Patent Description:
Portable, handheld power tools are used to perform a variety of tasks. Such tools include a power source such as a battery, an electric motor, and a working component, such as a saw, cutting blade, grinding wheel, or crimper. Some portable tools incorporate a hydraulic pump to drive a piston to apply a relatively large amount of force or pressure for a particular task. Some of these hydraulic tools include a working head with working surfaces shaped to perform a particular action on a workpiece, for example, crimping or cutting. Force from the piston actuated by the hydraulic system is applied to the workpiece to perform the desired task.

Battery powered hydraulic tools are employed in numerous applications to provide an operator with a desired flexibility and mechanical advantage. For example, an operator of a hydraulic power tool equipped with a head having a cutting blade can cut large conductors e.g., #<NUM> conductors and larger. Likewise, an operator using a hydraulic tool equipped with a head including crimping surfaces can use the tool to make crimped connections on large conductors.

Many hydraulic tools require relatively expensive components to provide sufficient power, durability, and reliability for industrial and commercial tasks. Such tools may also require strong components to withstand significant forces required to perform industrial processes. Thus, such tools may be expensive, heavy, and bulky.

Hydraulic tools may be specialized to perform different tasks. The shape and materials forming the workpiece may differ depending on the task. Different working surfaces provided on the head of the tool may be required to shape the workpiece into the desired configuration. In addition, different dies may be attached to the head to accomplish particular tasks, e.g., deforming a particular crimp or lug connector onto a conductor to create a reliable mechanical and electrical connection. Moreover, the shape and configuration of the head or the die may differ depending on the metal (for example, copper or aluminum) forming the conductor.

Hydraulic power tools are designed to apply a particular force to perform a particular task. A tool might be designed to provide <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> short tons of force. The force appropriate for a task may depend on such factors as the size of the conductor, whether the conductor is being cut or connected via a crimp or lug connector, the type of crimp or lug connector, the size of the conductor, and the metal forming the conductor (e.g. aluminum or copper). Generally, the amount of force applied by a hydraulic tool is fixed by the design of the tool.

Because hydraulic power tools are designed to apply a fixed amount of force, a different power tool may be required to perform different tasks. Where a job requires multiple kinds of operations, an installer may need to carry a number of different tools, each configured to provide the correct amount of force to accomplish a particular task. This may be expensive. Where a jobsite is difficult to access, carrying multiple tools may be inconvenient. Some examples of such tools are disclosed in <CIT>, <CIT>, <CIT> and in <CIT>.

The present invention provides exemplary embodiments of hydraulic power tools with a tool frame that can be connected with interchangeable heads. Such tools allow an operator to change the function of a single tool frame so the same tool frame can perform a variety of different tasks. This may reduce the expense required to equip the user because a single tool frame can be joined with different working heads to perform different tasks. Using interchangeable working heads on a single tool frame may also reduce the weight and bulk of the equipment a user must bring to the job site.

The present invention also provides exemplary embodiments for a hydraulic power tool where the force applied to deform a workpiece is adjusted, depending on the configuration of the working head, as well as the configuration of dies forming the working surfaces that shape the workpiece.

The present invention also provides exemplary embodiments for a hydraulic power tool that automatically detects the configuration of the interchangeable head connected with the tool, determines the amount of force appropriate for that head, and alters the operation of the hydraulic system to apply the appropriate force.

The present invention also provides exemplary embodiments for a hydraulic power tool that detects the type of die connected with the working head and adjusts the force applied by the hydraulic system based on the type of die.

The present invention also provides exemplary embodiments for a hydraulic power tool for installing connectors, such as crimp connectors and lug connectors, that detects the type of connector and adjusts the force applied by the hydraulic system based on the connector type.

The present invention also provides exemplary embodiments for a hydraulic power tool that allows the installer to identify the metal forming the conductor being connected and adjusts the force applied by the hydraulic system based on the conductor metal.

According to the invention, there is provided a hydraulic tool as defined by claim <NUM>.

According to a further aspect of the invention, the tool further comprises a die, the die comprising indicia that identify a type of the die from a plurality of die types, and a die sensor connected with the controller, wherein the die sensor communicates information identifying the type of the die based on the indicia to the controller, and wherein the controller determines the force based at least in part on the determined die type.

According to the invention, the tool further comprises a connector sensor in communication with the controller, the connector sensor adapted to read an indicia of a connector indicating a type of the connector from a plurality of connector types, wherein the controller determines the force based at least in part on the determined connector type.

According to a further aspect of the invention, the tool further comprises an input device connected with the controller, the input device adapted to receive an input indicating a characteristic of a workpiece such as the metal forming a conductor that is part of the workpiece, and wherein the controller determines the force based at least in part on the characteristic.

A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:.

Illustrative embodiments of the present invention may be provided as improvements to portable, hand held, battery operated, hydraulic tools and one or more interchangeable working heads for performing different tasks where the force applied by the tool is adjusted based on factors including the type of working head, the type of die fitted to the working head, the type of connectors to be installed on a conductor, and the type of metal forming the conductor.

<FIG> show an exemplary embodiment of a hydraulic power tool <NUM> according to the present invention. The tool <NUM> includes a tool frame <NUM> and a working head <NUM>. Within the frame <NUM> is a battery driven hydraulic system <NUM> illustrated schematically in <FIG>. Battery <NUM> provides electrical power to the hydraulic system. The tool frame <NUM> includes a main body <NUM> and a handle <NUM> that form a pistol-like shape. However, the tool frame <NUM> could be in any suitable type of shape.

<FIG> shows head <NUM> separated from main body <NUM>. Head <NUM> and main body <NUM> engage together as shown by the dotted line in <FIG>. Head <NUM> includes a head connecting portion <NUM> that engages with tool connecting portion <NUM> on main body <NUM>. <FIG> shows the facing surfaces of tool connecting portion <NUM> and head connecting portion <NUM>. <FIG> show a partial cross section of head <NUM> connected with main body <NUM>.

Head <NUM> includes an impactor <NUM> that connects with piston <NUM> via drive shaft <NUM>. Impactor <NUM> engages with a guide <NUM> on arm <NUM>. When the working head <NUM> is connected to the main body <NUM> and the piston <NUM> is driven in the distal direction, drive shaft <NUM> forces the impactor <NUM> along guide <NUM>, as shown in <FIG>. Arm <NUM> is connected at its proximal end with the ring <NUM>. At its distal end, arm <NUM> supports an anvil surface <NUM>. When a workpiece is placed between the impactor <NUM> and anvil surface <NUM> and the piston <NUM> is driven in the distal direction, the impactor <NUM> and anvil <NUM> deform the workpiece.

Impactor <NUM> and/or anvil <NUM> may also include surface features that allow a die, such as those shown in <FIG> to be connected. The die forms working surfaces to shape the workpiece into a desired configuration. For example, to splice two conductors together, a crimp connector, such as the one shown in <FIG> is fitted onto the ends of the conductors. A die, such one shown in <FIG>, is selected that will shape the finished crimp so that both conductors are securely connected. The die is fitted onto impactor <NUM> and anvil <NUM>. The crimp connector with the conductor ends inserted is placed between the die surfaces. The tool is actuated, compressing the crimp connector between the die surfaces to form the finished splice.

Main body <NUM> has a head sensor <NUM> on the tool connecting portion <NUM> facing the head <NUM> as shown in <FIG>. Head sensor <NUM> may be a bar code reader or other device designed to inspect indicia <NUM> on a facing surface of head <NUM>, as will be explained in more detail below. As shown in <FIG>, die/connector sensor <NUM> is located on another surface of main body <NUM>. Die/connector sensor <NUM> may also be a barcode reader or other device for inspecting indicia of a die or connector that will be used to perform a task, as will be described more fully below.

The handle <NUM> includes one or more operator controls, such as trigger switches <NUM> and <NUM>, and pushbutton <NUM> which can be manually activated by an operator. The handle <NUM> may include a hand guard <NUM> to protect an operator's hand while operating the tool <NUM> and to prevent unintended operation of trigger switches <NUM> and <NUM>. According to an embodiment of the present invention, one of the trigger switches (e.g., trigger switch <NUM>) may be used to activate the hydraulic system <NUM> to pressurize hydraulic drive <NUM> to drive the piston <NUM> in the distal direction as shown by the arrow in <FIG> to deliver force to the working head to perform a task, such as crimping or cutting. The other trigger switch (e.g., trigger switch <NUM>) may be used to cause the hydraulic system to depressurize hydraulic drive <NUM> to retract the piston <NUM> in the proximal direction to the home position shown in <FIG>. Pushbutton <NUM> is provided on the handle <NUM>. As will be explained below, pushbutton <NUM> allows a user to actuate the die/connector sensor <NUM> and also to communicate other information to the tool <NUM> such as the type of metal forming a workpiece.

The battery <NUM> is removably connected to the bottom of the handle <NUM>. In another embodiment, the battery <NUM> could be removably mounted or connected to any suitable position on the tool frame <NUM>. In another embodiment, the battery <NUM> may be affixed to the tool <NUM> so that it is not removable. The battery <NUM> is preferably a rechargeable battery, such as a lithium ion battery, that can output a voltage of at least <NUM> VDC, and preferably in the range of between about <NUM> VDC and about <NUM> VDC. In the exemplary embodiment shown in <FIG>, the battery <NUM> can output a voltage of about <NUM> VDC.

<FIG> shows a schematic of the hydraulic system <NUM>. Battery <NUM> provides power to controller <NUM>. Battery <NUM> also provides power to motor <NUM> under the control of controller <NUM>. Motor <NUM> drives pump <NUM> via gear reduction <NUM>. Pump <NUM> is in fluid connection with a hydraulic fluid reservoir <NUM>. When driven by motor <NUM>, pump <NUM> delivers fluid under pressure from reservoir <NUM> to hydraulic drive <NUM>. Force generated by hydraulic drive <NUM> is delivered via piston <NUM> to head <NUM> and applied to deform a workpiece, as shown in <FIG>. Pressure sensor <NUM> is connected with hydraulic drive <NUM> and senses the hydraulic pressure in hydraulic drive <NUM>. Controller <NUM> receives data indicating the pressure in hydraulic drive <NUM> from pressure sensor <NUM> and computes a force applied by piston <NUM> as a function of the pressure.

Relief valve <NUM> connects hydraulic cylinder <NUM> with fluid reservoir <NUM>. Relief valve <NUM> can be opened and closed by controller <NUM>. When relief valve <NUM> is opened, fluid flows back to reservoir <NUM> relieving pressure in hydraulic drive <NUM> and removing the force applied on the workpiece. A spring (not shown) may be provided as part of hydraulic drive <NUM> to return piston <NUM> to the home position shown in <FIG> when pressure in hydraulic drive <NUM> is relieved.

Controller <NUM> may be a microprocessor, microcontroller, application specific integrated circuit, field programable gate array (FPGA) or other digital processing apparatus as will be appreciated by those skilled in the relevant art. Controller <NUM> communicates with memory <NUM> to receive program instructions and to retrieve data. Memory <NUM> may be read-only memory (ROM), random access memory (RAM), flash memory, and/or other types of electronic storage know to those of skill in the art. Controller <NUM> may also communicate with external devices or networks via a port (not shown) such as a USB port or wireless communication interface (e.g., WiFi, Bluetooth, and the like). Memory <NUM> includes data identifying operating parameters including the proper force to be used with various heads <NUM>, as well as with various dies, connectors, and conductor materials and/or combinations thereof. Such data may be load into and/or updated in memory <NUM> via the port or interface or may be provided in memory <NUM> when the tool is assembled.

Controller <NUM> receives signals from head sensor <NUM> and/or die/connector sensor <NUM> and compares those signals with information stored in memory <NUM> to determine the type of head <NUM> and/or die connected with main body <NUM> and to determine the proper force to be applied by hydraulic drive <NUM>. Controller <NUM> also receives signals from pushbutton <NUM> to activate die/connector sensor <NUM> and/or to determine the metal comprising the workpiece, as will be described below. Controller <NUM> also receives signals from triggers <NUM>, <NUM> located on handle <NUM> to activate and deactivate hydraulic drive <NUM>.

Working head <NUM> is separable from the main body <NUM>. A variety of mechanisms may be provided to removably connect different working heads <NUM> to main body <NUM>, as set forth in co-pending <CIT>. According to the embodiment shown in <FIG>, main body <NUM> includes tool connecting portion <NUM>. Working head <NUM> includes head connecting portion <NUM>. Tool connecting portion <NUM> includes a T-shaped slot <NUM>. The head connecting portion <NUM> includes upper and lower connecting arms <NUM>, <NUM> connected with a ring <NUM>. In operation, piston <NUM> provides force to drive shaft <NUM> distally to deliver force to a workpiece, as shown in <FIG>. The cross section of the connecting arms <NUM>, <NUM> correspond to the cross section of the T-shaped slot <NUM> so that when the head connecting portion <NUM> is aligned with the tool connecting portion <NUM>, the arms <NUM>, <NUM> slide into the T-shaped slot <NUM>, as shown by the dotted line in <FIG>.

When head <NUM> is joined with main body <NUM> head sensor <NUM> is positioned facing indicia <NUM> on head <NUM>. Sensor <NUM> may be a barcode scanner, such as the MT80 Mini Scan Engine manufactured by Marson Technology Co. Indicia <NUM> may be an adhesive label, etched surface, or painted area of head <NUM> that includes a barcode such as a UPC code. Sensor <NUM> collects identifying information about head <NUM> and communicates it to controller <NUM>. According to the embodiment shown in <FIG>, <FIG>, a gap between the location of sensor <NUM> and barcode <NUM> is provided to allow sensor <NUM> a sufficient angular field of view to read the barcode <NUM>. Such a gap may be formed by recessing sensor <NUM> below the surface of main body <NUM>. According to another embodiment, instead of a bar code, indicia <NUM> include alphanumeric characters, for example, a model name of the head. Sensor <NUM> includes a camera equipped with character recognition software to identify the type of head based on the alphanumeric characters.

According to one embodiment, memory <NUM> includes a look-up table including operating parameters for a variety of heads <NUM>. Controller <NUM> compares the data from sensor <NUM> with records on the look-up table to determine the correct force to apply. According to another embodiment, instead of a look-up table, controller <NUM> uses an algorithm to determine a correct force to apply based on the type of head. The sensor <NUM> may be activated by controller <NUM> when trigger <NUM> is pressed to identify the type of head <NUM>.

In operation, a user selects head <NUM> from among a variety of heads <NUM> to perform a particular task, for example, installing a crimp connector to splice together two conductors. The user arranges tool <NUM> along with the crimp connector, such as the one shown in <FIG>, and conductors to be spliced so that the conductors are inserted into the ends of the connector and the connector is positioned between the faces of the tool. The user actuates the hydraulic system <NUM> by pressing trigger <NUM>. Controller <NUM> activates sensor <NUM> to detect the type of head <NUM> and identifies the proper force to apply for the type of head <NUM> identified based on data stored in memory <NUM>. Controller turns on motor <NUM>, causing pump <NUM> to pressurize hydraulic drive <NUM>. Piston <NUM> delivers force to head <NUM>, deforming the crimp around the conductors, forming the splice. Controller <NUM> monitors pressure in hydraulic drive <NUM> detected by pressure sensor <NUM>. When controller <NUM> determines that the detected pressure corresponds to the proper force to apply, based on the identified type of head <NUM>, controller turns off motor <NUM> and opens relief valve <NUM>, depressurizing hydraulic drive <NUM>, thus removing the force applied to the workpiece.

Instead of or in addition to a barcode reader, sensor <NUM> may be a contact-type sensor <NUM>' that determines the type of head <NUM> based on features on the corresponding surface of the head <NUM> as shown in <FIG>. As shown in <FIG>, sensor <NUM>' consists of an array of mechanical switches 181a-h. Two of such switches 181a and 181b are illustrated in cross section in <FIG>. The switches are actuated by corresponding spring-driven pins 182a-h. Head <NUM> includes indicia <NUM>' in the form of an array of holes 191a-d. When head <NUM> is installed on main body <NUM>, the spring driven pins 182a-h are pressed against indicia <NUM>' on the surface of head connecting portion <NUM>. Certain of the pins 182a-h engage with holes 191a, b, c, d, actuating corresponding switches 181a-h. The number and location of holes 191a, b, c, d is varied, depending on the type of head <NUM>. Switches 181a-h are electrically connected with controller <NUM>. Eight switches 181a-h and four holes 191a, b, c, d are shown in <FIG> for illustrative purposes, but more or fewer switches and holes could be provided.

<FIG> is a cross section showing head <NUM> engaged with main body <NUM>. Sensor <NUM>' is located on tool connecting portion <NUM>. Indicia <NUM>' are located on head connecting portion <NUM> adjacent sensor <NUM>'. Pins 182a-h engage with holes forming the indicia <NUM>'. Output from the switches is communicated as data to controller <NUM>. The combination of actuated switches is decoded by controller <NUM> to identify the type of head <NUM>. Controller <NUM> determines from the look-up table in memory <NUM> the proper parameters to use with that type of head, including the correct force to apply.

<FIG> shows another alternative embodiment of sensor <NUM>" and indicia <NUM>". In this embodiment pins 182a-h are conductive and are electrically isolated from the bulk of the connecting portion <NUM>. Pins 182a-h are coupled with electrodes that communicate electrical signals to controller <NUM>. According to one embodiment, the controller <NUM> detects current flowing through selected ones of the pins into the bulk of head <NUM> when head <NUM> is connected with tool frame <NUM>. The selected ones of the pins 182a-h that electrically connect with the bulk of the head <NUM> is determined by indicia <NUM>" which are a pattern of insulating and non-insulating areas on the surface of head <NUM>. According to one embodiment, shown in <FIG>, an insulating decal <NUM>" with an array of holes is provided on the surface of head <NUM>. Selected pins 182a-h that align with the holes pass through the decal and electrically connect with the bulk of the head <NUM>, allowing current to flow. Pins that do not align with holes are insulated from the head <NUM> and no current flows through those pins. The number and location of holes is selected to identify which type of head is connected with the main body <NUM>. Controller <NUM> monitors which pins 182a-h conduct current (i.e., are not electrically insulated from head <NUM>) and uses that information to identify the type of head <NUM> connected. As with the previous embodiment, controller <NUM> determines a proper force to apply based on the determined type of head.

Other types of sensors <NUM> and indicia <NUM> can also be used to allow controller <NUM> to identify the type of head <NUM> connected with the main body <NUM>. For example, an RFID tag may be attached to the head <NUM> and an RFID reader may be provided on the main body <NUM>.

According to a further embodiment, controller <NUM> may also receive a signal from the die/connector sensor <NUM>. Die/connector sensor <NUM> is located on the outer surface of tool <NUM>. The die/connector sensor <NUM> may be a barcode sensor, such as the MT80 Mini Scan Engine manufactured by Marson Technology Co. <FIG> show exemplary embodiments of dies used with the tool <NUM>. Dies <NUM> includes indicia <NUM>, such as a barcode pattern that may be applied as an adhesive label or etched or painted onto the die. <FIG> show examples of a lug connector <NUM> and a splice <NUM>, respectively used with the tool <NUM>. Barcodes <NUM> and <NUM> are applied to a surface of the connector and splice identifying them by type.

In operation, a user places the barcode for the die <NUM> and/or connector <NUM>, <NUM> to be used to perform a task so that it is readable by sensor <NUM>. The user presses pushbutton <NUM>. In response to the pushbutton press, controller <NUM> causes sensor <NUM> to read the barcode and send data indicating the type of die or connector back to controller <NUM>. Controller <NUM> compares that data with information stored in memory <NUM> to identify the die and/or connector being used to perform a task. Once a die <NUM> is identified, the process is repeated to identify the connector <NUM>, <NUM> or vice versa. The user then fits die <NUM> onto tool <NUM> by engaging an outer surface of the die with an inner surface of impactor <NUM> and anvil <NUM> of head <NUM>. Based on the identified die and/or connector type, the controller <NUM> determines a force to be applied by hydraulic drive <NUM> based on information stored in memory <NUM>.

According to one embodiment, controller <NUM> also monitors pushbutton <NUM> to allow a user to communicate to the controller certain information, such as the metal forming the conductor to be worked on for a task. According to one aspect, the user presses the button once to actuate the die/connector sensor <NUM>, as described above. The user presses the button <NUM> twice in quick succession to indicate that the conductor being worked on is formed from copper. The user presses the button three times in quick succession to indicate that the conductor being worked on is aluminum. Controller <NUM> monitors pushbutton <NUM> to determine if the user has identified a particular metal and compares that information to information stored in memory <NUM> to determine a force to apply. According to one embodiment, if the user does not indicate a type of metal forming the conductor, a default metal type, e.g. copper, is assumed by controller <NUM> when determining the force to apply. According to a further embodiment, the user inputs other information about the conductor, such as the size of the conductor, by actuating the pushbutton or by another input means such as additional buttons, keypad, dial, or the like (not shown). This additional information is used by controller <NUM> to determine an appropriate force to apply.

In addition to, or in alternative to using a hydraulic pressure sensor <NUM> to monitor the force being applied to a workpiece, a load cell, strain gauge, or other force sensing device <NUM> may be used to directly sense the force being applied. As shown in <FIG>, <FIG>, load cell <NUM> is positioned on a proximal-facing surface of T-shaped slot <NUM> on tool connecting portion <NUM> in contact with a distal-facing surface of upper arm <NUM> of head connecting portion <NUM>. As shown in <FIG>, load cell <NUM> is in communication with controller <NUM>. In operation, controller <NUM> monitors the force measured by load cell <NUM>. When that force reaches the appropriate force for the particular type of head, die, and/or connector, controller <NUM> turns off motor <NUM> and opens relief valve <NUM>.

Claim 1:
A hydraulic tool comprising:
a working head (<NUM>), the working head comprising head indicia that identify a type of the working head;
a tool frame (<NUM>) having a piston;
a hydraulic system coupled to piston;
a coupling mechanism, the coupling mechanism releasably coupling the head to the frame and coupling the piston to a working surface of the head;
a head sensor (<NUM>), the head sensor being adapted to detect the head indicia; and
a controller connected with the head sensor and the hydraulic system,
wherein the controller receives a signal generated by the head sensor in response to the head indicia, determines the type of the head, determines a maximum force to apply to the working surface based at least in part on the determined head type, and controls the hydraulic system to apply the maximum force,
characterised in that the coupling mechanism comprises a tool connecting portion (<NUM>) with a T-shaped slot (<NUM>) on the tool frame (<NUM>) and a head connecting portion (<NUM>) on the working head (<NUM>) including connecting arms (<NUM>, <NUM>) where a cross section of the connecting arms (<NUM>, <NUM>) correspond to the cross section of the T-shaped slot (<NUM>)so that when the head connecting portion (<NUM>) is aligned with the tool connecting portion (<NUM>), the arms (<NUM>, <NUM>) slide into the T-shaped slot (<NUM>).