MXPA96006419A

MXPA96006419A - Inertial stress device of straps and method for flexed machine

Info

Publication number: MXPA96006419A
Application number: MXPA/A/1996/006419A
Authority: MX
Inventors: Abrams Jack; Pearson Timothy; Gurak Ronald
Original assignee: Illinois Tool Works Inc
Priority date: 1995-12-15
Filing date: 1996-12-13
Publication date: 1997-06-01

Abstract

The present invention relates to tensioning mechanisms of the strap for a strapping device, comprising dragging mechanisms for pulling the strap from the strap roll, and connecting mechanisms for connecting the strap roll to the pulling mechanisms for pulling the strap from the strap. the roll so that the pulling mechanisms by rotating the roll of the strip, independently of any other power supply, and so that no overloading of the roll of the strip causes the pulling mechanisms more strap of the roll of the strap to maintain the tension in the strip that extends between the roll of the strip and the mechanisms of drag

Description

INERTIAL STRESSING DEVICE OF STRIPS AND METHOD FOR STRAPPING MACHINE Cross reference to related applications: The present invention is related to the following copending applications: Obstruction removal device and method for strapping machine. Fastening device in two stages and method for strapping machine. Strapping path access device and method for strapping machine. Strapping and strip ejector device and method for strapping machine. BACKGROUND OF THE INVENTION Caapo of the invention: The present invention relates to strapping machines for placing and securing a binding strap around an object or objects and, specifically, the present invention relates to a device and method for maintaining tensioning in the end of a strap by the inertia of rotating members of the device. Description of the Related Art: The strip that is pulled from the strapping coil of a strapping machine must be maintained at a particular tension, for the proper functioning of the strapping machine. In the past, several devices and methods were proposed to maintain the tension of the strip. A prior art device requires a floating arm with a spring clutch to apply a force to a strap segment, and tape brakes to stop the rotation of the coil after stopping the pulling of the strap from the strap coil, in order to prevent a loose and insufficient tension of the strap. Other prior art devices require electric or electromagnetic brakes to stop the rotation of the coil, and also require constant rotation suspension wheels that constantly slide over the strap. All of these prior art systems operate only in the forward direction of the strip pull, where the strip is fed from the strip coil. The tensioning devices of the prior art do not work in reverse, or rewind direction. All systems of the prior art have the disadvantage of a general mechanical complexity. The floating arms, which function properly for various blade speeds and varying conditions of belt acceleration and deceleration, are difficult to design, as it is also difficult to keep them tight. In addition, the braking systems are generally complex, particularly the sensor and signal systems for the application and removal of the braking action against the coil. The present invention solves the problem of retaining the appropriate tension of the strap by providing an inertial system, eliminating the need for complex systems of floating arms and braking. Since the strap is maintained in an essentially constant tensioning condition, the formation of strap turns that would otherwise fall from the strap coil is prevented. The strap is prevented from twisting in the strip coil. In addition, the laxity of the strap is gently eliminated, thus eliminating abrupt forces that would otherwise have to be applied to the strap and machine parts during conventional strap tensioning. The present invention also solves the problems associated with stopping the rotation of the rotating elements of the strapping machine, and rewinding strap to remove it from the machine and return it to the coil. SUMMARY OF THE INVENTION The present invention uses the inertia of the rotating elements of the strip coil to drive the shaft of the driving motor after the electric power to the driving motor is interrupted. The inertia of the rotating coil of the front strap driven by an electric motor is transferred by means of an arrangement of pulleys and belts back to the axis of the driving motor, moving the shaft of the driving motor towards the forward direction, and consequently continues to maintain the tension in the end of the strap. Friction and other resistance forces in the system will cause the rotating members to rotate at a decreasing rate, for eventual being stopped gradually. By electrically driving the drive motor in the reverse direction, the band moves in the reverse direction. A one-way clutch connects the bench to the strip coil, reversing the rotation of the strip coil, in order to remove the strap from the strapping machine and rewind it to the strip coil. An object of the present invention is to maintain the tension in a strap of a strapping machine without the need for a floating arm tensioning device. Another object of the present invention is to provide a way to stop the rotating members of the strapping machine without the need for electrical or electromechanical braking devices. Still another object of the present invention is to provide a rewind of strip by reversing the direction of the driving motor. These and other objects of the present invention will be fulfilled by the device and methods described below. BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 shows a front view of the invention described herein. FIGURE 2 shows a side view of the invention described herein. DESCRIPTION OF THE PREFERRED MODE With reference to Figure 1, the invention comprises a frame 15 and drive motor 1 with a first motor shaft 2. A drive wheel 4 is attached to the first motor shaft 2. A guide roller 6, attached to a guide roller arm 16 is coincident with the driving wheel 4. The force by which the guide roller arm 16 and the guide wheel are driven towards the driving wheel 4 can be adjusted by a guide roller spring 17. When electrical power is supplied or of another kind to the driving motor to drive it in the forward direction produces the forward rotation of the first motor shaft 2. The driving wheel 4 is therefore driven in the forward direction. A strip 13 with a loose end 14 is pulled from a strip coil 9, by physical connection of the strip with the rotating driving wheel 4 and the guide roller 6. The unwinding of the strip 13 ca the strip coil 9 to turn in one direction. forward direction. Referring now to Figure 2, a first pulley 5 is connected to a second motor shaft 3. The first pulley 5 and the second motor shaft 3 are connected by a transmission belt 11, or chain or other devices to a second one. pulley 10. The second pulley 10 is connected with a fixed shaft and with flanges 8 by a one-way clutch 12. The flange cooperates to form a strap coil 9 to maintain a quantity of strap in a coiled arrangement. In operation, the loose end of the strap 14 is held mechanically between the driving wheel 4 and the guide roller 6. The guide roller 6 is movable relative to the driving wheel 4 in a direction that is generally on a line connecting its two centers, in order to exert an appropriate force against the strip 13 by activating the spring of the guide roller 17 in connection with the guide roller arm 16 against the guide roller 6. The electric power supplied to the driving motor 1 which rotates it in the forward direction it also ca the rotation of the first motor shaft 2 and the rotary wheel 4 in the forward direction. The strip 13 is therefore pulled from the strip coil 9, causing the rotation of the strip coil 9, the flange 7 and the fixed shaft with flange 8 in the forward direction. The fixed shaft with flange 8 is connected by a one-way clutch 12, and in one of the embodiments is a guide-type clutch, to a second large pulley 10. The fixed shaft with flange 8 and the second pulley 10 can share a common central axis. A transmission belt or other device, such as a chain, connects the second pulley 10 to a first pulley 5 which is mounted on a second motor shaft 3 of the driving motor 1. In one embodiment, the first pulley 5 has a common central axis with the driving wheel 4. In a modality, the ratio of the diameter of the first pulley 5 and the diameter of the second pulley 10 is greater than the ratio between the maximum diameter of the strip coil 9 and the diameter of the driving wheel 4. As the coil is pulled 13 from the coil of strip 9, the diameter of strip coil 9 decreases. Accordingly, the strip coil 9 rotates at a speed that correspondingly increases. However, due to the constant speed of the driving wheel 4 and the guide roller 6, the speed of rotation of the strip coil 9 does not affect the speed at which the strip 13 of the strip coil 13 is pulled. to the action of the one-way clutch 12, the second pulley 10 rotates on the fixed shaft with flange 8 during the forward rotation of the driving motor 1. The tension of the strap is maintained during this step of the operation as the strap 13 is pulling of the strap coil 9 by the driving wheel 4. When the electric power to the driving motor 1 is discontinued, the inertia of the strap coil 9 and the flange 7 will continue to drive the driving motor in the forward direction. This driving force is supplied from the rotating band / flange coil system by the fixed shaft with flange 8, towards the one-way clutch 12, to the second pulley 10, to the transmission belt 11, to the first pulley 5, to the second motor shaft 3, and finally to the driving motor 1. The rotation of the driving motor 1 in this forward direction causes the driving wheel 4 to continue to pull the strap 13 under the tension of the strip coil 9. The friction and other forces of resistance finally cause the rotating members to stop rotating, by which the system reaches a resting position. However, the loose end of the strap 14 is consequently kept under constant tension. The removal of the strapping 13 from the strapping machine and the rewinding of the strapping 13 to the strapping coil 9 can be achieved by supplying electric or other power to the driving motor 1 in the reverse direction after releasing the tension of the guide roller 6 from the strapping 13 and the driving wheel 4. The driving motor 1 will now drive the first pulley 5, which drives the transmission belt 11, the second pulley 10, the one-way clutch 12 and the fixed shaft with flange 8, thereby driving the flange 7 and the strip coil in the reverse direction, causing the strip 13 to be removed from the strapping machine and rewinding it in the strip coil 9. The present invention encompasses the range of equivalents to which it is entitled, and is only limited by the following claims.

Claims

REVINDINGS 1. An inertial strap tensioning device for a strapping device, comprising a device for pulling strap of a strap coil, a device for pulling the strap to be i pulsed by means of the rotation of the strapping coil where the strap is pulled, independently of an external force supply, where the rotation of the strap coil is transferred by a connecting device from the strap coil to the device for pulling the strap.
2. An inertial strap tensioning device for a strapping device, according to claim 1, further comprising an external power supply device for driving the strap pulling device.
3. An inertial strap tensioning device for a strapping device, according to claim 2, wherein the drive device with external power supply is a driving motor, wherein the driving motor has a first motor shaft and a second motor shaft. motor, a driving wheel attached to the first motor shaft, a first pulley attached to the second motor shaft, a strap pulling device comprising a guide roller acting in cooperation with the driving wheel, a loose end of strap held firmly between the drive wheel and the guide roller, where the forward rotation of the driving motor by applying external energy rotates the first motor shaft and the driving wheel in a forward direction, where the action of the driving wheel and the guide roller against The strap causes the strap to pull under the tension of the strap coil.
4. An inertial strap tensioning device for a strapping device, according to claim 3, wherein the strapping coil has a fixed shaft with a flange fixed to and rotating with the strap coil, a one-way clutch attached to the fixed shaft with flange, and a second pulley fixed to the one-way clutch, where the one-way clutch rotates on the fixed and flanged shaft when the driving wheel rotates in the forward direction by the external supply drive motor of energy.
An inertial strap tensioning device for a strapping device, according to claim 4, wherein the connecting device is a transmission belt connecting the second pulley with the first pulley, where the transmitting belt is pulsed in the direction forward by the rotation of the strip coil, the fixed shaft with flange and the one-way clutch where, upon cessation of the external power supply of the driving motor, the inertial rotation of the strap coil through the clutch One-way drive drives the transmitting belt, the first pulley, the second motor shaft, the first motor shaft and the driving wheel, where the driving wheel acts with the guide roller to continue pulling the strip that is under tension of the coil strip until the rotary motion ceases due to resistance forces.
6. An inertial strap tensioning device for a strapping device, according to claim 5, wherein the driving motor is driven in a reverse direction by an external source of energy, where the strip coil is driven by the second axis of motor, the first pulley, the transmitting belt, the second pulley and the fixed shaft with flange, where the fixed shaft with flange is driven by the second pulley by the action of a one-way clutch, where by means of the operation of the driving motor in the reverse direction, the strip coil is driven in the reverse direction, removing the strap from the strapping machine and rewinding the strap to the strap coil.