Closed-system lifter

Abstract

A fastener driving tool that uses pressurized gas to drive a piston, thereby pushing the fastener into the workpiece via a driver blade, and then uses an induction coil to "lift" the piston (as an armature) back towards its pre-drive position at the top. The pressurized gas is not released into the atmosphere, but instead reused for multiple drive cycles. An optional induction coil may have multiple stages. A more preferred induction coil includes multiple stages, some of which extend beyond the piston's "ready" position and beyond the piston's end stroke.

Description

Cross - reference to related applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 468,325, titled "CLOSED SYSTEM LIFTER", filed on May 23, 2023.

Technical Field

[0002] The technology disclosed herein generally relates to fastener - driving tools, and more particularly to tools of the type that use pressurized gas to drive a piston, and where the piston advances a fastener into a target workpiece within a driver blade. Embodiments that use an electromagnetic field as a closed - system lifter to "lift" and return the driver blade and piston to a "ready - to - go" position are specifically disclosed.

[0003] After the fastener has been "driven" into the workpiece, the piston must be lifted to a "ready - to - go" position for the next "driving stroke". An induction coil is energized to generate an electromagnetic field that attracts at least the metallic portion of the piston, forcing the piston to be lifted to the ready - to - go position. In this "lifting" role, the piston acts as a movable armature, similar to the plunger of a solenoid.

[0004] In a second embodiment, a multi - stage induction coil is used to generate an electromagnetic field that attracts at least the metallic portion of the piston. This attraction forces the piston to be lifted, and as the piston approaches each successive stage of the multi - stage coil, the next coil stage is energized while the previous stage is de - energized, thereby lifting the piston to the ready - to - go position.

[0005] The gas system of the fastener drive tool used herein includes a pressure chamber, which is in fluid communication with the working cylinder, which is filled with pressurized gas to rapidly propel the piston and driver through the drive stroke motion when driving the fastener into the workpiece. The cylinder is at least partially surrounded by the pressure chamber, which holds most of the pressurized gas used to "launch" the piston. During use, the pressurized gas is not released into the atmosphere and can be reused for thousands of cycles. Thus, when the piston / driver combination undergoes a lifting stroke, the movement of the piston is hindered by its pressurized gas.

[0006] In a third embodiment, a multistage induction coil is used that at least partially surrounds the operating cylinder and extends beyond the operating cylinder. The induction coil generates an electromagnetic field that attracts at least the metallic portion of the piston. This attraction forces the piston upward, and as the piston approaches each successive stage of the multistage coil, the next coil stage is energized while the previous stage is demagnetized, thereby raising the piston to the ready position.

[0007] In a fourth embodiment, a fastener drive tool using line voltage as a power source has a multistage induction coil that generates an electromagnetic field that attracts at least a metallic portion of a piston. This attraction forcibly lifts the piston, and as the piston approaches each successive stage of the multistage coil, the next coil stage (or more stages) is energized while one or more of the previous stages are demagnetized, thereby lifting the piston to a ready position.

[0008] Description of research and development funded by the federal government. none. [Background technology]

[0009] Many conventional fastener drive tools use a piston to move a driver blade that pushes a nail or staple into a target workpiece as part of their operating cycle. These pistons are typically driven by compressed air, or sometimes by combustion air. In the pressurized air tool product line known as FUSION®, sold by Senco, the pressurized air is stored in a main storage chamber and is not released into the atmosphere; instead, it can be reused multiple times to drive multiple drive strokes (including thousands of operating cycles per refill of pressurized air).

[0010] Conventional tools employ mechanical techniques to lift the piston from the driven position to the ready position. Such techniques may include (as used in previous FUSION tools sold by Senco) elastic members (i.e., springs), vacuum, flywheels, rack and pinions, or rotatable lifters with lifter pins. FUSION fastener drive tools that use the same pressurized air multiple times typically have an electric motor and an electronic controller that controls the overall operation of the tool, the electric motor providing the starting force (as the driving force) to lift and return the movable piston towards its ready position after driving the fastener.

[0011] However, a drawback of using mechanical techniques to lift the piston is the possibility of it becoming stuck if the driver does not end its "drive stroke" motion at the expected position. [Overview of the project]

[0012] Therefore, an advantage is that the mechanical and pneumatic techniques used to lift the piston in gas spring-driven fastener drive tools are eliminated.

[0013] Another advantage is to provide a gas spring-type fastener drive tool with a closed-system lifter that uses an induction coil to lift the piston after the drive stroke.

[0014] Another advantage is to provide a gas spring-driven fastener tool with a closed-system lifter, in which a guide coil is used to lift the piston from the exit end of the guide body.

[0015] A further advantage is to provide a fastener drive tool having a closed-system lifter in which pressurized gas is used to propel the piston / driver blade and drive the fastener into the workpiece, and the pressurized gas is reused and not released into the atmosphere.

[0016] A further advantage is the provision of a gas spring-driven fastener with a closed-system lifter, in which a high-power portable battery powers an induction coil used to lift the piston after the drive stroke.

[0017] Another advantage is to provide a composite fastener drive tool equipped with a closed-system lifter that uses pressurized gas to move a piston in the drive stroke to drive the fastener into the workpiece, and then uses electromagnetic force in the lift stroke to "lift" or return the piston to the "ready" position.

[0018] A further advantage is to provide a fastener drive tool having a closed-system lifter, the latch being used to hold the driver in a fixed position in the "ready" position, and the latch also being able to catch the driver from shifting out of the drive direction when the fastener becomes stuck during the drive stroke, allowing a human user to release the fastener from sticking, which could allow the driver to suddenly "launch" at an inappropriate moment.

[0019] A further advantage is to provide a gas spring fastener drive tool with a closed-system lifter, in which a power cord and an AC / DC power converter supply power to an induction coil used to lift the piston after the drive stroke.

[0020] Some of the additional advantages and other novel features are described below, some of which will become apparent to those skilled in the art by considering the following, or can be acquired by practicing the art disclosed herein.

[0021] To achieve the aforementioned advantages and other advantages, according to one embodiment, a fastener drive tool with a closed-system lifter comprises: (a) a guide body having a receiving end, an exit end, and a passage between them, and being physically configured to receive a fastener; (b) a hollow cylinder having a cylindrical wall and including a movable piston therein, including a first end and a second opposite end, and accommodating the displacement volume generated by the stroke of the piston; and (c) an elongated driver including a first end and a second end, the first end being mechanically in communication with the movable piston and the second end being sized to push a fastener from the exit end of the guide body. A fastener drive tool is provided, comprising (d) an elongated driver having a slender shape, and (e) an induction coil at least partially wrapped around a hollow cylinder, wherein (i) the displacement volume contains pressurized gas which is not discharged into the atmosphere after the drive stroke but is instead reused for multiple operating cycles, (ii) the cylinder and piston act as a gas spring during the drive stroke using the pressurized gas of the displacement volume acting on the piston to move the driver toward the driven position, and (iii) the induction coil is energized during the lifting stroke of the operating cycle to move the piston toward the ready position by using a magnetic field.

[0022] In another embodiment, a fastener drive tool is provided, comprising a closed-system lifter, a housing for containing pressurized gas, a hollow cylinder including a movable piston, a driver mechanically communicating with the piston at least during a drive stroke, an induction coil magnetically communicating with the piston at least during a lift stroke, a mechanical latch, and an electrical energy source, wherein the hollow cylinder is configured to use pressurized gas to propel the piston toward a driven position during a drive stroke, the induction coil is configured to use a magnetic field to propel the piston toward a ready position during a lift stroke, and the latch is configured to hold the driver toward a ready position after a lift stroke.

[0023] In yet another embodiment, a method for using a fastener drive tool equipped with a closed-system lifter, comprising: (a) a housing for containing pressurized gas; a hollow cylinder including a movable piston; a driver mechanically communicating with the piston at least during a drive stroke; an induction coil magnetically communicating with the piston at least during a lift stroke; a magazine having a plurality of fasteners; a mechanical latch; and an electrical energy source; (b) positioning the latch to hold the driver in a ready position before the drive stroke is actuated; and (c) during the drive stroke, (i) engaging and repositioning the latch and releasing the driver. A method is provided which includes (ii) using pressurized gas to propel a piston toward a driven position, thereby moving a driver and pushing a fastener out of the tool housing; (d) after completion of the drive stroke, initiating a lift stroke by (i) exciting an induction coil to generate a magnetic field, and (ii) using the magnetic field to propel the piston toward a ready position, thereby moving a driver toward a ready position; and (e) after completion of the lift stroke, positioning a latch to hold the driver toward a ready position until another drive stroke.

[0024] According to yet another aspect, there is provided a fastener driving tool having a closed system lifter, comprising a housing for containing pressurized gas, a hollow cylinder including a movable piston, a driver that mechanically communicates with the piston at least during a driving stroke, an induction coil that magnetically communicates with the piston at least during a lifting stroke, a mechanical latch, and an electrical energy source. The hollow cylinder is configured to propel the piston toward a driven position using pressurized gas during the driving stroke, the induction coil is configured to propel the piston toward a ready position using a magnetic field during the lifting stroke, the latch is configured to hold the driver in the ready position, the induction coil is wound around the hollow cylinder and extends beyond an end of the hollow cylinder in a direction of the lifting stroke. A fastener driving tool is provided.

[0025] Further advantages will become apparent to those skilled in the art from the following description and drawings, which illustrate and describe a preferred embodiment among the best modes contemplated for carrying out the technology. As will be understood, the technology disclosed herein is capable of other different embodiments and several details thereof are capable of modification in various obvious respects without departing from the principles thereof. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive.

Brief Description of the Drawings

[0026] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate several aspects of the technology disclosed herein and, together with the description and claims, serve to explain the principles of the technology. In the drawings,

[0027] [Figure 1] A cutaway side view showing the internal parts of a fastener driving tool of a first embodiment constructed in accordance with the principles of the technology disclosed herein, showing the piston / armature in a pre-driving (or "ready") position and using a single-stage induction coil.

[0028] [Figure 2] It is an enlarged cutaway side view showing some of the internal parts of the fastener driving tool of the first embodiment in FIG. 1.

[0029] [Figure 3] It is a cutaway side view showing the internal parts of the fastener driving tool of the first embodiment in FIG. 1, and the driver / armature after the driving stroke (after the driving stroke, that is, in its "driven" position) is shown.

[0030] [Figure 4] It is an enlarged cutaway side view showing some of the internal parts of the fastener driving tool of the first embodiment in FIG. 3 after the driving stroke.

[0031] [Figure 5] It is a side view from the opposite side of the fastener driving tool in FIG. 1, showing the entire tool including all housing covers and including the magazine cover from the appearance.

[0032] [Figure 6] It is a top view of the tool in FIG. 5.

[0033] [Figure 7] It is a cutaway side view showing the internal parts of the fastener driving tool of the second embodiment constructed according to the principles of the technology disclosed herein, showing the piston / armature in the pre-driving stroke (or "ready") position and using a multi-stage induction coil.

[0034] [Figure 8] It is an enlarged cutaway side view showing some of the internal parts of the fastener driving tool of the second embodiment in FIG. 7.

[0035] [Figure 9]Figure 7 is a cutaway side view showing various internal parts of the fastener drive tool of the second embodiment, and shows the driver / armature after the drive stroke (i.e., in its "driven" position after the drive stroke).

[0036] [Figure 10] This is an enlarged cutaway side view showing some of the internal parts of the fastener drive tool of the second embodiment in Figure 9 after the drive stroke.

[0037] [Figure 11] Figure 1 is a block diagram showing some of the main electronic and electrical components of the fastener drive tool in the first embodiment.

[0038] [Figure 12] Figure 1 is a block diagram showing some of the main electronic and electrical components of the fastener drive tool of the first embodiment, with the addition of a high-voltage power supply.

[0039] [Figure 13] Figure 7 is a block diagram showing some of the main electronic and electrical components of the fastener drive tool in the second embodiment.

[0040] [Figure 14] Figure 7 is a block diagram showing some of the main electronic and electrical components of the fastener drive tool in the second embodiment, with the addition of a high-voltage power supply.

[0041] [Figure 15] Figure 1 is a cutaway top view showing some of the internal components of the fastener drive tool of the first embodiment, with the driver / piston in its "ready" position, and the latch engaging in interference with the driver opening, thereby holding the driver / piston in the ready position.

[0042] [Figure 16]Figure 1 is a cutaway top view showing some of the internal components of the fastener drive tool of the first embodiment, where the driver / piston is in its "driven" position, and the latch engages with the driver opening in an interfering relationship, thereby temporarily holding the driver / piston just before the lifting stroke begins.

[0043] [Figure 17] Figure 7 is a cutaway top view showing some of the internal components of the fastener drive tool of the second embodiment, with the driver / piston in its "ready" position, and the latch engaging in interference with the driver opening, thereby holding the driver / piston in the ready position.

[0044] [Figure 18] Figure 7 is a cutaway top view showing some of the internal components of the fastener drive tool of the first embodiment, with the driver / piston in its "driven" position and the latch engaged in interference with the driver opening, thereby temporarily holding the driver / piston just before the lifting stroke begins.

[0045] [Figure 19] Figure 1 is a cutaway top view showing some of the internal components of the fastener drive tool of the first embodiment, where the driver / piston is moving in a drive stroke and is intermediate between the "ready" position and the "driven" position, and the latch solenoid is energized so that the latch is forced into a non-interfering relationship with the driver, thereby enabling the drive stroke to be performed.

[0046] [Figure 20] Figure 1 is a cutaway top view showing some of the internal components of the fastener drive tool of the first embodiment, where the driver / piston is positioned between its "ready" and "driven" positions, and the latch engages with the driver opening in an interfering relationship, thereby holding the driver / piston in this intermediate position, which can occur if the nail being driven causes some kind of seizing condition.

[0047] [Figure 21] This is a side view of a fastener drive tool of a third embodiment, constructed in accordance with the principles of the technology disclosed herein.

[0048] [Figure 22] Figure 21 is a cutaway side view showing the internal components of a fastener drive tool of the third embodiment, showing the piston / armature in the pre-drive stroke (or "ready") position, and including a 53-stage induction coil.

[0049] [Figure 23] Figure 21 is an enlarged side view of a portion of the 53-stage induction coil used in the fastener drive tool of the third embodiment.

[0050] [Figure 24] This is a side view of a fastener drive tool of a fourth embodiment, having a power cord, constructed in accordance with the principles of the technology disclosed herein.

[0051] [Figure 25] Figure 24 is a cutaway side view showing the internal components of the fastener drive tool of the fourth embodiment, showing the piston / armature in the pre-drive stroke (i.e., "ready") position and using a power cord with an AC / DC power converter.

[0052] [Figure 26] Figure 24 is a graph showing the force generated by multiple active coils required to return the driver of the fastener drive tool in the fourth embodiment, relative to the piston stroke. [Modes for carrying out the invention]

[0053] Herein, preferred embodiments of the present invention will be referenced in detail, which are shown in the accompanying drawings, and similar figures indicate the same elements throughout the drawings.

[0054] It should be understood that the technologies disclosed herein are not limited in their application to the details of component structure and arrangement described in the following description or shown in the drawings. Other embodiments of the technologies disclosed herein are possible and can be practiced or implemented in various ways. It should also be understood that the expressions and terms used herein are for illustrative purposes only and should not be considered limiting. The use of “including,” “comprising,” or “having,” and their variations herein, means to include the items listed below and their equivalents, as well as additional items. Unless otherwise specified, the terms “connected,” “coupled,” and “mounted,” and their variations herein, are used broadly and include direct and indirect connections, couples, and mounts. In addition, the terms “connected” and “coupled,” and their variations, are not limited to physical or mechanical connections or couples. Furthermore, the terms “communicate with” or “connect with” indicate that two different physical or virtual elements exchange signals or information with each other in some way, regardless of whether the transmission of the signal or information is direct or whether there are additional physical or virtual elements between them that are similarly involved in the transmission of the signal or information. Additionally, the term “connect with” can also refer to a mechanical, hydraulic, or pneumatic system where one end of the “connection” (the “first end”) may be the “cause” of a particular kinetic force (mechanical movement, or hydraulic or pneumatic state change) that occurs, and the other end of the “connection” (the “second end”) may be “affected” by that movement / state change, regardless of whether there are intermediate components between the “first end” and the “second end”. The same applies to “magnetically connecting” with something, where one end of the “connection” induces a magnetic field, and the other end receives that magnetic field and may be acted upon (or otherwise affected) by it.

[0055] The terms “First” and “Second” preceding element names, such as “First Entrance” and “Second Entrance,” are used for identifying purposes to distinguish similar or related elements, results, or concepts, and are not necessarily intended to imply order, nor are the terms “First” and “Second” intended to exclude the inclusion of additional similar or related elements, results, or concepts unless otherwise stated.

[0056] Furthermore, while embodiments disclosed herein may be shown and described, for illustrative purposes, as if the majority of the components were implemented solely in hardware, it should be understood that they include both hardware and electronic components or modules.

[0057] However, those skilled in the art will recognize, based on reading the detailed embodiments for carrying out this invention, that in at least one embodiment, the electronic-based aspects of the technology disclosed herein can be carried out in software. Therefore, it should be noted that multiple hardware-based and software-based devices, as well as multiple different structural components, may be used to carry out the technology disclosed herein. Furthermore, where software is used, the processing circuit that runs such software may be that of a general-purpose computer. This general-purpose computer can perform all the functions that would otherwise be performed by a dedicated computer that could be specifically designed to carry out this technology.

[0058] As used herein, the term “circuit” can refer to an actual electronic circuit, such as an integrated circuit chip (or a portion thereof), or to a function performed by a processing circuit, such as a microprocessor or ASIC, which includes a logic state machine or other form of processing element (including a sequential processing circuit). A particular type of circuit may be several types of analog or digital circuits, and such circuits may, in some cases, be implemented in software by a logic state machine or sequential processor. In other words, if a processing circuit is used to perform a desired function (such as a demodulation function) used in the technology disclosed herein, there may not be a specific “circuit” that can be called a “demodulation circuit,” but there should be a demodulation “function” performed in software. All of these possibilities are conceived by the inventors and are within the principles of the art when considering “circuit.”

[0059] First Embodiment: Single-Stage Coil

[0060] Referring here to Figure 1, a first embodiment of the fastener driving tool is generally designated by reference numeral 10. This tool 10 is primarily designed to linearly drive fasteners such as nails and staples. The tool 10 includes a handle portion 12, a fastener driver portion 14, a fastener magazine portion 16, and a fastener exit portion 18.

[0061] The left outer housing portion of the driver section is indicated by 20 (see Figure 5). The top outer housing portion is indicated by 22, while the front outer housing portion of the driver section is indicated by 24. The rear outer housing portion of the handle section is indicated by 26, while the rear cover of the magazine section is indicated by 28. The above terms for various directions relate to the examples in Figure 1, and it will be understood that the fastener drive tool 10 of the first embodiment can be used in many other angular positions without departing from the principles of the present art.

[0062] The region of the tool 10 from which the fastener is released is roughly indicated by reference numeral 30, and this region is the “bottom” of the fastener exit portion of the tool 10. Before the tool is actuated, the safety contact element 32 extends to or beyond the bottom 30 of the fastener exit, and this extension of the safety contact element (reference numeral 34) is the lowest or “front” portion of the entire tool 10.

[0063] Other elements shown in Figure 1 include a guide body 36 and a drive depth adjuster 38, which are mechanically connected to the magazine portion 16. The trigger switch 52 is activated by a trigger actuator 54. The handle portion 12 is designed to be gripped by a human hand, and the trigger actuator 54 is designed to be operated linearly by a human finger while the handle portion 12 is being gripped. The trigger switch 52 provides input to the tool control system. There is also another input device used with the system controller, for example, a safety contact element switch 56, which is activated when the front end of the tool is pressed against the workpiece, thereby causing the safety contact element 32 to be "pressed" into the rest of the tool.

[0064] In the illustrated embodiment, the tool 10 includes a light-emitting diode (LED) 43 within the front housing 44, which provides some status information to the user of the tool. Furthermore, the tool 10 may optionally house one or more position sensors (not shown in Figure 1) inside the guide body 36, which can provide specific information regarding the movement of the driver "blade" 90.

[0065] The fastener drive tool 10 also includes an electromagnetic induction coil subassembly, generally designated by reference numeral 100. The induction coil subassembly 100 includes an induction coil 102, which is a single-stage coil having multi-turn windings, which is a single continuous conductor constituting a single fairly long inductor. The coil 102 is wound around a bobbin 104, and the coil 102 is partially enclosed by a yoke 106. The bobbin 104 is typically made of a non-conductive and non-magnetic material. The yoke 106 is typically made of a magnetic material such as magnetic mild steel or an iron alloy that readily conducts magnetic flux (i.e., a material with high permeability that is useful for confining and inducing magnetic fields).

[0066] In the illustrated embodiment, both the bobbin 104 and the coil 102 are fitted around the outer circumference (or periphery) of the operating cylinder 71. However, to create a physically smaller device, the induction coil 102 should be at least partially wound around the cylinder, but it is not necessary for the entire coil to wrap around the cylinder wall 70. This type of coil typically has a winding with multiple turns, most, if not all, of which are wound around the cylinder wall 70.

[0067] The battery pack 48 is mounted near the rear of the handle portion 12, and this battery supplies power to the induction coil subassembly 100 and the control system. In the illustrated embodiment of Figure 1, the battery pack 48 is mounted at the very rear of the handle, just behind the printed circuit board 42 in an exemplary embodiment.

[0068] The fastener drive tool 10 disclosed herein uses an induction coil to "lift" a piston and driver from a lower position, also called its "driven" position, to an upper position, sometimes called its "ready" position. FUSION® nail drive tools previously sold by Kyocera Senco Industrial Tools, Inc. have used a mechanical "lifter" for this function. In these early FUSION® tools, the "front housing" 44, as seen in Figure 1, was typically called the "motor housing" because it is where the motor of the lifter is positioned within the tool housing. In this embodiment of the fastener drive tool 10, its front housing 44 houses a printed circuit board 40 having many high-power electronic components used to supply energy to the induction coil 102. This design also includes other printed circuit boards, for example, 42 and 50, which house other electronic components similarly used to control the tool 10. Some of these printed circuit boards also house more high-energy electronic components, such as switching transducers and energy storage capacitors, to drive the induction coil 102 with enough energy to perform its lifting function. Circuit board 50 is located inside the battery pack 48 and controls the use of the battery cells.

[0069] The piston 80 also acts as an armature, not only being acted upon by the pressurized gas from the main storage chamber 74 but also magnetically by the induction coil 102. In other words, when the induction coil 102 is energized, it generates a magnetic field that tends to "lift" the piston / armature toward the ready position. Therefore, the piston / armature 80 must be essentially airtight around its periphery as it fits inside the internal sleeve or cylinder wall 70, and must also be constructed, at least partially, of a magnetic material such as mild steel or a mild iron alloy, so that the magnetic field generated by the induction coil 102 acts on the piston / armature to push it "upward" toward the ready position, similar to how a coil acts on a plunger in a solenoid.

[0070] As described above, the tool 10 includes at least one printed circuit board that houses the system controller and carries other electrical and electronic components necessary for the proper functioning of the tool. These printed circuit boards 40 and 42 can be positioned almost anywhere inside the “empty” space of the housing, including inside the front housing 44 and the bottom portion of the tool just above the battery pack 48. Another optional feature of the tool is the inclusion of several vents within the housing, somewhat closer to the battery pack, such as within the handle portion 12. These vents can provide some forced cooling air flowing around the printed circuit boards to help carry away the heat generated by the electronic components, particularly the components that supply electrical energy to the induction coil 102. This forced cooling air is generated each time the piston 80 moves its stroke during the drive stroke and the lift (or “return” stroke). Details of this type of cooling air system are described in another patent application filed by Kyocera Senco Industrial Tools, Inc., U.S. Patent Application Publication No. 2019 / 0321955(A1) entitled "FORCED AIR COOLING FROM PISTON MOVEMENTS OF NAILER TOOL," filed on 28 August 2018.

[0071] The tool's system controller typically includes a microprocessor or microcomputer integrated circuit 150 acting as a processing circuit. Also typically part of the controller is at least one memory circuit 152, including a random access memory (RAM) device and a read-only memory (ROM) device. (If applicable to a particular tool model) a non-volatile memory device, such as an EEPROM, NVRAM, or flash memory device, is typically included to store user input information. Generally, the memory circuit 152 contains instructions that can be executed by the processing circuit 150.

[0072] The processing circuit communicates with external inputs and outputs by using an input / output (I / O) interface circuit 154. The processing circuit, memory circuit, and interface (I / O) circuit communicate with each other via a system bus 156 that carries various other signal lines, including address lines, data lines, and interrupt lines. The I / O circuit has appropriate electronics for communicating with various external devices, including input-type devices such as sensors and user-controlled switches, as well as output-type devices such as motors and indicator lamps. Signals between the I / O interface circuit and the actual input and output devices are carried by a signal path 158, typically by several conductors.

[0073] Some of the output devices may include an induction coil 102, a latch solenoid 68, and a light-emitting diode 43 which can potentially be replaced by an audio output device such as a Sonalert. Each of the output devices typically has a driver circuit, such as a coil driver circuit 160 for the induction coil 102, and a latch solenoid driver 162 for the latch solenoid 68 which controls the position of the latch 60.

[0074] The latch 60 presses against the driver 90 under specific conditions. The latch 60 has an engaging extension that directly presses against one of the surfaces of the driver 90, and as a result, when the latch 60 collides with the opening 92 of the driver, the latch is pushed into the opening (via spring force). When this happens, the driver can only move "downward" (in the direction of the drive stroke) until the latch contacts the "end" of the opening 92. See Figure 2 for examples of the arrangement and relative sizes of these driver blade openings 92.

[0075] It should be noted that the driver blade may alternatively use projections (not shown) instead of openings to engage with the latch 60. In this type of alternative design, the driver has multiple spaced projections, and the latch is moved toward that portion of the driver, thereby mechanically interfering with one of those projections of the alternative driver design, when the latch engages and prevents the driver from moving further “downward”. This alternative driver design is described and illustrated in other patents owned by Senco, particularly the patents for earlier versions of FUSION fastener drive tools. These patents are incorporated herein by reference as described below. An important principle relating to the interface between the driver and the latch is that the driver should have some type of irregular shape rather than a purely smooth surface, so that the latch can easily “grip” its driver (through its irregular shape) and thus prevent the driver from continuing to “descend” in situations where the driver should not move in that direction.

[0076] In one operating mode, the latch 60 allows the driver to be lifted upward but does not allow it to be moved downward. Thus, the latch 60 can act as a safety device in this first mode. In a second operating mode, the latch also acts as a "release device" that allows the driver to initiate a drive stroke and drive the fastener into the workpiece. In either case, the latch 60 is positioned to hold the driver in its "ready position" after each "lift stroke" until it is time for the next "drive stroke" to occur under the control of the human user of the tool.

[0077] Further details of the latch 60 are shown in Figures 15 to 20. In Figure 15, the latch 60 holds the driver / piston combination in its “raised” or “ready” position by engaging with one of the driver openings 92. This is the “first operating state” of the latch 60 and occurs during the “high pressure” condition of the pressurized gas system of the tool 10. The latch solenoid 68 must be actuated to pull the latch out of the driver opening 92 (by pivot action), thereby allowing the driver / piston to receive a drive stroke due to the pressurized gas in the displacement volume 76. When the latch releases the driver by pivoting to a non-interfering position, this is the “second operating state” of the latch 60, which occurs only during the drive stroke, as will be described in more detail below.

[0078] In Figure 16, the driver / piston is in its "downward" or "driven" position, and the latch 60 is momentarily engaged in interference with the driver opening 92, thereby temporarily holding the driver / piston just before the lifting stroke begins. This is a low-pressure situation for the pressurized gas system of the tool 10. If desired, the physical shape of the spring-loaded latch 60 can allow the driver to "slip" upward without using a solenoid to pull out the latch 60.

[0079] In Figure 19, the driver / piston is moving during the drive stroke and is shown in this figure as being somewhere between its “ready” and “driven” positions. The latch solenoid is energized, which forces the latch into a non-interfering relationship with the driver, thereby enabling the drive stroke to occur. In Senco’s FUSION line of nail drive tools, the latch solenoid is energized only for a short time interval and automatically de-energized at the end of that interval. During a “normal” drive stroke, once the nail (or other type of fastener such as a staple) is fully driven into the target workpiece, the latch remains “open” (as shown in Figure 19) throughout the entire drive stroke.

[0080] In Figure 20, the driver / piston is again shown to be in an intermediate position between its “ready” and “driven” positions. However, the latch 60 in this illustration engages with the driver opening 92 in an interfering relationship, thereby holding the driver / piston in this intermediate position. This illustration illustrates a situation that may occur if, for some reason, a sticking condition occurs when the nail is driven, preventing the driver from completing its full “normal” driving stroke and reaching the nominal driven position. In such a sticking condition, a timer controlling the amount of time the latch solenoid 68 is nominally energized eventually times out, and the latch 60 is released. A spring-loaded pivoting action engages the latch with the driver 90. In Figure 20, this spring-loaded pivoting action engages the latch with one of the driver openings 92, and when this occurs, the driver cannot move any further “downward” (towards its driven position).

[0081] As shown in Figure 20, it should be noted that even after a “stuck state” occurs, the driver 90 can still be lifted “upward” (towards its ready position). This is because the induction coil 102 forces the driver / piston to move upward regardless of whether it stopped moving in an abnormal position during the previous drive stroke. The physical orientation of the pivotable latch 60 and the shape of the driver opening 92 allow the driver to move “upward” when the latch solenoid is demagnetized and while the latch is attempting to engage with the driver opening. In the illustrated design, the latch “slides” along the longitudinal side of the driver as the driver is lifted towards the ready position. If the latch 60 collides with the driver opening 92 during the lifting stroke, it tends to easily enter the opening, but due to the mechanical design, the driver is not prevented from continuing its “upward” movement. This feature is similar to that of Senco’s previous versions of FUSION tools.

[0082] The latching action described above with reference to this first embodiment shown in Figures 15, 16, 19, and 20 is described below and also applies to the tool of the second embodiment shown in Figures 17 and 18.

[0083] If the LED is a bidirectional device, the LED driver circuit 164 can be a two-way driver circuit. Such a device is desirable, and red and green LEDs are common devices, where current in the first direction generates a red indicator lamp signal, and reversing the current generates a green indicator lamp signal.

[0084] The input devices for tool 10 may include a variety of sensors, including a trigger switch 52 and a safety contact element switch 56. If such switches are standard electromechanical devices (such as limit switches), a driver circuit is typically not required. However, if the trigger switch and safety element switch are replaced by solid-state sensing elements, some type of interface circuit (166 and 168) may be required.

[0085] As described above, the tool 10 may also include position sensors capable of detecting a specific physical position of the mechanical screwdriver 90. These sensors may be referred to as “UP sensors” 4 and “DOWN sensors” 2. If provided, these two sensors are preferably “non-contact” devices such as optical sensors, each of which may have a light-emitting lamp (such as an LED) and a photosensitive detection element (such as a photodiode). Alternatively, these sensors may be magnetic sensing devices such as Hall effect sensors having at least one small permanent magnet attached to the screwdriver. Such position sensors may require signal conditioning circuits as shown in Figures 11 170 and 172.

[0086] If provided, UP and DOWN position sensors may be located in a small cylindrical area near the driver track 93. The driver 90 in the illustrated embodiment includes several openings 92 used to engage with the latch 60. When the driver receives a lift stroke and reaches near its top position in the driver track, the latch 60 is activated to extend into one of the driver openings 92 and make physical contact. At this point, the driver (and piston) is held in its “ready” position and remains in that ready position until the tool is activated again by user operation to trigger another drive stroke. Thus, the driver and piston are always held under relatively high pressure when the tool is “waiting” to be used, but by selecting this mode of operation, the tool is ready to be used to drive fasteners almost immediately. In other words, the entire drive cycle begins with a drive stroke, followed by a lift stroke to complete the drive cycle, and therefore the user does not have to wait for the lift stroke to occur first when activating the trigger. More specifically, the next drive stroke can be quickly initiated when a human user pulls the trigger 54 and presses the bottom of the tool against the target workpiece (at the front end 34 of the safety contact element 32).

[0087] If desired, the fastener drive tool 10 may include additional input and output devices. For example, a small display may be added to indicate specific information regarding the use or status of the tool. However, the indicator light 43 can also be used to indicate the system status under a small number of different conditions. Other types of sensing or output devices may also be added if desired by the system designer without departing from the principles of the art disclosed herein.

[0088] Please note that some of the sensors described herein are optional. Tool 10 can function very well without many of these sensors, including the UP position sensor and DOWN position sensor. While these sensors provide an improved tool in many ways, they are not entirely necessary, for example, if you want to sell a less expensive tool.

[0089] An operating cylinder subassembly, designated by reference numeral 71, is included as part of the fastener driver portion 14. As shown in Figure 2, the operating cylinder 71 includes a cylinder wall 70, within which are a movable piston 80 and a fixed piston stopper 84. Part of the piston mechanism in this embodiment includes a piston seal 86 and a piston guide ring 88. In the illustrated embodiment, the cylinder wall 70 is partially surrounded by the main storage chamber 74 (also referred to herein as the “pressure vessel storage space”) and the outer pressure vessel wall 78. The uppermost portion of the operating cylinder is indicated by 72 of the fastener driver portion 14, as seen, for example, in Figure 2.

[0090] Furthermore, within the fastener driver section 14 there is a mechanism that actually drives the fastener into the solid object. This includes a driver 90, a cylinder "vent chamber" 75 (typically always at atmospheric pressure), a driver track 93, and a latch 60. Note that the driver track 93 also acts as a fastener track, in that the lower part of the entire passage through the guide body that guides the driver also guides the fastener. More specifically, the passage through the guide body is designed to receive fasteners (such as nails) from the magazine 16 at the "receiving end" of that part of the entire track 93, and the driver 90 then pushes the fastener through the lower part of the entire track (or passage) 93 until the fastener reaches the "exit end" of reference numeral 30, at which point the fastener is driven into the target workpiece. In a typical nail gun tool, the magazine holds multiple nails and feeds only one nail to the fastener track during a given drive stroke, which is done automatically without further action by the human user (except for operating the trigger and pushing the front end of the tool against the workpiece) once the magazine 16 is mounted on the tool 10.

[0091] The driver 90 is rather elongated, and the body of its elongated surface is substantially rectangular. There are several openings 92 positioned along the longitudinal surface of the driver. In the illustrated embodiment, these openings extend parallel to the longitudinal centerline of the driver 90 and are spaced apart from one another along the longitudinal surface of the driver 90. It will be understood that the exact positions of the openings 92 may differ from those illustrated for the driver 90 without departing from the principles of the art disclosed herein.

[0092] The latch 60 is designed to "capture" the driver 90 when the driver should not be allowed to move through the entire "drive stroke". The latch has a capture portion which can engage with the opening 92 of the driver 90 when the latch is moved to its engaged or "interfering" position. When the drive stroke is about to occur, the latch is pivoted to its "disengaged" position where its capture surface does not obstruct the driver, and therefore its capture surface does not interfere with any of the openings 92 of the driver. An exemplary embodiment of a similar latch that engages with a driver projection (rather than a driver opening) is described in its entirety in U.S. Patent No. 8,011,441, owned by Senco Brands, Inc., which is incorporated herein by reference.

[0093] A cylinder base 96 is located which primarily separates the gas pressure portion of the fastener driver portion 14 from the lower mechanical portion of the driver portion 14. Below the piston 80, a variable-volume portion is also called the cylinder vent chamber 75, which is vented to the atmosphere. In one embodiment of the exemplary embodiment, a vent (not shown) near the cylinder base 96 is used for ventilation to the atmosphere. In an alternative embodiment of the exemplary embodiment, one or more vents (not shown) are located in the handle portion 12 to force cooling air through to the printed circuit board, as described above.

[0094] In Figure 2, the piston 80 is located near or at its uppermost or apex, and a small gas pressure chamber 76 can be seen above the apex region of the piston and above the piston seal 86. It will be understood that the gas pressure chamber 76 and the main storage chamber (or storage space) 74 are in fluid communication with each other. It will also be understood that the portion inside the cylinder wall 70 forms a displacement volume generated by the stroke of the piston 80. In other words, the gas pressure chamber 76 is not a fixed volume, and this chamber changes in volume as the piston 80 moves up and down (as can be seen by comparing Figure 2 with Figure 4). This type of mechanical configuration is often called a “displacement volume,” and the term is used herein primarily for this non-fixed volume 76.

[0095] The main storage chamber 74 preferably has a fixed volume, which would typically make manufacturing less expensive, although it will be further understood that it is not an absolute requirement that the main storage chamber actually has a fixed volume. Without departing from the principles of the art disclosed herein, it is possible to deform the size and / or shape of a portion of the chamber 74 during operation of the present invention, resulting in an actual change in the size of its volume.

[0096] In the illustrated embodiment of the fastener drive tool 10 of the first embodiment, the main storage chamber 74 substantially surrounds the operating cylinder 71. The main storage chamber 74 is annular in shape and is essentially coaxial with the cylinder 71. While this is a preferred configuration of the illustrated first embodiment, it will be understood that alternative physical arrangements can be designed without departing from the principles of the art disclosed herein.

[0097] At the bottom of the handle 12, the enclosure (or housing) 26 has a wider cross-sectional area to accommodate the printed circuit board 42. This electronic control circuit and coil driver circuit not only houses intelligent electronic components such as a microprocessor or microcontroller, but also switching semiconductors that control the current and voltage supplied to the induction coil 102, and therefore may operate at very high temperatures. As mentioned above, the expected use of forced cooling air can help lower the overall temperature of the internal space of the tool's housing.

[0098] Referring now to Figure 3, essentially the same components as those shown in Figure 1 are shown. However, in Figure 3, the piston / armature 80 is shown in the "down" position after the drive stroke has been performed. In Figure 1, of course, the piston / armature 80 is shown in the "ready" or "up" position before the drive stroke has been performed. Figure 4 is a magnified view of a portion of Figure 3, just as Figure 2 was a magnified portion of Figure 1.

[0099] It should be noted that, for the sake of clarity, some of the embodiments shown herein do not include all of their components in some of the drawings herein. To see examples of such outer housings and other components, particularly with respect to prior designs, readers should refer to other U.S. patents and applications owned by Senco. Similarly, information on "how" the electronic controller operates to control the function of the tool is described in other U.S. patents and applications owned by Senco. Furthermore, other aspects of the tool technology of the present invention may exist in previous fastener drive tools sold by the assignee, Kyocera Senco Industrial Tools, Inc., including information disclosed in prior U.S. patents and published applications. Examples of such publications include U.S. Patent Nos. 6,431,425, 5,927,585, 5,918,788, 5,732,870, 4,986,164, 4,679,719, 8,011,547, 8,267,296, 8,267,297, 8,011,441, 8,387,718, 8,286,722, 8,230,941, and 8,763,874, as well as U.S. Patent Application Publication Nos. 2016 / 0288305 and U.S. Patent Application Publication Nos. 2018 / 0178361. These documents are incorporated herein by reference in their entirety.

[0100] Second Embodiment: Multistage Coil

[0101] Referring now to Figure 7, a second embodiment of the fastener drive tool is shown, generally designated by reference numeral 110. This tool is very similar to the first embodiment 10 shown in Figures 1 to 4, but this second embodiment includes a multi-stage induction coil, which is part of a subassembly generally designated by reference numeral 120.

[0102] The multistage induction coil is shown in detail in Figure 8, and the multistage coil is designated collectively by reference numeral 122. The subassembly 120 also includes a bobbin 124, a yoke 126, and several annular spacers 128. The individual coil windings themselves are designated by reference numerals 130, 132, 134, and 136, corresponding to four separate induction coils. Each of these induction coils is a separate electrical inductor with a single multi-turn winding (i.e., they are electrically isolated windings), and each coil is designed to impart magnetism to the piston / armature 80 at the appropriate time during the lift stroke. The bobbin 124 and yoke 126 are essentially the same parts as those described above with reference to Figures 1-4. The spacers 128 are simply mechanical configurations for physically separating the four different induction coils, as shown in Figure 8. Again, the bobbin is typically made of a non-conductive and non-magnetic material, and the yoke is typically made of a magnetic material (with high permeability).

[0103] As can be seen in Figures 7 and 8, the piston / armature is near or proximal to its "top" position, which is the "ready" position where the tool is ready to receive a drive stroke. Figures 9 and 10 show the tool 110 of the same second embodiment in operation, with the piston / armature 80 driven and currently in the "driven" position, ready to receive a lift stroke. As with other Senco FUSION® tools, this driven position shown in Figures 9 and 10 is only a temporary position, and during a normal drive event, unless the tool has literally failed or is in some type of failure mode, the piston / armature will automatically lift and return to its ready position almost immediately after receiving the drive stroke. In other words, the “driven position” shown in Figures 9 and 10 is only temporary (in milliseconds), and the multi-stage coil 122 begins to energize almost immediately, pushing the piston / armature back from this driven position towards its ready position as seen in Figures 7 and 8. (The same applies to the diagrams in Figures 1 to 4 for the tool 10 of the first embodiment.)

[0104] The multi-stage coil 110 of the second embodiment allows the overall driving force to be intermittently applied by any one of these single coils 130, 132, 134, or 136. In the position shown in Figure 10, the fourth, i.e., the "bottommost" coil 136 is the first coil to be energized by the control circuit, and after the piston / armature begins to be pushed upward toward the ready position, the third coil 134 is energized and the fourth coil 136 is de-energized. In the latter half of the lifting stroke, the second coil 132 is energized and the third coil 134 is de-energized, and finally, as the piston / armature approaches the top position, the first coil 130 is energized and the second coil 132 is de-energized. At that point, the coil 130 is energized to push the piston / armature 80 toward its top or near-top stroke position (also called the “ready position”), and the coil remains temporarily energized until the latch solenoid 68 energizes and engages the latch 60 with one of the drive openings 92. Once the latch engagement occurs, the first coil 130 can be demagnetized, and the latch holds the piston / armature in the ready position until the tool is ready for use in a future drive stroke.

[0105] In Figure 17, the latch 60 holds the driver / piston combination in its “raised” or “ready” position by engaging with one of the driver openings 92. This is a high-pressure situation for the pressurized gas system of the tool 110. The latch solenoid 68 must be actuated to pull the latch out of the driver opening 92 (by pivot action), thereby allowing the driver / piston to receive a drive stroke due to the pressurized gas in the displacement volume 76.

[0106] In Figure 18, the driver / piston is in its "downward" or "driven" position, and the latch 60 is momentarily engaged in interference with the driver opening 92, thereby temporarily holding the driver / piston just before the lifting stroke begins. This is a low-pressure situation for the pressurized gas system of the tool 110. If desired, the physical shape of the spring-loaded latch 60 can allow the driver to "slip" upward without using a solenoid to pull out the latch 60.

[0107] General characteristics of the tool

[0108] The tools 10 and 110 described herein share many features with the FUSION product line of tools sold by Kyocera Senco Industrial Tools, Inc. For example, the drive stroke is generally carried out by a gas spring containing reusable pressurized gas stored in a main storage chamber, e.g., chamber 74. In the illustrated embodiment, the main storage chamber substantially surrounds at least a portion of the working cylinder 71. In the FUSION product line, as hereby, the pressurized gas is not released into the atmosphere after generating the drive stroke, but instead remains in the upper part of the working cylinder (above the piston, within the displacement volume) and in the main storage chamber itself.

[0109] The presence of a main storage chamber ensures that the internal pressure of the "air spring gas" does not become too low to force the driver to effectively drive the nail into the workpiece, because the entire volume of this "air spring gas" does not expand proportionally (as the piston moves) to a point where it becomes ineffective for its purpose. Generally, the main storage chamber 74 and the top portion of the hollow cylinder in the so-called gas pressure chamber 76, which is above the piston and has a variable volume (i.e., "displacement volume"), are always in fluid communication with each other. There is no intermediate valve to prevent the pressurized gas in the storage volume 74 from entering the top portion of the working cylinder 71.

[0110] Tools 10 and 110 are designed to reuse pressurized gas for thousands of operating cycles, allowing for repeated use without the need for an onboard gas replenishment system. (Some conventional "air tools" use an "air bottle" attached to the nail drive tool during normal operation. These types of air tools truly have a "gas replenishment system.")

[0111] On the other hand, even FUSION tools eventually require gas "refilling" to replenish the gas that slowly leaks out of the tool after numerous operating cycles. Therefore, gas replenishment valves can be installed on FUSION-type tools such as tools 10 and 110 described herein. Providing such an onboard valve does not constitute a gas replenishment "system" because it cannot be expected that simply opening the valve will cause gas to flow into the main storage chamber. Instead, a high-pressure gas source (well over 150 PSI) is required to add more gas to one of these tools. This requires some special equipment, and typically, replenishment is performed by an authorized Senco dealer.

[0112] Regardless of the presence or absence of a gas replenishment valve, the design of tools 10 and 110 is such that they operate under normal conditions without an external gas hose and external power cable, similar to Senco's FUSION tools. This makes these tools truly portable for ease of use in the field. However, it will be understood that these tools 10 and 110 may be provided with a power cable to use AC line voltage instead of a battery pack, if desired in certain types of field. Optionally, such tools may have both battery pack and AC power cord connections, so that the user can use one type of power in certain areas of the field and switch to the other type of power in other areas of the field.

[0113] Electronic controller

[0114] Referring here to Figure 11, as described above, the tool's system controller typically includes a microcomputer integrated circuit 150 that acts as a microprocessor or processing circuit. Other typical circuits include at least one memory circuit 152, an input / output interface circuit 154, and a system bus 156 carrying various other signal lines, including address lines, data lines, and interrupts. The I / O circuit 154 communicates with various external devices, including input-type devices such as sensors and user-controlled switches, as well as output-type devices such as inductive coils and indicator lamps. Signals between the I / O interface circuit 154 and the actual input and output devices are carried by a signal path 158.

[0115] LED43 typically has an LED driver circuit 164, and if the LED is a bidirectional device, the LED driver circuit can be a two-way driver circuit. Such devices are desirable, and red and green LEDs are common devices, where current in the first direction generates a red indicator lamp signal, and reversing the current generates a green indicator lamp signal.

[0116] The input devices for tool 10 may include a variety of sensors, including a trigger switch 52 and a safety contact element switch 132. If switches 52 and 132 are standard electromechanical devices (such as limit switches), typically no driver circuit is required. However, if the trigger switch and safety element switch are replaced by solid-state sensing elements, some type of interface circuit may be required, which are shown in Figure 12 by reference numerals 166 and 168, respectively.

[0117] Figure 11 includes a coil driver circuit 160 that drives an induction coil 102, also referred to as "C1" in Figure 11. Figure 11 also includes a latch driver circuit 162 that drives a latch solenoid 68, also referred to as "S1" in Figure 11. Figure 11 also includes a battery 48, which is typically a battery pack consisting of multiple cells of a battery such as a lithium-ion battery. The battery drives a DC power supply 46, which provides a suitable voltage source to the processing circuit and other interface circuits, including the high-energy power required for the coil driver 160.

[0118] Referring now to Figure 12, the same major electronic components as those seen in Figure 11 are shown. The main difference is that in Figure 12, there is an additional high-voltage power supply 47 that provides a higher energy output to the coil driver 160 at a higher DC or AC voltage to drive the induction coil 102. A typical battery pack 48 used in such power tools supplies an output voltage of approximately 18 volts DC. The high-voltage power supply 47 can be used to supply a higher output voltage while reducing the amount of current required to supply to the coil driver circuit 160. This high-voltage power supply is an optional feature of this design.

[0119] Here, referring to Figure 13, a block diagram is shown showing the main electrical components of a second embodiment 110 of a fastener drive tool that uses multi-stage coils such as an induction coil subassembly 120. The main difference between Figure 13 and Figure 11 is that Figure 13 shows four different coil driver circuits and four different induction coils. The induction coils are designated “C1”, “C2”, “C3”, and “C4”, and these are also designated by reference numerals 130, 132, 134, and 136, as seen in Figures 7–10. Each of these distinct induction coils requires a coil driver circuit, and in Figure 13, these driver circuits are designated by reference numerals 180, 182, 184, and 186, respectively. The block diagram of Figure 13 still includes a battery pack 48 and a DC power supply 46.

[0120] Instead of providing four separate coil driver circuits (circuits 180, 182, 184, 186, etc.), it will be understood that the tool of the second embodiment may be designed using a single coil driver circuit whose output current is electronically switched so that it is sequentially directed to one of the four coils as a multiplexed high-energy output. However, this involves several design trade-offs: firstly, only one of the four coils can be excited at a given moment; and secondly, the single coil driver circuit operates at a 100% duty cycle throughout the entire lift stroke, and therefore its switching device (e.g., power transistor) is subject to a large amount of heat generation. (In this regard, this is similar to the type of coil driver circuit required by the tool 10 of the first embodiment, which has only one induction coil 102.)

[0121] Referring now to Figure 14, another block diagram is shown that is very similar to the block diagram in Figure 13. The main difference is the use of a high-voltage power supply 47, which can be used to provide a high-energy voltage source higher than the 18 volts that is the typical battery pack voltage used in Senco power tools. The higher voltage power supply reduces the current capacity required for the coil driver circuits 180, 182, 184, and 186.

[0122] It will be understood that the electronic controller includes sufficient circuitry to be an intelligent device, including a processing circuit, a memory circuit containing instructions that can be executed by the processing circuit, and an input / output (I / O) interface circuit that senses specific input conditions of the tool and transmits and receives signals to command specific active devices to perform their intended functions. More specifically, the electronic controller is configured to transmit and receive signals to (a) determine the operating state of a latch solenoid, (b) determine the operating state of a trigger switch and a safety contact switch, (c) move the piston 80 from its ready position to its driven position under a first predetermined condition, and (d) actuate one or more induction coils under a second predetermined condition to move the piston / armature 80 (and driver 90) from the driven position to the ready position.

[0123] The “first predetermined condition” described above includes the activation of the trigger 54 by a human user and the activation of a safety contact element that occurs when the human user presses the front end of the tool (located in part 18) against the target workpiece. The “second predetermined condition” described above occurs when the piston receives a drive stroke and reaches its driven position, which would be at the piston stopper 84. In a typical Senco FUSION tool, the electronic controller here automatically engages the induction coil 102, moving the piston back to its ready position through a lift stroke. These “second predetermined conditions” may also include a safety circuit to detect, for example, whether the driver and its piston have moved and returned to the ready position, using a driver position sensor.

[0124] Third Embodiment: 53-Stage Coil

[0125] Referring here to Figure 21, a third embodiment of the fastener driving tool is generally designated by reference numeral 210. This tool 210 is primarily designed to linearly drive fasteners such as nails and staples. The tool 210 includes a handle portion 212, a fastener driver portion 214, a fastener magazine portion 216, and a fastener exit portion 218.

[0126] The left outer housing portion of the driver section is indicated by 220. The top outer housing portion is indicated by 222, while the front outer housing portion of the driver section is indicated by 224 (see Figure 22). The rear outer housing portion of the handle section is indicated by 226, while the rear cover of the magazine section is indicated by 228. The above terms for various orientations relate to the examples in Figure 21, and it will be understood that the fastener drive tool 210 of the third embodiment may be used in many other angular positions without departing from the principles of the present art.

[0127] Referring here to Figure 22, the region of the tool 210 from which the fastener is released is roughly indicated by reference numeral 230, which is the “bottom” of the fastener exit portion of the tool 210. Before the tool is activated, the safety contact element 232 extends to or beyond the bottom 230 of the fastener exit, and this extension of the safety contact element (reference numeral 234) is the lowest or “front” portion of the entire tool 210.

[0128] Other elements shown in Figure 21 or 22 include a guide body 236 and a drive depth adjuster 238, which are mechanically connected to the magazine portion 216. The trigger switch 252 is activated by a trigger actuator 254. The handle portion 212 is designed to be gripped by a human hand, and the trigger actuator 254 is designed to be operated linearly by a human finger while the handle portion 212 is being gripped. The trigger switch 252 provides an input signal to the tool control system. There are also other input devices used with the system controller, such as a safety contact element switch 56 (see Figure 11), which is activated when the front end of the tool is pressed against the workpiece, thereby causing the safety contact element 232 to be "pressed" into the rest of the tool.

[0129] In the illustrated embodiment, the tool 210 includes a light-emitting diode (LED) 243 within the front housing 244, which provides some status information to the user of the tool. Furthermore, the tool 210 may optionally house one or more position sensors (not shown in Figure 22) inside the guide body 236, which can provide specific information regarding the movement of the driver "blade" 290.

[0130] The fastener drive tool 210 also includes a 53-stage electromagnetic induction coil subassembly, generally designated by reference numeral 300. The subassembly 300 also includes a plurality of bobbins 304 and a plurality of yokes 306. The individual coil windings themselves are designated by reference numeral 302, corresponding to 53 distinct induction coils. Each of these induction coils is a distinct electrical inductor with a single multi-turn winding (i.e., they are electrically isolated windings), and each coil is designed to impart a magnetic force to the piston / armature 280 at the appropriate time during the lift stroke.

[0131] Generally, during the lift stroke, as the piston is progressively lifted, individual coils or groups of coils are energized in a predetermined sequence of movements. In other words, at least one of the individual coils is energized in a predetermined sequence of movements. For example, the individual induction coils can be numbered 1 to 53, starting with coil #1, which is "closest" to the piston stop, and therefore closest to the movable piston immediately after the drive stroke occurs. Thus, in this example, in "sequence step #1", the five "closest" induction coils (i.e., coils numbered 1 to 5) can be energized to quickly move the piston for the lift stroke. Then, at an appropriate time interval, "sequence step #2" occurs, and coils 2 through 6 are energized. Alternatively, depending on the exact design of the entire electromagnetic induction coil subassembly 300, instead of coils #2 to #6 being energized in "sequence step #2", the electronic controller may instead energize coils #6 to #10, or perhaps coils #8 to #12, over sequence step #2. Alternatively, in yet another alternative design, the number of coils energized in each so-called “sequence step” can be varied so that fewer or more individual coils are energized in some of the individual sequence steps. It should be remembered that as the piston is lifted further away from the piston stop, the effective gas pressure on the “high pressure side” of the piston increases, and therefore, as the piston approaches the “top” of its lifting stroke, the number of individual coils required for each sequence step may increase.

[0132] The bobbin 304 and yoke 306 are essentially the same parts as those described above with reference to Figures 1 to 4. In this case as well, the bobbin is typically made of a non-conductive and non-magnetic material, and the yoke is typically made of a magnetic material (with high magnetic permeability).

[0133] In the illustrated embodiment, both the bobbin 304 and the coil 302 are fitted around the outer circumference (or periphery) of the operating cylinder 271. However, to create a physically smaller device, the induction coil 302 should be at least partially wound around the cylinder, but it is not necessary for the entire coil to wind around the cylinder wall 270. This type of coil typically has a winding with multiple turns, many, if not the majority, of which are wound around the cylinder wall 270.

[0134] The battery pack 248 is mounted near the rear of the handle portion 212, and this battery supplies power to the induction coil subassembly 300 and the control system. In the illustrated embodiment of Figure 22, the battery pack 248 is mounted at the very rear of the handle, just behind the printed circuit board 242 in this exemplary embodiment.

[0135] The fastener drive tool 210 disclosed herein uses an induction coil subassembly to “lift” a piston and driver from a lower position, sometimes called the “driven” position, to an upper position, sometimes called the “ready” position. FUSION® nail drive tools previously sold by Kyocera Senco Industrial Tools, Inc. have used a mechanical “lifter” for this function. In these early FUSION® tools, the “front housing” 244, as seen in Figure 22, was typically referred to as the “motor housing” because it is where the motor of the lifter is positioned within the tool housing. In this embodiment of the fastener drive tool 210, its front housing 244 houses a printed circuit board 240 having many high-power electronic components used to supply energy to the induction coil 302. In this design, there are also other printed circuit boards, for example, 242 and 250, which house other electronic components similarly used to control the tool 210. Some of these printed circuit boards also house more high-energy electronic components, such as switching transducers and energy storage capacitors, to drive the induction coil 302 with enough energy to perform its lifting function. Circuit board 250 is located inside the battery pack 248 and controls the use of the battery cells.

[0136] The piston 280 also acts as an armature, not only being acted upon by the pressurized gas from the main storage chamber 274, but also magnetically by the induction coil 302. In other words, when the induction coil 302 is energized, it generates a magnetic field that tends to "lift" the piston / armature toward the ready position. Therefore, the piston / armature 280 must be essentially airtight around its periphery as it fits inside the internal sleeve or cylinder wall 270, and must also be constructed, at least in part, from a magnetic material such as mild steel or a mild iron alloy, so that the magnetic field generated by the induction coil 302 acts on the piston / armature to push it "upward" toward the ready position, similar to how a coil acts on a plunger in a solenoid.

[0137] As described above, the tool 210 includes at least one printed circuit board that houses the system controller and carries other electrical and electronic components necessary for the proper functioning of the tool. These printed circuit boards 240 and 242 can be positioned almost anywhere inside the “empty” space of the housing, including inside the front housing 244 and the bottom portion of the tool just above the battery pack 248. Another optional feature of this tool is the inclusion of several vents within the housing, somewhat closer to the battery pack, such as within the handle portion 212. These vents can allow some forced cooling air to flow around the printed circuit boards to help carry away the heat generated by the electronic components, particularly the components that supply electrical energy to the induction coil 302. Forced cooling air is generated each time the piston 280 moves its stroke during the drive stroke and the lift (or “return” stroke). Details of this type of cooling air system are described in another patent application by Kyocera Senco Industrial Tools, Inc., U.S. Patent Application Publication No. 2019 / 0321955A1, filed on 28 August 2018, entitled "FORCED AIR COOLING FROM PISTON MOVEMENTS OF NAILER TOOL".

[0138] The latch 260 presses against the driver 290 under certain conditions. The latch 260 has an engaging extension that directly presses against one of the surfaces of the driver 290, and as a result, when the latch 260 collides with the opening 292 of the driver, the latch is pushed into the opening (via spring force). When this happens, the driver can move "downward" (in the direction of the drive stroke) only to the point where the latch contacts the "end" of the opening 292.

[0139] An operating cylinder subassembly, designated by reference numeral 271, is included as part of the fastener driver portion 214. As shown in Figure 22, the operating cylinder 271 includes a cylinder wall 270, within which are a movable piston 280 and a fixed piston retainer 284. In the illustrated embodiment, the cylinder wall 270 is partially surrounded by the main storage chamber 274 (also referred to herein as the “pressure vessel storage space”) and the outer pressure vessel wall 278. The uppermost portion of the operating cylinder is indicated by 272 of the fastener driver portion 214, as seen, for example, in Figure 22.

[0140] Furthermore, within the fastener driver section 214 is a mechanism that actually drives the fastener into the solid object. This includes a driver 290, a cylinder "vent chamber" 275 (typically always at atmospheric pressure), a driver track 293, and a latch 260. Note that the driver track 293 also acts as a fastener track, in that the lower portion of the entire passage through the guide body that guides the driver also guides the fastener. More specifically, the passage through the guide body is designed to receive fasteners (such as nails) from the magazine 216 at the "receiving end" of that portion of the entire track 293, and the driver 290 then pushes the fastener through the lower portion of the entire track (or passage) 293 until the fastener reaches the "exit end" of reference numeral 230, at which point the fastener is driven into the target workpiece. In a typical nail gun tool, the magazine holds multiple nails and feeds only one nail to the fastener track during a given drive stroke, which is done automatically without further action by the human user (except for operating the trigger and pushing the front end of the tool against the workpiece) once the magazine 216 is mounted on the tool 210.

[0141] The driver 290 is rather elongated, and the body of its elongated surface is substantially rectangular. There are several openings 292 positioned along the longitudinal surface of the driver. In the illustrated embodiment, these openings extend parallel to the longitudinal centerline of the driver 290 and are spaced apart from one another along the longitudinal surface of the driver 290. It will be understood that the exact positions of the openings 292 may differ from those illustrated for the driver 290 without departing from the principles of the art disclosed herein.

[0142] The latch 260 is designed to "capture" the driver 290 when the driver should not be allowed to move through the entire "drive stroke". The latch has a capture portion which can engage with the opening 292 of the driver 290 when the latch is moved to its engaged or "interfering" position. When the drive stroke is about to occur, the latch is pivoted to its "disengaged" position where its capture surface does not obstruct the driver, and therefore its capture surface does not interfere with any of the openings 292 of the driver. An exemplary embodiment of a similar latch that engages with a driver projection (rather than a driver opening) is described in its entirety in U.S. Patent No. 8,011,441, owned by Senco Brands, Inc., which is incorporated herein by reference.

[0143] A cylinder base 296 is located which primarily separates the gas pressure portion of the fastener driver portion 214 from the lower mechanical portion of the driver portion 214. Below the piston 280, a variable-volume portion is also called the cylinder vent chamber 275, which is vented to the atmosphere. In one embodiment of the exemplary configuration, a vent (not shown) near the cylinder base 296 is used for ventilation to the atmosphere. In an alternative configuration of the exemplary configuration, one or more vents (not shown) are located in the handle portion 212 to force cooling air through to the printed circuit board, as described above.

[0144] Referring now to Figure 23, a portion of the induction coil S / A300 is shown in detail. Several of the induction coils 302 are shown, each having multiple windings between the yoke 306 and the bobbin 304.

[0145] As can be seen in Figure 22, the coil subassembly 300 extends well beyond the end of the maximum piston stroke along the centerline of the pressure chamber. The individual coil stages to the left of the piston 280's "ready" position (as shown in this illustration in Figure 22) are energized as the piston is "lifted" during the final stage of the return stroke, and they exert a very strong "pulling" force on the piston, essentially pulling it further to the left until it reaches its ready position.

[0146] When the piston 280 reaches the appropriate ready position, the latch 260 can be engaged to hold the piston in that ready position without further assistance from the induction coil subassembly, and the induction coil can then be demagnetized. This physical configuration of the multiple coil stages in this third embodiment is preferable to the configurations shown for the first two embodiments, as described above with reference to Figures 1 to 20.

[0147] Fourth embodiment with power cord

[0148] Referring here to Figure 24, a fourth embodiment of the fastener driving tool is generally designated by reference numeral 310. This tool 310 is primarily designed to linearly drive fasteners such as nails and staples. The tool 310 includes a handle portion 312, a fastener driver portion 314, a fastener magazine portion 316, and a fastener exit portion 318.

[0149] The left outer housing portion of the driver section is indicated by 320. The top outer housing portion is indicated by 322, while the front outer housing portion of the driver section is indicated by 324 (see Figure 25). The rear outer housing portion of the handle section is indicated by 326, while the rear cover of the magazine section is indicated by 328. The above terms for various orientations relate to the examples in Figure 24, and it will be understood that the fastener drive tool 310 of the fourth embodiment may be used in many other angular positions without departing from the principles of the present art.

[0150] Referring here to Figure 25, the region of the tool 310 from which the fastener is released is roughly indicated by reference numeral 330, which is the “bottom” portion of the fastener exit of the tool 310. Before the tool is activated, the safety contact element 332 extends to or beyond the bottom 330 of the fastener exit, and this extension of the safety contact element (reference numeral 334) is the lowest or “front” portion of the entire tool 310.

[0151] Other elements shown in Figure 24 or 25 include a guide body 336 and a drive depth adjuster 338, which are mechanically connected to the magazine portion 316. The trigger switch 352 is activated by a trigger actuator 354. The handle portion 312 is designed to be gripped by a human hand, and the trigger actuator 354 is designed to be operated linearly by a human finger while the handle portion 312 is being gripped. The trigger switch 352 provides an input signal to the tool control system. There is also another input device used with the system controller, for example, a safety contact element switch 56 (see Figure 11), which is activated when the front end of the tool is pressed against the workpiece, thereby causing the safety contact element 332 to be "pressed" into the rest of the tool.

[0152] In the illustrated embodiment, the tool 310 includes a light-emitting diode (LED) 343 within the front housing 344, which provides some status information to the user of the tool. Furthermore, the tool 310 may optionally house one or more position sensors (not shown in Figure 25) inside the guide body 336, which can provide specific information regarding the movement of the driver "blade" 390.

[0153] The fastener drive tool 310 also includes a 53-stage electromagnetic induction coil subassembly, generally designated by reference numeral 400. The subassembly 400 also includes a plurality of bobbins 404 and a plurality of yokes 406. The individual coil windings themselves are not shown in Figure 25 (see induction coil 302 in Figure 22). Each of these induction coils (not shown in Figure 25) is a separate electrical inductor with a single multi-turn winding (i.e., they are electrically isolated windings), and each coil is designed to magnetize the piston / armature 380 at the appropriate time during the lift stroke. As described above, each or a group of these coils is excited in a predetermined movement sequence. The bobbins 404 and yokes 406 are essentially the same parts as those described above with reference to Figures 1-4. Again, the bobbins are typically made of a non-conductive and non-magnetic material, and the yokes are typically made of a magnetic material (with high permeability).

[0154] In the illustrated embodiment, both the bobbin 404 and the coil (not shown in Figure 25) are fitted around the outer circumference (or periphery) of the operating cylinder 371. However, to create a physically smaller device, the induction coil should be at least partially wound around the cylinder, but it is not necessary for the entire coil to wrap around the cylinder wall 370. This type of coil typically has a winding with multiple turns, many, if not the majority, of which are wound around the cylinder wall 370.

[0155] A power cord 348 is mounted near the rear of the handle portion 212, and this battery supplies power to the induction coil subassembly 300 and the control system. In the illustrated embodiment of Figure 25, the power cord 348 is mounted at the very rear of the handle, just behind the printed circuit board 342 in this exemplary embodiment.

[0156] The fastener drive tool 310 disclosed herein uses an induction coil subassembly to "lift" a piston and driver from a lower position, sometimes called the "driven" position, to an upper position, sometimes called the "ready" position. FUSION® nail drive tools previously sold by Kyocera Senco Industrial Tools, Inc. have used a mechanical "lifter" for this function. In these early FUSION® tools, the "front housing" 344, as seen in Figure 25, was typically called the "motor housing" because it is where the motor of the lifter is positioned within the tool housing. In this embodiment of the fastener drive tool 310, its front housing 344 houses a printed circuit board 340 having many high-power electronic components used to supply energy to the induction coil. In this design, there is also another printed circuit board, for example, 342, which houses other electronic components similarly used to control the tool 310. Some of these printed circuit boards also house more high-energy electronic components, such as switching transducers and energy storage capacitors, to drive the induction coils with enough energy to perform their lifting function. The AC / DC power converter 350 interfaces with the power cord 348 and converts the incoming AC power flowing through the power cord 348 into DC power and / or different AC voltages for use by the tool 310.

[0157] The piston 380 also acts as an armature, not only being acted upon by the pressurized gas from the main storage chamber 374 but also magnetically by the induction coil. In other words, when the induction coil is energized, it generates a magnetic field that tends to "lift" the piston / armature toward the ready position. Thus, the piston / armature 380 must be essentially airtight around its periphery as it fits inside the internal sleeve or cylinder wall 370, and must also be constructed, at least in part, of a magnetic material such as mild steel or a mild iron alloy, so that the magnetic field generated by the induction coil acts on the piston / armature to "upward" push toward the ready position, just as the coil acts on the plunger of a solenoid.

[0158] As described above, the tool 310 includes at least one printed circuit board that houses the system controller and carries other electrical and electronic components necessary for the proper functioning of the tool. These printed circuit boards 340 and 342 can be positioned almost anywhere inside the “empty” space of the housing, including inside the front housing 344 and the bottom portion of the tool just above the power cord 348. Another optional feature of this tool is the inclusion of several vents within the housing, somewhat closer to the battery pack, such as within the handle portion 312. These vents can allow some forced cooling air to flow around the printed circuit boards to help carry away the heat generated by the electronic components, particularly the components that supply electrical energy to the induction coils. Forced cooling air is generated each time the piston 380 moves its stroke during the drive stroke and the lift (or “return” stroke). As mentioned above, details of this type of cooling air system are described in another patent application by Kyocera Senco Industrial Tools, Inc., U.S. Patent Application Publication No. 2019 / 0321955(A1) entitled "FORCED AIR COOLING FROM PISTON MOVEMENTS OF NAILER TOOL," filed on 28 August 2018.

[0159] The latch 360 presses against the driver 390 under certain conditions. The latch 360 has an engaging extension that directly presses against one of the surfaces of the driver 390, and as a result, when the latch 360 collides with the opening 392 of the driver, the latch is pushed into the opening (via spring force). When this happens, the driver can move "downward" (in the direction of the drive stroke) only to the point where the latch contacts the "end" of the opening 392.

[0160] An operating cylinder subassembly, designated by reference numeral 371, is included as part of the fastener driver portion 314. As shown in Figure 25, the operating cylinder 371 includes a cylinder wall 370, within which are a movable piston 380 and a fixed piston retainer 384. In the illustrated embodiment, the cylinder wall 370 is partially surrounded by the main storage chamber 374 (also referred to herein as the “pressure vessel storage space”) and the outer pressure vessel wall 378. The uppermost portion of the operating cylinder is indicated by 372 of the fastener driver portion 314, as seen, for example, in Figure 25.

[0161] Furthermore, within the fastener driver portion 314 there is a mechanism that actually drives the fastener into the solid object. This includes a driver 390, a cylinder “vent chamber” 375 (typically always at atmospheric pressure), a driver track 393, and a latch 360. Note that the driver track 393 also acts as a fastener track, in that the lower portion of the entire passage through the guide body that guides the driver also guides the fastener. More specifically, the passage through the guide body is designed to receive fasteners (such as nails) from the magazine 316 at the “receiving end” of that portion of the entire track 393, and the driver 390 then pushes the fastener through the lower portion of the entire track (or passage) 393 until the fastener reaches the “exit end” of reference numeral 330, at which point the fastener is driven into the target workpiece. In a typical nail gun tool, the magazine holds multiple nails and feeds only one nail to the fastener track during a given drive stroke, which is done automatically without further action by the human user (except for operating the trigger and pushing the front end of the tool against the workpiece) once the magazine 316 is mounted on the tool 310.

[0162] The driver 390 is rather elongated, and the body of its elongated surface is substantially rectangular. There are several openings 392 positioned along the longitudinal surface of the driver. In the illustrated embodiment, these openings extend parallel to the longitudinal centerline of the driver 390 and are spaced apart from one another along the longitudinal surface of the driver 390. It will be understood that the exact positions of the openings 392 may differ from those illustrated for the driver 390 without departing from the principles of the art disclosed herein.

[0163] The latch 360 is designed to "capture" the driver 390 when the driver should not be allowed to move through the entire "drive stroke". The latch has a capture portion which can engage with the opening 392 of the driver 390 when the latch is moved to its engaged or "interfering" position. When the drive stroke is about to occur, the latch is pivoted to its "disengaged" position where its capture surface does not obstruct the driver, and therefore its capture surface does not interfere with any of the openings 392 of the driver. An exemplary embodiment of a similar latch that engages with a driver projection (rather than a driver opening) is described in its entirety in U.S. Patent No. 8,011,441, owned by Senco Brands, Inc., which is incorporated herein by reference.

[0164] A cylinder base 396 is located which primarily separates the gas pressure portion of the fastener driver portion 314 from the lower mechanical portion of the driver portion 314. Below the piston 380, a variable-volume portion is also called the cylinder vent chamber 375, which is vented to the atmosphere. In one embodiment of the exemplary configuration, a vent (not shown) near the cylinder base 396 is used for ventilation to the atmosphere. In an alternative configuration of the exemplary configuration, one or more vents (not shown) are located in the handle portion 312 to force cooling air through to the printed circuit board, as described above.

[0165] As can be seen in Figure 25, the coil subassembly 400 extends well beyond the end of the maximum piston stroke along the centerline of the pressure chamber. The individual coil stages to the left of the "ready" position of the piston 380 (as shown in this illustration in Figure 25) are energized as the piston is "lifted" during the final stage of the return stroke, and they exert a very strong "pulling" force on the piston, essentially pulling it further to the left until it reaches its ready position.

[0166] When the piston 380 reaches the appropriate ready position, the latch 360 can be engaged to hold the piston in that ready position without further assistance from the induction coil subassembly, and the induction coil can then be demagnetized. This physical configuration of the multiple coil stages in this fourth embodiment 310 is preferable to the configurations shown for the first two embodiments, as described above with reference to Figures 1 to 20. Furthermore, the power requirements of the multiple induction coil stages are considerably higher, and the use of AC line voltage via the power cord 348 is probably more practical than the use of a battery pack as described above with reference to the third embodiment 210.

[0167] Active coil required for lifting the graph

[0168] Referring here to Figure 26, Graph 500 shows how many coils are required in a given time interval to lift and return the driver to the ready position. Graph 500 has three axes: the X-axis 520 of piston stroke in millimeters (mm), the Y-axis 522 of force in pounds (lbs.), and the Y-axis 524 of the number of active coils. These three axes are drawn on Graph 500 as three straight sides of a rectangle. There are also graphical representations of three distinct variables: required force 510 (in pounds), coil force 512 (in pounds), and number of active coils 514. The line for required force 510 is a small dashed line, the line for coil force 512 is a solid line, and the line for number of active coils 514 is a long dashed line.

[0169] The graph is calculated based on the piston's center being 6 mm from the active coil. Graph 500 generally shows that, due to the increasing compression of the pressurized gas in the pressure chamber, the number of coils required to lift the piston increases as it advances and approaches its ready position. For example, note that the first 10 mm of the piston stroke requires only 8 active coils applying a force of 261 lbs. However, to reach the ready position, the piston must advance 110 mm, requiring 19 active coils applying a force of approximately 450 lbs.

[0170] Note that this graph 500 was calculated using one embodiment of a 53-stage coil assembly. Also note that not all 53 coils are ever activated simultaneously. The coils are switched on and off in stages as the piston is raised towards the ready position, and therefore, at any given time, only a few coils are in use.

[0171] Electronic controller for multi-stage coils

[0172] The third and fourth embodiments described above each include a considerable number of stages for their main induction coils 300 and 400. In fact, each induction coil 300 and 400 includes 53 individual coil stages, each of which needs to be currented by a driver circuit similar to the driver circuits 180, 182, 184, and 186 shown in Figures 13 and 14 for the second embodiment. It is recommended that each of the 53 coil stages of the induction coils 300 and 400 have its own individual driver circuit, even though some of the coil stages are often (or perhaps always) driven at the same time interval as some of their adjacent coil stages.

[0173] In short, the electrical block diagram of the third embodiment has the same components as shown in Figure 13 or Figure 14, except that it has 53 coil driver circuits similar to coil driver #1 in reference numeral 180, and 53 induction coils similar to coil "C1" in reference numeral 130. Other sensors and driver circuits, along with the system controller components and battery, are still included in the third embodiment.

[0174] Similarly, the electrical block diagram of the fourth embodiment also has the same components as those shown in Figure 13 or Figure 14, and again has 53 coil driver circuits similar to coil driver #1 in reference numeral 180, and 53 inductive coils similar to coil "C1" in reference numeral 130. Furthermore, other sensor and driver circuits are still included in the fourth embodiment along with the system controller components, but in this case, there is no battery. Instead, a power cord is used to connect the tool to a line voltage such as single-phase 120VAC, 60Hz. A DC power supply (similar to reference numeral 46 in Figure 14) is still present to supply a relatively low DC voltage to the processing circuit and other sensors and drivers, but this power supply is AC rather than battery. This fourth embodiment is also likely to include a "high voltage" power supply similar to reference numeral 47 in Figure 14, however, its energy is supplied from the AC line voltage instead of a battery.

[0175] Fewer moving parts than advantages

[0176] Conventional fastener-driven tools have certain mechanically moving parts that must function properly for the tool to operate. For example, an "air tool" includes certain air valves to first move a piston (in a "drive" stroke) to drive the fastener, and then move the piston in the opposite direction (in a "lift" stroke or "return" stroke). To perform these functions, first a pilot valve is actuated when a human user pulls the tool's trigger, then the pilot valve acts a much larger "main valve," which releases compressed air into the cylinder, forcing the piston to move in the drive stroke, and finally another valve or two valves must close the main valve and also open a passage, allowing the compressed air "below" the piston to "lift" the piston back to its starting position. All of these air valves are moving parts and can wear out, become clogged with dirt, or simply break, thus rendering the tool inoperable.

[0177] The FUSION® line of gas spring tools sold by Kyocera Senco Industrial Tools also features several moving parts primarily related to "lifting" and returning the piston to its starting position. While these Senco lifters are very robust, misalignment with the driver blade can still occur if a nail gets stuck in the driver during the drive stroke, and something else in the mechanical lifting hardware can break or wear out over thousands of operating cycles. Nevertheless, FUSION tools offer improved reliability because they do not have an air valve that needs to be activated to initiate the drive stroke.

[0178] In the technologies disclosed herein, the only significant moving part is the latch. (This statement, of course, ignores the movable piston and driver, which cannot be eliminated in these tools unless they are intended to be a “railgun”). Furthermore, Senco’s FUSION® tools already include a similar latch, meaning that the various embodiments disclosed herein essentially have no moving parts compared to previous conventional FUSION tools. Of course, most fastener drive tools also include a movable trigger and a movable safety contact element, but even if these tools were to evolve into railguns someday, these parts still cannot be eliminated. Fewer moving parts mean greater reliability.

[0179] It will be further understood that any type of product described herein that has moving parts or performs a function (such as a computer having processing and memory circuits) should be considered a “machine” rather than merely some kind of inanimate device. Such “machine” devices should automatically include power tools, printers, electronic locks, etc., since each of these exemplary devices has specific moving parts. Furthermore, computerized devices that perform a useful function should also be considered machines, and such terminology is often used to describe many such devices; for example, a solid-state answering machine may not have moving parts, but it performs a well-known useful function and is therefore still commonly called a “machine.”

[0180] Furthermore, it will be understood that a computing product that includes a display for showing information to a human user, and also includes a “user-operated input circuit,” and therefore a human user can input commands or data, may be provided in a single device known as a “touchscreen display.” In other words, if the claims list “display” and “user-operated input circuit” as two separate elements, a single touchscreen display is in fact exactly the same thing. It should be noted that a touchscreen display typically includes a virtual keypad, and therefore the “user-operated input circuit” typically comprises a virtual keypad, particularly on smartphones and tablet computers. Furthermore, in this context, the word “virtual” means that it is not a hardware keypad, and more specifically, “virtual” means that it is formed (i.e., “generated”) on the display screen because the software is executed by the processing circuit.

[0181] As used herein, the term “proximal” may mean positioning one physical object close to a second physical object such that the two objects are, in some cases, adjacent to each other, but it is not necessarily required that a third object be positioned between them. In the art disclosed herein, a “male positioning structure” may be positioned “proximal” to a “female positioning structure.” Generally, this may mean that the two male and female structures are in physical contact with each other, or that they are “interlocked” with each other by a particular size and shape, which essentially holds one structure oriented in a predetermined direction relative to the other and in an XY (e.g., horizontal and vertical) position, regardless of whether the two male and female structures are actually in contact with each other along a continuous surface. Alternatively, two structures of any size and shape (male, female, or other shapes) may be positioned somewhat close to each other, regardless of whether they are in physical contact with each other, but such a relationship can still be called “proximal.” Alternatively, two or more possible locations relative to a particular point can be specified in relation to the precise attributes of a physical object, such as being "near" or "at" the end of the rod, and all of these possible, near / at locations can be considered "proximal" to the end of the rod. Furthermore, the term "proximal" can also have a meaning strictly relating to a single object, which may have two ends, where the "distal end" is the end located somewhat further away from the reference point (or region) of the object, and the "proximal end" is the other end that would be located somewhat closer to that same reference point (or region).

[0182] It will be understood that the various components described and / or illustrated herein can be manufactured in a variety of ways, including being manufactured as part of multiple components or as integral components for each of these components, without departing from the principles of the art disclosed herein. For example, a component included as an enumerated element in the following claims may be manufactured as an integral component, or it may be manufactured as a combined structure of several individual parts assembled together. However, such “other component” still falls within the scope of the claimed and enumerated element for the purpose of infringement of the claims, even if the claimed and enumerated element appears to be described and shown herein only as an integral structure.

[0183] All documents cited in the "Background Art" and "Modes for Carrying Out the Invention" sections are incorporated herein by reference in the relevant parts, but no citation of any document should be construed as accepting prior art to the art disclosed herein.

[0184] The above description of preferred embodiments is provided for illustrative and explanatory purposes only. It is not intended to be exhaustive or to limit the art disclosed herein to the exact form disclosed herein, and the art disclosed herein can be further modified within the spirit and scope of this disclosure. Any embodiment described or illustrated herein is intended to be a non-exclusive embodiment, and many modifications or variations of such embodiment or preferred embodiment(s) are possible by considering the above teachings without departing from the spirit and scope of the art disclosed herein. The embodiments(s) are selected and described to illustrate the principles and practical applications of the art disclosed herein, thereby enabling those skilled in the art to utilize the art disclosed herein in various embodiments and with various modifications suitable for specific intended uses. Therefore, this application is intended to cover all variations, uses, or adaptations of the art disclosed herein using its general principles. Furthermore, this application intends to cover such deviations from the disclosure so as to fall within the scope of known or customary practices in the art to which the art disclosed herein relates and which are included within the scope of the appended claims.

Claims

1. A fastener drive tool (10, 110, 210, 310) equipped with a closed-system lifter, (a) A guide body (36, 236, 336) having a receiving end, an exit end, and a passage between them, which is physically configured to receive a fastener, (b) A hollow cylinder (71, 271, 371) comprising a cylindrical wall (70, 270, 370) and including a movable piston (80, 280, 380) therein, including a first end and a second end on the opposite side, which accommodates a displacement volume (76) generated by the stroke of the piston, (c) An elongated driver (90, 290, 390) including a first end and a second end, wherein the first end is mechanically in communication with the movable piston and the second end is sized and shaped to push a fastener from the exit end of the guide body, (d) comprising induction coils (100, 120, 300, 400) at least partially wound around the hollow cylinder, (e) (i) The displacement volume contains pressurized gas, which is not discharged into the atmosphere after the drive stroke, but is instead reused for multiple operation cycles. (ii) The cylinders (71, 271, 371) and pistons (80, 280, 380) act as gas springs during the drive stroke, using the pressurized gas of the displacement volume (76) acting on the piston to move the driver (90, 290, 390) toward the driven position. (iii) The induction coils (100, 120, 300, 400) are energized during the lift stroke of the operating cycle, and the magnetic field is used to move the piston toward the ready position. Fastener driving tool.

2. The fastener driving tool (10) according to claim 1, wherein the induction coil (100) comprises a single-stage inductor (102) having a winding including a plurality of turns around the cylindrical wall (70) of the hollow cylinder (71).

3. The fastener drive tool (110, 210, 310) according to claim 1, wherein the induction coil (120, 300, 400) comprises a multistage inductor subassembly (122, 302, 402) having a plurality of electrically isolated windings (130, 132, 134, 136, 302, 402), each of which windings includes a plurality of windings around the cylindrical wall (70, 270, 370) of the hollow cylinder (71, 271, 371).

4. The fastener drive tool (10, 110, 210, 310) according to claim 1, further comprising the hollow cylinders (71, 271, 371), the elongated drivers (90, 290, 390), and the induction coils (100, 120, 300, 400), and further comprising a housing (20, 22, 220, 222, 320, 322), and lacking an external energy source cable and an external hose.

5. The system further comprises a main storage chamber (74, 274, 374) that is in fluid communication with the displacement volume (76) of the hollow cylinder (71, 271, 371) during the drive stroke of the operating cycle, wherein the main storage chamber and the displacement volume contain pressurized gas, and the pressurized gas is not discharged into the atmosphere after the drive stroke but is instead reused for multiple operating cycles. The fastener driving tool (10, 110, 210, 310) according to claim 1.

6. The fastener driving tool (10, 110, 210, 310) according to claim 1, wherein the cylinders (71, 271, 371) and pistons (80, 280, 380) act as gas springs to move the driver (90, 290, 390) toward the driven position under first predetermined conditions.

7. The fastener driving tool (10, 110, 210, 310) according to claim 1, wherein the induction coils (100, 120, 300, 400) move the drivers (90, 290, 390) toward the ready position under second predetermined conditions.

8. The drivers (90, 290, 390) have an irregular shape along at least one surface, and the irregular shape of the drivers is (a) A longitudinal edge having multiple spaced projections, (b) Multiple spaced openings (92, 292, 392) along the longitudinal surface The fastener driving tool (10, 110, 210, 310) according to claim 1, including the above.

9. It also has latches (60, 260, 360), (a) When the latch is in the first operating state, the latch holds the driver (90, 290, 390) in the ready position by mechanical contact with the irregular shape of the driver, (b) When the latch is in the second operating state, the latch releases the mechanical contact with the driver (90, 290, 390), thereby releasing the driver from the ready position and initiating the drive stroke. The fastener driving tool (10, 110, 210, 310) according to claim 8.

10. It also has latches (60, 260, 360), (a) When the pistons (80, 280, 380) are moved to the ready position, the induction coils (100, 120, 300, 400) temporarily hold the pistons in the ready position until the latches are engaged. (b) Thereafter, the induction coils (100, 120, 300, 400) are demagnetized, and the latch continues to hold the pistons (80, 280, 380) in place by using the mechanical contact between the latch and the irregular shape of the driver. The fastener driving tool (10, 110, 210, 310) according to claim 8.

11. (a) An electronic control circuit including a computer processing circuit (150), a memory circuit (152) containing instructions executable by the processing circuit, an input / output interface circuit (154), and an induction coil driver circuit (160). The fastener driving tool (10, 110, 210, 310) according to claim 1, further comprising the above.

12. A fastener drive tool (10, 110, 210, 310) according to claim 1, further comprising a magazine (16, 216, 316) containing a plurality of fasteners, wherein one of the fasteners is supplied to the guide body (36, 236, 336) over one of the drive strokes.

13. The fastener drive tool (10, 110, 210, 310) according to claim 1, wherein the electrical energy source comprises at least one of (a) a battery (48, 248) and (b) a power cable for deriving AC power from line voltage.

14. The fastener driving tool (110, 210, 310) according to claim 3, wherein the plurality of electrically isolated windings (130, 132, 134, 136, 302) are energized in a predetermined sequence during the lifting stroke.

15. A fastener drive tool (10, 110, 210, 310) equipped with a closed-system lifter, It comprises a housing (20, 22, 220, 222, 320, 322) for containing pressurized gas, a hollow cylinder (71, 271, 371) including a movable piston (80, 280, 380), a driver (90, 290, 390) that mechanically communicates with the piston at least during the drive stroke, an induction coil (100, 120, 300, 400) that magnetically communicates with the piston at least during the lift stroke, a mechanical latch (60, 260, 360), and an electrical energy source. The hollow cylinder is configured to use the pressurized gas to propel the piston toward the driven position during the drive stroke, The induction coil is configured to use a magnetic field to propel the piston toward the ready position during the lifting stroke. The latch is configured to hold the driver in the ready position after the lifting stroke. Fastener driving tool.

16. (a) A guide body (36, 236, 336) having a receiving end, an exit end, and a passage between them, which is physically configured to receive a fastener, (b) A magazine (16, 216, 316) including a plurality of fasteners, wherein one of the fasteners is supplied to the guide body over one of the drive strokes, (c) A solenoid (68) that controls the position of the latch, (d) An electronic control circuit including a computer processing circuit (150), a memory circuit (152) containing instructions executable by the processing circuit, an input / output interface circuit (154), a solenoid driver circuit, and an induction coil driver circuit (160), The fastener driving tool (10, 110, 210, 310) according to claim 15, further comprising the above.

17. (a) The induction coil (120, 300, 400) comprises a multi-stage coil including a plurality of individual electrical inductors (130, 132, 134, 136, 302), (b) The induction coil driver circuit has a plurality of outputs, at least one of which corresponds to each of the plurality of individual electrical inductors, (c) During the lifting stroke, the electronic control circuit is configured to control the induction coil driver circuit so as to excite at least one of the plurality of individual electrical inductors in a predetermined sequence. The fastener driving tool (110, 210, 310) according to claim 16.

18. The fastener drive tool (110, 210, 310) according to claim 17, wherein the multi-stage coil extends beyond the end of the piston stroke within the hollow cylinder (271, 371).

19. A method for using fastener drive tools (10, 110, 210, 310) equipped with a closing system lifter, (a) To provide a housing (20, 22, 220, 222, 320, 322) for containing pressurized gas, a hollow cylinder (71, 271, 371) including a movable piston (80, 280, 380), a driver (90, 290, 390) that mechanically communicates with the piston at least during the drive stroke, an induction coil (100, 120, 300, 400) that magnetically communicates with the piston at least during the lift stroke, a magazine (16, 216, 316) equipped with a plurality of fasteners, a mechanical latch (60, 260, 360), and an electrical energy source. (b) Positioning the latch to hold the driver in the ready position before the drive stroke is activated, (c) When the drive stroke is in operation, (i) Engaging the latch to change its position and releasing the driver, (ii) By using the pressurized gas, the piston is propelled toward the driven position, thereby moving the driver and pushing the fastener out of the tool housing, (d) After the completion of the drive stroke, (i) Exciting the induction coil to generate a magnetic field, (ii) By using the magnetic field, the piston is propelled toward the ready position, thereby moving the driver toward the ready position, and thereby initiating the lifting stroke, (e) After the lifting stroke is completed, (i) A method comprising positioning the latch to hold the driver in the ready position until another drive stroke.

20. (a) Providing a solenoid (68) that controls the position of the latches (60, 260, 360), (b) Providing an electronic control circuit including a computer processing circuit (150), a memory circuit (152) containing instructions executable by the processing circuit, an input / output interface circuit (154), a solenoid driver circuit (162), and an induction coil driver circuit (160), (c) Controlling the solenoid driver circuit to position the latch so as to release the drivers (90, 290, 390) and start the drive stroke, and then, when the drivers reach the ready position, to position the latch so as to physically engage with and hold the drivers; (d) The steps of controlling the induction coil driver circuit to energize the induction coil to initiate a lift stroke and to keep the induction coil energized until the driver reaches the ready position and the latch moves to its holding position, The method according to claim 19, further comprising:

21. (a) The induction coil (120, 300, 400) comprises a multi-stage coil including a plurality of individual electrical inductors (130, 132, 134, 136, 302), (b) The induction coil driver circuit has a plurality of outputs, at least one of which corresponds to each of the plurality of individual electrical inductors, (c) During the lifting stroke, the induction coil driver circuit is controlled to energize at least one of the plurality of individual electrical inductors in a predetermined sequence. The method according to claim 20.

22. A fastener drive tool (10, 110, 210, 310) equipped with a closed-system lifter, It comprises a housing (20, 22, 220, 222, 320, 322) for containing pressurized gas, a hollow cylinder (71, 271, 371) including a movable piston (80, 280, 380), a driver (90, 290, 390) that mechanically communicates with the piston at least during the drive stroke, an induction coil (100, 120, 300, 400) that magnetically communicates with the piston at least during the lift stroke, a mechanical latch (60, 260, 360), and an electrical energy source. The hollow cylinder is configured to use the pressurized gas to propel the piston toward the driven position during the drive stroke, The induction coil is configured to use a magnetic field to propel the piston toward the ready position during the lifting stroke, The latch is configured to hold the driver in the ready position, A fastener drive tool wherein the induction coil is wound around the hollow cylinder and extends beyond the end of the hollow cylinder in the direction of the lifting stroke.

23. (a) A guide body (36, 236, 336) having a receiving end, an exit end, and a passage between them, which is physically configured to receive a fastener, (b) A magazine (16, 216, 316) including a plurality of fasteners, wherein one of the fasteners is supplied to the guide body over one of the drive strokes, (c) A solenoid (68) that controls the position of the latches (60, 260, 360), (b) An electronic control circuit including a computer processing circuit (150), a memory circuit (152) containing instructions executable by the processing circuit, an input / output interface circuit (154), a solenoid driver circuit (162), and an induction coil driver circuit (160), The fastener driving tool (10, 110, 210, 310) according to claim 22, further comprising the above.

24. (a) The induction coil (120, 300, 400) comprises a multi-stage coil including a plurality of individual electrical inductors (130, 132, 134, 136, 302), (b) The induction coil driver circuit has a plurality of outputs, at least one of which corresponds to each of the plurality of individual electrical inductors, (c) During the lifting stroke, the electronic control circuit is configured to control the induction coil driver circuit so as to excite at least one of the plurality of individual electrical inductors in a predetermined sequence. The fastener driving tool (110, 210, 310) according to claim 23.

25. The fastener driving tool (110, 210, 310) according to claim 24, wherein the multi-stage coil includes at least four individual electrical inductors (130, 132, 134, 136, 302).

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