US2347908A - Wire stitching machine - Google Patents

Description

May 2, W44. R. s. HOFFERT WIRE STITCHING MACHINE Filed June 19, 1942 2 Sheets-Sheet 1 May 2, 1944.

R. G. HOFFERT WIRE STITCHING MACHINE 2 Sheets-Sheet 2 Filed June 19, 1942 Patented May 2, 1944 Um'reo s'r'res arr orrlce 8 Claims.

This invention relates to the art of wire stitching machines for stitching corrugated and solid fibre shipping containers and particularly to that class of wire stitchers which employ a clinching post which is movable from a position in front of the machine so that a shipping container may be easily placed thereon, to a position to cooperate with the staple forming and driving mechanism.

The object of my invention is to provide a con trol device of simple, durable and inexpensive construction for coordinating the relative movements of the clinching post and the staple driving mechanism. Heretofore the movements of the clinching post and staple driving mechanism have been controlled mechanically by one or more pedals. I have provided an electrical control, and my objects in so doing are to provide a control in which the clinching post is positively moved to clinching position and there firmly held before the electric current can operate to start the wire stapling mechanism, and upon completing the stapling operation on a shipping container, the current for operating the staple driving mechanism is necessarily cut off before it is possible to release the clinching post for its return to its position extended outwardly from the ma chine, thereby avoiding all possibility of having these two operations occur in other than proper sequence, or so nearly simultaneously as to make it possible for the staple driving mechanism to operate when the. clinching post is wholly or partially removed from clinching position.

Another advantageous result that I attain by my improved electrical control is that the control electric switch pedal is freely movable on the fioor to any desired position relative to the machine. With mechanically operated pedals, and when the pedals are positioned to suit the convenience of the operator when working on relatively small shipping containers, then when relatively large shipping containers are being up erated on or when the containers are turned in the clinching post at such an angle that the corner of the container projects straight outwardly from the machine the. operator cannot conveniently and easily reach the pedal with his foot, whereas, with my improvement the pedal is easily moved to any position which suits the ease and convenience of the operator, thereby saving time and; labor in the use of the machine.

In the accompanying. drawings- Figure 1 shows a side elevation of a wire stitching machine having my improvement applied thereto, a part of the machine being broken away spring, and showing the two positions of the clinching post by dotted lines;

Figure 2 shows a diagram of the electric circuit;

Figure 3 shows a detail sectional view of the driven shaft of the staple forming and driving mechanism, the motor operated driving shaft and a part of the clutch device for operatively connecting and disconnecting them, taken on the line 33 of Figure 4;

Figure 4 shows a sectional view of the clutch device on the line 4-4 of Figure 3 and also shows the solenoidfor actuating same;

Figure 5 shows a detail sectional View illustrating the sliding clutch pin and the wedge arm for operating the clutch and associated parts;

Figure 6 shows a detail perspective View of the wedge arm and the collar on the driving shaft in which the clutch pin is contained; and

Figure 7 shows a vertical sectional View of the pedal switch.

The machine frame is indicated generally by the reference numeral l0 and has the usual staple forming and driving mechanism, indicated generally inFig. 1 by the letter M. This mechanism, as is well known in the art, is carried in a stitched head such as H and has means for feeding wire including the reel R, means for cutting the Wire into lengths and forming the lengths into staples, and means for successively driving the staples into the work illustrated as a carton N. This mechanism is operated from a driving shaft l l, and this driving shaft is driven from the motor I2 by a' belt l3.

Pivoted on the front of the machine base is the clinching post I 4 of the usual construction; It has a downwardly extended arm l5 below its fulcrum, and attached to this arm is a spring l6 for normally holding the clincher post to its outwardly extended position, as shown by dotted lines at IT. For limiting the movement of the clincher post when at its working position I have provided a lug 18 on the post and screw l9 on the base and a nut 29 on the screw to engage the lug l8. By adjusting the nut the movement of the clinching post may be limited, and it is positively held by the nut 23 against further movement toward the machine.

For moving the clinching post toward its working position Iv have attached to the arm l5 a solenoid core 2| which is associated with a solenoid coil 22 in the usual manner and which coil is fixed to the machine base.

' For controlling the movements of the driving to show the clinching post operating solenoid and shaft it I have provided a solenoid coil 23 fixed to the machine frame and a solenoid core 24 which, as will hereafter appear, actuates a clutch device between the driving shaft II and the driven shaft of the staple forming and driving mechanism.

For controlling the electric circuit flowing between the two said solenoids I have provided a switch pedal, shown in Fig. 7, which comprises a base 25 of insulating material in which is slidingly mounted an upright switch post 26 of conducting material. The post is normally held upwardly by a spring 21. Near the lower end of the post 26 is an annular groove 28, and spaced above itis another similar groove 29. Mounted in the base 25 near its lower portion are two opposed sliding conductor pins 39 yieldingly held toward the post 26 by the springs 3|, and above held by the solenoid 22 in an upright position until after the operation of the stitching mechthem are two similar pins 32 having springs 33."

The springs 3! and 33 are adjusted by the screws 34.

In the diagram of the electric circuit, shown in Fig. 2, there is illustrated the generator 35, the solenoid 22, the solenoid 23 and the pedal post 26. A conductor 36 leads from the generator to both of the conductor pins and 32 at one side of the pedal switch, a conductor 31 leads from the lower conductor pin 36 on the opposite side of the pedal post, and a return 38'leads from the solenoid 23 to the generator. A conductor 39 leads from the upper conductor pin 32 on the opposite side of the switch to the solenoid 22, and the return wire 40 conducts the current to the return wire 38. For driving the motor [2, lead and return wires 4| and 42 are provided. I

When the foot pedal 26 is depressed against the action of the spring 21 to a position where the pins 32 enter the groove 28, a circuit is established through the pedal post and through the solenoid 22. On a further or continueddepression of the pedal post 26 the groove 28 is moved out of engagement with the pins 32 and into engagement with the pins 30 to close the circuit through the solenoid 23. The pins 32, during this continued depression of the pedal post, are in frictional sliding engagement with the pedal post; so as to retain the circuit for the solenoid 22 closed. Substantially concurrently with the location of the pins 30 in the groove 28 the pins 32 are located in the groove 29 to define the operating position of the pedal post 26 when both of the solenoids 22 and 23 are energized.

It is seen, therefore, that the solenoid 22 on movement downwardly of the pedal post 26 is initially energized to move the clinching post or work support M from its dotted line position ll, shown in Fig. 1, to its normal operating or upright position, also shown in dotted lines in Fig. 1, and to hold the clinching post in such operating position. During the movement of the pedal post 26 to establish a circuit through thesolenoid 23 the clinching post 14 is retained in its upright position by virtue of the continued energization of the solenoid 22. I

.The pedal post 26, on being released, is moved upwardly by the action of the spring 21 which, as clearly appears from Fig. '7, is compressed between the base 25 and the head portion H on the pedal post 26 when the pedal post is depressed. On upward movement of the pedal post the circuit of the solenoid23 is initially opened to stop the operation of the stitching mechanism. The circuit through the solenoid 22 is subsequently opened so that the clinching post His anism is stopped. The solenoid 22 thus operates to hold the clinching post l4 in an upright position, against the action of the spring [6, prior to and during the operation of the stitching mechanism, and after the operation of the stitching mechanism is stopped. Further, on a complete release of the foot pedal 26, or at least to a position of the pedal post 26 at which it is free of the pins 32, the clinching post I 4 is moved to its dotted line position I! by the spring 16 to facilitate the handling and positioning of cartons or the like on the clinching post.

It is of importance that the grooves 28 and 29 in the pedal post be quite deep and that the springs for the conductor pins be relatively stifi, for the reason that when thus provided the operator may distinctively feel with his foot when the clinching post solenoid has been energized and again may distinctly feel when the clutch operating solenoid has been energized. The spring 21, however,- is powerful enough to raise the pedal post when foot pressure has been removed.

The solenoid 23 is for the purpose of actuating a clutch device for operatively connecting and disconnecting the power driven shat II from the shaft 43 which operates the staple formingand driving mechanism. a

I have illustrated a form of clutch device suitable for this purpose, as follows: Fixed to the main shaft H by a set screw 45 is a hub 46 to which the hand wheel 46a is fixed. Rotatably mounted on the shaft II is a sleeve 48. A shaft 43 is insertedin this sleeve 48 in line with the shaft H, and the sleeve is fixed to the shaft 43 by the set screw 48a.

Slidingly mounted in the sleeve 48 is a latch bar 49 having a bevelled notch 50 at one side and having a spring 5| for forcing it toward the hub 46, which is provided with an opening at 52 to receive the latch bar and operatively connect the hub H with the sleeve 48. For releasing the latch bar and thereby stopping the operation of the stitching machine I have provided the solenoid 23.

At one side of the shaft H is a shaft 54 carried at one end in a portion 55 of the main frame l0 and extended outwardly from the frame 19 in a direction substantially parallel with the shaft H (Figs. 3 and 4). Fixed to the extended end of the shaft 54 is a collar 0. An arm 56 is rotatably mounted on the shaft 54 between the collar 0 and a second collar C which is also fixed on the shaft 54. The arm 56 is connected by links 56a with the core 24 of the solenoid 23 and is normally slidably received in an annular groove 58 formed in the periphery of the sleeve 48 for guidable travel in the path of the notch 56 in the latch bar 49. An end 59 of the arm 56 is tapered, as shown in Fig. 5, for mating engagement with the bevelled notch 56 so that the tapered end 59 normally holds the latch bar 49 in the position shown by dotted lines in Fig. 5 to disconnect the hub 46 from the shaft ll.

The arm 56 is normally held in the groove 58 by a coil spring S wrapped around the shaft 54 intermediate the collar C" and the arm 56. The spring S is connected at one end to the collar C and at its other end to the arm 56 and exerts a pressure on the arm 56 to yieldably retain this arm within the groove for engagement with the slide bolt 49. The solenoid 23, on being energized, moves the arm 56 out of engagement with the slide bolt 49' which is then free to be moved by the spring into engagement with the hub 46 at the hub opening 52. Since the hub 45 is on the continuously rotating shaft 5 I it is to be understood that this engagement takes. place when the opening 52 is in arial alignment with the slide bolt 49 as shown in Fig. 3.

From the. foregoing it is seen that when the solenoid 23 is not energized the stapling device is not operated by the motor. When it is desired to have it operate the solenoid 23 is energized to move the arm 56 to permit the slide bolt 49 to enter the notch 52 in the hub 46 so as to connectthe shaft it with the shaft ll. On the completion of this connection of the shafts H and. 83 the stapling device is in a position for starting a cycle of movement. This cycle is completed when the solenoid 23 is de-energized and: the arm 56 moved by the spring S to engage and move the slide bolt 59 to a position free of the hub 46, thereby stopping the stapling device. Thus when the circuit for the solenoid 23 is momentarily closed the stapling device is operated through a complete cycle and then stopped. A friction device F (Fig. 1) is preferably applied to the sleeve 43 to cause it to stop instantly when the drive shaft is disconnected from the driven shaft.

From the foregoing it will be seen that by means of my improved electrical control mechanism the clinching post is swung to operative position by the solenoid and is always moved at the same properly adjusted speed regardless of the speed or amount of pressure applied by the operators foot. Further the clinching post is firmly held in its operative position by the solenoid and Without the use of any mechanical latch devices. The limit of this movement of the clincher post is governed by a simple adjustable stop lug, and regardless of the adjustment of the stop lug, the solenoid functions to move and hold the post hi in position against the stop lug.

In view of the fact that the solenoid 23 for the clutch can be actuated only after the post solenoid 22 has been energized, and the solenoid 22 for the post cannot be released until after the solenoid 23 for the clutch has been de-energized, it is obvious that a careless operator cannot damage the machine or its product by having the machine perform these operations in other than their proper sequence as may be done with prior art mechanically operated pedals and post moving and clutch releasing devices. An important advantage that is produced by my improved electrically wired clinching post and clutch devices is that it enables me to utilize a pedal in the form of an electric switch which, being connected by the ordinary flexible wires, may be freely moved relative to the machine to any position suited to the ease and convenience of the operator, whereas, with the prior art mechanical pedals this was not possible and has caused inconvenience and delay.

By the term solenoid I mean to include any electromagnet suitable for the purpose.

I claim as my invention:

1. In a wire stitching machine, the combination of a staple driving mechanism, means for operating the staple driving mechanism, a clutch device for throwing said driving mechanism into and out of operation, electrical means for operating said clutch device, a movable clinching post, a second electrical means connected to said clinchingpost which, when energized, movessaid post to a position for cooperating with said staple driving mechanism, tension means for moving said clinching post out of said position. an electric switch device including a pedal, contacts whereby a downward movement of said pedal energizes said second electrical means, and means whereby a further downward movement of said pedal energizes said first electrical means, and tension means for elevating said pedal.

2; In a wire stitching machine including stapling means, a work support movable into and out of an operating position relative to said stapling means, electrically operated means for moving and holding said work support in said operating position, a second electrically operated means for controlling the starting and stopping of opera tion of said stapling means, and a manually operated switch unit'electrically connected with said two electrically operated means to provide for their operation in a predetermined sequence so that said work support is in said operating position during the operation of said stapling means.

3. In a wire stitching machine including a staple driving mechanism, a movable clinching post normally in a rest position and movable to an operating position relative to said staple driving mechanism, electrically operated means for moving and retaining said clinching post in said operating position, means for driving said staple driving mechanism, electrically operated means for connecting said driving means and said staple driving mechanism, and a switch means for selectively controlling the operation of said two electrically operated means.

4. In a wire stitching machine including a staple driving mechanism, a clinching post normally retained in a rest position but movable to an operating position relative to said staple driving mechanism, electrically operated means for moving and holding said clinching post in said operating position, a second electrically operated means for controlling the operation of said staple driving mechanism, an electrical circuit for said two electrically operated means, and switch means in said circuit providing for the selective operation of said two electrically operated means so that said clinching post is in said operating position during the operation of said staple driving mechanism.

5. In a wire stitching machine including a stapling means, a work support movable into and out of an operating position relative to said stapling means, electrically operated means for moving and holding said work support in said operating position, a second electrically operated means for controlling the operation of said stapling means, a circuit for said two electrically operated means, and a manually-operated switch unit in said circuit including a reciprocally movable contact portion providing for the successive energization of said two electrically operated means on movement thereof in one direction, and for the successive de-energization of said two electrically operated means on movement in an opposite direction so that said work support is in said operating position during the operation of said stapling means.

6. In a Wire stitching machine including a base portion. and staple driving means, a movable clinching post normally yieldably retained in a position outwardly of the stitching machine and movable toward the stitching machine to an operating position relative to the staple driving means,'first electrically operated means for moving and holding said clinching post in said operatin position, an energizing circuit for said first electrically operated means, a second electrically operated means for controlling the operation of said staple driving means, an energizing circuit for said second electrically operated means, a switch unit in said two circuits including a foot-operated portion normally yieldably held in a position to render said two circuits inoperative, said portion being movable in one direction to successively energize said two circuits, and in an opposite direction to successively. de-energizesaid two circuits so that said clinching post is in said operating position during the operation of said staple driving means, and means for connecting said switch unit with said two circuits to provide for its location at any desired position relative to said base portion. 7. In a wire stitching machine including a stapling means, a work support movable to rest and operating positions relative to said stapling means, electrically operated means for moving and holding said work support in one of said positions; a second electrically operated means for controlling the starting and stopping of said stapling means, and a switch means for selectively controlling the operation of said two electrically operated means.

8. In a wire stitching machine having a stapling means, electrically operated means for starting and stopping the operation of said stapling means, a work support movable into and out of-an operating position relative to said stapling means, a second electrically operated means for moving, and holding said work support, in said operating position, and a switch means for controlling the operation of said two electrically operated means including a manually operated portion movable in one direction to

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