GB2144876A

GB2144876A - Clamping device for a microtome

Info

Publication number: GB2144876A
Application number: GB08417200A
Authority: GB
Inventors: Werner Behme; Manfred Berleth
Original assignee: Parke Davis and Co LLC
Current assignee: Parke Davis and Co LLC
Priority date: 1983-07-30
Filing date: 1984-07-05
Publication date: 1985-03-13
Also published as: SE8403891D0; GB8417200D0; GB2144876B; FR2549960A1; SE8403891L; DE3327618A1; DE3327618C2; JPS6053830A

Abstract

A device for clamping a specimen or a specimen 8 carrier 2 in a microtome, comprises a support for holding the specimen or specimen carrier 2 opposite a microtome knife 9, the support being displaceable along a guide 5 parallel to the cutting edge, so that any portion of the cutting edge can be selectively utilised. The support also bears lock means 10, 17 for temporarily locating the support in a chosen position on the guide 5. <IMAGE>

Description

SPECIFICATION Clamping device for a microtome This invention relates to a clamping device for clamping a specimen body in a microtome.

Microtomy has found widening use in medicine and biology as a result of the introduction of new methods, such as plastic embedding and the cutting of non-decalcified bones.

Also microtomy is gaining increasing importance in engineering applications.

Specimen carriers are employed for thinsection specimens, the carriers being in the form of a cylindrical body in which the thin specimen is embedded. Small specimens are often embedded in an extension which projects from the cylindrical body. The specimen carrier must be clamped in such a way that the embedded specimens are not deformed so that the best possible thin sections can be cut from the embedded -specimens by means of a microtome cutter.

It is important to orientate the specimen relative to the knife edge in a desired position or make the cutter of the microtome pivotable relative to the orientation of the thin-section specimen in order to cut the required sections.

Generally the cutter is used in only a relatively narrow region of its cutting edge, so that this narrow region is exposed to wear, whilst the remaining larger regions of the cutter are not worn at all. As a result, the service life of a cutter of this type is very limited.

An object of the present invention is to provide a clamping device for a microtome in which a clamped specimen carrier is deformed to the least possible extent and can be displaced relative to the width of the cutter in a simple way, so that the entire width of the cutting edge of a cutter can be utilised as effectively as possible.

According to the present invention we provide a clamping device for clamping a specimen or specimen carrier in a microtome, the device comprising a support for holding the specimen or specimen carrier opposite the cutting edge of a microtome knife, the support being displaceable along a guide parallel to the knife edge.

The clamping device according to the invention provides for a lateral displacement, without play, of a specimen carrier clamped in a support in a very simple way. This enables the cutter of a microtome to be used most effectively along its entire cutting edge. As a result, the service life of an expensive cutter of this type is increased substantially.

Because the support is guided parallel to the cutting edge of the microtome cutter, the parallel alignment of successive thin sections is immediately ensured, even when the support is displaced laterally relative to the cutting knife, so as to utilise the entire width of cutting edge as efficiently as possible.

Advantageously, the support is rotatable about an axis which is perpendicular to the cutting edge. This enables the specimen carrier to be aligned very precisely relative to the cutting edge. When a cylindrical specimen carrier is clamped, it can be adjusted very simply by releasing the support on which the specimen body carrier is fixed, rotating the specimen carrier and the support into the correct position and locking the support again.

Preferably, the support comprises two parts, a first part containing clamping segments for clamping a specimen carrier and being lockable on a slider by means of a second part. In a preferred embodiment of the invention, the locking of the support on the slider is effected by means of a locking device arranged laterally on the slider. The locking device for the support preferably has an eccentric pin mounted rotatably in the slider so that the support can be released from the slider and locked on it again simply and quickly.

The first part of the support can be a stub axle with a flange, and the second part of the support can be a threaded ring retained by means of the flange of the first part. It is thereby possible to fix a cylindrical specimen carrier between clamping segments by means of a clamping ring, the clamping ring forming mechanically a single unit with the threaded ring of the support; at the same time, however, the stub axle can be fixed so as to be movable within limits or by means of the eccentric pin, so that the threaded ring is rotatable about its centre axis to align the specimen carrier.

When the specimen carrier is aligned relative to the cutting edge the slider can be adjusted relative to the length of the cutting edge very simply, because the slider includes guide surfaces which cooperate with a guide to provide a play-free sliding movement. Preferably the guide and guide surfaces have a dove-tailed cross-section. To lock and release the slider on the guide the slider is equipped with a locking device. This locking device can contain a wedge which is matched to the dovetaii of the guide.

Further details, features and advantages of the invention will be apparent from the following description of a prefered embodiment illustrated in the accompanying drawing in which: Figure 1 is a front view of a clamping device for clamping a cylindrical specimen carrier in a microtome; Figure 2 is a plan view of the device shown in Fig. 1, with a portion of a cutter; Figure 3 is a section through the device shown in Fig. 1; and Figure 4 is a plan view of the device shown in Fig. 3 on a guide strip, only a portion of which is shown.

The drawings illustrate a clamping device for clamping a cylindrical specimen carrier 2, having a wedge-shaped extension 21 in which is embedded a thin-section specimen 8 which is to be sliced into thin sections by means of the cutter 9. For this purpose, the cutter 9 is advanced in very small steps in the direction of the arrow shown in Fig. 1.

The specimen carrier 2 is clamped by means of clamping segments 7 retained by an O-ring 1 2 in a clamping ring 11. The clamping ring 11 has an internal thread which is screwed on the threaded ring 1 3 of a support.

The support also comprises a stub axle 1 5 mounted on a slider 4 and having a flange 151 to retain the threaded ring 13. The threaded ring 1 3 is first fixed to the slider 4 by means of an eccentric pin 1 4 projecting through the stub axle 1 5 of the support. The specimen carrier 2 is then inserted between the clamping segments 7 which, as is evident from Fig. 3, have a wedge-shaped rear surface which matches an inner conical surface of the clamping ring 11.

Rotation of the clamping ring 11 on the threaded ring 1 3 causes the clamping segments 7 to move diagonally relative to clamping ring 13 as a result of the wedge effect arising between the conical surface and the clamping segments 7 so that they contact the cylindrical specimen carrier 2 around its periphery and clamp it with a minimum of deformation.

An optimum clamping action is achieved when the clamping peg 1 6 shown in Fig. 4 is inserted in the blind bore 111 in the clamping ring 11 and, is rotated in one of the arrowed directions indicated. To release the clamping ring 11 the clamping peg 1 6 is rotated in the opposite arrowed direction. After clamping the cylindrical specimen carrier 2 can still rotate together with the clamping ring 11 until the stub axle 1 5 is locked to the slider 4 by means of the eccentric pin 14. The pin 14 can be rotated by the quick-acting clamping lever 3 to lock the stub axle 1 5 against rotation. When the pin 14 is rotated to release the stub axle 1 5 the specimen carrier 2 can be rotated to a desired orientation.

When the thin-section specimen 8 is oriented correctly relative to the cutting edge, the slider 4 can be displaced into the desired region of the cutting edge of the cutter 9 on the guide 5 on the baseplate 6. The slider 4 can be clamped in the desired position on the guide 5 by means of the locking lever 10 which actuates a wedge 1 7 engaging into the dovetail surfaces of the guide 5.

The above-described clamping device as a whole is received by a microtome slide which is preferably located in a horizontal plane corresponding to the sectional plane of the cutter 9.

The cutting thickness is adjusted in a known way by lowering the cutting knife 9 stepwise.

Claims

1. An adjustable mount for a specimen clamp on a microtome having a knife compris ing an elongated slide mounted on the microtome arm, said slide being elongated in a direction parallel to the microtome knife, a body slidably mounted on said slide, lock means mounted on said body for temporarily locating said body in a chosen position on said slide, and a specimen clamp carried by said body whereby a specimen can be sectioned by a selected portion of the microtome knife by moving said body to the chosen location.

2. An adjustable mount according to Claim 1, in which said clamp is selectively rotatable about an axis perpendicular to the knife.

3. An adjustable mount substantially as described with reference to and as illustrated in the accompanying drawings.