CN117157173A - Fastener driving tool with chamber component holding assembly - Google Patents

Abstract

A combustion-powered fastener-driving tool includes a chamber member retention assembly configured to enable a controller of the tool to prevent a chamber member of the tool from moving to an open unsealed position and to ensure that a combustion chamber of the tool remains sealed until the piston is fully returned to its pre-firing position.

Description

Fastener driving tool with chamber component holding assembly

Priority

The present patent application claims priority and benefit from U.S. provisional patent application Ser. No. 63/159,696, filed on day 3 and 11 of 2021, and U.S. non-provisional patent application Ser. No. 17/687,154, filed on day 3 and 4 of 2022, each of which is incorporated herein by reference in its entirety.

Background

The present disclosure relates to powered fastener driving tools. Powered fastener driving tools employ one of several different types of power sources to drive fasteners, such as nails or staples, into a workpiece. The power fastener driving tool uses a power source to drive a piston carrying driver blades through a cylinder from a pre-firing position to a firing position. When the piston moves to the firing position, the driver blade travels through a nosepiece (nosepiece) that guides the driver blade into contact with a fastener housed in the nosepiece of the tool. Continued movement of the piston through the cylinder toward the firing position forces the driver blade to drive the fastener out of the nosepiece and into the workpiece. The piston is then forced back to the pre-firing position in a manner that depends on the configuration of the tool and the power source employed by the tool. The fastener-advancing device of the tool forces another fastener from a magazine (magazine) of the tool into the nosepiece, and the tool is ready to fire the next fastener.

Combustion-powered fastener-driving tools are one type of powered fastener-driving tool. Combustion-powered fastener-driving tools use a small internal combustion assembly as their power source. For various known combustion-powered fastener-driving tools, when an operator presses a workpiece contact element ("WCE") of the tool against a workpiece to move the WCE from an extended position to a retracted position, one or more mechanical linkages cause: (1) The chamber member is moved to a sealing position to seal a combustion chamber in fluid communication with the cylinder; and (2) the fuel delivery system dispenses fuel from the fuel tank into the (now sealed) combustion chamber. When the operator pulls the trigger, the trigger actuates the trigger switch, causing the spark plug to generate a spark and ignite the fuel/air mixture in the combustion chamber. This generates high pressure combustion gases that expand and force the piston through the cylinder from a pre-firing position to a firing position, causing the driver blade to contact the fastener received in the nosepiece and drive the fastener out of the nosepiece into the workpiece. Just prior to the piston reaching the firing position, the piston passes through an exhaust check valve defined by the cylinder and some of the combustion gases pushing the piston are vented to atmosphere through the check valve. This is combined with the fact that the heat exchange to atmosphere and the combustion chamber remain sealed during firing to create a vacuum pressure above the piston and retract the piston to the pre-fired position. When the operator removes the WCE from the work piece, the spring biases the WCE from the retracted position to the extended position such that the one or more mechanical linkages move the chamber member to the unsealed position to unseal the combustion chamber.

One problem associated with certain combustion-powered fastener-driving tool operations may occur if the chamber member moves and the combustion chamber is unsealed before the piston returns to the pre-firing position. For example, if an operator removes the WCE from the work piece after firing but before the piston returns to the pre-fired position, this may result in the chamber member moving to an unsealed position and unsealing the combustion chamber. When this occurs, at least some vacuum pressure is lost. This may cause the piston to stop before reaching its pre-firing position, which in turn may cause the tool to fail when the operator next attempts to use the tool to drive the next fastener.

Some fastener-driving tools have two different types of modes of operation and one or more mechanisms that enable an operator to selectively select one of the two different modes of operation that the operator wants to use to drive a fastener. One such mode of operation is known in the art as a sequential or single actuation mode of operation. In this mode of operation, actuation of the trigger mechanism (itself) will not cause actuation of the powered fastener-driving tool (and driving a fastener into a workpiece) unless the WCE is sufficiently pressed against the workpiece. In other words, in order to operate the powered fastener-driving tool in a sequential or single actuation mode of operation, the WCE must first be pressed against the work piece and then the trigger mechanism actuated. Another mode of operation is known in the art as a contact actuation or bump-fire mode of operation. In this mode of operation, the operator may hold the trigger mechanism in or in its actuated position, and then the fastener-driving tool will actuate (and thereby drive a fastener into a workpiece) each time the WCE contacts and fully presses against the workpiece.

One problem with various commercially available combustion-powered fastener-driving tools (sometimes referred to as cordless frame nailers) is that the tools operate in sequential firing mode, but not in impact firing mode. Operating such tools in the sequential firing mode alone may lead to operator fatigue.

Accordingly, there is a need for a combustion-powered fastener-driving tool that addresses these issues.

Disclosure of Invention

The present disclosure provides various embodiments of combustion-powered fastener-driving tools that address the above-described problems by including a chamber member retaining assembly to ensure that the chamber member does not move to an unsealed position, and that the combustion chamber remains sealed until the piston has completely returned to its pre-firing position. The chamber component holding assembly is controlled by a suitable controller and is engageable with the chamber component, providing control with the ability to prevent some undesired movement of the chamber component from the sealing position.

In various embodiments, the chamber member holding assembly includes a gas-assisted actuation member and an electromagnet that holds the actuation member in a holding position. The tool provides a gas that causes the actuating member to move from the non-holding position to the holding position. A controller of the tool energizes the electromagnet to hold the actuation member in the holding position. In certain embodiments, the actuation member, in turn, causes the chamber member to engage the lever preventing the chamber member from moving from its sealed position toward its unsealed position.

In certain embodiments, the actuation member directly prevents the chamber member from moving from its sealed position toward its unsealed position. The controller de-energizes the electromagnet based on a specified amount of time, which gives the piston time to return fully to its pre-firing position. This enables the tool to operate in a bump firing mode. The rate of operation is limited by various factors including the necessary electromagnet "on" time and the time between fastener driving cycles when the tool is repositioned and the combustion chamber receives fresh air. The combustion-powered fastener-driving tool of various embodiments of the present disclosure can provide an automatic combustion chamber lockout control feature and a collision firing mode feature.

Various embodiments of the combustion-powered fastener-driving tool of the present disclosure operate in a default sequential mode and in a collision firing mode in response to a user switching mode. In various embodiments, the controller of the tool employs a timeout function in the bump firing mode that prevents tool operation in the bump firing mode after a specified idle period (e.g., five to ten seconds). The combustion-powered fastener-driving tool of various embodiments of the present disclosure enables an operator to quickly select between a sequential or single actuation mode of operation and a contact actuation or bump-firing mode of operation.

Additional features and advantages are described in, and will be apparent from, the following detailed description and the accompanying drawings.

Drawings

FIG. 1 is a perspective view of a combustion-powered fastener-driving tool of one example embodiment of the present disclosure.

Fig. 2A, 2B, 2C and 2D are fragmentary, partial cross-sectional views of the fastener-driving tool of fig. 1 in a resting state, with the chamber member in an unsealed position, the piston in a fully retracted position, and the chamber member-retaining assembly in an inactive state.

Fig. 3A, 3B and 3C are fragmentary, partial cross-sectional views of the fastener-driving tool of fig. 1 in a ready-to-fire state with the chamber member in a sealed position, the piston in a fully retracted position, and the chamber member retaining member in an inactive state.

Fig. 4A, 4B and 4C are fragmentary, partial cross-sectional views of the fastener-driving tool of fig. 1 in a fired state with the chamber member in a sealed position, the piston in a partially-driven position, and the chamber member-retaining assembly in an activated state with the actuating member in a retaining position, the electromagnet energized and retaining the actuating member in the retaining position, and the chamber member-engaging lever positioned to engage the chamber member.

5A, 5B and 5C are fragmentary partial cross-sectional views of the fastener-driving tool of FIG. 1 in a fired state with the chamber member in a sealed position, the piston fully driven and beginning to move back toward a retracted position, and the chamber member-retaining assembly in an activated state with the actuating member in a retaining position, the electromagnet energized and retaining the actuating member in the retaining position, and the chamber member-engaging lever positioned to engage the chamber member.

6A, 6B and 6C are fragmentary partial cross-sectional views of the fastener-driving tool of FIG. 1 in a fired state with the chamber member still not moved (or significantly moved) from the sealed position, the piston moving back toward the fully retracted position, and the chamber member-retaining assembly in an activated state with the actuating member in the retaining position, the electromagnet energized and retaining the actuating member in the retaining position, and the chamber member engaging lever engaging the chamber member to prevent movement of the chamber member.

Fig. 7A, 7B and 7C are fragmentary partial cross-sectional views of a portion of a combustion-powered fastener-driving tool of another example embodiment of the present disclosure, wherein the chamber member retaining assembly does not include a chamber member engagement lever, and engagement of the chamber member is directly engaged by the actuating member.

Fig. 8A and 8B are diagrammatic views of a chamber component holding assembly of a combustion-powered fastener-driving tool of another example embodiment of the present disclosure.

Fig. 9A, 9B, and 9C are diagrammatic views of a chamber component holding assembly of a combustion-powered fastener-driving tool of another example embodiment of the present disclosure.

Fig. 10A and 10B are diagrammatic views of a chamber component holding assembly of a combustion-powered fastener-driving tool of another example embodiment of the present disclosure.

11A and 11B are fragmentary views of a portion of a combustion-powered fastener-driving tool of another embodiment of the present disclosure and showing possible positions of its cavity member retaining assembly.

Detailed Description

The figures illustrate and the description describe certain exemplary and non-limiting embodiments, however, the systems, devices, and methods described herein may be embodied in various forms. Not all of the components shown in the figures and described in the specification are required, and some embodiments may include additional, different, or fewer components. The arrangement and type of components may be varied without departing from the spirit or scope of the claims; the shape, size and materials of the components and the manner in which the components are connected vary. Unless otherwise indicated, any directions mentioned in this specification reflect the orientation of the components shown in the corresponding drawings and do not limit the scope of the present disclosure. Further, terms relating to mounting methods such as mounting, connecting, and the like are not intended to be limited to direct mounting methods, but rather should be construed broadly to include indirect and operative mounting, connecting, and the like. The description is intended as a whole and is to be construed in accordance with the principles of the present disclosure and as understood by those of ordinary skill in the art.

Turning now to the drawings, FIGS. 1-6C illustrate one example embodiment of a combustion-powered fastener-driving tool 100 (sometimes referred to as a "tool" for brevity) of the present disclosure. The tool 100 generally includes a multi-piece housing 110; a nose assembly 130 including a workpiece contact element 136 supported by the housing 110; a trigger assembly 140 supported by the housing 110; a fastener magazine 150 supported by the housing 110 and connected to the nose piece assembly 130; an internal combustion assembly 200 at least partially within the housing 110; and a chamber component holding assembly 300 supported by the housing 110. Because certain portions of the fastener driving tool 100, such as the housing 110, nose piece assembly 130, workpiece contact element 126, fuel delivery system (not shown), and fastener cartridge 150 are known in the art, they are only partially shown in certain figures and are not described herein for brevity.

The internal combustion assembly 200 of the tool 100 includes: (1) A cylinder 210 at least partially within and supported by the housing 110; (2) A piston 220 slidably disposed within the cylinder 210; (3) A driver blade 230 attached to the piston 220 and extending below the piston; and (4) a bumper 240 positioned within the cylinder 210 and at the bottom of the cylinder. The piston 220, which is attached to the driver blade 230, is movable relative to the cylinder 210 between a pre-firing position and a firing position. The cylinder 210 includes an exhaust check valve or flap valve (not shown) near its bottom and defines a vent 252 below the exhaust check valve. An exhaust check valve 250 and vent 252 fluidly connect the cylinder 210 to the atmosphere.

A chamber member (sometimes referred to in the art as a valve bushing) 260 is at least partially within, supported by, and movable relative to the housing 110. A chamber member or valve bushing 260 partially surrounds the cylinder 210. The chamber component or valve bushing 260 is movable relative to the housing 110, the cylinder head 212, and the cylinder 210 (among other components) between an unsealed position and a sealed position. The chamber component or valve liner 260, cylinder head 212, cylinder 210, and piston 220 collectively define a combustion chamber (not labeled). When the chamber component or valve bushing 260 is in the sealed position, the combustion chamber is sealed. Conversely, when the chamber component or valve bushing 260 is in the unsealed position, the combustion chamber is unsealed.

A suitable linkage (not shown) connects the chamber member or valve bushing 260 and the workpiece contact element 136. The workpiece contact element 136 is movable relative to the housing 110, the cylinder head 212, and the cylinder 210 (among other elements) between an extended position and a retracted position. A biasing element (not shown), such as a spring, biases the workpiece contact element 136 to the extended position. Movement of the workpiece contact element 136 from the extended position to the retracted position causes the chamber member or valve bushing 260 (via the linkage) to move from the unsealed position (see fig. 2A and 2B) to the sealed position (see fig. 3A, 3B, 4A, 4B, 5A, 5B, 6A, and 6B) and vice versa.

In this example embodiment, the chamber component holding assembly 300 of the tool 100 generally comprises: a housing 310; a gas-assisted actuation member 330 positioned in the housing 310; and an electromagnet 360 positioned in the housing 310 and configured to hold the actuation member 330 in a held position under control of a controller (not shown) of the tool 100. The actuation member 330 includes an actuation pin 334, and an actuation plunger 338 connected to a distal end of the actuation pin 334. The tool 100 provides a gas that moves the actuation member 330 from the non-holding position (fig. 2C, 2D, and 3C) toward the holding position (fig. 4C, 5C, and 6C). The controller of the tool 100 is configured to selectively energize the electromagnet 360 to hold the actuation member 330 in the holding position (fig. 5C and 6C). The actuation member 330, in turn, causes the chamber member engagement lever 400 to prevent the chamber member 260 from moving from its sealed position toward its unsealed position. The controller energizes the electromagnet 360 for a specified amount of time, such as 100 to 160 milliseconds (milli-second), to fully return the piston 220 to its pre-firing position before allowing the chamber member 260 to move to its unsealed position. Thus, in the example embodiment, the chamber component holding assembly 300 ensures that the chamber component 260 does not move to the unsealed position and that the combustion chamber remains sealed until the piston 220 is fully returned to the pre-firing position. This in part enables the tool 100 to operate in a bump firing mode.

In this example embodiment, the chamber member engagement lever 400 includes an upper arm 410, a central pivot member 430, and a lower arm 450. The upper arm 410 is connected to the central pivoting member 430 and extends upwardly from the central pivoting member 430. The upper arm 410 includes a chamber member engagement handle (415) configured to engage the chamber member 260 to prevent the chamber member 260 from moving to an unsealed position. The lower arm 450 is connected to the central pivot member 430 and extends downwardly from the central pivot member 430. The lower arm 450 includes a lever 455 that facilitates pivotal connection to the actuation member 330. The central pivot member 430 is pivotally attached to a lever support 490 that is attached to the housing 310 by a pivot pin 435. The upper arm 410, the central pivot member 430, and the lower arm 450 of the chamber member engagement lever 400 are thus pivotally connected to the actuation member 330, and movement of the chamber member engagement lever 400 is thus controlled by the actuation member 330 and the chamber member holding assembly 300 under the control of the controller of the tool 100. It should be understood that the pivot point at which the chamber member engages the lever may vary in accordance with the present disclosure. It should be appreciated that the configuration (including shape and/or size) of the chamber member engagement lever (including the upper arm, the central pivot member, and/or the lower arm) may vary in accordance with the present disclosure.

Fig. 2A, 2B, 2C and 2D illustrate the tool 100 in a resting state, with the chamber member 260 in an unsealed position, the piston 220 in a fully retracted position, and the chamber member holding assembly 300 in an unactivated state. In this example embodiment, the chamber component holding assembly 300 includes a rubber bumper 370 that provides cushioning behind the electromagnet 360. This allows for a certain amount of compression due to the gas pressure on the actuation member 330, allows for adjustment of the stroke of the actuation member 330, and allows for adaptation to the material thickness of the housing 310 of the chamber member holding assembly 300. In this example embodiment, the chamber member holding assembly 300 includes a biasing member (such as a spring 380) that biases the actuation member 330 to the non-holding position, as shown in fig. 2C and 2D.

Fig. 3A, 3B and 3C illustrate the tool 100 in a ready to fire state with the chamber member 260 in a sealed position, the piston 220 in a fully retracted position, and the chamber member holding assembly 300 in an inactive state.

Fig. 4A, 4B and 4C illustrate the tool 100 in a fired state with the chamber member 260 in a sealed position, the piston 220 in a partially actuated position, and the chamber member holding assembly 300 in an activated state with the actuating member 330 in a held position (against the bias of the spring 380), the electromagnet 360 energized and holding the actuating member 330 in the held position, and the chamber member engagement lever 400 positioned to engage the chamber member 260. In this state, the actuation member 330 has moved the lower arm 450 of the chamber member engagement lever 400 toward the electromagnet 360, the entire chamber member engagement lever 400 pivots about the pivot pin 435, and the upper arm 410 of the chamber member engagement lever 400 pivots inwardly so that the chamber member engagement handle 415 of the chamber member engagement lever 400 may engage or be engaged by the chamber member to prevent the chamber member 260 from moving to its unsealed position.

Fig. 5A, 5B and 5C illustrate the tool 100 in a fired state with the chamber member 260 in a sealed position, the piston 220 in fully driven and beginning to move back toward its retracted position, and the chamber member holding assembly 300 in an activated state with the actuating member 330 in a held position, the electromagnet 360 energized and holding the actuating member 330 in the held position, and the chamber member engagement handle 415 of the chamber member engagement lever 400 positioned to engage or be engaged by the chamber member 260.

Fig. 6A, 6B and 6C illustrate the tool 100 in a fired state, wherein the chamber member 260 begins to move from the sealed position, the piston 220 moves back toward the fully retracted position, and the chamber member holding assembly 300 is in an activated state, wherein the actuating member 330 is in the holding position, the electromagnet 360 is energized and holds the actuating member 330 in the holding position, and the chamber member engagement handle 415 of the chamber member engagement lever 400 engages the chamber member 260 or is engaged by the chamber member to prevent further movement of the chamber member 260 until the piston 220 returns to its fully retracted position. After the piston 220 has returned to its fully retracted position, the chamber component holding assembly 300 will return to its inactive state, such as shown in fig. 2A, 2B, 2C, and 2D. To this end, the controller will de-energize the electromagnet 360 and thus release the actuation member 330, so that the spring 380 will return the actuation member to its non-holding position. This will cause the lower arm 450 of the chamber member engagement lever 400 to move away from the electromagnet 360, the entire chamber member engagement lever 400 pivoting back about the pivot pin 435, and the upper arm 410 of the chamber member engagement lever 400 pivoting outwardly such that the chamber member engagement handle 415 of the chamber member engagement lever 400 is no longer in a position to engage or be engaged by the chamber member 260 and thus allows the chamber member 260 to move to its unsealed position.

Fig. 7A, 7B, and 7C are fragmentary partial cross-sectional views of certain components of another example embodiment of a combustion-powered fastener-driving tool 1100 of the present disclosure, wherein the chamber member retaining assembly 1300 does not include the chamber member engagement lever 400, and the chamber member 1260 is directly engaged by the actuation member 1330. In this example embodiment, the chamber member holding assembly 1300 may include a solenoid or gas-assisted actuation member 1330, and may include an electromagnet 1360 that holds the actuation member 1330 in a held position. The tool 1100 moves the actuation member 1330 from the non-holding position (fig. 7C) to the holding position (fig. 7A and 7B). A controller (not shown) of the tool 1100 energizes the electromagnet 1360 to hold the actuation member 1330 in the holding position (fig. 7A and 7B). In this embodiment, when the actuation member 1330 is in its non-holding position (fig. 7C), the actuation member 1330 directly prevents the chamber member 1260 from moving from its sealed position toward its unsealed position. This operates in the reverse manner to the above-described embodiments. If this embodiment includes an electromagnet 1360, the controller may de-energize the electromagnet 1360 to engage the actuation member with the chamber member 1260 to prevent the piston 1220 from returning completely to its pre-firing position. If the embodiment includes a solenoid, the controller may energize the solenoid to engage the actuating member with the chamber member 1260 to prevent the piston 1220 from being returned to its pre-firing position. If various such embodiments, the springs may be eliminated.

Fig. 8A and 8B illustrate another example embodiment of certain components of a chamber component retaining assembly 2300 of another example combustion-powered fastener-driving tool of the present disclosure. In the example embodiment, the actuation member 2330 is integrated into the engine bushing 2310. In this example embodiment, the chamber component holding assembly 2300 includes: a gas-assisted actuation member 2330 positioned in and movable within engine bushing 2310; and an electromagnet 2360 (and its electrical leads 2362) positioned adjacent to the actuation member 2330 and supported by a housing (not shown). Electromagnet 2360 is configured to maintain actuation member 2330 positioned in the holding position shown in fig. 8A under control of a controller (not shown) of the tool. The chamber component holding assembly 2300 further includes a gas pressure feed tube 2420 configured to supply gas to move the actuation member 2330 to a holding position. In some embodiments, the gas pressure feed pipe 2420 is optional. The chamber component holding assembly 2300 further includes a gas pressure inlet valve 2440 configured to enable the combusted gas to move the actuation member 2330 to a holding position. The chamber component retaining assembly 2300 further includes a biasing member (such as a wave spring 2380) configured to bias the actuation member 2330 to the non-retaining position shown in fig. 8B. The chamber component holding assembly 2300 further includes a rubber bumper 370 that provides cushioning behind the electromagnet 3360. The chamber component retaining assembly 2300 further includes a retaining ring 2450 connected to the engine bushing 2310 and configured to limit outward movement of the actuation member 2330. The chamber component retaining assembly 2300 further includes one or more seals 2460 configured to provide an airtight seal between the actuation member 2330 and the engine bushing 2310. The chamber component retaining assembly 2300 further includes a spring retainer (such as a stainless steel washer) configured to retain the wave spring 2380. In this example embodiment, when chamber member retaining assembly 2300 is activated, actuating member 2330 moves toward electromagnet 2360, and electromagnet 2360 holds actuating member 2330 in the retaining position to prevent chamber member or valve bushing 2260 from moving downward, as shown in fig. 8A. In this example embodiment, when the chamber member retaining assembly 2300 is not in activation, a portion of the chamber member or valve bushing 2260 moves between the actuation member 2330 and the electromagnet 2360, as shown in fig. 8B.

Fig. 9A, 9B, and 9C illustrate another example embodiment of certain components of a chamber component holding assembly 3300 of another example combustion-powered fastener-driving tool of the present disclosure. In this example embodiment, the actuating member 3330 may be moved toward the electromagnet 3360, with the electromagnet 3360 holding the actuating member 3330 in place to prevent the chamber member or valve bushing 3260 from moving downward. In this example embodiment, the chamber component retaining assembly 3300 includes a locking bar 3400 configured to engage one or more features of the chamber component or valve bushing 3260 when in a retaining position, as shown in fig. 9B.

Fig. 10A and 10B illustrate another example embodiment of certain components of a cavity member holding assembly 4300 of another example combustion-powered fastener-driving tool of the present disclosure. This example embodiment is similar to the embodiment of fig. 8A and 8B to some extent, except that electromagnet 4360 is located elsewhere. In this example embodiment, the electromagnet 4360 is positioned completely or partially around the actuation member 4330, but when in the inactive state, is in a direction biased toward the chamber member 4260. In this example embodiment, the actuation member 4330 is integrated into the engine bushing 4310. In this example embodiment, for compactness, an electromagnet 4360 is located around the actuation member 4330. In this example embodiment, the actuation member 4330 is movable relative to the electromagnet 4360, and the electromagnet 4360 holds the actuation member or piston 4330 in place to prevent the chamber member or valve bushing 4260 from moving downward, as shown in fig. 11B. This embodiment also utilizes a stronger magnetic field location (i.e., the actuation member 4330 operates closer to the center of the electromagnet 4360 to achieve a smaller force reduction). In this example embodiment, when not active, a portion of the chamber member or valve bushing 4260 moves between the actuation member 4330 of the chamber member retention assembly 4300 and the damper 4370, as shown in fig. 11A.

Fig. 11A and 11B illustrate an example combustion-powered fastener-driving tool 5100, with possible positions of the chamber component holding assembly 5300 of the present disclosure shown in dashed boxes indicated by reference numerals 5200A and 5300B.

Various modifications to the above described embodiments will be apparent to those skilled in the art. Such modifications may be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. All of the depicted components described in this disclosure may not be required, and some implementations may include additional, different, or fewer components than those described herein. Changes may be made, without departing from the spirit or scope of the claims set forth herein, in the following: arrangement and type of components; the shape, size, and material of the components; and the manner of attachment and connection of the components. Moreover, unless otherwise indicated, any directions noted herein reflect the orientation of the components shown in the corresponding figures and do not limit the scope of the present disclosure. The description is intended as a whole and is to be construed in accordance with the principles of the present invention and as taught herein and understood by one of ordinary skill in the art.

Claims (20)

1. A combustion-powered fastener-driving tool, comprising:

a housing;

a controller supported by the housing;

a chamber member supported by the housing and movable relative to the housing from an unsealed position in which the chamber member does not seal the combustion chamber to a sealed position in which the chamber member seals the combustion chamber;

a trigger supported by the housing and movable between an extended position and a retracted position; and

a chamber component holding assembly supported by the housing and comprising:

an actuating member movable from a non-holding position to a holding position in which the chamber member is prevented from moving from a sealed position to an unsealed position, and

an electromagnet controlled by the controller and activatable to hold the actuation member in the holding position.

2. The combustion-powered fastener-driving tool of claim 1, wherein the actuating member is a gas-assisted actuating member.

3. The combustion-powered fastener-driving tool of claim 2, wherein gas for the gas-assisted actuation member is fluidly receivable from the combustion chamber.

4. The combustion-powered fastener-driving tool of claim 3, wherein the chamber component holding assembly comprises a gas pressure feed tube.

5. The combustion-powered fastener-driving tool of claim 3, wherein the chamber member-retaining assembly includes a gas pressure inlet valve configured to enable combusted gas to move the actuation member to the retaining position.

6. The combustion-powered fastener-driving tool of claim 1 including a chamber member engagement lever supported by the housing and positionable to prevent movement of the chamber member from the sealed position to the unsealed position.

7. The combustion-powered fastener-driving tool of claim 6, wherein the chamber member engagement lever is supported by the housing and positionable by the actuation member.

8. The combustion-powered fastener-driving tool of claim 1, wherein the controller is configured to energize the electromagnet for a specified amount of time to hold the chamber member in the sealed position so as to provide sufficient time for the housing-supported piston to return to a pre-firing position.

9. The combustion-powered fastener-driving tool of claim 1, wherein the chamber member-retaining assembly includes a rubber bumper positioned to provide cushioning to the actuation member.

10. The combustion-powered fastener-driving tool of claim 1, wherein the chamber member retention assembly includes a biasing member that biases the actuation member to the non-retained position.

11. The combustion-powered fastener-driving tool of claim 1, wherein the actuation member is positionable to directly prevent movement of the chamber member from the sealed position to the unsealed position.

12. The combustion-powered fastener-driving tool of claim 1, wherein the actuation member is positionable to directly engage the chamber member to prevent movement of the chamber member from the sealed position to the unsealed position.

13. The combustion-powered fastener-driving tool of claim 1, wherein the retaining position of the actuating member is closer to the electromagnet than the non-retaining position of the actuating member.

14. The combustion-powered fastener-driving tool of claim 1, wherein the chamber member is movable between the actuation member and the electromagnet when the actuation member is in the non-holding position.

15. The combustion-powered fastener-driving tool of claim 1, wherein the chamber member retention assembly includes a locking bar configured to engage a portion of the chamber member.

16. The combustion-powered fastener-driving tool of claim 1, wherein the electromagnet extends at least partially around the actuation member.

17. A combustion-powered fastener-driving tool, comprising:

a housing;

a controller supported by the housing;

a chamber member supported by the housing and movable relative to the housing from an unsealed position in which the chamber member does not seal the combustion chamber to a sealed position in which the chamber member seals the combustion chamber; and

a chamber component holding assembly supported by the housing and comprising:

a chamber member engagement lever supported by the housing;

an actuation member movable from a non-retaining position to a retaining position, wherein in the retaining position the actuation member causes the chamber member engagement lever to be in a position preventing the chamber member from moving from the sealed position to the unsealed position;

an electromagnet controlled by the controller and activatable to hold the actuation member in the holding position.

18. The combustion-powered fastener-driving tool of claim 17, wherein the actuating member is a gas-assisted actuating member.

19. The combustion-powered fastener-driving tool of claim 18, wherein gas for the gas-assisted actuation member is fluidly receivable from the combustion chamber.

20. The combustion-powered fastener-driving tool of claim 19, wherein the chamber member-retaining assembly includes a gas pressure inlet valve configured to enable the combusted gas to move the actuation member to the retaining position.