Roll grinding system

Worn rubber-like coating around a printing roll or the like is resurfaced by bringing a regrinder with spaced abrasive belts to the place where the roll operates, and operating the belts to regrind the roll as it is rotated by its operating drive. The regrinder moves along a rail parallel to the roll axis during regrinding, and has mechanism to move the belts into position to begin grinding.

BACKGROUND OF THE INVENTION 
Large rubber rolls are conventionally used in industrial plant equipment 
for directing the path of travelling webs of paper, for inking other 
rolls, and the like. When the rolls need resurfacing the established 
practice has been to remove them for resurfacing elsewhere, with 
consequent delay and expense. Furthermore, when a roll is reground 
elsewhere it may be rotated about a slightly different axis and hence its 
new outer surface may not be accurately concentric with its axis of 
rotation in the equipment in which it is to be used. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, industrial rubber rolls are 
retained in the equipment in which they are used while being rotated and 
ground to a new surface. This avoids the expense and delay of sending the 
rolls out, facilitates quality control and correction of errors in 
regrinding, and assures good operating concentricity. 
The regrinding apparatus of the invention is portable and readily set up to 
move along tracks parallel to the roll axis while grinding against an 
exposed part of the roll periphery. Regrinding is done by the grinding 
surface of at least one motor driven belt where it is tangent to and 
moving in the same direction as the roll surface but faster, or in the 
opposite direction. Two belts are preferably used, driven by a common 
motor between them, and moving in spaced parallel planes perpendicular to 
the roll axis. This permits one belt to grind up to one end of the roll, 
in cases where the end clearance is limited, and the other belt to grind 
up to the other end, where clearance is likewise limited. Where end 
clearances are not limited, both belts can be used at once with the same 
coarse grit, moving one immediately after the other down the whole length 
of the roll, in order to grind deeper in one pass; or a coarse belt can 
precede a fine belt down the length of a roll and thereby do both 
operations in one pass. 
The invention provides efficient means to change the angles of the belt 
flights against the roll, to the extent necessary to grind an upper or 
lower or middle part of the roll periphery, and thereby succeed in 
reaching parts of the periphery which may otherwise be hard to get at for 
purposes of regrinding at place of use. 
The regrinding apparatus is adapted to be raised and lowered and moved 
laterally or swung toward or from the roll to be ground, preliminary to 
progressing along the length of the roll during regrinding. 
A motor and set of supporting rails are preferably provided to move the 
grinding apparatus along the rails at a controllable predetermined speed, 
and to stop automatically at the end of the desired movement. 
Other objects, advantages and details of the invention will become apparent 
as the following disclosure proceeds.

DESCRIPTION OF PRESENT PREFERRED EMBODIMENT 
Referring now more particularly to the drawings, and initially to FIGS. 1 
and 2, there is shown a rubber-covered roll 10 for use in guiding a 
travelling length of paper (not shown) in a printing press or the like, 
and axles 12 at opposite ends of roll 10 rotate in bearings 14 on a pair 
of fixed supports 16. 
A belt grinder 18 in accordance with the invention is shown resurfacing 
roll 10 after it has become worn down or roughened on its outer 
cylindrical surface 20. The regrinding is done by a pair of closed-loop 
abrasive belts 22 and 23 driven by pulleys 24 and 25 keyed on oppositely 
extending drive shafts 25a and 25b of a motor 26. Belt 22 passes from 
drive pulley 24 to a drag bar 27 and idler pulley 28 mounted on two 
corners of a triangular plate 30. It is then pulled back to drive pulley 
24. Plate 30 also mounts a bracket carrying a flange 32 for restraining 
movement of belt 22 away from plate 30 (FIG. 6). A bolt 34 attaches the 
third corner of plate 30 to a post 35 fixed on a platform 36. 
Belt 23 is similarly trained around a drag bar 38 and idler pulley 39 on a 
corresponding triangular plate 40 bolted to a post 42 fixed on platform 
36. 
In order to tighten belt 22 a pair of flanges 44 and 45 secure the base 46 
of motor 26 to platform 36 so that the motor can slide on platform 36 
toward and away from plates 30 and 40 (FIG. 2). A spaced pair of threaded 
rods 48 and 49 (FIGS. 1 and 2) each have an end fixed to the motor base. 
Their other ends extend slidably through brackets 50 and 51. Wing nuts 52 
(FIG. 1) are threaded on the outer ends of rods 48 and 49 and can be 
tightened against either or both of brackets 50 and 51 to draw motor 26 
selectively away from plates 30 and 40 and thereby tighten either or both 
of belts 22 and 23 until each is tight enough to prevent flutter against 
the roll. 
Belts 22 and 23 are moved along the length of roll 10 by moving platform 36 
along a pair of rails 52 and 53 which extend parallel to each other and to 
the roll axis. Rails 52 and 53 are secured in grooves in two or more 
spaced lower cross members 54 resting on posts 56 mounted on the floor or 
on plant equipment on the floor. Side braces may be added where necessary. 
A pair of runners 57 extend across the tops of rails 52 and 53 and have 
grooves underneath to fit around and slide along the upper peripheries of 
the rails. 
The bottom of platform 36 is secured to the top elements 58a of a pair of 
spaced parallel slide assemblies 58. The bottom elements 58b of the slide 
assemblies 58 are secured to the tops of runners 57. Ball bearigs 58c in a 
race 58d roll between each set of upper and lower elements. Such slides 
are used as center mounted drawer slides. The slides 58 extend across 
rails 52 and 53 and permit movement of platform 36 to carry belts 22 and 
23 toward and from roll 10, independently of movement of the platform 
along the rails. Movement of platform 36 toward and from roll 10 is 
controlled by rotating a threaded rod 61 which screws through a plate 62 
secured to the ends of slide elements 58a closest to handle 60. The other 
end of rod 61 has a swivel connection with a plate 63 secured to the ends 
of slide elements furthest from handle 60. 
A chain 66 controls movement of platform 36 and the whole motor and belts 
assembly on it along rails 52 and 53. The chain is trained around an idler 
pulley 68 positioned on rails 52 and 53 beyond one end of roll 10, and 
around a drive pulley 70 positioned on rails 52 and 53 beyond the other 
end of roll 10. The ends of the chain are secured by attachments 69 to the 
base of motor 26. A geared reversible and controllable speed motor 72 
drives pulley 70, and a control unit 74 has operating controls connected 
through cables to each of the motors 26 and 72. When motor 72 turns one 
way (clockwise in FIG. 2), chain 66 pulls belt motor 26 and with it 
platform 36 and everything thereon toward chain motor 72. When motor 72 
turns the other way, chain 66 is tightened around idler pulley 68 and 
thereby pulls belt motor 26 and with it platform 36 and everything thereon 
toward idler pulley 68. 
When the grinder is to be used for regrinding a roll it is taken to the 
place where the roll is installed and rails of suitable length (longer 
than the roll) are set up at an elevation and distance from the roll which 
will place the belts where they can grind an exposed part of the roll 
periphery along the whole length of the roll. The angles of the triangular 
plates 30 are then adjusted to put the belts 22 and 23 in contact with the 
roll periphery 20 between drag bars 27 and 38 and idler pulleys 28 and 39; 
see FIGS. 1, 7 and 8. To hold the plates 30 and 40 in the adjusted 
position a bolt 74 may be seated in one of a series of predrilled openings 
in plate 30 so that the bolt head (or a nut securing the other end of the 
bolt) engages post 35 and thereby braces the plate against the pull of the 
belt supported by the plate. A like bolt is similarly mounted on plate 40 
to brace it against post 42. 
Once the plates 30 and 40 are adjusted, wing nuts 52 are operated to 
tighten the belts, handle 60 is operated to position the belts against the 
roll periphery, motor 72 is operated to position the belts to begin 
grinding, motor 26 is turned on to drive the belts, and motor 72 is 
operated to pass the belts down the length of the roll as earlier 
described. After regrinding the roll is inspected and any further grinding 
required can be done without further delay. 
While present preferred embodiments of the apparatus and method of the 
invention have been illustrated and described, it will be understood that 
the invention may be otherwise embodied and practiced within the scope of 
the following claims.