Glue applicator roll assembly

Wiper blades are mounted on the end bearing blocks and are located at each end of a rotatable cylindrical glue applicator roll and are arranged to wipe the glue from the flat ends of the applicator roll and from the end portions of the annular surface of the applicator roll. The wiper blades include a horizontal leg having a concave roll contact surface normally in engagement with the end curved portion of the cylindrical roll and a flat surface in contact with the flat end of the roll. A portion of the wiper blade adjacent the flat end of the roll is angled between a tangent and a radius from the axis of rotation of the roll on the downward moving side of the roll and includes a groove for deflecting and guiding the glue in a downward direction off the flat end of the roll. A pick finger support bar extends above and parallel to the cylindrical roll, a plurality of pick fingers are mounted on the pick bar, and the pick bar is adjustably supported at its ends substantially without any bending forces being applied to the pick bar so as to permit the pick bar to remain rectilinear and to properly position the pick fingers against the cylindrical glue applicator roll.

BACKGROUND OF THE INVENTION 
This invention relates to glue applicator assemblies of the type used to 
apply liquid glue to sheet material, such as to blanks which are 
ultimately formed into paper boxes. More particularly, the invention 
relates to a glue applicator roll assembly for a gluer. 
Various prior art glue applicator equipment has been developed for the 
purpose of feeding sheets of material in sequence to a series of 
processing stations and coating the sheet material with glue and other 
liquids at one of the processing stations. These machines typically 
include equipment for picking off the end sheet from a stack of sheet 
material, feeding the sheet along a path generally parallel to the plane 
of the sheet material past a rotating cylindrical glue applicator roll, 
and then to various subsequent work stations. The glue applicator roll 
usually continuously rotates in contact with another wetting roll which is 
partially submerged in a body of liquid glue or other liquid. As the 
system operates, the liquid glue tends to accumulate and harden on the 
various parts of the processing equipment, particularly on the end 
portions of the glue applicator roll. The accumulation of glue at the ends 
of the glue applicator roll is undesirable, particularly because an 
accumulation of glue tends to interfere with the proper continuous 
operation of the equipment. 
Various wiper blades and other devices have been used in the past to scrape 
or wipe glue from the cylindrical glue applicator roll. The typical prior 
art wiper blades have been positioned at the ends of the glue applicator 
roll by mounting the wiper blades on the pick finger support bar which is 
usually located above the cylindrical applicator roll and which is in a 
convenient location for mounting the wiper blades or by supporting the 
wiper blades form the bearing blocks at the ends of the glue applicator 
roll. The pick finger support bar supports a plurality of pick fingers 
which are arranged across the length of the glue applicator roll and which 
function to wedge the sheet material away from the glue applicator roll 
and guide the sheet material along its processing path toward the next 
work station. It is important that the pick fingers have their pointed 
ends in close juxtaposition with respect to the curved surface of the 
cylindrical glue applicator roll so as to properly pick the sheet material 
away from the roll instead of allowing the sheet material to pass between 
the pick fingers and the glue applicator roll. Any vibrations or other 
external forces imparted to the pick support bar tends to disrupt the 
positions of the pick fingers, causing the pick fingers to allow the sheet 
material moving with the cylindrical glue applicator roll to pass beneath 
the pick fingers and therefore jam the equipment. 
The prior art pick finger support bars have been supported at their ends 
adjacent and parallel to the cylindrical glue applicator roll. The prior 
art structure used to support the pick finger support bar tends to cause 
the pick finger support bar to bow or bend downwardly at its center 
portion. The amount of curvature in the bow varies, depending upon the 
force applied at the ends of the pick finger support bar. For example, one 
prior art structure comprises slots formed in the end bearing blocks of 
the equipment, and internally threaded bore extending through each end of 
the pick finger support bar, and elevational screws threaded through the 
bores for engagement with the bottom of the slots. The machine operator is 
able to adjust the height of the ends of the pick finger support bar by 
rotating the elevation screws to raise or lower the ends of the bar. After 
the ends of the bar have been properly located, the prior art assembly 
included a means for clamping the end portions of the middle portion of 
the bar downwardly into the slots to hold the bar at its ends. This 
downward clamping force tends to bow the bar downwardly, with more force 
at the ends causing a larger bend in the bar. The pick fingers supported 
intermediate the ends of the pick finger support bar are arranged so as to 
be properly positioned when the pick finger support bar is properly 
elevated at its ends, and when there is no curvature in the bar. When the 
bar is bowed downwardly with the clamping action of the prior art 
assemblies, the pick fingers at the middle portion of the pick finger 
support bar are supported at an elevation lower than those pick fingers 
nearer the ends of the bar. The machine operator is therefore required to 
adjust the pick finger support bar, by loosening the clamps somewhat, or 
by raising the ends of the bar so that the middle pick fingers better fit 
about the cylindrical glue applicator roll. Loosening of the support tends 
to cause the pick finger support bar to be less stable, and readjusting 
the elevation of the ends of the support bar to properly position the 
middle pick fingers tends to cause the pick fingers nearer the ends of the 
support bar to be moved slightly out of their proper positions. In either 
instance, there is at least some likelihood that the equipment will 
malfunction. 
SUMMARY OF THE INVENTION 
Briefly described, the present invention comprises a glue applicator roll 
assembly for a gluer which has improved end roll wiper structure and 
improved pick finger support means. Wiper blades are mounted at opposite 
ends of the cylindrical glue applicator roll and are shaped and supported 
so as to wipe the flat end surfaces of the roll as well as a small area of 
the curved end portion of the roll, thereby causing the glue to be 
effectively removed from the areas of the cylindrical applicator roll 
where the glue tends to accumulate. The wiper blade is supported from the 
bearing blocks at the ends of the cylindrical glue applicator roll and any 
vibrations or forces received from the wiper blade are transmitted to the 
end bearing blocks. The pick finger support bar of the assembly is mounted 
at each of its ends in slots of the bearing blocks, with the clamping 
mechanism which holds the ends of the pick finger support bar applying its 
clamp forces in a horizontal direction against the end of the bar, with 
the opposite flat surface of the bar being urged against a complimentary 
flat surface in the slot of the end bearing block. This arrangement tends 
to urge the rectilinear pick finger support bar to remain in its 
rectilinear configuration, even though an elevation screw can be utilized 
to modify the elevation of the end of the pick finger support bar. 
Thus, it is an object of this invention to provide an improved glue 
applicator roll assembly for use in a gluer and the like in which the 
cylindrical glue applicator roll is wiped clean of glue at its opposite 
ends, in which the wiper blades do not transmit vibrations or other forces 
to the pick finger support bar, and in which the pick finger support bar 
is maintained in a substantially rectilinear configuration. 
Another object of this invention is to provide a glue applicator roll 
assembly which is inexpensive to manufacture and repair, which is 
expedient to adjust, and which is reliable in operation. 
Other objects, features and advantages of this invention will become 
apparent upon reading the following specification, when taken in 
conjunction with the accompanying drawings.

DETAILED DESCRIPTION 
Referring now in more detail to the drawings, in which like numerals 
indicate like parts throughout the several views, FIG. 1 illustrates a 
portion of a gluer 10 which includes a glue supply pan 11, a glue wetting 
roll 12, a cylindrical glue applicator roll 14, a wiper blade assembly 15, 
pick finger support bar 16, a plurality of pick fingers 18, guide cams 19, 
and vacuum conveyor assembly 20. Supply platform 21 is located at an 
elevation lower than the cylindrical applicator roll 14 and is moved by 
cams up and down, toward and away from the suction fingers 22. The suction 
fingers 22 are mounted on a suction tube 24 which oscillates or rotates in 
timed relationship with the system to pick up the uppermost sheet 25 from 
the platform 21 and move the uppermost sheet between the feed rolls 26 and 
28. Various guide plates and guide fingers (not shown) are used to help 
direct the leading edge of the sheet 25 to and beyond the feed rolls 26 
and 28. The sheets are directed between the glue applicator roll 14 and 
presser roll 29. The roll 12 which is partially submerged in the liquid 
glue 30 in pan 11 rotates with a surface speed approximately equal to the 
surface speed of glue applicator roll 14 so as to wet the glue applicator 
roll with glue. When the sheet 25 passes in contact with the glue 
applicator roll 14, it becomes coated with the glue. 
The plurality of pick fingers 18 each includes a curved lower edge 31 which 
is close juxtaposition with respect to the upper curved surface of the 
cylindrical glue applicator roll 14, and a pointed end 32 which faces the 
oncoming sheet material. As the sheet material moves past the line of 
contact between the presser roll 29 and glue applicator roll 14, the 
pointed ends 32 of each pick finger 18 tends to pick the leading edge of 
the sheet material away from the glue applicator roll 14, and the vertical 
edge 34 of each of the pick fingers tends to deflect the oncoming edge 
upwardly toward the guides 19, and the guides 19 further deflect the sheet 
material on toward the suction conveyor 20. The vertical edge 34 of each 
pick finger 18 as well as the contacting surfaces of the guides 19 are 
usually formed with a curvature that compliments the shape of the adjacent 
portion of the suction conveyor 20. 
Suction conveyor 20 includes a conveyor belt 35 with a plurality of 
apertures 36 formed therein, and the belt moves in the direction indicated 
by arrow 38. A suction tray 39 is positioned immediately below the upper 
flight of the conveyor belt 35, and the inletof a blower (not shown) 
communicates with the tray 39 so as to induce a flow of air through the 
upper flight of the conveyor, through the openings 36. This tends to cause 
the sheets of material being fed through the system to cling to the upper 
flight of the belt conveyor as the upper flight moves in the direction 
indicated by arrow 38, away from the gluer 10. 
As illustrated in FIG. 2, the wiper blade assembly 15 located at each end 
of the glue applicator roll 14 (only one wiper blade assembly blade being 
illustrated in FIG. 2) is mounted from the end bearing blocks 40 of the 
gluer. The wiper blade assembly (FIG. 3) includes horizontal support strap 
41, vertical support strap 42, and wiper blade 44. The horizontal support 
strap 41 includes a slot 45 at one end and a pair of holes (not shown) at 
its other end. Screw 46 extends through the slot 45 and into an internally 
threaded bore (not shown) in the end bearing block 40 to hold the 
horizontal strap in position. The elongated slot 45 permits the wiper 
blade assembly 15 to be adjusted in various positions so as to properly 
locate the wiper blade 44 at the end of the glue applicator roll 14. 
Screws 48 extend through the opening at the other end of the horizontal 
support strap 41 and through a slot 49 at the upper end of the vertical 
support strap 42. The size of the slot 49 allows the support straps 41 and 
42 to be adjusted with respect to each other. 
Wiper blade 44 is rigidly connected to the lower end of vertical support 
strap 42. The vertical support strap 42 is bent intermediate its ends at 
50 so that the wiper blade 44 is disposed at an angle beneath the 
cylindrical glue applicator roll 14. 
Wiper blade 44 is fabricated from Delvin, Nylon, Teflon or other suitable, 
low-friction, long-lasting material. The blade 44 is connected by screws 
51 extending through aligned openings in the blade and the lower end of 
the vertical strap 42. The blade 44 includes a substantially flat, 
vertical roll contact surface 52, a grooved portion 54 which includes a 
glue deflector surface 55, and a horizontal wiper leg 56. The wiper leg 56 
includes a curved roll contact surfact 58 and a glue deflection surface 59 
which is coextensive with the back of the wiper blade. 
The wiper blade assemblies 41 are mounted at each end of the glue 
applicator roll 14, with the wiper blade assembly at the left end of the 
glue applicator roll (not shown) being a mirror image of the wiper blade 
assembly illustrated in the drawing. Each wiper blade assembly is mounted 
so that the flat vertical contact surface 52 of the wiper blade 44 is in 
abutment with the flat end surface of the cylindrical glue applicator roll 
14. The bend 50 in the vertical strap 42 of the assembly permits the 
assembly to be supported from the end block 40, with the bend causing the 
vertical support strap 42 to have its lower portion reach around axle 60 
of the glue applicator roll 14 and to locate the wiper blade 44 adjacent 
the lower portion of the roll 14. 
When the equipment is in operation, the glue applicator roll 14 rotates in 
the direction indicated by arrow 61. The glue deflection surface 55 of the 
wiper blade 44 is angled back toward the axle 60, so that its edge 62 is 
located away from the periphery of the flat end of the roll 14 and 
therefore tends to be effective on a large area of the flat end of the 
roll 14 to wipe and accumulate and deflect the glue from the end of the 
roll. The angle formed by the glue deflection surface 55 extends between a 
tangent to the roll from the position of the horizontal leg 56 of the 
wiper blade and a radius from the axle 60 to the horizontal leg 56. As a 
result, the glue deflection surface 55 functions to divert the glue at an 
angle radially outwardly from the axle 60 off the flat end of the roll 14, 
so that the direction of rotation of the roll 14 assists in the removal of 
the glue from the end surface of the roll. In the meantime, the glue 
deflection surface 59 of the horizontal leg 56 of the wiper blade 44 tends 
to deflect the glue from the curved end portion of the roll 14, with the 
direction of rotation of the roll 14 also assisting in the wiping and 
deflection function. 
Pick finger support bar 16 has an outside cylindrical surface along a major 
portion of its length, and its end portions 64 are rectangular in cross 
section. An internally threaded vertical opening 65 is formed 
therethrough, and an elevation screw 66 is threaded through the opening 
65. The rectangular ends 64 of the pick finger support bar 16 are received 
in a rectilinear upward facing open end slot 68 formed in the upper 
portion of each bearing block 40 (only one shown). An internally threaded 
horizontal opening 69 is formed through the bearing block 40 and 
intersects the slot 68. An externally threaded screw 70 is threaded 
through the opening 69 and functions as a set screw. The facing surfaces 
of the slot 68 are substantially flat, and the corresponding surfaces of 
the rectangular end portion 64 of the pick finger support bar 16 are also 
substantially flat. 
When the pick finger support bar 16 is mounted at its ends in the slots 68, 
the elevation screws 66 at each end of the bar will be rotated to properly 
position the bar 16 in an attitude that is approximately parallel to the 
glue applicator roll 14. The machine operator attempts to adjust the 
attitude of pick finger support bar 16 so that the pick fingers 18 will 
properly rest with their curved surfaces 31 in close juxtaposition with 
respect to the curved exterior surface of the glue applicator roll 14. 
When the proper adjustments are made by the operator by adjusting the 
elevation screws 66, the set screws 70 are tightened through their 
threaded openings 69 so that they are wedged against a vertical surface of 
the end portion 64 of the pick finger support bar, thereby forcing the 
other opposite flat surface of the end portion 64 into abutment with the 
facing flat surface of the slot 68 of the bearing block 40. The clamping 
forces between the facing flat surfaces of the end portions of the pick 
finger support bar and the slot 68 tend to maintain the pick finger 
support bar in its rectilinear configuration, and no bending or torsion 
forces are applied to the pick finger support bar. 
While this invention has been described in detail with particular reference 
to a preferred embodiment thereof, it will be understood that variations 
and modifications can be effected within the spirit and scope of the 
invention as described hereinbefore and as defined in the appended claims.