GB2029263A

GB2029263A - Improvements in or relating to rollermills

Info

Publication number: GB2029263A
Application number: GB7835303A
Authority: GB
Original assignee: Henry Simon Ltd
Current assignee: Henry Simon Ltd
Priority date: 1978-09-01
Filing date: 1978-09-01
Publication date: 1980-03-19
Also published as: GB2029263B; CH631087A5

Abstract

A rollermill having a pair of grinding rolls (13, 14) one of which (13) has a fixed axis of rotation and the other of which (14) has an axis which is movable to place the rolls in grinding relationship, the movable roll (14) being connected via a compound lever (16, 19, 21) to a pneumatic cylinder (25) whose action is assisted by the mechanical advantage of the compound lever to an extent whereby only a small cylinder is needed when compared with cylinders used in simple lever systems for the same purpose. <IMAGE>

Description

SPECIFICATION Improvements in or relating to rollermills This invention relates to rollermills, and more particularly to means for causing the grinding rolls of a rollermill to move into and from grinding engagement.

It is usual in rollermills to provide a pair of parallel or substantially parallel grinding rolls one of which has a fixed axis of rotation whilst the other is capable of movement between positions in which the grinding surfaces of the two rolls are in and out of grinding contact respectively. The movable roll is supported in bearings which are mounted on a movable member which is connected by one or more levers to an operating handle or to some drive means such as a pneumatic cylinder.

As the grinding load to be applied at the nip of the rolls must be substantial enough to effect the grinding process, it is necessary to provide a device such as a heavy spring which acts upon the movable roll urging it into engagement with the fixed roll. Where, as an alternative, a pneumatic cylinder is used to move the rolls into engagement and to apply the grinding load, the cylinder must be of considerable size and capable of operating at a substantial working pressure in order to replace the heavy spring used in the mechanical arrangement.

An object of the present invention is to provide a rollermill having a pneumatic cylinder for placing the rolls in grinding contact, but wherein a cylinder of reduced size when compared with conventional arrangements, can be used.

According to the present invention, there is provided a rollermill having a pair of grinding rolls one of which has a fixed axis of rotation and the other of which is capable of movement to place the rolls in grinding relationship, the movable roll being rotatably mounted in a carrier which is pivotally connected, for example, to the machine frame, the carrier forming one part of a compound lever wherein the rotatable axis of the movable roll is disposed at one end, the other end being connected to a pneumatic cylinder thus adapted to drive the movable roll into grinding relationship with the fixed roll.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing which schematically illustrates an arrangement, including a pair of grinding rolls, for providing relative movement of the two rolls.

In the drawing, there is shown one half of a standard rollermill having an outer casing 10 and a pair of feed rolls 11 arranged to deliver stock to be milled to the nip of a pair of grinding rolls 13 and 1 4. The roll 1 3 is mounted for rotation with its rotational axis fixed with respect to the machine side frame 1 Oa.

The roll 1 4 however, is mounted for rotation in bearings 1 5 one of which is shown, supported on a carrier 16 which is pivotally connected at 1 7 to the machine frame 1 Oa.

Pivotally connected at 18 to the carrier 1 6 is a link 1 9 which is further pivotally connected to a lever 21 which itself is pivotally connected to the machine frame at 22. The pivotal connection 20 is disposed part-way along the length of the lever 21 and the end thereof remote from the pivotal connection 22 is attached at 23 to the operating rod 24 of a pneumatic cylinder 25 also attached to the machine frame. It will be seen therefore that a compound lever is constituted by the carrier 1 6, the link 19, and the lever 21, considerable mechanical advantage to the cylinder 25 being thus provided by the system.

An adjustable stop 26 can be preset at 27 by a machine operator to determine the relative positions of the grinding surfaces 1 3 and 1 4 when the rolls are placed in the grinding condition.

It will be appreciated that the provision of a compound lever to transmit movement to the roll 14 permits the use of a pneumatic cylinder of considerably reduced size when compared with conventional pneumatic systems. The arrangement enables a mechanical advantage in excess of 4:1 and preferably in the region of 6:1 as opposed to one of about 2:1 where the cylinder is connected by a simple lever to the movable roll thus demanding the use of a very large pneumatic cylinder in order to apply sufficient grinding load to the rolls.

1. A rollermill having a pair of grinding rolls one of which has a fixed axis of rotation and the other of which is capable of movement to place the rolls in grinding relationship, the movable roll being rotatably mounted in a carrier which is pivotally connected, for example, to the machine frame, the carrier forming one part of a compound lever wherein the rotatable axis of the movable roll is disposed at one end, the other end being connected to a pneumatic cylinder thus adapted to drive the movable roll into grinding relationship with the fixed roll.

2. A rollermill according to claim 1, wherein the compound lever further comprises a link pivotally connected to the carrier and a lever connected to the link, which lever is pivotally connected to the machine frame and to the pneumatic cylinder.

3. A rollermill according to claim 1 or claim 2, wherein the compound lever provides a mechanical advantage in excess of 4:1.

4. A rollermill according to claim 2, wherein the lever is pivotally connected at one end to the machine frame and at the other end to the pneumatic cylinder, the link being pivotally connected to the lever part-way along its length.

5. A rollermill according to claim 2, wherein the link extends beyond its connection to the lever to engage a stop adjustable from outside of the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or relating to rollermills This invention relates to rollermills, and more particularly to means for causing the grinding rolls of a rollermill to move into and from grinding engagement. It is usual in rollermills to provide a pair of parallel or substantially parallel grinding rolls one of which has a fixed axis of rotation whilst the other is capable of movement between positions in which the grinding surfaces of the two rolls are in and out of grinding contact respectively. The movable roll is supported in bearings which are mounted on a movable member which is connected by one or more levers to an operating handle or to some drive means such as a pneumatic cylinder. As the grinding load to be applied at the nip of the rolls must be substantial enough to effect the grinding process, it is necessary to provide a device such as a heavy spring which acts upon the movable roll urging it into engagement with the fixed roll. Where, as an alternative, a pneumatic cylinder is used to move the rolls into engagement and to apply the grinding load, the cylinder must be of considerable size and capable of operating at a substantial working pressure in order to replace the heavy spring used in the mechanical arrangement. An object of the present invention is to provide a rollermill having a pneumatic cylinder for placing the rolls in grinding contact, but wherein a cylinder of reduced size when compared with conventional arrangements, can be used. According to the present invention, there is provided a rollermill having a pair of grinding rolls one of which has a fixed axis of rotation and the other of which is capable of movement to place the rolls in grinding relationship, the movable roll being rotatably mounted in a carrier which is pivotally connected, for example, to the machine frame, the carrier forming one part of a compound lever wherein the rotatable axis of the movable roll is disposed at one end, the other end being connected to a pneumatic cylinder thus adapted to drive the movable roll into grinding relationship with the fixed roll. An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing which schematically illustrates an arrangement, including a pair of grinding rolls, for providing relative movement of the two rolls. In the drawing, there is shown one half of a standard rollermill having an outer casing 10 and a pair of feed rolls 11 arranged to deliver stock to be milled to the nip of a pair of grinding rolls 13 and 1 4. The roll 1 3 is mounted for rotation with its rotational axis fixed with respect to the machine side frame 1 Oa. The roll 1 4 however, is mounted for rotation in bearings 1 5 one of which is shown, supported on a carrier 16 which is pivotally connected at 1 7 to the machine frame 1 Oa. Pivotally connected at 18 to the carrier 1 6 is a link 1 9 which is further pivotally connected to a lever 21 which itself is pivotally connected to the machine frame at 22. The pivotal connection 20 is disposed part-way along the length of the lever 21 and the end thereof remote from the pivotal connection 22 is attached at 23 to the operating rod 24 of a pneumatic cylinder 25 also attached to the machine frame. It will be seen therefore that a compound lever is constituted by the carrier 1 6, the link 19, and the lever 21, considerable mechanical advantage to the cylinder 25 being thus provided by the system. An adjustable stop 26 can be preset at 27 by a machine operator to determine the relative positions of the grinding surfaces 1 3 and 1 4 when the rolls are placed in the grinding condition. It will be appreciated that the provision of a compound lever to transmit movement to the roll 14 permits the use of a pneumatic cylinder of considerably reduced size when compared with conventional pneumatic systems. The arrangement enables a mechanical advantage in excess of 4:1 and preferably in the region of 6:1 as opposed to one of about 2:1 where the cylinder is connected by a simple lever to the movable roll thus demanding the use of a very large pneumatic cylinder in order to apply sufficient grinding load to the rolls. CLAIMS

5. A rollermill according to claim 2, wherein the link extends beyond its connection to the lever to engage a stop adjustable from outside of the rollermill to determine the relevent positions of the grinding surfaces of the fixed and movable rolls when placed in the grinding condition.

6. A rollermill, substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawing.