US2647439A - Apparatus for cutting thin sections - Google Patents

Description

Aug. 4, 1953 P. G. ROOFE ET AL APPARATUS FOR CUTTING THIN SECTIONS Filed Aug. 253 1949 mm m ATT'Y Patented Aug. 4, 1953 APPARATUS FOR CUTTING THIN SECTIONS Paul G. Roofe and Frank E. Hoecker, Lawrence, Kans.

Application August 23, 1949, Serial No. 111,921

Claims. 1

This invention relates in general to the cutting of thin sections of teeth, bones, rocks and other hard objects and is more particularly described in the sectioning of bones for photomicrographic and autoradiographic purposes, although it may have a more general use wherever applicable.

The recent development of interest in the absorption, distribution and biological effects of radioactive substances absorbed into the bodies of experimental animals has led to the development of methods of studying various tissues by autoradiographic methods. A really satisfactory method of preparing sections of bone has been lacking for studies which precluded decalcification.

One method which involved rather elaborate treatment of the bone before and during the process ofsectioning, included, among other disadvantages, the necessity of mounting the bone to be sectioned in celloidin, a process requiring at least ten days delay and some uncertainty as to the proper hardness of the celloidin block. One of the serious objections to this method is the difficulty and time consuming process of grinding nicks out of the microtome knife after a few sections have been out.

The distribution and possible effects of radium deposited in the bones of test animals have emphasized the necessity of a rapid method of sectioning the bones of animals which have been injected with radium chloride. The present invention has the following advantages, objects, and virtues:

No treatment of the bone before sectioning is required;

The method is rapid, as thirty serial sections of a rat tibia can be made in an hour;

The sections are sufficiently thin (of the order of microns) for microscopic and photomicrographic study of the cellular structure of the bone; and

No subsequent treatment of the bone section is required, the section is simply removed from a section retainer of the cutter and mounted directly upon a slide with sumcient adhesive in insure attachment.

A further object of the invention is to provide an apparatus which is easily and rapidly operated, it is readily adjustable for difierent articles and different sections, and improved means are provided for holding the bones and the sections as they are removed.

Other objects of the invention will appear in the specification and will be apparent from the accompanying drawing, in which The figure is a part-sectional view of an apparatus for holding an article, such as a bone, without damaging it and for cutting and retaining each thin section as it is separated from the bone.

In carrying out this invention a section holding carriage 8 is movable relatively to a motor driven saw [0 for cutting a thin section I2 from a bone I4 held by the carriage, and a section retainer blade It holds the thin section [2 during the time and after it is cut off.

Referring now more particularly to the drawings, the carriage 8 is shown in the form of a channel mounted for relative raising and lowering movement upon a support l8 by means of a post 20 connected to the bottom of the carriage and having a rack 22 in the post and a pinion 24 engaging the rack and rotatably mounted in the support It. If desired a feeding pawl 26 movably mounted in the support l8 engages the pinion 24 to rotate it in a step-by-step movement for raising or advancing the bone I4 the thickness of the cut desired.

The carriage is also movable reciprocably with the support relatively to the saw [0 in any suitable manner, as represented by a rack 30 on the support l8 and a pinion 32 meshing therewith and movable in opposite directions. As thus represented the saw is fixed in location while the carriage is shifted, but the same result is obtained if the the carriage is stationary and the motor saw is moved horizontally and vertically with respect to the carriage.

In the carriage channel are blocks 34 and 36, each with a leather piece 38 secured to one face and a soft rubber piece 40 secured to the outer surface of the leather piece. These two blocks are placed oppositely with the leather and rubber pieces adjacent and the bone [4 to be sectioned between the rubber faces. The blocks are pressed together, binding the bone tightly in place between them as cushioned by the leather and rubber pieces, by a metal spacer 42 engaged on one side by a clamping screw 44 extending through one side of the carriage channel member and having a head 46 at the outer end for adjusting the screw.

In one of the blocks 36 and extending upwardly therefrom is a supporting rod 50 upon which a collar 5| is slidably adjustable by means of a screw 52. Extending from the collar is the section retainer blade l6 comprising a spring strip preferably of metal, bent outwardly and downwardly therefrom. The outer end of the strip is attached to the upper end of the bone [4 before it is severed by a suitable adhesive 56. This spring strip supports the upper section as it is being severed and retains it after it has been cut ofi by the saw H1. The section thus cut on is removed from the spring strip and mounted on a microscope slide by a thin clear adhesive, and the photomicrogram is made therefrom.

After one section is cut off, the carriage is withdrawn if necessary, raised the thickness of the cut section desired, the end of the spring strip [6 is adhesively secured to the cut and projecting end of the bone, and the cutting operation is repeated. It ,may b necessary to adjust the bone 14 in the holder which comprises the clamping blocks 34 and 36 with their interposed yielding and resilient pieces. These pieces may be separate from the blocks for independently positioning them, if desired.

Although this apparatus has been described in detail as applied to the cutting and mounting of a thin bone section, it should be regarded asan example or illustration and not as a limitation or restriction, as various changes may be made in the construction and application of the parts for cutting thin sections of other mavterials without departing from the spirit and scope of the invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

We claim:

1. The combination with a holder for an article and a cutter movable with respect to the holder and the article for severing a thin section from one end of the article, of a retainer for the thin section comprising an adhesive to engage the said one end of the articl before the severing operation, the retainer comprising a spring for carrying the adhesive yielding urged against the said one end of the section being flexible to enabl the retainer and severed sec- ..tion adhering thereto to be moved away from the article after the severing operation.

2. The combination with a holder for an article and a cutter movable with respect to the holder andthe article for severing a thin section from one end of the article, of a resilient retainer for the thin sectionhaving anadhesive at one end to engage th said one end of the article before the severing operation and secured 4 at its other end in fixed relation with respect to the holder so as to cause the adhesive and said one end of the retainer to be yieldingly urged against the said one end of the article, whereby the said one end of the retainer along the severed section adhering thereto may be moved away from the articl for removal of the section from the retainer.

3. They apparatus specified in claim 2, the retainerbeing a flexiblespring strip.

4. The combination with a holder for a bone and a cutter movable with respect to the holder for severing .a thin section from one end of the bone, of a retainer 'for the thin section of bone comprising. a resilient strip having an adhesive at one end to engage the said one end of the bone before the severing operation, and means for adjustably securing the other end of the a holder movable relative to said cutter for clamping the article to be sliced atv only one end thereof to allow the free end thereof to extend into the path of said cutter, a resilient strip supported by the holder and curved to, yieldingly press against theouter end of said article. and an adhesive carried by the strip for engagingand for retaining the portion sliced in its position relative to the rest of said article both during and subsequent to the slicing operation.

PAUL G. ROOFE.

FRANK E. HQECKER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,013,897 7 Reilly et a1 Jan. 9, 1912 1,923,854 Van Hoorn Aug. 22; 1933 1,929,543 Van Hoorn Oct. 10, 1933 2,086,159 Wood July 13, 1937 FOREIGN PATENTS Number Country Date 402,888 'Germany Sept. 19, 1924

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