US1944983A - Viscosimeter - Google Patents

Description

Jam 3% 1934 A. KAMPF VISCOSIMETER Filed Jan. 7, 1929 2 Sheets-Sheet l fan. so, 1934. A, KAMPF 1,944,983

VISCOSIMETER Filed Jan. 7, 1929 ZSheets-Sheet 2 0 l1 l! B a 0% /E o 0 0 M "a" ".1 0 :0 Bu n00 Dal] H V T o p- 17 Y 1 z X I F l i Patented Jan. 30, 1934 UNITED STATES PATENT OFFICE Application January 7, 1929, Serial No. 330,923, and in Germany January 11, 1928 5 Claims. (Cl. 265-11) The present invention relates to a viscosimeter which in known manner utilizes the rotation of a body immersed in a liquid, inorder to determine the internal friction of the liquid by the force necessary for the rotation or the time required with a given force for a certain number of revolutions. It is obvious that the accuracy of such an instrument and the possibility of using the measurements directly, or with the least possible corrections, depend upon the friction of the apparatus itself when the said rotary body is rotated freely.

The object of the present invention is the construction of an apparatus which fulfills these requirements as completely as possible. For this purpose, the rotary body is arranged at the lower end of an overhung vertical spindle, and the force, due to a thread actuated by a falling weight, rotating the immersed body, is applied as closely as possible to a centering device or bearing formed by a needle point and conical cup. The friction of the point is theoretically and to a great extent also practically almost ml. The moment of the force exerted by the thread at right angles to the axis of the spindle, therefore, acts on the spindle at the part of its mounting where its action is least prejudicial and is practically entirely taken up by the bearing of the point.

. In the accompanying drawings, Fig. 1 is a side elevation of my viscosimeter partly in section; Fig. 2 is a modified form; and Fig. 3 shows the needle point and the conical cup bearing in detail; like reference characters designate the same or the corresponding part throughout the various figures of the drawings.

Referring to Fig. 1 of the drawings, the viscosimeter comprises a vertical support A which is supportedby the base B and which carries with its arm C a casing e. The arm D serves as a support to carry the spindle F and the parts fastly connected with this spindle, while the apparatus is in rest. The rotating body G is mounted on the spindle or rotary shaft F which is actuated by the thread roller H. The latter is positioned to nearly close the casing e, and its diam eter is sufilciently large, so that when a moderate vacuum is applied to the casing E through the tube J, the roller H, together with the spindle F and the rotating body G, is forced upward by the pressure difierences within and without said said casing. The spindle F passes the roller H and forms at its upper end a conical cup K into which projects a needle L fixed in the closin plate P of the casing E.

In the modified form, shown in Fig 2, the point of the needle L and the conical cup K of the spindle F are displaced approximately to the middle point of the thread roller H. In this form, the arms C and D carry the outer casing E which preferably is provided with holes 0. Fastly mounted on the spindle F is a tubular extension M which serves to guide and to center the spindle with a ring N. At the upper end of the tubular extension M, a disc Q is disposed having a diameter sufficiently large to be lifted together with the tubular extension M and the different parts mounted upon the latter by the pressure difierences when a moderate vacuum is applied to an inner casing R provided with a tube J for connection with a vacuum apparatus.

The bearing formed by the point of the needle L and a conical cup K is substantially identical with that shown in Fig. 1. Fig. 3 illustrates the said bearing in detail.

It has been found that a rotary body mounted in this manner, in spite of its small inertia, will remain for a considerable time in rotation when a very slight impulse has been imparted to it, that is, the friction of the apparatus itself is extremely small.

To protect the point of the needle L while the rotating body G is being cleansed, the spindle F must be fixed in a position in which the point is outof engagement with the conical cup K. For this purpose, at the bottom of the casing E at the place where the spindle passes through the casing, a conical seating Y is provided in which a cone Z on the spindle F engages in the stationary position. Consequently, the rotary body G can be quickly and effectively cleansed from adhering viscose liquid without any danger of damaging the mounting of the needle.

The point of the needle L is also protected from the' entrance and the attack of rust-forming gases by the tubular extension M. For the purpose of preventing rusting, all the parts effecting the friction ofv the apparatus itself are prepared from highly polished stainless steel, such as V2A steel. (cf. U'llmann, Enzyklopadie der technischen Chemie, 1929, vol. 4, page 178, last paragraph to page 184.)

To avoid any disturbance of the rotary movement by particles of dust which may be caused by the air drawn in between the disc Q and the exhausted casing R above it, the disc Q is formed with a sharp edge on its circumference and its diameter is sufficiently large so that the moderate pressure differences within and without the casing R are sufficient to lift the body G without the space between the disc Q and the exhausted casing R being very narrow.

In setting up the apparatus for use, the rotating body G and the spindle F are immersed to a distinct depth into the liquid, the viscosity of which is to be determined. The thread roller H is set to elevate the weight S carried bythe cable Twhich is guided over a roll U to the thread roller H, and a vacuum apparatus is attached at the tube J. Then the weight S is released by the operator whereupon it acts upon the thread roller, thus rotating the spindle F and the body G immersed in the fluid. The viscosity of the fluid is measured directly by determination of the time which elapses until the weight S exactly registers with the zero mark V and with another point W on scale X.

I claim:

1. In an apparatus for ascertaining the viscosity of a liquid, a supporting structure, an

exhaustible casing carried by said supporting structure and having a bottom portion thereof open to the atmosphere, a depending needle bearing within said casing, a rotatable vertical spindle normally supported by said support but movable vertically away from said support and having a cup bearing formed therein, a symmetrical liquid contacting member carried by said spindle, and means carried by said spindle and received within the opening of said casing so as to nearly close the same whereby the said spindle will be lifted by atmospheric pressure against said means when the casing is exhausted to bring the cup bearing into contact with the needle bearing and disengage said spindle from said support.

2. In an apparatus for ascertaining the viscosity of a liquid by determining the resistance experienced by a body rotating in the liquid, the combination of a support, an exhaustible, vertical, cylindrical casing carried by said support and having the lower end thereof open to the atmosphere, said casing bearing a depending needle axially thereof, a rotatable spindle provided with a cup bearing, a symmetrical body secured to said spindle, means for rotating said spindle, a disc secured to said spindle and disposed within the open end of said casing so as to nearly close the same, thus allowing said spindle cup bearing to be brought into engagement with said pin by atmospheric pressure acting against the bottom of said disc when said casing is exhausted, and a support for said spindle when in its rest position. 3. In an apparatus for ascertaining the viscosity of a liquid, a supporting structure, an exhaustible casing carried by said supporting structure and having a bottom portion thereof open to the atmosphere, a depending needle bearing within said casing, a rotatable vertical spindle normally supported by said support but movable vertically away from said support and having a cup bearing formed therein, a symmetrical liquid contacting member carried by said spindle, a roller carried by said spindle adjacent to said cup bearing and received within the opening of said casing so as to nearly close the same whereby the said spindle will be lifted by atmospheric pressure against the lower face of said roller when the casing is exhausted to bring the cup bearing into contact with the needle bearing and disengage said spindle from said support, a weight, and a thread secured to said weight and wound on said roller.

4. In an apparatus for ascertaining the viscosity of a liquid by determining the resistance experienced by a body rotating in the liquid, the combination of a support, an exhaustible, vertical, cylindrical casing carried by said support and having the lower end thereof open to the atmosphere, said casing bearing a depending needle axially thereof, a rotatable spindle provided with a cup bearing, a symmetrical body secured to said spindle, a roller secured to said spindle with its center corresponding to that of said cup bearing, a weight, a thread secured to said weight and wound on said roller, a disc secured to said spindle and disposed within the open end of said casing so as to nearly close the same, thus allowing said spindle cu'p bearing to be brought into engagement with said pin by atmospheric pressure acting against the bottom of said disc when said casing is exhausted, and a support for said spindle when in its rest position.

5. In an apparatus for ascertaining the viscosity of a liquid by determining the resistance experienced by a body rotating in the liquid, the combination of a support, an exhaustible, vertical, cylindrical casing carried by said support and having the lower end thereof open to the atmosphere, said casing bearing a depending needle axially thereof, a rotatable spindle provided with a cup bearing and a tubular extension, a ring secured to said tubular extension and embracing said needle for guiding said spindle, a symmetrical body secured to said spindle, a roller secured to said spindle with its center corresponding to that of said cup bearing, a weight, a thread secured to said weight and wound on said roller, a disc secured to said spindle and disposed within the open end of said casing so as to nearly close the same, thus allowing said spindle cup bearing to be brought into engagement with said pin by atmospheric pressure acting against the bottom of said disc when said casing is exhausted, and a support for said spindle when in its rest position.

ADOLF

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