. Since the connecting plate 12 moves to the straight section 9a, the plate 2 is guided in the same direction, called the x-coordinate, both on the one hand by the toothed rack 8 and the connecting plate 12 and by a guide surface 13 like a slot in the plate 3. The

  Therefore, if the rotating shaft 5 is swung by the swivel knob 7, the transmission mechanism of the pinion 10 and the toothed rack 8 is located below the plate 3 supporting the plate 2 along the guide surface 13 (FIG. 2). Move the plate 2 and thus move to the x coordinate of the sample stage 1. By bending the groove 9 of the support plate 3, the displacement stroke of the movable plate 2 is relatively long, but when the plate reaches the end position, the toothed rack extends laterally beyond the outer shape of the sample stage 1. Never stick out.

  If the sample stage is formed as a cross slide and can be moved in a direction corresponding to the x and y coordinates, a support plate similar to the support console or plate 3 in FIG. It must be provided, but with a connecting plate that moves along the other straight part 9c. Therefore, it is clear that the cross slide must pass through each pinion connected to the other shaft 5 or 4 so that one of the shafts 4 and 5 is connected to the pinion 10 supported by the plate 3. It is.

  As already mentioned, the toothed rack is illustrated in detail in FIGS. In particular, a comparison between FIGS. 3 and 4 reveals that the rack 8 must have sufficient flexibility to bend over its length as it moves through the bent portion 9b. To increase the flexibility, as will be explained later, the toothed rack 8 comprises a cut 18 on the radially inner surface if it is used in the embodiment according to FIG. On the other hand, the teeth 17 are not bent, but it is important to be able to keep their shape and allow precise engagement of the pinion 10 and accurate displacement of the plate 2. It is therefore clear that this toothed rack 8 is subject to the opposite requirements.

To solve the problem, the toothed rack 8 is formed from an extruded rod of a maximum static pressure load halogenated ethylene material, preferably polytetrafluoroethylene (PTFE), with no substantial change of 1 N / mm ² or less. . This is a relatively low permissible pressure per surface area and gives the material a relatively good flexibility. Particularly preferred is PTFE of 0.5 N / mm ² or more, for example 0.7 N / mm ² .

  However, such an elastic material bent the teeth 17 and prevented precise adjustment of the position of the plate 2. Surprisingly, however, the heat treatment of the surface of the toothed rack makes the surface more robust. The possible reasons for this phenomenon have been explained above.

  Since the teeth 17 must be cut or machined at any surface, the heat generated by machining is used to cure only the surface, but the body of the rack 8 is maintained in a flexible state. It is suitable to do. In order to keep this under control, it is suitable to cool the rack 8 immediately after machining when heat of about 40 ° C., for example higher than 50 ° C. is generated. In this way, the toothed rack 8 is obtained having both a flexible cover or body and a hardened surface containing the teeth 17.

  The flexible toothed rack 8 has various shapes and various types of teeth. The teeth each lie in a plane perpendicular to the longitudinal axis 19 of the toothed rack, but in this way the movement imparted to the plate 2 is smoother, so that as shown in FIG. Preferably, the teeth are inclined with respect to 19. By providing a tilt angle between 20 ° and 30 ° and a module of about 0.5, the best results were achieved as accuracy. In an actual example, the inclination angle is 21.4 °.

  As seen in FIG. 4, there is preferably a wedge-shaped incision 18 on the radially inner surface of the toothed rack 8 (with respect to the curved portion 9b) to reinforce the bending. At least in the case of FIG. 7, the incision 18 is approximately opposite the teeth 17. These incisions 18 are appropriately cut in a plane perpendicular to the longitudinal axis 19 of the rack, as shown in FIG. In FIG. 4, the incisions 18 are spaced so that the distance between adjacent teeth 17 is less than the distance between the incisions 18. However, this is not necessary in each case because it is advantageous to have approximately the same distance between the teeth and the incision 18 in the embodiment of FIG. This is because the distance of the incision 18 depends on the radius of curvature of the bent portion 9b (FIG. 2). Therefore, the incision 18 distance smaller than the tooth 17 distance could be selected. The shape of the incision 18 is wedge-shaped as shown, but has a different shape that best fits the bending of the rack 8. Furthermore, it helps to omit the teeth in the end region of the rack 8 for better guidance in the groove 9.

  As can be seen in FIG. 6, the groove 9 has a depth in the support plate 3 such that the introduced flexible toothed rack 8 is entirely below the surface 14 of the support plate 3. The width 15 of the slot 16 formed by the groove in the surface 14 of the support plate 3 is different in the different parts 9a, 9b and 9c. In the portion 9a where the connecting plate 12 is located, the width 15 of the slot 16 coincides with the maximum width of the groove 9 for convenience. However, in the curved or bent portion 9b of the groove, if the width 15 of the slot 16 is gradually reduced over the length, the pinions 10 are arranged in the straight portion 9c, and the width 15 is the groove. Preferably it is sufficiently smaller than the maximum width of 9 (see FIG. 3).

  Although the extent of the bent portion 9b and the arrangement of the pinions 10 on the radially inner surface is helpful from the fact that the pinions 10 are surrounded by the toothed rack 9 over a certain angle, the requirements opposite to flexibility and stiffness are flexible toothed In this application of racks it has been found that another problem arises: having sufficient flexibility as well as sufficient rigidity (at least without producing a toothed rack of different assembled components at an increased price) Because it is difficult, people must seek intermediates. Therefore, only the flexible core of the toothed rack 8 has a tendency to extend in the region of the bent portion 9b, as illustrated by the arrow 20 in FIG. This means that if the pinion was on the radially inner surface, the teeth of the rack 8 were detached from the teeth of the pinion 10 as represented in FIG. Therefore, as seen in FIG. 7, it is most beneficial to arrange the pinions 10 on the radially outer surface. This promotes the cooperation of the pinion 10 and the teeth 17 on the one hand and does not interfere with the effect of the incision 18 (FIG. 4) on the opposite side. In contrast, the resiliency of the rack results in tooth-free engagement of play, thus improving the accuracy of adjustment or displacement of the plate 2 or 3.

  FIG. 7 once again shows some details of the drive arrangement. Although only one pinion 10 connected to the inner shaft 5 of the shafts 4 and 5 is shown, it is clear that the shaft 4 ends in a plane parallel to the plane of the surface of the plate 3. Therefore, if the plate 3 moves in a direction perpendicular to the direction of the plate 2 to form a cross slide, the lower end of the shaft 4 is another pinion supported by a third (in FIG. 7: upper) support plate. And the shaft 5 passes through the support plate. For example, by providing a central hole in a pinion that deviates from a circular shape (such as a star shape or circular, but flattened or similar), a complementary external cross-sectional axis 4 or 5 is paired through the hole. In this way, the screw forming the unit with the coaxial axes 4 and 5 and penetrating through the slot hole 22 while being connected in a known manner to the respective pinion It is possible to provide a bearing block 21 (shown as a transparent block) fixed to the plate 3 by. In this way, a pair of shafts 4, 5 with different lengths and / or dimensions and / or selectively manually actuable swivel knobs or connections to a motor drive are provided and the bearing block 21 is simply replaced. It is easy to install and connect the shafts 4, 5 of such a pair to the pinion 10 according to the requirements, the dimensions of the microscope, etc.

Example:
Although polytetrafluoroethylene (PTFE) rods of length 273 mm and diameter 4 mm were extruded to obtain substantially parallel polymer chains and then cut by a tooth cutter, a special shape was possible, Rather than giving the tooth a special shape such as involute or cycloid, it forms a tooth with a simple cut shape. Simple cuts are easier and faster to produce to keep heating to a limited extent. The toothed portion was 160 mm in length starting at one end of the rack. The cuts or teeth have an angle of 21.4 ° with respect to the longitudinal axis (see FIG. 5), the distance of the teeth from each other is 1 mm, the width of each cut is 0.3 mm and the depth The length measured from the top of each tooth was 1.3 mm.

  The straight incisions were cut on the diametrically opposite surface of the rod (with respect to the teeth) at a distance of 1 mm from each other, with each incision having a width of 0.3 mm and a depth of 1.3 mm. It is therefore clear that the incision and the teeth are equally sized.

  During machining, the rod is somewhat heated above 50 ° C, but is cooled in a 1 second period or lowered to room temperature (20 ° C) to allow heat to penetrate into the interior of the rack body. avoid.

  Thus, the obtained toothed rack was inserted into the groove 9 of the plate like the plate 3 of the above embodiment, and was driven so as to travel the length of the groove 9 from one end to the other end. After running 120,000 times, no perceptible change in the surface of the toothed rack was observed.

  A myriad of embodiments are possible within the scope of the present invention; for example, a guide for a toothed rack 8 need not necessarily be in the shape of a groove 9, although such a groove enhances accuracy and accuracy.

FIG. 2 shows a perspective view of a sample stage formed as a cross slide with a plate array in which each plate can be moved in either the x or y coordinate direction by an actuator device. FIG. 3 shows another perspective view pivoted on top, as opposed to FIG. 1, illustrating a drive mechanism including a flexible toothed rack for a single movable plate. FIG. 2 shows details of FIG. 2 in enlarged dimensions. FIG. 4 shows a perspective view of an embodiment of a flexible toothed rack. FIG. 3 shows a plan view of an embodiment of a toothed rack having teeth inclined with respect to the plane of its longitudinal axis. Figure 2 shows a cross-sectional view of a guide arrangement for a toothed rack. FIG. 2 is a detail shown as a perspective view similar to FIG. 2, but is an alternative embodiment.

Explanation of symbols

1. . . . . Sample stage 2,3. . . Horizontal plate 3a. . . . Console 4,5. . . Axes 6,7. . . Swivel knob 8. . . . . Toothed rack 9. . . . . Groove 10. . . . Pinion 12. . . . Connecting plate 13. . . . Guide surface 17. . . . Teeth 18. . . . Incision

Claims (12)

Support means; a first length of elongated guide means on the support means; a movable plate on the support means guided by the guide means; drive means for moving the plate means, The driving means includes a rotatable shaft means, an actuator means connected to the shaft means for rotating the shaft means, a pinion means connected to the shaft means for transmitting rotation, and extends along a longitudinal axis. A second length toothed rack means, the rack means comprising teeth engaged with the pinion means and connected to the movable plate to move the plate means; And connecting means connected to the movable plate means, wherein the guide means is a guide connecting portion with the toothed rack means, and the first means Is longer than the second length, it consists of at least one curved portion, for the toothed rack means is flexible under different temperature conditions to be able to follow the curved portion, 1N / mm A specimen stage characterized by being a halogenated ethylene material having a maximum allowable static pressure load of ² or less and substantially unchanged.   The sample stage according to claim 1, wherein the halogenated ethylene is polytetrafluoroethylene.   The sample stage of claim 1, wherein the toothed rack comprises an incision that is positioned to face the bent portion at intervals over its length, thereby facilitating bending.   4. The sample stage according to claim 3, wherein the incisions are spaced so as to have a distance of about ± 10% of the teeth of the toothed rack. The sample stage according to claim 1, wherein the halogenated ethylene has an allowable static pressure load of 0.5 N / mm ² or more and substantially unchanged. ^{2. The} sample stage of claim 1, wherein the ethylene halide has an allowable static pressure load of about 0.7 N / mm < ² > and substantially unchanged.   2. The sample stage according to claim 1, wherein the teeth of the toothed rack means have a simple cutting shape.   The sample stage according to claim 1, wherein the teeth of the toothed rack means are inclined with respect to a plane of the longitudinal axis.   Support means; a first length of elongated guide means on the support means; a movable plate on the support means guided by the guide means; drive means for moving the plate means, The driving means includes a rotatable shaft means, an actuator means connected to the shaft means for rotating the shaft means, a pinion means connected to the shaft means for transmitting rotation, and a second length toothed The rack means and the rack means are composed of teeth engaged with the pinion means and are connected to the movable plate to move the plate means, and the toothed rack means is connected to the movable plate means The guide means is a guide connection portion with the toothed rack means, the first length being longer than the second length, Comprising at least one curved portion and at least one straight portion, the toothed rack means being arranged to face a radially outer surface when bent at the curved portion, the pinion therebetween A sample stage characterized in that the means are suitably arranged to face the outer surface of the toothed rack means.   8. The sample stage according to claim 7, wherein the pinions are arranged to press against the toothed rack at a position where the bent portions are just joined.   Support means; a first length of elongated guide means on the support means; a movable plate on the support means guided by the guide means; drive means for moving the plate means, The driving means includes: rotatable shaft means; actuator means coupled to the shaft means for rotating the shaft means; pinion means coupled to the shaft means for transmitting rotation; the shaft means and the pinion means A first connecting means for connecting the toothed rack means to the movable plate means; and a second connecting means for connecting the toothed rack means to the movable plate means. Wherein the guide means is a guide connection with the toothed rack means, the first length being longer than the second length and at least one curvature. Portion and the sample stage, characterized in that it consists of at least one straight portion.   The sample stage according to claim 9, wherein the shaft means includes a pair of coaxial axes.

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