US3295491A

US3295491A - Glue-applying apparatus

Info

Publication number: US3295491A
Application number: US339130A
Authority: US
Inventors: George J Cassarno
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-01-21
Filing date: 1964-01-21
Publication date: 1967-01-03
Anticipated expiration: 1984-01-03

Description

Filed Jan. 21, 1964 George J. Cassarno INVEN TOR.

United States Patent 3,295,491 GLUE-APPLYING APPARATUS George J. Cassarno, P.0. Box 49-6,

Lake Oswego, Greg. 97034 Filed Jan. 21, 1964, Ser. No. 332130 Claims. (Cl. 118-2) This invention relates to apparatus for applying glue or adhesive, and more particularly to improvements in apparatus operable to coat with glue distinct areas on the surface of a workpiece on such workpiece traveling through the apparatus.

The apparatus of the invention is particularly useful in applying an adhesive coating to the edges of sheets, such as veneer sheets. This is an operation commonly performed prior to making one relatively large continuous sheet from a series of smaller sheets abutted edge to edge. While the invention is described below in connection with apparatus intended for the edge gluing of veneer sheets, certain features of the invention may have broader application, and with respect to these features it is not intended to be limited only to apparatus for processing veneer sheets.

As will hereinafter become apparent, there is disclosed herein apparatus for applying glue simultaneously to opposite edges of sheets of veneer of varying widths comprising means for advancing 1e sheets through the ,apparatus along a path, and glue applicators on either side of this path including at least one which is adjustable, whereby the applicator may be placed in proper glueapplying position when a change in the width of the veneer handled occurs. Thus, the apparatus includes means that automatically determines the width of the material being handled, and that on determining this width is operable to space oppositely disposed glue applicators relative to each other whereby opposite edges of veneer may be coated simultaneously. The apparatus in the usual instance handles stacked veneer sheets, with the sheets of any given stack having uniform width, so that along each side of a stack all edges of the sheets in the stack are aligned.

A general object of the invention, therefore, is to provide improved glue-applying apparatus, which includes an adjustable glue applicator, and novel means for bringing the applicator into proper glue-applying position with respect to the surface which is to be coated with glue.

More specifically, an object is to provide improved apparatus of the above general description, which is operable simultaneously to coat opposite edges of a piece of material (such as a veneer sheet) with glue, such coating being done after a detector means first determines the width of the material being coated whereby the means applying the glue to opposite edges may first be placed in proper glue-applying position with respect to said opposite edges.

A further object is to provide glue-applying apparatus, featuring means for clamping against opposite faces of a sheet (or stack of sheets) whereby the sheet or stack may be held firmly as it is advanced, and at least on preferably two glue applicators, which apply glue to the edges of the sheet or stack where such sheet or stack is advanced through the apparatus while clamped onto through its opposite faces.

Another object is to provide novel apparatus including a glue applicator, where said apphcator applies glue to a sheet edge by spraying the glue on the edge, the appa- "ice ratus further including novel shield structure that coacts with the face of a sheet to inhibit glue deposits from forming on the face.

The apparatus of the invention roduces good glue coatings without wasting glue. The apparatus is fully reliable, and requires little supervision.

Other objects, features, and advantages are attained by the invention, which is described hereinbelow in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevation of apparatus constructed according to one embodiment of this invention;

FIG. 2 is a cross sectional view, taken generally along the line 22 in FIG. 1, showing means in the apparatus for advancing material such as a stack of veneer therethrough, and applicators adjacent opposite sides of the apparatus for applying glue to opposite edges of said material;

FIG. 3 is a cross sectional view taken along the line 33 in FIG. 2; and

FIG. 4 is a cross sectional view taken generally along the line 4-4 in FIG. 2.

In the making of plywood or similar products from veneer, an operation which is sometimes performed comprises abutting the edges of veneer sheets together, with a glue line or deposit between adjacent edges, and then bonding the glue lines between the sheets thus to form a continuous sheet. Special problems present themselves when this procedure is carried out with veneer sheets used to face a panel. Such veneer sheets often times are cut from the more expensive woods, and for reasons of economy are usually quite thin in comparison to other types of veneer sheets. With very thin veneer sheets, in most instances it is desirable tohave glue applied to both of the opposite edges of the sheets, in order to produce a thicker and stronger glue line between adjacent sheets. A'relatively thick glue line is needed, not only because of the thinness of the veneer (which means a relatively small surface area to receive glue), but also because with facing material, one side of the material in a finished panel is exposed (which means there is less support for two adjacent veneer sheets in the facing material where these sheets join).

There is the additional factor to be considered that veneer sheets derived from the more expensive woods frequently are prepared by cutting a log with a plurality of parallel, straight cuts extending between the sides of the log (as opposed to peeling the veneer from the log using a lathe). A stack of veneer sheets cut in this manner may be book matched when preparing a facing sheet, by flipping over alternate pieces from the stack prior to joining the pieces, to produce a grain continuity effect in the finished facing sheet. If the veneer sheets in a stack of such sheets were to have glue or adhesive applied to one set of edges only, the veneer sheets after book matching would have'glue between adjacent edges only at alternate joint locations.

Another consideration, which is particularly important when veneer sheets are used for facings, is that not only should the veneer sheets have their edges adequately covered with glue, but their faces preferably should be substantially free of glue. With thin veneer as 21 facing, at the most only a very light sanding is performed on a finished panel, to avoid sanding completely through the facing. If excessive quantities of glue found their way to the faces of the veneer sheets, a light sanding would not be suflicient to remove the glue.

The glue-applying apparatus of the invention is particularly useful in applying glue to opposite edges of sheets in a stack (or flitch), in that the glue is properly applied to both sets of edges of each piece in the stack, and the apparatus includes means that inhibits glue deposits from forming on the faces of the veneer sheets bounding the stack.

Referring now to the drawings, and first of all more particularly to FIG. 1, 8 indicates generally a frame for the apparatus, including sides 9 and 10 and legs 12 at the base thereof for suitably supporting the frame above a floor. On the feed side or end of the apparatus, i.e.-, the right side in FIG. 1, is a table or support means 14, which supports a stack of veneer prior to the application of glue thereto. On the oifbearing side or end of the apparatus is a conveyer table 16, shown which receives a stack of veneer after the glue-applying operation.

Referring now to FIGS. 2 and 3, advancing means 17 is provided for moving a veneer stack through the apparatus. Advancing means 17 comprises a first pinch roll mechanism 18, including lower supporting roll 18a and an upper clamping roll 18b, and a second pinch roll mechanism 19, including a lower supporting roll 19a and an upper clamping roll 1%. The various supporting rolls, table 14, and conveyer table 16 on the offbearing side of the apparatus define a path of travel for a stack of veneer through the apparatus.

Rolls 18a, 19a are journaled on frame 10 through bearings 22 for rotation about their longitudinal axes, these extending transversely of the path of travel of a veneer stack through the apparatus. The upper surfaces of these rolls are approximately at the level of table 16 and conveyer table 14.

Rolls 18b, 19b, i.e., the clamping rolls (or clamp means), are movable from the position spaced apart from the supporting rolls (shown in solid outline in FIG. 2'), to a position adjacent the supporting rolls (as shown by the dashed outline in FIG. 2). These constitute release and clamping positions, respectively.

Considering more specifically the mountings for the clamping rolls, the rolls are journaled at their ends in bearings, such as bearings 23. Bearings 23 for the left set of ends of rolls 18b, 19b, as best illustrated in FIGS. 2 and 3, are secured to a mounting plate 24. Plate 24 has its ends mounted for vertical movement in guides 26 joined to frame 8. Integral with mounting plate 24, and. I projecting downwardly therefrom, are opposed racks or' elements 27.

Vertical upward movement of the mountingplateis produced under power, through extension of single-acting ram 30. Ram 30 has its cylinder end 30a suitably mounted on a shelf 32 which is part of frame 8. The rod'or extensible end 30b of ram 30 is connected to rack 27;

Bearings 22 for the right set of ends of rolls 18b, 19b are mounted on a mounting plate 34 which is similar in shape to plate 24. As in the case of plate 24, mounting plate 34 is vertical-ly movable, in guides 36. Projecting down-from the mounting plate are racks 37.

Extending between opposite sides9, 10 of frame 8, and journaled in bearings 40 suitably mounted on these sides, are a pair ofshafts 42, 44. The left set of ends of shafts 42, 44 in FIG. 2 have sprockets 46 secured thereto. Similarly, fixed to the right set of ends of these shafts in FIG. 2 are sprockets 49. 'The teeth of sprockets 46 mesh with the teeth of racks 27, as best illustrated in FIG. 3, and the teeth of sprockets 49 similarly mesh with the teeth of racks 37.

Shafts 42, 44 together with the sprockets mounted thereon, and the racks which these sprockets engage, are provided for the purpose of producing vertical movement supporting rolls. Similarly parallelism is maintained upon contraction of the ram.

The various rolls of advancing means 17 are rotated under power. Thus, andreferring to FIGS. 1, 2, and 3 mounted beneath the rolls adjacent one side of the apparatus is a motor 52. The motor is supported on platform 54.

Sprockets

56, 57, 58, and 59 are connected to the rolls of the advancing mechanism. Trained over these sprockets, and a sprocket 61 secured to output shaft 62 of motor 52, is a chain 64. The way the chain is trained over the sprockets is such that upon energizing of motor 52, all the rolls are rotated in a direction to produce travel from right to left in FIGS. 1 and 3, i.e., from the feed o the offbearing end of the apparatus.

Platform 54 is pivotally supported on a stub shaft 66 extending outwardly from side 9 of the frame. By this pivotal mounting of the platform, the weight of motor 52 operates to keep chain 64 without slack therein, with the pinch roll mechanisms in either their clamping or release positions. 7

As indicated earlier, this invention features a glue applicator on each side of the apparatus. These apply glue simultaneously to opposite sides of a stack of veneer travel-ling through the apparatus. Such structure will now be described in more detail.

Referring to FIG. 1, it will be noted that a fence or guide means 70 is provided on one side of table 14. The

fence is used to position properly one side of a stack of veneers with respect -to one of the glue applicatorsin the apparatus. The inner face of this fence occupies the plane indicated at A in FIG. 2. With different stacks of veneer, one side of the stack always passes through the apparatus while lying in plane A, and thus a stationary applicator may be provided for applying glue to this one side (i.e., one set of edges of the veneer pieces in the stack).

This stationary applicator is indicated in FIGS. 1 and 2 at 74. The applicator includes a nozzle 76 through an A glue applicator 82 is provided for applying glue to' the opposite side of a stack of veneer. Since different stacks of veneer may have different widths, means is provided for adjusting this applicator in a direction extending transversely of the path of travel of ,veneer through the apparatus, whereby the applicator may be placed in proper glue-applying position with respect to this opposite side of the veneer stack (i.e., the opposite set of edges in the stack).

As can be seen in FIGS. 2 and 4, applicator 82 (which resembles applicator 74 in that it includes a nozzle 83 for' producing a spray of glue) is mounted on a bracket 84 joined to a vertical plate 86. Plate 86 is joined, at the base thereof, to a bar 88 which has its ends secured to sleeves 90. Extending transversely of the apparatus, be-

tween sides 9 and 10 of the frame, are a pair of guide rods 94. Sleeves 90 are slidably supported on these guide.

rods, and thus the guide rods define a path of travel for the sleeves (and plate 86 mounted thereon) that parallels the axes of the rolls.

Movement of plate 86 and .the applicator -rnounted thereon is effected :by means of an extensible ram 97 pivotally mounted at 98 to the frame, having its extensible end pivotally connected at 100 to an arm 102. Ann 102 is pivotally mounted intermediate its ends, at 104, on frame 8 of the apparatus. The upper end of the arm is connected by pin and slot connection 106 to an ear 108 which is joined to bar 88. Through the mechanism described, upon extension of. the ram, arm 102 is swung in a counterclockwise direction in FIG. 2 to shift plate and the applicator mounted thereon to the left. Upon contraction of the ram, the arm may be returned to shift the plate and applicator to the right.

Movement'of the plate and the applicator along the path defined by guide rods 94, 95 is controlled by a detector 110 (see FIG. 2) mounted on bar 88, comprising a sensor arm 111 which extends upwardly above the plane defined by the top of rolls 18a, 19a. The upper end of sensor 111 is in position to come into contact with the side of a stack of veneers supported on roll 18a. Arm 111 actuates a switch .112 which controls a suitable valve controlling the supply of fluid pressure to opposite sides of ram 97. Switch 112 also controls the supply and exhaust of pressure fluid to ram 30 connected to rolls 18b, 1912.

As indicated hereina-bove, it is import-ant that the glue coatings prepared by the apparatus be confined just to the opposite sides of a stack, and that deposits of glue or adhesive be prevented from collecting on the faces of the veneer pieces bounding the stack. In this invention, novel shield structure is contemplated, disposed in front of each glue applicator, which includes means that seeks the face of the top veneer sheet in a stack of veneer, and which rides on this .face as the stack passes through the apparatus. The structure covers the face adjacent the side of the stack and prevents glue from being sprayed on the face.

More specifically, and with reference to applicator 82, it will be noted that plate 86 (see FIG. 4) has an elongated vertical slot 118 therein, which glue travels through when ejected from nozzle 83. In front of this plate is a shield 12%, including along the margin thereof a curved cam flange 122. Projecting from the back side of shield 120, is an element 124, which is guided for vertical movement in slot 118. Also guiding the shield, are rods 126 extending upwardly therefrom and received within complementing bores provided within a flange 86a of plate 86. Nuts 128 fastened to the top of these rods define a lowered position for the shield.

Referring to FIG. 4, in this figure the shield is shown in its lowered position, with the base thereof substantially at the level of the top of rolls 18a, 19a. When a stack of veneer advances into the shield from the right in FIG. 4, the forward part thereof engages cam flange 122, causing the shield to rise the distance necessary to accommodate the passage of the stack under the shield. As a stack of veneer passes under the shield, the shield rides directly on the face of the top veneer piece in the stack, and presents a barrier preventing glue from being deposited or otherwise collecting on the face of the veneer. Excess glue ordinarily will not collect on the bottom face of the veencr piece on the bottom of the stack, due to the action of gravity.

Considering applicator 74, as can be seen in FIG. 3, on the other side of the apparatus a plate 130 is provided which is afiixed to the frame by fastener 132. Plate 139 contains a slot 134, which performs the function of slot 118 in plate 85. Mounted for vertical movement in front of plate 139 is a shield 136 similar to shield 12%). Like shield 129, shield 136 functions to prevent glue from collecting on the face of the top veneer piece in the stack.

Mounted on a bracket 14!) joined to the base of plate 139 is a switch 144 with a switch finger 146 located between molls 19a, 18a and extending above the top of the rolls. This finger is actuated by a veneer stack traveling thereagainst to start operation of

glue applicators

74, 82.

A bracket .148 joined to frame 8 mounts a switch 150 disposed on the offbearing side of roll 19a. Finger 152 for switch 150 is engaged by a veneer stack traveling out of the apparatus. Finger 152 and switch 150 are provided for the purpose of returning the parts to their original starting position after a stack of veneer has had glue applied to its opposite sides. 7

A foot pedal 156 is connected to a switch '158 which is actuated to start a cycle of operation.

Explaining now the operation of the apparatus, an operator first places a stack of veneer on table 14 with one side of the stack against fence 70. The stack of veneer is placed with the forward end thereof over roll 18a. Fence 70 positions one side of the stack whereby it will travel through the apparatus while substantially in the plane indicated at A in FIG. 2.

Pedal 156 is then depressed to actuate switch 158. Switch 158 actuates a valve whereby pressure fluid is caused to extend ram 97. This results in movement of applicator 32. and detector 119 to the left in FIG. 2. Movement continues until sensor 111 strikes a side of the stack of veneer. When this occurs, switch 112 is actuated, with the result that the valve controlling extension of ram 97 is actuated to stop further extension of the ram. At the same time switch 112 actuate-s a valve controlling ram 30, whereby this ram contracts (by the exhaust of pressure fiuid from its pressure side). Rolls 18b, 1% then move downwardly .by gravity, until roll 18b contacts the top of the veneer stack. This produces clamping of the stack. Since motor 52 ordinarily is running constantly, thus to cause rotation of rolls 18b, 191;, with clamping of the stack roll movement is imparted to the stack, and the stack then moves forwardly.

The stack then moves past the glue applicators positioned on either side of the apparatus. On the stack passing finger .145, switch 144 is actuated to cause a glue spray to be ejected from the applicators Glue continues to be sprayed until the stack clears switch finger 146.

On the tail end of the veneer stack moving past switch finger 152, switch is actuated, which causes ram 97 to contract and ram St to extend. This results in the parts returning to their original starting position, i.e., the position shown in solid lines in FIG. 3.

It will be noted that the apparatus of the invention includes a number of novel features. Various widths of the veneer stacks can be handled with equal facility. With each stack, the detector determines the width of the stack, whereby the traveling glue applicator may be shifted to proper glue-applying position. The stacks may have varying thicknesses. If desired, sheets may be handled singly.

By providing two applicators, opposite sides of a stack are coated simultaneously. The glue is applied upon movement of the veneer stack forwardly in the path extending adjacent the applicators.

While there has been described an embodiment of the invention, it is obvious that changes and variations are possible without departing from the scope of the invention. It is desired to cover all modifications and variations that would be apparent to One skilled in the art, and that come within the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In glue-applying apparatus for applying glue to a workpiece bounded on opposite sides by opposed edges,

means defining a path for a workpiece through the apparatus with such workpiece moving from infeed to ofibearing ends of the apparatus,

a pair of glue applicators mounted with one on one side and one on the other side of said path,

guide means positioned toward the infeed end of the apparatus from one applicator and adjacent said one side of said path operable to guide one edge of a workpiece past said one applicator along a predefined course with the latter in proper glue-applying position for said one edge,

detector means toward the infeed end of the apparatus from the other of said pair of applicators and adjacent said other side of said path for detecting the position of the edge of a workpiece opposite its said one edge,

means movably mounting the other of said pair of glue applicators accommodating shifting of said other applicator transversely of said path and into a proper glue applying position for said opposite edge of a workpiece, and

means interconnecting the detector means and said other glue applicator for producing shifting of said other applicator in response to the detector means detecting the position of said opposite edge.

2. Apparatus for applying glue to the edge of a sheet comprising a frame,

a horizontal supporting roll journaled on said frame,

means for guiding a sheet in a path extending transversely of said supporting roll,

an edge detector movable in a direction extending along the axis of said supporting roll,

a glue applicator movable in a direction extending along the axis of said supporting roll,

means operatively interconnecting the edge detector and glue applicator for producing movement of the glue applicator on movement of the edge detector,

a rotatable clamping roll disposed over said supporting roll, and

means whereby said clamping roll and supporting roll are brought together to pinch onto a sheet after said edge detector moves against an edge of the sheet.

3. Apparatus for applying glue to the edge of a sheet comprising a frame,

a horizontal supporting roll journaled on said frame,

a glue ap licator,

means movable in a direction extending along the axis of said supporting roll mounting said applicator,

a shield mounted for vertical movement on said means mounting said applicator,

said shield including means adapted to seek the face of a sheet lying on said supporting roll thus properly to position the shield vertically relative to said face of a sheet, and

means operatively interconnecting said edge detector and means mounting the applicator for producing movement of the means mounting the applicator on movement of the edge detector.

4. The apparatus of claim 3, which further comprises clamping means spaced vertically from said supporting roll, and means whereby said clamping means is brought towards said supporting roll after said edge detector moves against an edge of a sheet.

5. Apparatus for applying glue to the edge of a stiff sheet comprising pinch roll mechanism including a pair of substantially horizontal rolls mounted in the'apparatus with the rolls spaced apart from each other in a release position for the roll mechanism, and means for bringing the rolls together whereby they occupy a clamping position for the roll mechanism and clamp onto opposite spaces of a sheet,

support means for supporting a sheet on the feed side of said pinch roll mechanism with the sheet substantially horizontal and aligned with the space between the rolls of said pinch roll mechanism with the latter in its release position,

a glue applicator on the otfbearing side of said pinch roll mechanism to one side of an edge of a sheet supported on said support means, said applicator being movable in a direction extending axially of the rolls of said pinch roll mechanism toward such edge of such a sheet,

detector means spaced toward the feed side of said pinch roll mechanism from said applicator for detecting the location of such edge of a sheet in a region of the sheet which is supported on said support means, and

.means operatively interconnecting said detector means 8 and said glue applicator for producing movement of the applicator in response to the detector means detecting the position of such sheet edge.

6, The apparatus of claim 5 which further comprises a vertically movable shield mounted for movement in a direction extending axially of the rolls of said pinch roll mechanism together with said glue applicator, said shield including means adapted to seek the face of a sheet lying on one of the rolls of said pinch roll mechanism thus properly to position the shield vertically relative to said face of a sheet,

7. Glue-applying apparatus comprising a frame,

pinch roll mechanism mounted on said frame including opposed rolls adjustable between clamp and release positions, respectively,

support means on the feed side of said pinch roll mechanism for supporting a sheet to be fed into said pinch roll mechanism,

a fence on the feed side of said mechanism forpositioning one edge of a sheet supported on said support means,

detector means on the feed side of said pinch roll mechanism operable to detect the edge of sheet opposite its said one edge,

a glue applicator mounted on the offbearing side of said pinch roll mechanism in proper glue-applying position for said one edge of a sheet,

another glue applicator on the otfbearing side of pinch roll mechanism mounted for movement in a direction extending along the axis of the rolls in said pinch roll mechanism, means operatively connecting said detector means and other glue applicator for producing movement of said other applicator controlled by the detector means, and

a vertically movable shield mounted adjacent each applicator including means adapted to seek the face of a sheet lying on one of the rolls of said pinch roll mechanism thus properly to position the shield vertically relative to said face of a sheet.

8. The apparatus of claim 7,where said detector includes a sensing element movable in a direction extending along the axes of said rolls, and which further comprises power-operated means for moving said sensing element, power-operated means for moving the rolls of said pinch roll mechanism between clamp and release positions, and control means operatively interconnecting said two power-operated means.

9. Glue-applying apparatus comprising a frame,

advancing means mounted on said frame for advancing a sheet through the apparatus comprising a pair of pinch roll mechanisms positioned with one in front of the other,

each of said pinch roll mechanisms including a pair of opposed rolls adjustable between clamp and release positions, respectively,

support means on the feed side of said advancing means for supporting a sheet to be fed into the advancing means,

a fence on the feed side of said advancing means for positioning one edge of asheet supported on said support means,

detector means on the feed side of said advancing means operable to detect the edge of a sheet opposite its said one edge,

a glue applicator mounted between the pair of pinch roll mechanisms in proper glue-applying position for said one edge of a sheet, and

another glue applicator between the pair of pinch roll mechanisms mounted for movement in a direction extending along the axes of the rolls in said roll mechanisms and means connecting said detector means and other applicator for producing movement of said other applicator controlled by the detector means.

10. The apparatus of claim 9, wherein said detector means includes a sensing element movable in a direction extending along the axes of the rolls in said pinch roll mechanisms, said sensing element and said other applicator are mounted on a common movable support, and which further comprises automatically controlled poweroperated means operable to adjust said pinch roll mechanisms from their release to their clamping positions after movement of the applicator.

References Cited by the Examiner UNITED STATES PATENTS Nicholas 1188 Bonneau 15-307 Haverberg 15-307 X Williams et a1. 118-8 Burlebach et a1. 1188 X Davis 1188 DANIEL BLUM, Primary Examiner.

Claims

1. IN GLUE-APPLYING APPARATUS FOR APPLYING GLUE TO A WORKPIECE BOUNDED ON OPPOSITE SIDES BY OPPOSED EDGES, MEANS DEFINING A PATH FOR A WORKPIECE THROUGH THE APPARATUS WITH SUCH WORKPIECE MOVING FROM INFEED TO OFFBEARING ENDS OF THE APPARATUS, A PAIR OF GLUE APPLICATORS MOUNTED WITH ONE ON ONE SIDE AND ONE ON THE OTHER SIDE OF SAID PATH, GUIDE MEANS POSITIONED TOWARD THE INFEED END OF THE APPARATUS FROM ONE APPLICATOR AND ADJACENT SAID ONE SIDE OF SAID PATH OPERABLE TO GUIDE ONE EDGE OF A WORKPIECE PAST SAID ONE APPLICABOR ALONG A PREDEFINED COURSE WITH THE LATTER IN PROPER GLUE-APPLYING POSITION FOR SAID ONE EDGE, DETECTOR MEANS TOWARD THE INFEED END OF THE APPRATUS FROM THE OTHER OF SAID PAIR OF APPLICATORS AND ADJACENT SAID OTHER SIDE OF SAID PATH FOR DETECTING THE POSITION OF THE EDGE OF A WORKPIECE OPPOSITE ITS SAID ONE EDGE, MEANS MOVABLY MOUNTING THE OTHER OF SAID PAIR OF GLUE APPLICATORS ACCOMMODATING SHIFTING OF SAID OTHER APPLICATOR TRANSVERSELY OF SAID OPPOSITE EDGE OF A GLUE APPLYING POSITION FOR SAID OPPOSITE EDGE OF A WORKPIECE, AND MEANS INTERCONNECTING THE DETECTOR MEANS AND SAID OTHER GLUE APPLICATOR FOR PRODUCING SHIFTING OF SAID OTHER APPLICATOR IN RESPONSE TO THE DETECTOR MEANS DETECTING THE POSITION OF SAID OPPOSITE EDGE.