DE8606445U1 - Object clamping device for a microtome - Google Patents

Description

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clamping lever to» final

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jaws and thus a spring-loaded clamping of the object between the two clamping jaws. In this way, dimensional tolerances of different objects clamped between the two clamping jaws can be easily compensated for using the spring element, so that a consistent clamping is achieved for different objects. By selecting the spring force of the spring element appropriately, an object is clamped between the two clamping jaws in an excellent manner, without the clamped object being deformed or destroyed.

The spring element can be provided between the actuator and the quick-release lever, whereby the final clamping of an object is achieved by moving the actuator via the quick-release lever and the spring element. With such a device, it is possible to roughly adjust the movable jaw using the actuator to a distance specified by the dimensions of the object to be clamped in relation to the fixed clamping jaw until the spring force of the spring element becomes effective and noticeable through this rough pre-adjustment. As soon as this state is reached, the object can be clamped between the two clamping jaws using the quick-release lever. When clamping using the quick-release lever, the actuator connected to the movable jaw is moved and the spring element is mechanically tensioned at the same time. The clamping force of the object clamped between the two clamping jaws thus corresponds to the spring force of the mechanically tensioned spring element. Since the spring force of the spring element depends on the distance by which the length of the spring element is changed when the quick release lever is pivoted,

influence possible

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_lioh6 Dimensional tolerances of various clamping devices - , affect the fader and thus the clamping force

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such that connections or arrangements are made.

^{0 y} ■&ldquor;, ,&ldquor;insert the clamping jaws

damage to a ziuiscnen

clamped object can be safely "avoided".

_The S.hneli clamping lever can be in the range of its swivel

axle an _E ,center on»iron, and the spring! msnt can ,wipe the» center of the

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and be resilient to pressure.

_Bl s proved particularly advantageous that the ederweg

of the compressible spring element at least

Due to the design of the quick release lever .xt

h i Sch»enk axis ««·"*·"■"

Through the expansion

one in the area of its pivot axis

Eccentric it is possible to ersch»ken by _U -

Clamping lever between a release and ·««

kiemm-Stenung with de» eccentric the

Eccentric and a stop provided on the actuator

arranged spring element on pressure «"""'"^'^

and thereby mechanically tensioned. The in.

.rtig. The elastic spring force caused by the tension of the spring element is equivalent to the clamping force,

.It is an object between the fixed and the

iespanned »ird ^*'

.It is an object

clamped in movable clamping jaws »ird ^*'

_d a3 the spring travel of the compressible spring..

at least _as large as the

Exzenter is achieved in a &ldquo;advantageous way that

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Obj.Ut.= sure verbs

has been found to be useful, since the 5t.ll a aelind.spindel and &ldquor;.. An.chla, .1. Ore

_d en the

the threaded spindle is screwed through

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to be set up until the Tederele.ent «.k... ^

After that, .ltl.1. of the Quick clamping of the object between the two

clamping jaws.

_Oi e pivot axis of the quick release lever

is, it is ..,Hch. the

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By mounting the swivel axis of the quick-release lever in the vicinity of the fixed clamping jaw, the bow-shaped quick-release lever can be made comparatively small without the rotary knob hindering the swiveling of the quick-release lever.

The swivel axis of the quick-release lever is preferably arranged perpendicular to the threaded spindle and has two partial axes which are mounted on both sides of the threaded spindle in the base plate, and each of the two partial axes preferably has a partial eccentric, whereby the two partial eccentrics are aligned with each other. The design of the swivel axis with two partial axes which are mounted on both sides of the threaded spindle in the base plate results in a space-saving structure of the object clamping device according to the invention , as well as the possibility of

A partial eccentric is to be provided on the partial axis so that a symmetrical structure of the clamping device can be achieved.

j; gives.

&rgr; The spring element subject to compression can be at least

have at least one annular disc spring,

through which the threaded spindle extends, and which faces the rotary knob with one side and the two partial eccentrics with the other side. Due to this design of the object clamping device, the at least one ring-shaped disc spring can rest with its second side on the two axially aligned partial eccentrics when the movable clamping jaw is in relation to the fixed

■ standing clamping jaws are preset roughly as far as

that the object to be clamped between the two clamping jaws is clamped with a certain small force between the

; is held in both clamping jaws.

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In order to design the spring travel of the spring element subjected to compression and thus the eccentricity of the two axially aligned partial eccentrics with a certain minimum size at a relatively high spring constant of the spring element, it has proven to be useful to arrange several ring-shaped disc springs one behind the other on the threaded spindle. The curvatures of adjacent disc springs can be oriented in opposite directions.

An annular disk can be arranged on the threaded spindle between the spring element and the two partial eccentrics. This annular disk prevents localized mechanical wear of the annular disc spring, which is adjacent to the two partial eccentrics, and achieves an even load on the disc springs, so that the spring properties of the spring element, which has at least one annular disc spring and can be subjected to pressure, are retained even after long use of the object clamping device according to the invention. In this way, an excellent service life of the clamping device according to the invention is achieved using simple means.

To limit the swivel angle of the quick-release lever, stops can be provided near its swivel axis. The stops to limit the swivel angle of the quick-release lever are preferably arranged in such a way that the quick-release lever is between

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a release and a clamping position, wherein the release position is at least approximately perpendicular to the plane spanned by the threaded spindle and by the two partial axes, and where the quick-release lever in the clamped position lies in the plane spanned by the threaded spindle and the two partial axes. The last two stops mentioned are preferably provided on the base plate or on the fixed clamping jaw in the vicinity of the two partial axes forming the pivot axis of the quick-release lever. In the release position, the rotary knob firmly connected to the threaded spindle can be rotated unhindered. The threaded spindle can be provided with a spring element on the end section opposite the rotary knob, which presses the threaded spindle in the direction from the fixed clamping jaw to the movable clamping jaw in order to hold the quick-release lever in its rest position. In the rest position, the pivot lever can be in a position that is at least approximately perpendicular to the base plate.

The spring element can be an arcuate leaf spring that is clamped between a disk attached to the threaded spindle and the face of the base plate opposite the fixed clamping jaw. With such a leaf spring, only a small amount of space is required. In addition, the threaded spindle only needs to protrude slightly over the face of the base plate with one end section.

The fixed clamping jaw can have a spring element near one of the stops, which slightly protrudes beyond the stop to dampen the contact of the quick-release lever on the stop.

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Further details, features and advantages emerge from the following description of a preferred embodiment of an object clamping device according to the invention shown in the drawing. They show:

Figure 1: a partially cutaway side view of a first embodiment of an object clamping device, which is attached to a locking device shown in sections,

Figure 1 a: a partially cutaway side view of a second embodiment of an object-saving "!device with a leaf spring and a stop spring.

Figure 2: a section through the object clamping device along the section line 11 - 11 from Figure

Figure 2a: a view of the end section of the object clamping device according to Figure la from above,

Figure 3: a section through the object clamping device along the section line IH-III from Figure 2.

Figure 4: a cross-section through a locking device for the object clamping device, only shown in sections in Figure 1,

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Figure 5 is a section along the line U-U in Figure 4,

Figure 6 shows a section along the section line UI-UI from Figure 4,

Figure 7 shows a section along the line UII-UII from Figure 6,

Figure 8 shows a cross section through a second embodiment of a locking device for an object clamping device shown in sections in Figure 1, and

Figure 9 shows a section along the line IX-IX from Figure 8.

Figure 1 shows an object clamping device 10 of a microtome, which is fastened to a locking device shown in sections. The locking device is described in detail below in connection with Figures 4 to 9. The clamping device 10 has a base plate 12, a fixed clamping jaw 14 and a movable clamping jaw 16. The movable clamping jaw 16 can be moved linearly along its guide 18 (see also Figure 2) towards the fixed clamping jaw 14 or away from the fixed clamping jaw 16. A threaded spindle 20, which extends through a threaded hole 26 in the movable clamping jaw 16, is used to adjust the distance between the fixed clamping jaw 14 and the movable clamping jaw 16. A rotary knob 22 is fastened to the threaded spindle 20. The base plate 12 is fastened to a support body 28 of the locking device. For this purpose, the base plate 12 has a

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plate 12 has a number of holes 29 (see Figure 2) through which fastening screws are screwed into the support body 28. These fastening screws are only indicated schematically in Figure 1 by their center lines 30 shown in dot-dash lines. The spherical shell-shaped support body 28, the sleeve 38 against which the support body 28 rests, and the locking body 40 are described in detail below in connection with Figures 4 to 9.

As can be seen from Figures 1 and 2, the threaded spindle 20 screwed through the movable clamping jaw 16 extends through a hole 130 which is aligned with the guide 18 in the base plate 12 and which extends through the fixed clamping jaw 14. Such a design makes it possible to adjust the movable clamping jaw 16 together with the threaded spindle 20 linearly along the guide 18 without rotating the threaded spindle 20 about its longitudinal axis. This allows the movable jaw 16 to be adjusted very quickly in relation to the fixed clamping jaw 14. After such a rapid adjustment of the movable clamping jaw 16 until it and the fixed clamping jaw 14 rest against an object 132 to be clamped (see Figure 1), the movable jaw 16 can be moved in the opposite direction.

Clamping jaws 16 by means of the rotary knob 22 and the ·

Threaded spindle 20 can be finely clamped against the object 132. During this delicate clamping process j

the quick release lever 134 is in the ge- j

released position, which in Figure 1 is shown with solid j

lines and in which the quick release |

lever 134 assumes a position corresponding to the plane, f

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- 12 -

which is clamped by the threaded spindle and by the two partial axes 136 of the clamping lever 134, is at least approximately vertical. The two partial axes 136 of the quick-release lever 134 are aligned with one another in the axial direction and together form a pivot axis 138 about which the quick-release lever 134 can be ^adjusted between the released position and a fixed position. The pivot axis 138 of the quick-release lever 134 is indicated in Figure 1 by dashed lines and in Figure 2 by solid lines. The two partial axes are mounted in the base plate 12 in the vicinity of the fixed clamping jaw 14. The two partial axes 136 are formed with partial eccentrics 140 on the end sections facing the threaded spindle 20, which are axially aligned with one another. The eccentricity of the two partial eccentrics 140 is inclined by approximately 45° to the plane spanned by the quick-release lever 134, so that the partial eccentrics 140 cover a relatively large axial distance when the quick-release lever 134 is pivoted by 90°. The spring element 142 provided between the two partial eccentrics 140 and the rotary knob 22 is tensioned by the distance that the two partial eccentrics 140 cover when the quick-release lever 134 is pivoted. This spring element 142 is an annular disc spring (see Figure 2) or more than one annular disc spring (see Figure 3).

The guide 18 provided in the base plate 12 has a dovetail-shaped, an inverted T-shaped or any other cross-section with at least one undercut, so that the movable clamping jaw 16 is securely guided in the guide 18.

At the end section adjacent to the fixed clamping jaw 14, the base plate 12 is provided with a recess 144 into which the guide 18 fits. The base plate 12 is formed with a first stop 146 against which the two legs 148 of the quick-release lever 134 rest in the clamping position. The fixed clamping jaw 14 is provided with a stop 150 against which the two legs 148 of the quick-release lever 134 rest when the quick-release lever 134 assumes the released position. The stops 146 and 150 therefore limit the angular movement of the quick-release lever 134 in a precisely defined manner. The two legs 148 of the quick-release lever 134 are connected to one another by a handle 152.

Figures 1a and 2a show a second embodiment of the object clamping device 10 in a side view or in a view from above. The reference number 12 designates the base plate, which is designed with a guide 18. A movable clamping jaw 16 is guided in the guide 18 without play and is mounted so that it can move along the guide 18. The movable clamping jaw 16 is designed with a through hole 26 which has an internal thread. A threaded spindle 20 is screwed through the through hole 26 with the internal thread, which is firmly connected to a rotary knob 22. By turning the rotary knob 22, it is possible to adjust the movable clamping jaw 16 towards the fixed clamping jaw 14 or away from the fixed clamping jaw 14 in order to clamp an object 132 to be cut thinly between the fixed clamping jaw 14 and the movable clamping jaw 16. During such a clamping process, i.e. during the rotation of the rotary knob 22 to clamp an object 132 to be cut thinly, the quick-release lever 134 is in the at least approximately vertical position shown in Figure 1 a with solid lines.

In this position, the quick-release lever 134 rests against the stop 150 or a spring element 170,

' which is provided in the vicinity of a stop 150 on the fixed clamping jaw 14 and projects slightly beyond the stop 150.

In the second embodiment of the object clamping device 10 according to the invention shown in Figures 1a and 2a, a resilient element 172 is arranged on the end section of the threaded spindle 20 opposite the rotary knob 22, is arcuate and rests with its two end sections I on the front side 174 of the base plate 12.

n> The arched spring element 172 lies with its center

' area on an O-ring 176 which is attached to the threaded spindle 20. By means of the spring element 172 on the

f end section of the threaded spindle 20 it is possible to

! Frictional forces between the movable clamping jaws

L and the base plate 12 and the quick

f Clamping lever 134 during the replacement of a thin-

'| cutting' object 132 against another thin-

'.. cutting object in Figure 1 a with solid

Lines shown at least approximately vertical position. In this design of the object clamping device according to the invention, the threaded spindle 20 is only linearly displaced relative to the base plate 12 by the amount of the eccentricity of the partial eccentric 140. In this design, it is therefore not possible to quickly adjust the movable clamping jaw 16 with the threaded spindle 20 in relation to the fixed clamping jaw 14 along the guide 18. Rather, in this design, the movable clamping jaw is set to the dimensions of the object 132 to be cut thin by means of the rotary knob 22, and the clamping of the object 132 to be cut thin between the two clamping jaws 14 and 16 takes place as in the embodiment shown in Figures 1 and 2 by means of the quick-release lever 134,Xn in which the quick-release lever 134 is moved in the direction of the arrow 178 in

the at least approximately horizontal position shown in dashed lines in Figure 1 a. In this position, the quick-release lever 134 rests against the stop 146. The spring element 170 in the vicinity of the stop 150 serves in particular to dampen the contact of the quick-release lever 134 with the stop 150.

The object clamping device 10 is attached to a support body 28 which is mounted on a sleeve 38. The last-mentioned parts are described in detail below in connection with Figures 4 and 8.

The spring element 172 therefore serves in particular to hold the quick-release lever 134 in the at least approximately vertical rest position.

Figure 3 shows the fixed clamping jaw 14, a short section of the base plate 12 with the recess .144, a part of the threaded spindle 20 with the rotary knob 22, and the spring element 142 having two ring-shaped disc springs. The threaded spindle 20 extends through the two ring-shaped disc springs. The two disc springs are arranged on the threaded spindle 20 in such a way that their curvatures are oriented in opposite directions. This opposite orientation of the curvature of the ring-shaped disc springs results in a sufficiently large spring travel, which depends on the number of disc springs. A partial axis 136 extends into a hole 154 in the fixed clamping jaw 14 or in the base plate 12, which has a partial eccentric on its front end section facing the threaded spindle. In Figure 3, the partial eccentric 140 is shown in the position that compresses the spring element 142. In comparison, the dot-dash

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The partial eccentric 140 indicated in Figure 1 is shown in the position in which the spring element 142 is not tensioned. An annular disk 156 is arranged on the threaded spindle 20 between the partial eccentric 140 and the spring element 142. This disk 156 protects the spring element 142, i.e. the annular disc spring facing the eccentric 140, from wear caused by the partial eccentric 140 or the two partial eccentrics 140 (see Figure 2). The ring-shaped disc springs have an inner diameter that is equal to or slightly larger than the diameter of the threaded spindle 20, and they have an outer diameter such that the ring-shaped disc spring adjacent to the two partial eccentrics 140 rests against the two partial eccentrics 140 when the quick-release lever 134 is pivoted from the released position into the clamping position. The reference number 130 in Figure 3 also designates the through hole through the fixed jaw 14, through which the threaded spindle 20 extends freely. The quick-release lever 134 with its two legs 148 and the handle 152 is shown in this figure in the clamping position of the object clamping device.

To clamp an object 132, which can be a cassette in which an object to be cut thin is embedded, the object is placed between the fixed clamping jaw 14 and the movable clamping jaw 16 so that it rests on the base plate 12. The movable jaw 16 is then moved together with the threaded spindle 20 screwed through it along the guide 18 provided in the base plate until the object 132 lies tightly between the fixed clamping jaw 14 and the movable clamping jaw 16.

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During this process, the quick-release lever 134 is in its released position, i.e. its legs 148 rest against the two stops 150 of the fixed clamping jaw 14. In this position of the quick-release lever 134, the two partial eccentrics 140 are in the position indicated by dashed lines in Figure 1, i.e. in a position away from the spring element 142. The rotary knob 22 and thus the threaded spindle 20 are then rotated until the spring element 142 between the two partial eccentrics 140 and the rotary knob 22 is slightly subjected to pressure and is mechanically pre-tensioned in the process. This state is easy to feel because the force required to turn the rotary knob 22 noticeably increases in this state. As soon as this state is reached, in which the spring element 142 is slightly mechanically tensioned, the quick-release lever 134 can be moved into the clamping position in which the two legs 148 of the quick-release lever 134 rest against the stops 146. When the quick-release lever 134 is pivoted, the two partial eccentrics 140 describe a corresponding pivoting movement from the position shown in dashed lines in Figure 1 to the position shown in Figure 3. In the process, the spring element 142 is compressed and mechanically tensioned by means of the two partial eccentrics 140. The clamping force with which the object 132 is clamped between the two clamping jaws 14 and 16 corresponds to the spring force of the compressed spring element 142. Since the eccentricity of the two partial eccentrics 140 is smaller or at most equal to the spring travel of the compressible spring element 142, a constant clamping force is produced acting on the clamped object 132, so that warping or damage to the clamped object 132 as a result of excessive clamping forces

I »III to

can be safely avoided.

Figure 4 shows a locking device for the object clamping device 10 of a microtome. The reference number 12 designates the base plate, the reference number 16 the movable clamping jaw, the reference number 11 the fixed clamping jaw, the reference number 134 the quick-release lever and the reference number 22 the rotary knob for adjusting the movable clamping jaw 16. An object 132 to be clamped is indicated between the two clamping jaws 14 and 16. The base plate 12 of the object clamping device 10 is fastened to a support body 28. The support body 28, which is designed as a spherical shell, is connected to the base plate 12 of the object clamping device 10 with screws. This fastening is carried out by a number of screws, which are indicated in Figure 4 by their center lines 30 shown in dot-dash lines. The spherical shell-shaped support body 2C has a partially spherical surface 32 and a partially spherical inner surface 34. The support body 28 rests with its partially spherical surface 32 on an end face 36 of a sleeve 38 and can be pressed onto the sleeve 38 by means of a locking body 40.

The sleeve 38 has a partially spherical recess 42 on the front surface 36, the radius of curvature of which corresponds to the radius of curvature of the partially spherical surface 32 of the support body 2C. The locking body 40 has a guide part 44 and a threaded pin 46. The threaded pin 46 extends with an end section 48 through a recess 50

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- 19 -

in the support body 28. The end section 48
of the locking body 40 is a spherical section
formed, wherein the surface of the spherical section on the partially spherical inner surface 34
of the support body 28 formed in the shape of a spherical shell. The threaded pin 46 has

on its face facing away from the threaded section ^j

surface 52 a slot-shaped screw suspension suf. :

I The guide part 44 is provided with an internal thread 56 |

formed into which the threaded pin 46 with its I

External thread section is screwed in. The guide |

The locking part 44 of the locking body 40 is in a |

central cavity 58 of the sleeve 38 in axial j

direction. The sleeve 38 j

itself is by means of a in this figure only '

schematically indicated drive device 60 j

in axial direction to the cutting thickness infeed of the I.

Adjustment device 10 step by step or for coarse I

adjustment of the clamping device 10 in axial |

Direction continuously adjustable. When |

Operating device 60 is a device that complies with §

known cutting thickness and rough adjustment settings |

direction, so that it is unnecessary to go into it in more detail |

to enter into. |

In the sleeve 3 8 an axle 62 is mounted, which is connected to I

one end an eccentric 64 and at the other end
a pivot lever 66. The axis 62 is
rotatably mounted in a bearing bush 68 arranged in the radial direction of the sleeve 38.

The eccentric 64, which is also clearly visible in Figure 5, is arranged in a bore 70 | which extends in the radial direction of the guide part 44 of the locking body 40.

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- 20 -

When the axis 62 rotates about its center line 72, the eccentric 64, which is firmly connected to the axis 62, is rotated in the bore 70 so that the guide part 44 of the locking body 40 is moved in the axial direction in the central cavity 58 of the sleeve 38. This axial movement of the locking body results in either a locking of the mounting body 28 on the sleeve 38 or a release of the last-mentioned two parts from one another so that the object clamping device 10 can be adjusted to any position and then locked back on the sleeve 38 in the adjusted position.

The sleeve 38 is mounted in the housing 74 of the microtome, which is only partially shown in Figure 4, so that it can be moved in the axial direction without play. At a safe distance from the object clamping device 10 and thus at a safe distance from the cutting blade of the microtome, which is not shown in the figures, an actuating element 76 is provided for adjusting the eccentric 64 and thus for locking or unlocking the object clamping device or the sleeve 38. The actuating element 76 has an actuating button 78, which is attached to an axis 80. The axis 80 extends through the housing 74 and is mounted in roller bearings 82, which can be ball bearings. The axis 80 has a pinion 84 at its end section opposite the actuating button 78, which meshes with a rack 86 in every axial position of the sleeve 38, as can also be clearly seen from Figure 6. The rack 86, which is articulated to the pivot lever 66, forms between the actuating element

- 21 -

76 and the eccentric 64 engaging the locking body 40. The articulated connection of the rack 86 to the pivot lever 66 is effected by an axis 88 which extends through the pivot lever 66 and through the fork-shaped end section 90 of the rack 86. In Figures 4 and 6, the reference number 92 designates the toothing of the rack 86 in which the toothing of the pinion 84 connected to the actuating element 76 meshes. In order that the rack 86 with its toothing 92 in the jsdel ¹ position of the sleeve 38 meshes with the toothing of the pinion 84, an abutment device 94 holding the rack 86 in engagement with the pinion 84 is provided on the axis of the pinion 84.

As can be clearly seen from Figure 7, the abutment device 94 is designed as a U-shaped bracket, which has aligned holes 98 and 100 on its two opposite legs 96, with the pinion 84 extending through the hole 98 and the axis 80 through the hole 100. The holes 98 and 100 have different diameters, so that a spring ring 102 is sufficient to secure the pinion 84 against axial displacement, which is engaged in a circumferential groove 104 of the pinion 84 and which rests against the leg 96 of the U-shaped bracket 94 shown on the left in Figure 7. The reference number 86 in this figure also designates the rack with its teeth 92, which mesh with the teeth of the pinion 84. The U-shaped bracket 94 has a connecting rod 106 which connects the two legs 96 to one another and which rests on the back 108 of the rack 86 opposite the toothing 92.

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In Figure 5, reference number 44 designates a section of the guide part of the locking body 40. In Figure 6, reference number 110 designates an end stop which is attached to the end of the rack 86 opposite the articulated connection 88 between the rack 86 and the pivot lever 66. The end stop 110 prevents the rack 86 from moving away from the pinion 84.

Figures 8 and 9 show another embodiment of the locking device according to the invention for

the object clamping device 10 of a microtome, wherein the individual parts corresponding to Figures 4 to 7

for parts designated by the same reference numbers, but

f are not described again. This implementation

form of the locking device differs from

the embodiment described above in that the end section of the

5- with the eccentric 64 connected axis 62 a drive

element 114. This output element 114 is designed as a chain wheel, a gear wheel, or a V-belt

,' wheel with toothed flanks. Accordingly

a chain wheel, a gear wheel or a V-belt wheel with toothed side flanks is attached to the axis 80 of the actuating element 76 and serves as the drive element 116. The drive element 116 and the drive element 114 are operatively connected to one another by means of a connecting element which is designed as a chain, a toothed belt or a V-belt with toothed side flanks. The endless connecting element is designated in these figures with the reference number. In Figure 9, both the drive element 116 and the driven element 114 are only indicated by dot-dash circles. On one strand of the end-

A tensioning element 120 in the form of a roller rests on the loose connecting element 118. The roller 120 is provided with stumps 122 which protrude axially from the roller 120 in opposite directions and against which the fork-shaped ends 124 of a spring element 126 rest.

The end 128 of the spring element 126 opposite the fork-shaped ends 124 is attached to the housing 74 of the microtome, which is shown in sections. The spring element 126 is a helical tension spring, which is shown in section in Figure 6. The spring element 126 presses the tensioning element 120 in the form of a roller against the inside of the endless connecting element 1.18 with such a force that the connecting element 118 rests on the drive element 116 and the output element 114 in every position of the sleeve 38 relative to the stationary actuating element 66 and thus at every distance between the axis 80 and the axis 62 connected to the eccentric 64 in such a way that the two last-mentioned elements are securely operatively connected to one another. In this way, the rotation of the actuating element 76 is converted into a rotation of the eccentric 64 and thus into an axial movement of the locking body 40, wherein the axial movement of the locking body relative to the sleeve 38 results in a locking or unlocking of the object clamping device 10.

Claims (1)

Object clamping device for a microtome. The invention relates to an object clamping device for a microtome, with a base plate, a fixed clamping jaw and a movable clamping jaw, which can be roughly pre-adjusted relative to the fixed clamping jaw by means of an adjusting drive along a guide provided on the base plate, wherein a pivotable adjusting clamping lever is provided between the two clamping jaws for the final clamping of an object, which further displaces the movable clamping jaw. In such an object clamping device, the actuator is used to roughly pre-adjust the distance between the fixed and the movable clamping jaws to a specific object, e.g. to a specific object cassette in which the object to be thinly sliced is embedded. PATENT ATTORNEYS * '. .". . '. '. '. . &ldquor;".I". Dr. rer.nat. DIETER LOUIS ',.'·..'·..*'..'*..'*..· Dipl.-Phys. CLAUS POHLAU Dipl.-Ing. FRANZ LOHRENTZ Olpl.-Phys.WOLFG ANG SEGETH 25.164 70/fr KESSLERPLATZ 1 NUREMBERG 20 Parke, Davis & Co. Tabor Road Morris Plains New Jersey 07950 UNITED STATES. Expectations Object clamping device (10) for a microtome, with a base plate (12), a fixed clamping jaw (14) and a movable clamping jaw (16) which can be roughly preset relative to the fixed clamping jaw (14) by means of an actuator (20, 22) along a guide (18) provided on the base plate (12), wherein a pivotable quick-release lever (134) which further displaces the movable clamping jaw (16) is provided between the two clamping jaws (14, 16) for the final clamping of an object (132), characterized in that the quick-release lever (134) acts on the movable clamping jaw (16) via a spring element (142) for the final and resilient pressing of the two clamping jaws (14, 16) on the clamped object (132). I * t I * * i 2. Device according to claim 1,
characterized, that the spring element (142) is provided between the actuator (20, 22) and the quick-release lever (134), whereby the final clamping of an object (132) takes place by movement of the actuator via the quick-release lever (134) and the spring element (142). 3. Device according to claim 1 or 2, characterized in that the quick-release lever (134) has an eccentric (λλΩ) in the region of its pivot axis (138), and that the spring element (142) is arranged between the eccentric (140) of the quick-release lever (134) and a stop provided on the actuator (20, 22) and can be subjected to pressure. 4. Device according to claim 3,
characterized, that the spring travel of the compressible spring element (142) is at least as large as the eccentricity of the eccentric. 5. Device according to claim 3,
characterized in that the actuating drive is designed as a threaded spindle (20) and the stop is designed as a rotary knob (22) for the threaded spindle. 6. Device according to claim 3,
characterized, that the pivot axis (138) of the quick-release lever (134) is mounted on the base plate (12) in the vicinity of the fixed clamping jaw (14). a ti · · · · ·■« 7. Device according to claim 5 or 6, characterized in that the pivot axis (138) of the quick-release lever (134) is arranged perpendicularly to the threaded spindle (20) and has two partial axes which are mounted on both sides of the threaded spindle (20) in the base plate (12), and that each of the two partial axes (136) has a partial eccentric (140), the two partial eccentrics (140) being axially aligned with one another. 8. Device according to one of claims 3 to 7, characterized in that the spring element (142) which can be subjected to pressure has at least one annular disc spring, through which the threaded spindle (20) extends and which faces with its one side towards the rotary knob (22) and with its second side towards the two partial eccentrics (140). 9. Device according to claim 8, characterized in that several annular disc springs (142) are arranged one behind the other on the threaded spindle (20) &rgr; JO. Device according to claim 8 or 9, characterized in that an annular disk (156) is arranged on the threaded spindle (20) between the spring element (142) and the two partial eccentrics (140). ttt t ·
( . · · · i lt ^ 4 11. Device according to one of the preceding claims, characterized in that stops (146, 150) are provided in the vicinity of the pivot axis (138) to limit the angle of gravity of the quick-release lever (134). IZ. Device according to claim 5, characterized in that the threaded spindle (20) is provided with a spring element (172) at the end section opposite the rotary knob (22), which presses the threaded spindle (20) in the direction from the fixed clamping jaw (14) to the movable clamping jaw (16) in order to hold the quick-release lever (134) in its rest position. 13. Device according to claim 12, characterized in that the spring element (172) is an arcuate leaf spring which is clamped between a disk (172) fastened to the threaded spindle (20) and the end face (174) of the base plate (12) opposite the fixed clamping jaw (14). 14. Device according to claim 11, characterized in that the fixed clamping jaw (14) has a spring element (170) in the vicinity of one stop (150) which projects slightly beyond the stop (150) to dampen the contact of the quick-release lever (13&) on the stop (150).