Slice lip protector system

A paper machine headbox slice lip rotector system which permits limited incremental movement up or down by means of a pivoting lever arm 32 with lock bolt end portions 36 and 38 moving in adjacent protectors' adjustable keeper recesses 40. The recesses 40 are defined by stop nuts 42 on a threaded body fixed to the adjustable spindles 20. The lever arm 32 is pivotally mounted on the body for permitting up and down movement a distance which is the average of the distance defined by the keeper recesses 40 of the adjacent protectors. This prevents the prior art problem of a protector being "locked" between adjacent protectors.

BACKGROUND OF THE INVENTION 
This invention relates to the profile adjustment of a slice lip of a paper 
machine headbox. In papermaking, the slice opening of a headbox on a paper 
machine meters flow of the pulp slurry or stock in the headbox onto the 
fourdrinier wire. A number of axially movable spindles, perhaps 50 to 60, 
are connected to a headbox control lip or slice lip to vary the metering 
opening transversely across the machine. The spindles, typically, are 
threadedly attached at their upper ends to rotationally driven power nuts 
which linearly drive the individual spindles axially in known manner. The 
slice lip positional accuracy permits the production control of quality 
paper by basis weight profiles through the elimination of cross-machine 
variations. 
In adjusting the slice lip, however, care must be taken to have 
coordinated, gradual adjustments in order to avoid producing "lip kinking" 
or other force-applied damage to the delicate slice lip. Slice lip 
protector systems for this purpose are known. One such slice lip protector 
system permits limited incremental slice lip actuator movement through a 
series of adjacent slice profiling spindles having mechanically 
interconnected protectors mounted thereon. The problem with this system, 
however, is that it permits only first order bend limits which permit a 
given protector movement up or down a given distance from the position of 
either of two adjacent mechanically interconnected protectors, one on each 
side thereof, as will be seen hereinafter. 
The system referred to just above is sold by the Black Clawson Paper 
Machine Group of Watertown, N.Y. 13601 as part of the automatic slice 
profiling system it sells under the trademark "ESP" II. 
SUMMARY OF THE INVENTION 
In a paper machine headbox slice lip protector system permitting limited 
incremental slice lip actuator movement through a series of adjacent slice 
profiling spindles having mechanically interconnected protectors mounted 
thereon, the present invention provides passive second order bend limits. 
It therefore overcomes the disadvantage in known mechanically 
interconnected protectors which permit only first order bend limits 
wherein each spindle and protector mounted thereon can move only up or 
down a predetermined distance from the position of either of the adjacent 
protectors on its opposite sides. The undesirable result of which on long 
unstressed slopes is that movement of the middle protector is not 
permitted if the adjacent protectors are located at the bend limit, even 
though the middle protector could move up or down safely, without damage 
to the slice lip. 
The improvement of the instant invention is accomplished by means of 
interconnected protectors which each include an elongated lever member 
centrally pivoted on a hollow body attached to each of the spindles. The 
lever members have lock bolt portions on their opposite ends for 
engagement in and mechanical interconnection with keeper recesses defined 
by stop means in the form of nuts mounted on a threaded exterior portion 
of the hollow body mounted on each of the opposite side's adjacent 
spindles. The stop nuts are held in proper axially adjusted position by 
means of jam nuts which are also threadedly engaged with the body. 
The stop nuts are adjusted to permit the pivoted lever of one spindle to 
move in the keeper recesses of the bodies mounted on the two adjacent 
spindles to permit the one spindle to move up or down within limits 
established by the adjustment. On long unstressed slopes, this movement of 
the protectors permits movement of the one spindle within safe limits 
which do not damage the slice lip. Thus, a passive control is provided 
whether the axial spindle movement is either manually or automatically 
controlled.

DETAILED DESCRIPTION OF THE DRAWINGS 
The numeral 10 generally designates a paper machine headbox slice lip 
system for metering the stock 12 from a headbox 12 onto a fourdrinier wire 
to form a paper web 14. 
The stock-containing headbox has a front wall 16 from which extends a base 
plate 18. The base plate 18 has openings (not shown) through which axially 
adjustable spindles 20 extend. At the upper end of the spindles 20, 
supported by the base plate 18, are enclosures 22 which house the 
actuators for axially adjusting the spindles 20. 
Fixed to the lower ends of spindles 20 are hooks 24 or other suitable 
mechanical means for engaging a groove 26 in the slice lip 28. Axial 
movement of a spindle 20 in response to the actuator within an enclosure 
22 moves that segmental portion of the slice lip 28 length. The slice lip 
28 is thus adjusted across the machine at, typically, 60 locations to 
determine its metering profile of stock 12 and the resultant profile and 
basis weight of web 14. 
If during adjustment, particularly along a long unstressed slope of 
slice-lip 28, adjacent spindles are moved at extremely different axially 
adjusted positions, a kink or other damage to the slice lip 28 can occur. 
Such a kink, obviously, will ruin the quality of paper web 14. 
Accordingly, mechanically interconnected protectors 30 have been mounted 
on the spindles 20 to limit permitted relative axial positions of adjacent 
spindles 20. 
As seen in FIGS. 2 and 3, the prior art protectors 30 are labelled "M" for 
middle, "L" for left and "R" for right. In FIG. 2 the spindles are all in 
the same axial position. In FIG. 3 the illustrated portion of slice lip 28 
is in a long unstressed slope condition of adjustment with spindles "L" 
and "R" at the bend limit. The "M" protector could safely move up or down 
for a more finely adjusted slice lip profile but protector "M" cannot move 
up because of protector "L" and cannot move down because of protector "R". 
The protectors 30' of the invention are illustrated in FIGS. 4-7 and they 
provide passive second order bend limits rather than the first order bend 
limits provided by protectors 30, as explained above. 
Protectors 30, are hollow bodies which are fixed on spindles 20 and which 
each have an elongated lever member 32 centrally pivoted at a pivot 34 on 
the body. Opposite end portions of each lever 32 are shaped to act as lock 
bolts 36 and 38, 36 on the left end of the lever and 38 on the right end. 
The lock bolts 36 and 38 ride in keeper recesses 40 defined by nuts 42 
which are threaded on the outside of the hollow bodies. The levers 32 are 
free to pivot at 34 because the central openings 44 therein are large 
enough to permit both clockwise and counterclockwise travel of lock bolts 
36 and 38 within their keeper recesses 40 defined by nuts 42 and locked in 
place on the threaded body of the adjacent protector 30, by means of jam 
nuts 46. 
The invention is arranged as shown in FIG. 4 to start, and then, the 
actuators in housing 22 are utilized to adjust the slice lip through axial 
movement of spindles 20. On long unstressed slopes similar to that 
referred to in connection with prior art FIG. 3, the middle protector 
"M'", as shown in FIG. 5, is permitted additional incremental safe 
movement for adjustment of the slice lip. This is because the middle 
protector M' and its spindle 20 can move up or down a distance which is 
the average of the keeper recess 40 of protector L' and and keeper recess 
40 of protector R' as defined by their respective stop means nuts 42. 
Notice the pivots 34 are alternately above and below the keeper recesses 
40 of the adjusted protectors 30'. 
With the arrangement of the invention substantially as shown, the problem 
of the captured middle protector M of FIG. 3 is obviated. Thus, an 
absolutely fail-safe slice lip protector system for use with either manual 
or automatic actuator systems is provided.