US1915976A

US1915976A - Four corner box staying machine

Info

Publication number: US1915976A
Application number: US292306A
Authority: US
Inventors: Brodsky Gregory
Original assignee: Canada Valve & Hydrant Co
Current assignee: Canada Valve & Hydrant Co; Canada Valve & Hydrant Company Ltd
Priority date: 1928-07-12
Filing date: 1928-07-12
Publication date: 1933-06-27
Anticipated expiration: 1950-06-27

Description

June 27, 1933. G. BRODSKY FOUR-CORNER BOX STAYING MACHINE Filed July 12, 1928 6 Sheets-Sheet l WW aw June 27, 1933. e. BRODSKY FOUR-CORNER BOX STAYING MACHINE Filed July 12, 1928 6 Sheets-Sheet 2 I r l 72 of 07590 w z. 7

June 27, 1933.

G. BRODSKY FOUR-CORNER BOX STAYING MACHINE Filed July 12, 1928 6 Sheets-Sheet 5 June 27, 1933. BRODSKY 1,915,976

FOUR-CORNER BOX STAYING MACHINE Filed July 12, 1928 6 Sheets-Sheet 4 6?: 05 firodslfy j QTZG. r

June 27, 1933. G. BRODSKY FOUR-CORNER BOX STAYING MACHINE Filed July 12, 1928 6 Sheets-Sheet 5 Eva-72f):

y a 0 M W 9 P M 6 \MW qw o h June 27, G BRODSKY FOUR-CORNER BOX $TAYING MACHINE Filed July 12, 1928 6 Sheets-Sheet 6 w "/4 My Patented June 27, 1933 UNITED STATES PATENT OFFICE GREGORY BRODSKY, OF BR-ANTFOBD, ONTARIO, CANADA, ASSIGNOR 0F ONE-HALF TO THE CANADA VALVE 8c HYDRANT COMPANY, L'lll, OF BRANTF'ORD, CANADA, A CORPORATION OF ONTARIO,

FOUR CORNER BOX Application filed July 12,

My invention relates to box making machines and has for its object to provide a machine of the class described that is adapted to simultaneously apply corner stay strips to all four corners of a box. As will hereinafter appear, certain portions of my machine may also be used for staying box corners singly as well-as four at one time.

In my copending application Serial No. 155,672, filed December 18, 1926, there is shown and described a four corner box stay ing machine that is particularly characterized by the provision of separate power units for actuating the stay applying members simultaneously Operating on the corners of a box, the power units being identical and interchangeable and the whole machine being characterized by its extreme simplicity in its construction and effectiveness in operation. The object of the present invention is to provide certain improvements in a staying machine of the same general type as disclosed in my aforesaid pending application Serial N 0. 155,672, the main distinction between the machine of the present application and that of my copending application, residing in the substitution of fluid pressure operating means for electromagnetic operating means, for the power staying units. The machine of the present application also contemplates a re organization of the parts of the stay feeding mechanism whereby the feeding of a stay strip at each corner of the box and the operation of the associated staying member is automatically controlled so that a stay strip can not be severed and applied until it has been fully fed. lhe above and other advantageous features of my invention will hereinafter more fully appear, reference being had to the accompanying I drawings in which- Fig. 1 is a view in side elevation of a ma chin-e embodying my invention.

Fig. 2 is a plan view of the machine shown in 1.

Fig. 3 is a vertical sectional view along the line 33 of Fig. '2.

Fig. 4 is a horizontal sectional View along the line 4-4 of Fig. 3.

Fig. 5 is a view in side elevation looking at ONTARIO,

CANADA STAYING MAGHHQ'E 1928. Serial No. 292,306.

the other side of the machine shown in Fig- 1.

Fig. 6 is a horizontal sectional view along the line 66 of Fig. 5.

- Fig. 7 is a fragmentary View illustrating the relation between the box blank folders and the box form.

Fig. 8 is a plan view of the parts shown in Fig. 7.

Fig. 9 is a View in side elevation of one of the staying units removed from the machine.

Fig. 10 is a horizontal sectional view along the line 10-10 of Fig. 9. w Fig. 11 is a fragmentary plan view showmg on an enlarged scale the box blank feeding mechanism.

Fig. 12 is a sectional view along the line 12-12 of Fig. 11.

Fig. 13 is a sectional view along the line 13-13 of Fig. 11.

Fig. 14 is a detail view of one of the clutch ing devices for the stay strip feeding roll.

Fig. 15 is a view looking at the other side of the parts shown in Fig. 14.

Fig. 16 is a sectional view along the line 1616 of Fig. 14. i

Like reference characters refer to like parts and referring to Figs. 1 and 2 of the draW- ings, the machine comprises a base 1 which provldes an upwardly extending pedestal 2 r for supporting a pair of saddles 3 in spaced relation, each saddle 3 carrying a pair of staying units 4 arranged at an angle, the details of which staying units will be hereinafter described. A rectangular box form 5 is carried in the space between the saddles 3 by a vertical plunger 6 extending downwardly into a cylinder 7 carried by the pedestal 2 in the space between the trnnnions 8 for the saddles 3, see Fig. 5.

Power for operating the machine is derived from an electric motor 9 driving a shaft 10 through reduction gearing 11, the shaft 10 carrying

cams

12, 13 and 14 which are adapted to operate

plungers

15, 16 and 17 movable in the

cylinders

18, 19 and 20, respectively. As shown in Figs. 3 and 4, downward movement of the plunger 15 within the cylinder 18 by the cam 12 is adapted to cause fluid under pressure to be admitted to the box form cylinder 7 through a conduit 7a which operates the box form 5, while the depression of the piston 16 by the cam 13 is adapted to deliver fluid under pressure from the cylinder 19 to all of the staying units 4 through flexible tubing 21, leading from a manifold 19a. The third cam 14, when it depresses the plunger 17, is adapted to deliver fluid under pressure from the third cylinder 20 through a tube 21a to a cylinder 22 located' beneath a table 23 carried by the left hand saddle 3. As shown in Fig. 11, the table 23 provides a slot 24 within which works a slide 25 connected to a plunger 26 in the cylinder 22 by a yoke 27. The slide 25 provides a shallow slot 28, shown in Fig. 12 in which is adapted to be received the lowermost blank 29 of a stack of blanks supported by the table 23, so that movement of the slide 25 from left to right as viewed in Fig. 1 is adapted to carry the lowermost blank 29 of the stack into a position above the box form 5.

As best shown in Fig. 3, the

cams

12, 13 and 14 are mounted on the cam shaft 10 so that the plunger 17 in the cylinder 20 is adapted to be depressed in advance of the depression of the plunger 15 by the cam 12. Consequently, the plunger 26 in the blank feeding cylinder 22 is adapted to be operated in advance of the plunger 6 in the box form cylinder 7, so that a blank 29 is positioned above the lowered box form 5 before the latter starts to be moved upwardly to fold a box blank and carry the same into position to be operated upon by the staying units 4. The third cam 13 on the shaft 10 is adapted to de press the plunger 16 in the cylinder 19 after the box form 5 has reached its upper position so as to propel fluid under pressure to the several staying units 4, which will next be described.

As best shown in Figs. 9 and 10, each staying unit 4 consists of a casting adjustably mounted on a saddle 3, the staying unit casting providing a bore 30 for receiving a plunger 31 anda second smaller bore 32 above the bore 30 and offset therefrom for receiving a plunger 33. The plunger 31 extends beyond the bore 30 and provides at its end a vertical slot for receiving a presser 34 provided at each end with a right angled groove 34a adapted to receive a corner of a box. The presser 34 is held in the plunger 31 by a set screw 35 and is reversible. The rear groove 34a receives a triangular bar 36 to the lower end of which is connected a spring 37 extending rearwardly through an opening 37 a in the unit casting and anchored at its end. The spring 37 holds the presser 34 and its plunger 31 retracted within the bore 30, until fluid under pressure is admitted to the bore 30, as will be hereafter described.

The plunger 33, which extends above the plunger 31, extends outside the bore 32, and

I carries at its end a projection 38 to which is secured an endless belt 39, or other flexible element, which passes around a loose pulley 40 supported by a lug 41 carried by the top of the unit casting 4, just above the end of the bore 32. The belt 39 also passes around a pulley 42 mounted on a shaft 43 carried by a bracket 44 extending upwardly from the unit casting 4 just above the end of the bore 30. The shaft 43 carries a feed roll 45 and the pulley 42 is adapted to turn the feed roll 45 in one direction of rotation only, namely the direction in which the pulley 42 is turned by the belt 39, when the plunger 33 is moved outwardly within the bore 32.

The feed roll 45 has associated therewith, a pressure roll 46 held in yielding engagement with the roll 45 by a spring 47, and the

rolls

45 and 46 are adapted to receive between them a strip 48 of stay material. The stay strip 48 is supplied to the feed roll 45 from a suitable reel 49 rotatably supported on a bracket 50 extending upwardly from the side of the unit casting 4, and the strip 48 is adapted to be led from this reel 49 over a pivotally mounted guide roll 51 which presses one side of the strip 48 into engagement with a gumming or moistening roll 52 carried by a trough 53 holding liquid gum or water, de pending upon whether the strip 48 has been previously gummed, or not. The moistened and gummed strip 48 passes forwardly from between the

rolls

51 and 52 between the feed roll 45 and the associated pressure roll 46, the strip being twisted through 180 so as to present its moistened side towards the corner of the box about to be stayed.

Fluid under pressure from the cylinder 19 is adapted to be delivered to each unit casting 4 by means of one of the tubes 21, where it enters a passage 54, which is in direct communciation with the small bore 32 in which l operates the stay feed plunger 33. The passage 54 is normally shut off from the bore 30 by means of a ball valve 55 yieldingly seated in a passage 56 leading to the bore 30 from the passage 54. lVhen fluid under pressure is admitted to the passage 54, the plunger is moved outwardly, thereby imparting rotative movement to the feed roll 45 to feed a predetermined length of moistened stay strip downwardly in front of the retracted stay presser 34. As the plunger 33 reaches the end of its stroke, the plunger uncovers a port 57 connecting the bore 32 with the bore 30, whereupon fluid under pressure is admitted to the bore 30. When this occurs, the plunger 31 is moved outwardly to cause the presser 34 to sever a strip and apply it to the corner of a box, as provided by the folded down sides of the box blank 29 on the raised box form 5. The strip 48 is adapted to be severed as the presser 34 moves forward by cooperation between the presser 34 and a knife plate 58 carried by a lug 59 on the casting abave the presser 34. The knife plate 58 provides at each end a slot 58a which receives the stay strip 48, so that when the presser 34 starts its movement outwardly towards a box corner, the length'of moistened strip 48 which has just been-fed downwardly through the forward slot 58a is severed and carried forward by the presser 34 to be applied to the box corner. The knife plate 58 is secured to the lug 69 by a set screw 59a, so that it may be removed and reversed when the slot 58a be comes worn and as previously pointed out each presser 34 may be removed and reversed when its cutting edges become dull.

After the several plungers 31 carrying the pressers 34; have caused the severed stay strips to be simultaneously applied to the box cor ners with considerable pressure, the continued rotation of the cam shaft 10 brings the low point of the cam 13 into engagement with the plunger 16 thereby releasing the pressure into the cylinder 19. "springs 37 acting When this occurs the on the pressers 3i return the plungers 31 to their limiting positions in the bores 30, each ball valve then opening to'permit release of the fluid within the corresponding bore 30. At the same time, each stay feeding plunger 33 is returned by means of a spring connected at one end to the plunger projection 38 and at its other end to a lug 60a fixed on the unit casting.

Having described the relation between the principal operating parts of my machine there will next be described, in detail, the various mechanisms for controlling the feed ing of the box blanks 29, for folding the box blanks on the box form 5, as it moves upwardly, and for adjusting the relation between the saddles 3 and staying units 4 with respect to the box form 5, as well as for controlling the length of the stay strips that are applied to the corners of a box.

Referring now to Fig. 11, there is shown the outline of a box blank 29 resting on the table 23 and partially covering the slot '24: in front of the blank feeding slide 25 when the latter is in its retracted position. The box blank 29 provides four flaps 29a which form the sides of the box, when folded on the box form 5, and the stack of box blanks 29 is held in position on the table 23 in proper alinement between a pair of staying units 4 by means of vertical guides 61 received in the angle between adjacent side flaps 29a nearest the box form 5. The guides 61 are supported by brackets .62 each secured to the adjacent staying unit casting by means of a bolt 68.. The end of the stack of box blanks 29 farthest from the box form 51's engaged by upwardly extending stops ill on opposite sides of the table slot 24, these stops being in the form of angles with their bases 65 resting on the table '23. Each base 65 provides a slot 66 through which extends a bolt 67 carried by the table 23, a wing nut 68 cooperating with each bolt 5 serving to clamp the base of each stop 64: to the table 23 in the desired position.

It is evident that the forward guides 61 will move with the staying units lnvhen the same are adjusted as will be hereinafter described, so that the slots 66 permits the stops 64: to be positioned so as to always engage the rear end of the stack of blanks 29.

The guides 61 are vertically adjustable with respect to the table 23 so as to allow for difierences in the thickness of box blanks. Each guide 61 provides a slotted projection 61a through which extends the bracket 52, the adjustment being obtained by a thumb screw 62a threaded through the bracket 62 and clamped 62a permits end of the guide 61 and the table 23 to be ver accurately adjusted for the thickness of a b ank.

The edges of the blank stack on opposite sides of the table slot engaged by oppositely disposed guide plates .69, each supported by an arm pivotally secured to the base 4a of the adjacent staying unit casting 4. Each supporting arm 7 0 pro vides an upwardly extending portion 70; to

which is secured a plate 69 by means of a bolt '71 received in a slot 7 2 provided in the late 69. WVhen the staying units are ad.- ypsted on the saddles 3 thereby changing t 1e ings of the supporting arms 70 permit the plates 69 to be angularly adjusted with respect to the stack of blanks while the slots 72 permit the plates 69 to be adjusted in a direction substantially parallel to the supporting arms 70, so as to accommodate the plates 69 to the diilerent sizes of blanks which may be used.

As best shown in Fig. 13, which is the section across the table slot 24, the slot 2d pro vides parallel shoulders 24a for supporting the edges of the slide 25, the upper face of the yoke 27 being received in the lower narrow rtion of the slot 24 and being secured to the slide 25 by a set screw 73. This conat its ends. Turning the screw I the distance between the lower 24 are adapted to be position of the feet 411., the pivotal mount- 27 extends below the plunger head 26a and has connected thereto one end of a spring '74, the other end of which is connected to a stationary bracket 7 5 carried by the cylinder 22, the s ring '74 serving to hold the slide 25 retract in the slot 24 beyond the end of the stack of blanks 29, until pressure is admitted to the cylinder 22 as previously described As best shown in Figs. 11 and 12, the feed slide '25 has connected to its upper surface a plate 76, the edges of whichthat are at right angles to the slide :25 are beveled at 76c an; 7611. The plate 76 provides a seat 727 for a second plate 7.8., the forward edge of which is beveled at 780 oppositely with respect to the bevel 7 6a on the plate 76. Both the

plates

76 and 78 are secured to the slide 25 by countersunk set screws 79. The slide 25 also provides a concave seat 80 in which is received a block 81 having a convex underside to fit the seat 80, the upper surface of the block 81 having an upward inclination towards the plate 78 and the upper edge of the block 81 terminating just short of the beveled edge 78a of the plate 78 to provide the box blank receiving slot 28 previously referred to.

It is apparent from Fig. 12 that the entrance to this slot 28 is raised just enough above the edge of the table 23 to receive the edge of the lowermost blank 29 when the slide 25 is moved towards the box form 5 by the plunger 26 so that this blank is moved by the slide 25 over the box form 5. However, the slot 28 is so constructed that the box form flap 29a which is received in this slot 28 during the feeding movement readily frees itself from the slot 28 when the upwardly moving box form 5 engages the blank for the blank folding operation. On the return stroke of the slide 25 there is no tendency to disturb the lowermost blank 29, owing to the rear beveled edge76b provided by the plate 76.

Referring now to Fig. 7 there is shown the relation between the box form 5 and the box blank folders when the box form 5 is held .in its lowermost position by a spring 82 prior to the admission of fluid under pressure to the box form cylinder 7. A box blank 29 is shown as having been positioned over the lowered box form 5, and as the box form 5 is moved upwardly, it carries the'blank with it and at the same time the side flaps 29a of the blank are folded downwardly around the edges of the box form 5 by several sets of folders 83 arranged around the four edges of the box form just above the top thereof, with the box form in its lowered position.

As best shown in Fig. 8, the folders 83 are supported in surrounding relation to the box form 5 by means of a set of bars 84 extending at right angles to each other. These bars 84-are supported by the four presser unit castings from a portion of the underside of each presser unit casting, as shown in Fig. 8. One end of each folder bar 84 is secured to a presser unit casting 4 by means of a pivot bolt 85 while the other end thereof is received in a slot 86 provided in the adjacent presser unit casting, the sides of the slot 86 being parallel to the adjacent side of the box form 5. It will be evident from Fig. 8 that the above described mounting of-a given folder bar 84 is repeated for each bar 84, so that the four bars form a rectangle, the sides of which are always parallel to the box form 5. lVhen the relation between the presser units 4 is changed, as will be hereinafter described,

it is evident that the parallel relation between the bars 84 and the sides of the box form 5 will be maintained by reason of the fixed connection of the bars 84 to the presser units and their reception in the slots 86.

As best shown in Fig. 7, each folder 83 provides an upwardly extending portion 88 with a serrated face which permits the sidesof the box blank to be moved upwardly but resists downward movement of the sides 29a of a box blank 29. The base 83a of each folder 83 is slotted at 89 to permit its positioning on the folder bar 84, and a set screw 90 is provided to clamp the folder 83 to its bar 84. As best shown in Fig. 8, one folder 83 of each set is secured to the adjacent presser unit casting by an arm 91, so that when the presserunits 4 are adjusted, four of the folders 83 will be automatically positioned with relation to the box form 5, provided the set screws 90 are loosened before such adjustment. The four folders 83 adjacent the pivot pins 85 of the bars 84 remain set on the bars 84in fixed relation, while it is necessary to manually position the middle folders 83 of each set after an adjustment has been made. The middle folders 83 on the bars 84 on opposite sides of the center line of the table 23 have attached thereto upwardly extending guides 92 which are adapted to keep the completed box centered in one direction over the box form 5 while the middle folder 83 nearest the table 23 provides a guide 93 curving over the table to direct the completed box towards the edge of an inclined delivery chute 94 located opposite to the table 23, see Fig. 1. As the stayed boxes are cleared from the box form 5 upon its downward movement, the serrated surfaces of the folders 83 prevent the finished box from following the box form downwardly and it is evident that the last completed box will be raised between the folders 83 when the next box. blank is moved upwardly between the folders. Consequently, the completed boxes will rise step by step between the

guides

92 and 93 until the guide 93 delivers the uppermost box to the chute 94 down which the box will slide to remove it from the machine.

Referring now to Figs. 5 and 6, there is shown the arrangement whereby the saddles 3 and stay units 4 may be adjusted with respect to each other to permit the pressers 34 to operate on boxes of difierent proportions. As previously pointed out, the saddles 3 are mounted on trunnions 8 supported by the pedestal 2 on opposite sides of the box form plunger 6. The saddles 3 are slidable on the trunnions 8 in parallel relation and the saddles 3 are adapted to be maintained in position with any desired spacing between them by means of a screw shaft 95. This shaft provides

threads

96 and 97 of opposite pitch received in corresponding threads provided in the saddle walls and the intermediate portion of the shaft is held-within a bearing 98 secured to one of the trunnion supports 8a. The end of the shaft 95 provides a hand wheel 99 whereby it may be turned to cause the saddles 3 to be moved towards or away from each other, with respect to the centrally disposed box form plunger 8. As bestshown in Fig. 11, each saddle 3 provides a. pair of slots 100 within which is received a footportion 101 secured to the base 4a. of each presser unit casting. Each foot portion 101 extends downwardl Y through its slot 100 and terminates in a boss 102 providing a threaded open ing 103. The openings 103 of the feet 100 of units 4 on the same saddle are in axial alinement and these alined openings receive a shaft 104 providing

threads

105 and 106 of opposite pitch. This construction is repeated for each saddle 3 and the shafts 104 are adapted to be turned in unison by a shaft- 107 extending between the saddles 3 and connected to the shafts 104 by bevel gears 108. The shaft 107 is rotatably supported in bearin brackets 109 carried by the saddles 3 and is adapted to be turned by a hand wheel 110. Turning of the shaft 107 is adapted to cause the shafts 104 to be turned in unison which in turn will cause the presser units 4 to be moved towards or away from each other, depending upon which way the shaft 107 is turned.

It is therefore apparent from Fig. 8 that the four presser units 4 may be adjusted with respect to the box form 5 to operate on boxes of difierent sizes and proportions, as determined by the size of the box form. As previously pointed out, the folder bars'84 follow the adjustment of the presser units 4 so that the folders are always in position to fold down the sides of a box blank as it is carried upward on the box form 5.

In order to provide for the feeding of stay strips of different lengths in accordance with the depth of the box being formed, means are provided for regulating the length of the strokeof the stay feeding plunger 33. For this purpose the small cylinder bore 32 provides at its end a threaded opening 111 in which is received a bolt 112 with its end projectinginto the bore 32 and provided at its other end with a knurled head 113 whereby it may be readily turned. Normally the spring 60 maintains the inner end of the plunger 33 against the end of the bolt 112 so that the stroke of the plunger 33 when pressure is admitted to the bore 32 is determined by the setting of the adjusting bolt 112. Turning the bolt 112 into the bore 32 advances the plunger 33 thereby decreasing the distance through which the plunger 33 may be moved before engaging the stop 114. This has the efiect of decreasing the length of stay strip 48 that is fed by the roll 45 when the plunger 33 is moved outwardly. Turning the bolt 112 outwardly permits the plunger 33 to be retracted-further within the bore 32, thereby increasing the stroke of the plunger 33 and the amount of stay strip 48 that is fed when the plunger 33 is moved outwardly.

As previously pointed out the feed roll 45 is adapted to be turned in one direction of rotation only by the movement of the pl mger "33, the return movement of the plunger 33 failing to impart rotation to the feed roll 45 through the provision of a one way clutching device, the details of which are shown in Figs. 14, 15 and 16. The shaft 43 which carries the pulley 42 also carries a cam 115 disposed inside the feed roll 45, this cam providing alternate curved portions 116 concentric about the shaft 43 and flat portions 117. A series of rollers 118 are arranged between the flat portions 117 of the cam 115 and the inner periphery of the roll 45 and the rollers 118 are held in position by a cage member 119 providing fingers 119a between the rollers 118. The cage 119 is loose within the roll 45 and as shown in Fig. 15 is connected to the cam 115 through a coil spring 120 anchored at one end to the cage 119 and at the other end to av pin 121 carried by the cam 115. When the shaft 43 is at rest the tension of the spring 120 causes the cage fingers 119a to wedge the rollers 118 into the angles between the flat faces 117 and the inner periphery of the roll 45. Therefore, when the shaft is turned in the direction of the arrow in Fig. 14 the feed roll 45 turns with the shaft 43. However, when the direct-ion of rotation of the shaft 43 is reversed as'when the plunger 33 is returned by its spring 60 following the release of pressure in the bore 32, the pull on the cage 119 by the spring 120 is released, therethe rollers 118 to turn freely by permitting on the fiat faces 117, so that rotativemovement of the shaft 43 is not imparted to the feed roll 45. Consequently, the feed roll 45 feeds the stay strip only when the plunger 33 is moved outwardly.

As a means of regulating the pressure with which the stay strips are applied by the pressers 34, the casting 122 within which the

cylinders

18, 19 and 20 are formed also provides a regulating cylinder 123 connected to the cylinder 19 by a port 124 leading from the bottom of the cylinder 19. As best shown in Fig. 5, the cylinder 123 receives a plunger 125 which is forced downwardly within the cylinder 123 by a spring 126, the upper end of which is positioned by a regulating screw 127 acting on a disk 128. When the cam 13 depresses the plunger 16 within the cylinder 19, the fluid under pressure moves the plungers 31 within the bores 30 until the pressers 34 engage the corners of the box on the box form 5. This pressure is maintained while the stays are being applied, but should this ressure become too great, the by-passage 124 at the bottom of the cylinder 19 permits some of the fluid to enter the regulating cylinder 123, thereby moving the plunger 125 upward-- ly to compress the spring 126. The amount that the plunger may be moved upwardly to relieve the pressure is determined by the setting of the adjusting screw 127, turning the screw 12? down to limit movement of the plunger 125 serving to increase the pressure exerted by the pressers 34. The provision of this regulating cylinder 123 permits of a very wide range of pressure control to meet the varying operating conditions encountered when working on boxes of difierent sizes.

From the foregoing, it is apparent that by my invention I have provided an improved machine for simultaneously applying stay strips to the four corners of a box, the operation of all the various mechanisms being controlled entirely from the cam shaft 10 which operates the pressure cylinders. One revolution of this cam shaft is adapted to first cause the slide 25 to remove the lowermost blank 29 from the stack and position it over the then lowered box form 5, whereupon pressure is admitted to the box form cylinder 7 to raise the box form 5 and carry the box blank upwardly to be operated upon by the folders 83 surrounding the box form between the retracted pressers 34. As the box blank comes to rest with its sides folded down to present four corners, the simultaneous admission of pressure to the presser unit castings causes the four feed plungers 33 to be operated in unison to feed the desired lengths of stay strips downwardly through the knife plates in front of .the retracted pressers 34. As the several stay strips cease feeding, the exposure of the ports 57 leading to the presser cylinders 30 causes the plungers 31 to be operated in unison with the result that the four pressers 34 advance simultaneously to sever the moistened stay strips and apply them to the four corners of the folded box with an equal amount of pressure. After the stay strips have been applied, the release of the pressure in the cylinder 19 permits the pressers 34 to be retracted by their springs 37 whereupon the box form 5 is lowered to leave the completed box held by the serrated faces of the folders 83.-

All of the above described operations occur in rapid succession, but with absolute precision while the cam shaft is making one revolution, and upon the start of the next revolution of the cam shaft the cycle of operations starts again as the slide 25 removes another blank from the stack and presents it in position over the lowered box form. When the box form 5 is again raised carrying with it the new blank, the previously stayed box is moved upwardly, and as successive boxes are moved upwardly by the box form the guide 93 finally delivers the boxes to the delivery chute 94 down which the boxes slide to clear themselves from the machine.

I claim:

1. A box corner staying unit comprising a pair of plungers movable in separate bores, one plunger providing a recessed corner pressing element and the other plunger being operatively connected to a stay strip feeding device and means for admitting fluid under pressure to said bores to operate first said stay feeding plunger and then said pressing plunger.

2. A box corner staying unit comprising a pair of plungers movable in separate bores, one plunger providing a recessed corner pressing element and the other plunger being operatively connected to a stay strip feeding device, of means for admitting fluid under pressure to one of said bores to operate said stay feeding plunger and means for automatically admitting fluid under pressure to the other bore for operating said pressing plunger after said stay feeding plunger has moved a predetermined amount.

3. A box corner staying unit comprising a casing providing parallel bores, plungers operable in said bores, a stay strip feeding roll carried by said unit and operatively connected to one of said plungers and means for admitting fluid under pressure successively to said bores, whereby one of said plungers causes the feeding of a stay strip, while the following movement of the other plunger causes the severance of the stay strip and its application to the box corner.

4:. In a machine of the class described, the

combination with a source of fluid pressure, a rigid box form for supporting a folded box, a plurality of cylinders having plungers movable therein each carrying a presser element and a plurality of cylinders having pistons movable therein each carrying a stay strip feeding device, of means for first connecting said feeding cylinders to said pressure source to simultaneously cause the feeding of stay strips between said presser elements and the corners of the box on said form and then connecting said presser cylinders to said source to simultaneously cause all of said presser elements to apply stay strips to the corners of the box.

5. In a machine of the class described, the

combination with a rigid box form for supporting a folded box, a staying unit providing a cylindrical bore having a plunger movable therein carrying at its outer end a recessed presser element and means for yieldingly maintaining said presser plunger within said bore, of an operating cylinder having a piston movable therein and connections between said cylinder and said bore, movement of said piston in said cylinder in one direction displacing fluid pressure medium therein and causing movement of said plunger within said bore to engage the presser element with a corner of a box and movement of said piston in the opposite direction releasing said pressure medium and permitting a retraction of said plunger within said bore to disengage its presser element from the box corner.

6. In a machine of the class described, the combination with means for placing fluid under pressure, a rigid box form for supporting the inside of a folded box, a cylinder having a piston movable therein for supporting said box form, and a plurality of cylinders having pistons movable therein and carrying presser elements opposed to the corners of said box form, of means for first supplying fluid under pressure to said box form cylinder for raising said form and then supplying fluid under pressure to all of said presser cylinders for simultaneously moving said presser elements to engage the corners of said box form, release of the pressure medium in said cylinders resulting in the lowering of said box form and the withdrawal of said presser elements from the corners of Said form.

7. In a machine of the class described, the combination with means for placing fluid under pressure, a rigid box form for supporti ng the inside of a folded box, a cylinder having a piston movable therein for supporting said box form, a cylinder having a plunger therein for operating a slide adapted to engage a box blank and a plurality of cylinders having pistons movable therein and carrying presser elements opposed to the corners of said box form, of means for first supplying fluid under pressure to said box blank slide cylinder for moving said slide to position a box blank on said form, then supplying fluid under pressure to said box form cylinder to raise said box form and fold down the sides of the blank thereon, and finally in supplying fluid under pressure to all of said presser cylinders to simultaneously move the presser elements to engage the corners of the blank on said form, release of the pressure medium in said cylinders causing the retraction of said slide, the lowering of said box form and the movement of said presser elements away from the corners of said box form.

GREGORY BRODSKY.