US664118A - Microtome. - Google Patents

Description

. 'y am Ho. 664,118. f A 4 Patented Dec. I8, |900'f 7 5i.;

y A. BECKER. y 20/ mcnorons. yf 4v' [Anuman 52411 Aug. Q5. 10900 fff/ /I (l0 Indem 2 Sheec-Sl I,

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A. BECKER.

M I C R 0T 0 M E.

(Application med Aug. 25, 1899.)V

2 Sheets-Sheet 2.

Wil-fliessen? l I -l 'I i UNITED STATES AUGUST BECKER, E GTTINGEN, GERMANY, AssrGNoR To THE SPENCER ATENT OFFICE.

LENS COMPANY, OF BUFFALO, NEW YORK.v

MICROTOME.

SPECIFICATION forming part of Letters latent No. 664,118, dated December 18, 1900.

Application filed August 25. 1899. Serial No. 728,620. (No model.)

To all whom it may concern:

Be it known that I, AUGUST BECKER, a subject of the German Emperor, residing at Gttingen, in the Kingdom of Prussia, German Empire, have invented new and useful Improvements in Microtomes, of which the following is a specification. i

This invention relates to a microtome or slicing instrument designed for cutting very ro thin sections or slices from an object for microscopie examination.

The objects of this invention are to connect the knife-support with the operating hand-lever in such manner that the knife will x 5 not be displaced or disturbed by any deflection which may be caused in the operatinglever by the pressure exerted upon the same by the hand of the operator and to provide a simple and adjustable feed mechanism wherevvzo by the object is fed toward the path of the knifeafter each cutting operation.

In the accompanyingr drawings, consisting of two sheets, Figure 1 is a front elevation of my improvedmicrotome. Fig. 2 is atop plan z 5 view thereof. Fig. 3 is a fragmentary horizontal section in line 3 3, Fig. l. Fig. 4 is a vertical section in line 4 4, Fig. 1. Fig. 5 is a fragmentary vertical section in line 5 5, Fig. l. Figs. 6 and 7 are fragmentary vertical 3o sections at right angles to Figs. 4 and 5 and taken in lines 6 Gand 7 7, Fig. 2, respectively. Figs. 8 and 9 are horizontal sections in lines 8 8 and 9 9, Fig. 4-looking upward.

Like letters of reference refer to like parts in the several figures. The main frame of the microtome consists, essentially, of an upright or'standard A, of skeleton form, and ahollow base A', projecting forwardly from the lower end of the standard, 4o as shown in Figs. 1 and 4. The frame may -be secured in place in any suitable way, the means shown in the drawings being designed tosecure the frame to the edge of a work bench or table and consisting of an upper clamping-jaw a, projecting rearwardly from the standard, and a vertical clamping-screw Y a', arranged in alug a2, projecting rearwardly ffrom the standard.

B represents the horizontally-movable slic- 5o ing-knife, which is secured near its ends by moans of clamps c to a horizontal supporting- .posts, as shown in Figs. 1 and 6.

d of the right-hand rock-arm D.

bar C. This bar is pivotally connected at its, ends with the upper part of the standard by a pair of horizontally-swinging rock-arms D D. Each of the rock-arms is made comparatively Wide in a direction parallel with its pivots, so that it is very rigid and not liable to become distorted. The rear end of each rock-arm is pivoted to the standard by upper and lower cone-screws d d', secured to the 6o f cated ends of the rock-arms and engage with 7o sockets in the upper and lower ends vof the The posts ee provide a wide bearing for the knife-supporting bar, which eifectually prevents the same from being twisted or displaced. 75.; I i

The relative arrangement of the pivots connecting the rock-arms with the frame and the knife-supporting bar is such that a parallelogram is formed by these parts. The movement of the knife upon rocking the arms and 8c knife back and forth is therefore similar to the curvilinear movement when drawing a knife by hand. The knife thus receives a movement which permits of utilizing nearly the whole length of the knife, thereby wearing the knife more uniformly and enabling larger slices to be cut from the object than has been possible heretofore. The knife is supported and guided solely by the rock-arms and supporting-bar, and these parts are suf- 9o ficiently rigid to avoid any deflection of the. knife out of its course in moving forward or backward, thereby producing sections or slices of uniform thickness.

The knife and its supports are rocked back and forth by a horizontally-swinging handlever F,which turns on the upper pivot-screw The handlever bears with its upper side against the jam-nut e3 of this pivot-screw, and it is fricroo tionally held in place by a spring-washer f surrounding said pivot-screw'and interposed f between the under side of the hand-lever and the uppcr sidcof the frame. The hand-lever is provided near its pivot with a depending coupling-pin f', which has a screw connection at its upper end with the hand-lever and which engages with its lower end in an open- Aingf2 in the upper side of the rock-arm D',

Fig. 5, in such manner that the coupling-pin is capable of some endwise play in this openform cut of the slice from the object.

G, Figs. 1, 4, 5, and 9, represents the vertically-movable carriage or block which carries the device whereby the object is presented to the slicing-knife. This hloclcis pivotally connected with the lower portion of the standard by two pairs of vertically-swingving rock-arms g, the pivots of which are so arranged that a parallelogram is formed by the frame, the supporting-block, and the arms connecting the same. By thus supporting the object to be sliced the same receives a parallelograminatic movement toward the knife, and its top always remains in the same horizontal position, so that the slices cut from the objectare always uniformly thick. The rock-arms of each pair are connected midway by a cross-bar g' and are pivoted at their rear ends to opposite sides of the standard by cone-screws g2 and at their front ends to opposite sides of the supporting-block by cone-screws g3.

ll represents a vertical feed-screw having a inierometer-thread whereby the supportingblock is raised and which engages with its upper screw-threaded portion in a threaded opening in the block, while its lower conical end rests freely on the fiat head of a screw h, secured to the base. The feed-screw is held against accidental displacement by a frictional detent, consisting of a follower h', arranged in an opening in the side of the supporti iig-block and bearing against the threaded part of the feed-screw, and a pressurespring h2, secured to the supporting-block and bearing against the outer end of the follower.

The feed-screw is automatically turned for raising the supporting-block after each cut of the knife by the following mechanism:

I, Figs. 1, Ll, and 8, represents a ratchet.- wheel secured to the lower part of the feedscrew within the hollow base.

J is a pawl-'arm turning loosely on the upper part of the hub of the ratchet-wheel and lprovided with a pawlj, which is yieldingly 'wardl v, so as held in engagement with the tooth of the ratehetwheel by a springj.

K represents a vertical rock-shaft journaled in bearings in the frame and provided at itsupper and lower ends with rock-arms k 7c', respectively. The lower rock-arm 7o extends forwardly and is provided with an upwardly projecting pin k2, which engages with a radial slot 7c3 in the free end of the pawl-arm. The upper rock-arm 7c extends forto stand in the path of the knife rock -arm D, and is provided with an antifriction roller 704. During the backward movement of the knife the knife rock-arm D engages with the roller of the upper feed rock-arm 7o and turns the same into the position shown in Fig. 3, which movement is transmitted by the rock-shaft, lower rockarm, and pawl-arm to the ratchet-Wheel and feed-screw for raising the supporting-block.

During the forward movement of -the knife the rock-shaft is turnediin the' opposite direction, so that the pawl takes up new teeth on the ratchet-wheel by means of a spring Z,

which su rronnds the rock-shaft and is secured with one end to said shaft and with its other end to the main fram e. The backward movelment of the ratchet mechanism is limited by a stop mlwhich is arranged on the base and engaged by the lower feed rock arm 7c', as lshown in Figs. 4 and 8. This stop is so located that the backward movement of the upper feed rock-arm 7c is arrested before the knife engages with thefobject during its forward movement, and," after the knife has cleared the object during its backward movement the knife rock-arm D engages with the upper feed rock-arm 7c and turns the same for raising the block Aone space, By this means the feed of the object on the block takes place only during the last portion of the backward movement of the knife and at a time when the knife is wholly disengaged from the object, thereby preventingany inj ury to the apparatus and insuring accurate Work. As the supporting-block and the rock-arms connecting the same with the frame move upwardly the lower end of the feed-screw moves rearwardly slightly on the head of the screw z, on account of the shortening of the distance between the feed screw and the standard.

The extent of the oscillating movement of the feed-pawl is always the same, and in order to permit of, varying the extent of each feeding movement of the feed-screw for varying the thickness of the slices which are cut from the object an adjusting device is provided, which is constructed as follows:

N representsjan adjusting or cam -disk mounted loosely on the lower end of the hub of the ratcl1et\\'l1eelaiid provided with a camface fn, which is adapted to be yengaged by a pin or projection on the feed-pawl. :During the last portion of the backward movement of the pawl its pin engages with the high or IOO IIO

` 25 provided with a radial slot p', which receives v.35 the base.

salient. part of the cam-disk, and the pawl is 7 vthereby disengaged from the ratchet-wheel during the remainder of its backward movement. During the first part of the subsequent forward movement of the pawl the latil ter is held out of engagement with the ratchetwhecl by the cam-disk until the pin of the- N pawl clears the high part ofthe cam-disk, and Vthe pawl is then engaged with the ratchet io wheel by the spring j', after which the pawl turns the ratchet-wheel and feed-screw until l the end of'its forward movement. lBy 4adjusting the ca mfdisl 'backward or forward! the length of time during which the pawl is t held out of engagement'with the ratchet-l wheel can be varied, and'resultsjir'i a varial tion in the extent ofA theeffective orf-feeding; movement of the pawl. The pawl-arm and cam-disk are held in place on the hub of the zo ratchet-wheel by two retaining-plates o o', which are secured to opposite ends of the hub of the ratchet-wheel by screws o2. The camdisk is adjusted by a horizontally-swinging adjusting-arm p, pivoted on the screwh and a depending pin p2 on the camldisk. This adjusting-arm projects forwardly through a slot p3 in the base and is provided with a pointer p4, which traverses a graduated scale,

3o whereby the extent of feed and the thickness of the slice which the knife cuts ed from the object may be determined. This scale is preferably arranged at the front edge of a detachable plate q, which closes the top of When it is desired to lower the supporting, block and connecting parts, the feed-pawl is disengaged from the ratchet-wheel by the cam-disk, and the feed-screw can then be 4o turned backwardly. For this purpose the Y side of the hollow base is provided with an opening i' adjacent to the ratchetwheel,y which permits this wheel to be turned by means of a linger.

The object to be sliced by the knife is held in place by a freezing device, which is constructed as follows:

S represents an expansion-chamber which is secured upon the supporting-block G and 5o which is preferably cylindrical in form and provided with a top or table S', upon which the object is placed. This expansion-chamber is provided in its side with a number of openings s and on its bottom with a depending stem s', which is secured to the verticallymovable block by a clamping-screw s2.

T represents a guide-tube which extends diametrically across the lower part of the expansion-chamber and projects with its ends 6o tt from opposite sides of the chamber, while its central portion within the chamber opens upwardly, as shown in Figs. el and 7.

t2 represents an ether-nozzle which is inserted into the end t of the guide-tube and terminates with its inner end in the center of the chamber, while its outer end is connected by a flexible tube t3 or otherwise with a supply'of ether.' The inward movement of ether is regulated by a valve t4, arrangedy in i y the ether-nozzle. U is an air-nozzle which is introduced into the other end-t' of the guidetube until its external shoulder engages with a corresponding shoulder on the guide-tube. -'l`l1e innerend of the air-nozzle is provided with an u pwardly-openiu g outlet, which is arranged belowi the outlet of. the ether-nozzle, and its' ou'te'rend is'connected by' a exble 'tube n with'an air-pump' or other air-'forcing `device i..v i 5i-r. .'I) -i -2 In orderto guideth'e-'air and ethernozzles into the proper positions Awith reference to each other, each nozzle is provided with a V-shaped guide-lug u on one side, which engages with a correspondingly-formed recess in the adjacent end of the guide-tube,as shown in Fig. 2.

Upon opening the ether-valve the ether issuing from the ether-nozzle is vaporized by the blast of air from the air-nozzle and thrown against the under side of the top or table S of the expansion-chamber, whereby the temperature of the table is lowered to the freezing-point and the object to be sliced is frozen solid upon the table. By opening the ethervalve more or less the supply of ether may be varied as the process of freezing the object loo y may require.

I claim as my inventionl; The combination with the main frame and the object-support, of rock-arms pivoted lto said frame, a knife-supporting bar carried by said rock-arms, a hand-lever for actuating the knife, and a yielding coupling which is interposed between said hand-lever and the knife-supporting bar and which is capable of yielding in a direction parallel to the pivotal axis of the hand-levenwhereby the latter can IIO be deflected toward or from the knife-supporting bar without disturbing the position of the knife-supporting bar, substantially as set forth.

2. The combination with the main frame and the object-support, of rock-arms pivoted to said frame, a knife-supporting bar carried by-said rock-arms, ahand-lever for actuating the knife, and a yielding coupling which is interposed between said hand-lever and the knifesupporting bar and which consists of a coupling-pin arranged parallel with the pivot of said lever and a socket which receives said pin and permits of the endwise play of the pin therein, substantially as set forth.

3. The combination with the main frame and the object-su pport, of vertically-swingi ng arms connecting said support with the main frame, a vertical feed-screw which engages said support and means for supporting the feed-screw in the main frame, permittingr movement of the screw toward and from the pivots of said arms as the support is raisedand lowered, substantially as set forth.

4:. The combination with the main frame, the object-support arranged in front of the same, and a reciprocating knife-carrier, of vertically-swim gin g rock-arms extending from said frame forwardly to said snpport,'a vertical Afecal-screw engaging said support and capable of movement in the main frame toward and from the pivots of said arms, a ,ratchet-wheel secured to said screw, a pawlarm carrying a pawl which engages said wheel, Va vertical rock-shaft which is' journaled in the main frame and provided with an arm which engages said paWl-arm, a return-spring applied to said rockfshaft, and means whereby said rock-shaft is actuated from the knifecarrier, substantially as set forth.

5. The combination with themain frame,

ee4,11e

the knife and the object-support movable toward and from the knife, of a feed-screw ongaging with said support and provided with a ratchet-wheel, a pawl-arm provided with a pawl engaging with said wheel, an adjustable cam -disk mounted loosely ou the ratchet.- wheel and adapted to disengage the pawlfrom the ratchet-wheel, and an adj listing-arm pivoted on the frame and having a looseA connection with said cam-disk, substantially as set forth. Y

. Witnesses:

LEONORE Rasen, H. K. LATHROP, J r.',

Witness my hand this `28th day of July, n i

' AUGUST BECKER; 'e

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