US3292869A

US3292869A - Grinding apparatus for paste-like or dough-like material

Info

Publication number: US3292869A
Application number: US382327A
Authority: US
Inventors: Beyeler Ernst
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-07-12
Filing date: 1964-07-13
Publication date: 1966-12-20
Anticipated expiration: 1983-12-20
Also published as: DE1218854B; CH424436A

Description

E. BEYELER Dec. 20, 1966 GRINDING APPARATUS FOR PASTE-LIKE OR DOUGH-LIKE MATERIAL Filed July 13, 1964 Inventar= United States Patent 3,292,869 GRINDING APPARATUS FOR PASTE-LIKE 0R DOUGH-LIKE MATERIAL Ernst Beyeler, Beuthener Str. 25, Aalen, Wurttemberg, Germany Filed July 13, 1964, Ser. No. 382,327 Claims priority, application Germany, July 12, 1963,

4 Claims. (Cl. 24137) The present invention relates to a grinding apparatus for paste-like or dough-like material having at least two oppositely disposed and'adjustable grinding rollers.

For the fine grinding of paste-like or dough-like material, among others, a rolling mill having two or more rollers is used. The fineness of the material to be obtained is determined, thereby, by the distance between each pair of oppositely disposed rollers, whereby the layer thickness corresponds about to the half maximum grain size, since the grains of the material to be ground are flattened during grinding.

Until now, in order to obtain the desired fineness of the material, the distance between the rollers has been adjusted, instead of changing the effective pressure force exerted between the rollers. The material was tested from time to time and then the force was increased or reduced, depending on whether the material was too coarse or too fine. This method is cumbersome and has in addition the drawback, that the rollers must be observed continuously during their operation, even while they are idling and, thereby, liable to damage each other.

It is, therefore, one object of the present invention to provide a grinding apparatus for paste-like or dough-like material, wherein, for the sensing of the thickness of the layer of material adhering to one roller and passed between the rollers, a mechanical sensing member is radially and adjustably disposed adjacent the one roller and is connected, by means of a lever transmission enlarging the changes of the layer thickness, with a transmitter, which upon a deviation of the layer thickness which surpasses the tolerance relative to a given value, operates as adjust-- ment device depending upon the direction of this deviation for the change of the distanceof the rollers.

It is another object of the present invention to provide a grinding apparatus for paste-like or dough-like material, wherein immediately after the grinding process the layer thickness is sensed. Then by means of the lever transmission, the deviations of the layer thickness are increased and are transmitted to a transmitter, which compares these deviations with a given value and, in case of surpassing the tolerance, operates an adjustment device, which changes the distance of the rollers. Any changes of the layer thickness, which can be caused, for instance, by change of the nature of the fed material, as the humidity content or due to heat expansion of the rollers, are immediately observed and compensated for.

The apparatus designed in accordance with the present invention is applicable for very thin layer thicknesses, of the order of a few ,u. If by coincidence the distance between the rollers should get so low that no material can pass any more, this error is immediately observed, and the distance between the rollers is enlarged again.

Thus, the rollers are properly protected from damage.

It is still another object of the present invention to provide a grinding apparatus for paste-like or dough-like material, wherein, preferably, for the setting of the given value, a setting member for the given value is provided, which is adjustable opposite that part of the transmitter sitting at the end of the lever transmission. By adjustment of the setting member of the given value, the desired layer thickness can be set.

3,292,869 Patented Dec. 20, 1966 The rollers are subjected to wear during their operation after an appreciable time. The layer thickness would, however, increase to the same degree, since the setting member of the given value does not adjust the thickness of the layer, rather only the outer radius of the layer. The fact that the inner radius of the layer becomes smaller due to wear of the rollers, is not taken into consideration by the apparatus without particular measures. In order to remedy this situation, in accordance with a further development of the present invention, the setting member for the given value is adjustable relative to a scale slide, which in turn is settable for the calibration of the apparatus jointly with the setting member for the given value. By adjustment of the scale slide, it is possible to calibrate from time to time the apparatus to the roller diameter which has become smaller due to wear.

With these and other objects in View, which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawing, in which the only figure shows schematically an elevation of the grinding apparatus.

A grinding mill, means for feeding the material to be ground thereto and a wiper for removal of the material from the roller are known. These parts are, therefore, shown schematically only.

The grinding apparatus comprises an immovably mounted roller 1 and a second roller 3, which is movable towards the roller 1 from below by means of a setting device 5 to the desired distance between the rollers 1 and 3. The material to be ground is fed to the roller 3 as a layer 4 by any conventional suitable means (not shown) and runs on the right side of the roller 3, as shown in the drawing, then between the rollers 1 and 3, and finally around the faster rotating roller 1 in clockwise direction to the wiper 7.

A roller 9 is provided, which serves the purpose of sensing the layer thickness, which roller 9 is freely rotatably mounted in a double-armed lever 11 and is designed as a flat disc mounted on a ball bearing (not shown). The left end of this double-armed lever 11 is connected by means of a link 13 with a lever 15 close to the immovable pivot point of the latter. Likewise, the end of the lever 15 is connected by means of a link 17 with a lever 19 close to the immovable pivot point of the latter. Levers and links, respectively, 1119 constitute jointly the lever transmission by which small displacements of the roller 9 relative to the roller 1 under the influence of the layer thickness deviations are transformed into comparatively large displacements of the left end of the lever 19. The left end of the lever 19 is formed as a contact indicator 19a. A spring 21, one end of which is secured to the lever 19, maintains the lever transmission in a balance and maintains a slight pressure of the roller 9 to the layer 4 of the material provided on the roller 1.

A slide 25 is vertically adjustable in an immovable frame 23 by means of a set screw 27. The slide 25 carries a layer thickness scale 29, which is calibrated in /L. A setting member 33 for the given value is slidable relative to the scale slide 25 by means of another set screw 31, which is disposed axially in the scale slide 25. The setting member 33 is designed as a small slide, which is guided along the scale slide 25. The setting member 33 for the given value carries a scale indictaor 35, as well as electric contacts or terminals 37 and 39, between which the contact tongue 19a is disposed to perform a pendulum movement therebetween.

The contacts 37 and 39 are connected by means of conduits 41 to a reversible servo-motor 43. The further electric connections which lead from a current source (not shown), on the one hand, to the contact tongue 19a and,

on the other hand, to the serve-motor 43, are not disclosed in the drawing, since these connections are of conventional nature and not particular subject matter of the present invention. The servo-motor 43 is in driving connection with a control valve 45, which either feeds pressure fluid by means of a hydraulic conduit 47 to the hydraulically operating setting device 5, or which releases pressure fiuid therefrom. The control valve 45 is in usual manner in connection with a container receiving the pressure medium and with a pump (not shown).

For the setting of the desired layer thickness, the setting member 33 for the given value is set by means of the set screw 31 relative to the slide 25, until its pointer 35 points to the desired layer thickness. If the tongue 19a is in the center between the electric contacts 37 and 39, the roller 9 has the set distance from the surface of the roller 1. The freedom of movement of the tongue 19a up to the engagement with the contacts 37 and 39 corresponds with the tolerance. If the layer thickness is too great, the roller 9 and the levers 11, 15 and 19 move in the direction of the arrows indicated in the drawing. The contact 39 will then engage the tongue 19a, thereby, closingthe circuit to the servo-motor 43 for operation in such direction, that the control valve 45 feeds the pressure medium through the hydraulic conduit 47 to the setting device 5, so that the roller 3 is lifted and, thereby, the layer thickness is reduced. Due to this adjustment, the roller 9 and the levers 11, 15 and 19 move in a direction opposite to the arrows shown in the drawing, so that the contact 39 will be opened again by disengagement from the contact tongue 19a and the feed of pressure medium ceases. If the layer thickness is too small, an action in opposite direction takes place.

If the roller diameter changes due to wear, the apparatus can be newly calibrated in the following manner:

While the roller 1 is free from any material to be ground, the setting member 33 for the given value is set to a layer thickness zero. The roller 9 engages the surface of the roller 1. The scale slide 25 is now set jointly with the setting member 23 of the given value by the set screw 27 such, that the contact tongue 19a assumes a .position in the center between the contacts 37 and 39. The slide 25 remains then in its position, while the setting member 33 for the given value is adjusted by means of the set screw 31 relative to the slide 25 to the desired layer thickness.

Instead of the provision of electrical contacts 37 and 39, it is also possible to provide an arrangement with two light barriers and photocells, whereby light barriers (not shown) are provided, and always one of the light barriers is interrupted by a complementary designed tongue 19:: upon surpassing the tolerance and, thereby, the servomotor 43 is put into operation.

Instead of a hydraulic setting device 5, as shown in the drawing, it is of course also possible to provide a mechanical setting device for the roller 3, which is then directly operated from the servo-motor 43.

While I have disclosed one embodiment of the present invention, it is to be understood that this embodiment is given by example only and not in a limiting sense, the

scope of the present invention being determined by the objects and the claims.

I claim:

1. A grinding apparatus for paste-like or dough-like material comprising at least two grinding rollers adjustable realtive to each other and adapted to pass the material to be ground therebetween, said material to form a layer on said one of said rollers receiving said material,

a mechanical sensing member adjustably disposed radially to said one of said rollers for sensing the thickness of said layer of said material,

lever transmitting means operatively connected .with' said mechanical sensing member and enlarging the changes of thickness of said layer sensed by said sensing member,

a setting device supporting and adjusting the distance between the other of said rollers and said one of said rollers, and means operatively connected with said lever transmitting means for operation of said setting means in the required direction in response to a surpassing of a predetermined given value of the change of the thickness of said layer of material. 2. The apparatus, as set forth in claim 1, wherein said means for operation of said setting means includes a setting member for setting said predetermined given value, and

means for adjusting said setting member relative to said,

lever transmitting means. 3. The apparatus, as set forth in claim 2, wherein said setting member includes two oppositely disposed electric contacts spaced apart from each other,

an end member of said lever transmitting means is mounted to constitute a contact tongue and to perform a pendulum movement between said electric References Cited by the Examiner UNITED STATES PATENTS 496,272 4/ 1893 Miebach 33 172 2,339,359 1/1944 Shayne et al. 8374 X 2,384,519 9/1945 Aller 33172 3,084,314 4/l963 Ziffer 47 X ANDREW R. JUHASZ, Primary Examiner.

Claims

1. A GRINDING APPARATUS FOR PASTE-LIKE OR DOUGH-LIKE MATERIAL COMPRISING AT LEAST TWO GRINDING ROLLERS ADJUSTABLE REALTIVE TO EACH OTHER AND ADAPTED TO PASS THE MATERIAL TO BE GROUND THEREBETWEEN, SAID MATERIAL TO FORM A LAYER ON SAID ONE OF SAID ROLLERS RECEIVING SAID MATERIAL, A MECHANICAL SENSING MEMBER ADJUSTABLY DISPOSED RADIALLY TO SAID ONE OF SAID ROLLERS FOR SENSING THE THICKNESS OF SAID LAYER OF SAID MATERIAL, LEVER TRANSMITTING MEANS OPERATIVELY CONNECTED WITH SAID MECHANICAL SENSING MEMBER AND ENLARGING THE CHANGES OF THICKNESS OF SAID LAYER SENSED BY SAID SENSING MEMBER, A SETTING DEVICE SUPPORTING AND ADJUSTING THE DISTANCE BETWEEN THE OTHER OF SAID ROLLERS AND SAID ONE OF SAID ROLLERS, AND MEANS OPERATIVELY CONNECTED WITH SAID LEVER TRANSMITTING MEANS FOR OPERATION OF SAID SETTING MEANS IN THE REQUIRED DIRECTION IN RESPONSE TO A SURPASSING OF A PREDETERMINED GIVEN VALUE OF THE CHANGE OF THE THICKNESS OF SAID LAYER OF MATERIAL.