Automated nonuniform enclosure cutting tool

Embodiments are directed to an automated cutting tool that is configured to cut open nonuniform enclosures, such as cases containing electronic components. An example system comprises a multi-speed motor that is coupled to a cradle. The multi-speed motor rotates the cradle at a selected speed, and the cradle adapted to hold a case. A cutting head is positioned adjacent to the cradle and is configured to maintain contact with the case during rotation of the multi-speed motor. The multi-speed motor is configured to operate at a first speed when first segments of the case are in contact with the cutting head and to operate at a second speed when second segments of the case are in contact with the cutting head.

BACKGROUND

Many different types of portable electrical devices contain internal components that must be shielded from the surrounding environment to prevent degradation or that must be enclosed in a housing to prevent tampering. The size and shape of such sealed cases are dependent on the components of the electrical devices. Components common to most devices include a battery and a circuit board that carries digital circuits, such as integrated circuit chips, a microprocessor, and/or analog circuit components. Such components may be housed in a rugged, weatherproof, factory-sealed, plastic case that is shock resistant and waterproof to ensure reliable functionality under normal atmospheric and environmental conditions.

Often such cases are sealed to prevent malicious tampering and/or unskilled repairs on the enclosed electronic components. Such cases may comprise two shells made of impact-resistant plastic that are non-releasably connected to each other using glue, epoxy, or welding, for example. When the electronic devices require refurbishment or maintenance, the case mush be safely cut open without damaging internal electronic components. Prior solutions involve cutting open the case with a hand-held saw. This is a slow, labor-intensive, inaccurate, and potentially dangerous process. In addition to the risk of bodily injury such as cutting oneself, significant fumes and plastic dust can be produced in the cutting process. A need exists to provide a means to quickly cut open electronics cases with minimal human intervention to save on labor costs and to improve workplace safety.

SUMMARY

Embodiments are directed to an automated cutting tool that is configured to cut open nonuniform enclosures, such as cases containing electronic components. In one embodiment, a system comprises a multi-speed motor that is coupled to a cradle. The multi-speed motor rotates the cradle at a selected speed, and the cradle adapted to hold a case. A cutting head is positioned adjacent to the cradle and is configured to maintain contact with the case during rotation of the multi-speed motor. The multi-speed motor is configured to operate at a first speed when first segments of the case are in contact with the cutting head and to operate at a second speed when second segments of the case are in contact with the cutting head.

The first and second segments may correspond to any features of the case. For example, the case may have an oblong shape, and the first segments are short sides of the case while the second segments are long sides of the case. Alternatively, the first segments may correspond to one or more sides of the case, and the second segments correspond to one or more corners of the case. In other embodiments, the second segments may correspond to sections of the case that are thicker than the first segments of the case.

The system may further comprise a trolley that is slidably mounted on a rail. The cutting head is attached to the trolley and is configured to move toward or away from the cradle as the cradle rotates and as different sides or edges of the case are presented to the cutting head.

The system may further comprise a spring element that is coupled to the trolley. The spring element is configured to apply a spring force on the trolley to move the trolley toward the cradle. The system may further comprise a flexible link that is coupled between a pulley and the trolley. The flexible link is configured to overcome the spring force when the pulley is rotated in a first direction. The flexible link configured to allow the spring force to move the trolley when the pulley is rotated in a second direction. The system may further comprise a servo motor that is coupled to the pulley. The servo motor is configured to rotate the pulley in the first or second direction in response to signals from a controller.

The system may further comprise a rotary motor and a flexible extension that is coupled between the rotary motor and the cutting head. The flexible extension is configured to transfer torque from the rotary motor and the cutting head. The flexible extension allows the cutting head to move toward or away from the cradle while the rotary motor maintains a fixed position.

The system may further comprise a guard that is coupled to the cutting head. The guard is configured to limit a cutting depth that is allowed when the cutting head contacts the case. For example, the cutting head may cut into the case sidewall until the guard touches the sidewall. The guard then prevents the cutting head from cutting any deeper into the sidewall.

The system may further comprise a controller that is configured to control the speed of a multi-speed motor based upon a current angular position of the multi-speed motor. The multi-speed motor may be a stepper motor that is configured to rotate at the first speed while rotating through a first range of angles of rotation and to rotate at the second speed while rotating through a second range of angles of rotation. The controller may comprise a processor and a memory for storing instructions that may be executed by the processor. The instructions, when executed by the processor, may cause the controller to command the multi-speed motor to rotate at the first speed when the current angular position corresponds to the first segments of the case, and then command the multi-speed motor to rotate at the second speed when the current angular position corresponds to the second segments of the case, wherein the first speed is faster than the second speed.

In another embodiment, a method comprises commanding a multi-speed motor to rotate a device at different speeds depending upon a current angular position of the device relative to a blade or other reference point. The multi-speed motor rotates the device at a first speed when the current angular position corresponds to first segments of the device and rotates at a second speed when the current angular position corresponds to a second segments of the device. The first speed and second speed are different, such as the first speed may be faster than the second speed. The multi-speed motor may be a stepper motor. The method further comprises cutting a sidewall of the device using a rotary blade while the device is rotating at the first or second speed.

The method may further comprise applying a positioning force to the rotary blade. The positioning force is configured to move the rotary blade toward the sidewall of the device. The method may further comprise applying a retraction force to the rotary blade. The retraction force is greater than the positioning force and is configured to move the rotary blade away from the sidewall of the device.

The method may further comprise driving the rotary blade at a first cutting speed when the current angular position corresponds to the first segments of the device and driving the rotary blade at a second cutting speed when the current angular position corresponds to the second segments of the device. The first segments may correspond, for example, to one or more sides of the device, and the second segments may correspond to one or more corners of the device. The second segments may correspond, for example, to sidewalls of the device that are thicker than the first segments of the case.

DETAILED DESCRIPTION

FIG. 1depicts an automated cutting tool100according to an example embodiment. The automated cutting tool100comprises a frame101, which may be constructed of aluminum or any other appropriate material. Frame101has a bottom rail102and a top rail103, which is supported by two vertical supports104and105. Base support legs106and107provide stabilization for frame101. The bottom rail102, top rail103, vertical supports104,105, and base supports106,107may be individual components that are joined by 90 degree corner brackets108as shown inFIG. 1or may be parts of single frame device. The size and shape of the frame components may be selected based upon the size, weight, and desired positioning of the elements of the automated cutting tool100. For example, one or more rails or supports may be configured to resist torque or other forces caused by rotating components.

Rotary tool109is attached to top rail103by bracket110. Rotary tool109is an electronic tool powered by power supply111and may be single speed or variable speed. A flexible shaft extension112connects rotary tool109to a rotary right angle attachment113, which drives a cutting head114. Right angle attachment113and cutting head114are attached to a slidable cutting-head trolley115that moves along a linear rail system116mounted underneath top rail103. The linear rail system116provides maximum rigidity to avoid cutting head jams caused by either the rotating platform or the cutting head twisting perpendicular to the blade angle.

The cutting head114is tensioned with a spring-loaded cam follower mechanism. A spring117applies a force to pull trolley115to the left inFIG. 1. A wire118couples trolley115to a pulley119. A servo motor120drives pulley119counterclockwise to apply tension on wire118, which exceeds the force of spring117and pulls trolley115to the right. Clip121holds flexible shaft extension112and allows for movement of extension121as trolley115moves.

Cradle122is adapted to securely hold a device123to be cut open by cutting head114. In one embodiment, the device123may be an electronic apparatus, such as a Global Positioning System (GPS)-based monitoring device (e.g., ankle monitor), smartphone, or tablet, with a sealed plastic or metal case. Automatic cutting tool100is adapted to cut open the case quickly and without damaging internal electronics. Cradle122is attached to a stepper motor124that rotates cradle122during operation. Stepper motor124allows for precise control of angular position of cradle122. In an alternative embodiment, a servo motor may be used instead of stepper motor124and feedback from the motor may be used to determine a current rotation position.

FIG. 2illustrates device123mounted on cradle122while trolley115and cutting head114are retracted out of the way. Device123may be securely mounted on cradle122using bands, clamps, or other fasteners. Alternatively, the design of cradle122may be tightly fit to the form of device123so that device123securely “snaps into” cradle122. Device123fits into cradle122so that a desired cut line C on device123will remain clear of cradle122and exposed to cutting head114as cradle122is rotated. When device123is mounted on cradle122, stepper motor124may be turned on to rotate cradle122and device123. Additionally, rotary tool109may be turned on so that cutting head114begins turning.

FIG. 3illustrates automatic cutting tool100where wire118is no longer applying a force to move trolley115to the right. Tension on wire may be released if servo motor120allows pulley119to rotate freely or actively rotates pulley119clockwise. With the tension in wire118released, spring117pulls trolley115to the left so that cutting head114comes in contact with device123and begins cutting the case. The ideal blade used in cutting head114for a particular electronic device123case may be determined by testing to identify a blade that allows for high-speed cutting while limiting smoke and avoiding skipping and jamming. Similarly, rotary tool109may be selected based on efficiency, durability, and cost considerations.

FIG. 4illustrates automatic cutting tool100in operation after stepper motor124has rotated cradle122and device123by 90 degrees from the position shown inFIG. 3while continuing to cut the case. Spring117pulls trolley115to the left, which generally keeps cutting head114against device123during operation. While cutting the case on device123, cutting head114generates heat that can be dissipated using fan125, which is mounted on the same shaft as cutting head114. Fan125spins with cutting head114and forces ambient air across cutting head114and the case of device123. This reduces the temperature of the cut surface and prevents melting of the case and distortion of cutting head114. Fan125also disburses smoke and fumes created during operation. Additionally, automatic cutting tool100may be operated on a vacuum table that allows for fumes and dust to be collected during use.

FIG. 5is detailed view of the right angle attachment113and cutting head114that are attached to slidable cutting-head trolley115. A blade guard126mounted on two posts127is attached to trolley115and positioned to limit the depth that cutting head114can penetrate device123when mounted on cradle122. Blade guard126may be adjusted based on the type of device123that is being cut open to compensate for the case thickness on different devices.

Automatic cutting tool100may include one or more switches or other interfaces to control operation. For example, a system power switch128may control power to tool100and may also function as an emergency off switch. A spin control switch129may control the rotation of stepper motor124and cradle122, while a cutter control switch130may control the rotary tool109and cutting head114.

A control unit131may comprise a circuit board, application-specific integrated circuit (ASIC), or other control circuitry and/or software for controlling automatic cutting tool100. Control unit131may control, for example, the speed and direction of rotary tool109and cutting head114, the activation of servo motor120, and the speed and direction of rotation for stepper motor124. In one embodiment, the control unit131is custom coded to rotate stepper motor124at variable speeds depending upon the degree of rotation of the electronic device123. Control unit131may further comprise foam or rubber dampening material (not shown) to compensate for frame vibration and to protect the circuit board and hand-wired components.

The speed of rotation of the electronic device123is not uniform. This is because testing has demonstrated that the cutting head114will skip past areas adjacent to the corners of the device if the rotation speed is not moderated. Even with a high tension applied by spring117to keep cutting head114against device123, if the rotation speed is too fast, then the cutting head will bounce over the corners of the device123instead of making a constant cutting action.

In various embodiments, the rotary tool109, flexible shaft extension112, and rotary right angle attachment113may be commercially available products, such as DREMEL® tools and accessories available from Robert Bosch GmbH, or specialized or proprietary equipment that is manufactured for use in the automated cutting tool100.

FIG. 6Ais a top view of a portion of an automatic cutting tool according to an example embodiment. An electronic device case601is mounted in a cradle602and is held securely in place by various grips or stops603. A cutting head or blade604is held against the side of case601by a spring (not shown). Blade604rotates at a constant speed and is configured to cut into case601.

Case601has a generally oblong or rectangular shape with two short sides605and two long sides606. Blade604is shown initially against a short side605of case601. Stepper motor607rotates cradle602in a clockwise direction.

FIG. 6Billustrates the automatic cutting tool after cradle602has been rotated 45 degrees by stepper motor607from the position shown inFIG. 6A. Blade604has been pulled against the side of case601and continues to cut the case as it rounds the corner608between short side605aand long side606a.

FIG. 6Cillustrates the automatic cutting tool after cradle602has been rotated a further 45 degrees by stepper motor607from the position shown inFIG. 6B. Blade604is pulled against the side of case601and continues to cut the case along long side606a.

FIG. 6Dillustrates the automatic cutting tool after cradle602has been rotated another 45 degrees by stepper motor607from the position shown inFIG. 6C. Blade604has been pulled against the side of case601and continues to cut the case as it rounds the corner609between long side606aand short side605b.

Stepper motor607rotates cradle602at two different speeds during operation of the automatic cutting tool. While cutting along short sides605a,band long sides606a,b, the stepper motor607rotates cradle602and case601at a first, relatively high speed. However, when approaching the corners608and609, stepper motor607slows down and rotates cradle602and case601at a second, relatively low speed. Once the cradle602and case601has turned past a corner608and609relative to blade604, then stepper motor607resumes the first, high speed rotation until the next corner approaches blade604.

Referring toFIGS. 6A-C, in one embodiment, stepper motor607is operating at a high speed inFIGS. 6A and 6Cand is operating at a low speed inFIGS. 6B and 6D. In an alternative embodiment, if short sides605a,bare very short so that the corners are close together, then stepper motor607may maintain the second, lower rotational speed along the short sides605a,binstead of speeding up for a very brief period between corners.

In further embodiments, the rotational speed of blade604may also vary during operation. For example, blade604may spin faster when stepper motor607is rotating at a fast speed (i.e., along the sides of case601), and blade604may spin slower when stepper motor607is rotating at a slow speed (i.e., around corners on case601). This may be required in some embodiments to control heat generated by the cutting action and to manage temperature on case601.

In other embodiments, the speed of stepper motor607(i.e., the rotational speed of case601) and the speed of blade604may be dependent upon other features of case601instead of the locations of corners608. For example, a particular case601may be thicker in some areas compared to others. The stepper motor607may slow down rotation of case601when blade604is cutting in these thicker areas and/or may increase the speed of blade604in the thicker areas in order to remove additional material. The speed of stepper motor607and the speed of blade604may also be varied based upon differences in case materials (e.g., different types of plastics, or combinations of plastics and metals in the case) or differences in case shape (e.g., varying degrees of angle between the cutting head and the case sidewall depending upon case rotation).

The speed of blade604and stepper motor607may be controlled using software or firmware instructions or other logic circuits stored in control unit131, which sends signals to the rotary tool (109,FIG. 1) and/or the stepper motor607to command a desired rotational speed based upon the position of blade604relative to case601. In some embodiments, the rotary tool and stepper motor may have two or more available speeds and the automatic cutting tool selects from the among the available speeds based upon the construction of case601(e.g., case material and shape).