CN218285386U

CN218285386U - Gas spring power fastener driver

Info

Publication number: CN218285386U
Application number: CN202090000997.XU
Authority: CN
Inventors: D·比德曼; A·R·怀勒; N·A·阿尔伯斯; M·埃琳娜
Original assignee: Milwaukee Electric Tool Corp
Current assignee: Milwaukee Electric Tool Corp
Priority date: 2019-12-06
Filing date: 2020-12-04
Publication date: 2023-01-13
Anticipated expiration: 2030-12-04
Also published as: EP4072786A4; EP4072786A1; WO2021113570A1

Abstract

A gas spring powered fastener driver includes an outer cylinder and an inner cylinder positioned within the outer cylinder. The movable piston is positioned in the inner cylinder. The drive vane is attached to the piston and is movable with the piston between a Top Dead Center (TDC) position and a drive or Bottom Dead Center (BDC) position. The holding member is fixed to the inside cylinder. The retaining member couples the inside cylinder to the outside cylinder. The inner cylinder is axially fixed to the outer cylinder relative to a drive axis defined by the drive vanes. The outer cylinder is rotatable relative to the inner cylinder.

Description

Gas spring power fastener driver

Cross Reference to Related Applications

This application claims priority to U.S. patent application No. 16/706,365, filed on day 6, 12, 2019, which is a continuation-in-part application of U.S. patent application No. 16/437,621, filed on day 11, 6, 2019, which claims priority to U.S. provisional patent application No. 62/683,460, filed on day 11, 6, 2018, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to powered fastener drivers, and more particularly to gas spring powered fastener drivers.

Background

A variety of fastener drivers are known in the art for driving fasteners (e.g., nails, tacks, staples, etc.) into a workpiece. These fastener drivers operate using various means known in the art (e.g., compressed air produced by an air compressor, electrical energy, flywheel mechanisms, etc.), but these designs often encounter power, size, and cost limitations.

SUMMERY OF THE UTILITY MODEL

In yet another aspect, the present invention provides a gas spring powered fastener driver including an outer cylinder and an inner cylinder positioned within the outer cylinder. The movable piston is positioned in the inner cylinder. The drive vane is attached to the piston and is movable with the piston between a Top Dead Center (TDC) position and a drive or Bottom Dead Center (BDC) position. The holding member is fixed to the inside cylinder. A retaining member couples the inner cylinder to the outer cylinder. The inner cylinder is axially fixed to the outer cylinder relative to a drive axis defined by the drive vanes. The outer cylinder is rotatable relative to the inner cylinder.

In yet another aspect, the present invention provides a gas spring power fastener driver comprising: a cylinder; a movable piston positioned within the cylinder; and a driving vane attached to the piston and movable with the piston between a Top Dead Center (TDC) position and a driving position or a Bottom Dead Center (BDC) position. The gas spring powered fastener driver further includes a lifter operable to move the drive blade from the BDC position toward the TDC position. A transmission for providing torque to a hoist is provided. A buffer is positioned in the cylinder and is configured to absorb impact energy from the piston as the driver blade is driven toward the BDC position. A chamber is defined between the piston, cylinder and bumper when the driver blade reaches the BDC position. A plurality of slots are defined by the cylinder. The slot fluidly connects the chamber to the external atmosphere.

In another aspect, the present invention provides a gas spring power fastener driver, comprising: a housing having a first portion and a second portion; and an outer cylinder supported by the first portion. The gas spring powered fastener driver further comprises: an inner cylinder positioned within the outer cylinder; and a movable piston positioned within the inner cylinder. The gas spring powered fastener driver further includes a drive vane attached to the piston and movable with the piston between a Top Dead Center (TDC) position and a drive or Bottom Dead Center (BDC) position. The lifter is operable to move the drive vane from the BDC position towards the TDC position. The motor and transmission provide torque to the lifter. The motor and transmission are supported by the second portion. A plurality of damping elements are positioned between the housing and at least one of the inside cylinder, the transmission, or the motor. A plurality of damping elements are positioned such that at least one of the inside cylinder, transmission, and motor is mounted within the housing, but is movable relative to the housing to damp the force exerted on the housing by the inside cylinder, transmission, or motor.

In yet another aspect, the present invention provides a gas spring powered fastener driver including: a cylinder; a movable piston positioned within the cylinder; and a driver blade attached to the piston and movable with the piston between a Top Dead Center (TDC) position and a drive or Bottom Dead Center (BDC) position. The drive blade includes a body and a plurality of teeth extending from the body. The body has a first hardness. At least one of the teeth has a second hardness greater than the first hardness.

In yet another aspect, the present invention provides a gas spring power fastener driver comprising: a cylinder; a movable piston positioned within the cylinder; and a driving vane attached to the piston and movable with the piston between a Top Dead Center (TDC) position and a driving position or a Bottom Dead Center (BDC) position. The drive blade includes a body and a plurality of teeth extending from the body. The drive blade defines a drive axis. The drive blade includes a body having a first side and an opposite second side with a drive axis passing between the first side and the opposite second side. A plurality of teeth extend from the first side of the body. The body and the teeth are bisected by a common plane. The gas spring powered fastener driver further includes a lifter operable to move the drive blade from the BDC position toward the TDC position. The lifter is configured to engage with the teeth of the drive vane when moving the drive vane from the BDC position toward the TDC position. The gas spring powered fastener driver further includes a nosepiece guide having a channel in which the drive blade is slidably received. The body has a first width in a direction perpendicular to the common plane. The teeth have a second width in a direction perpendicular to the common plane. The second width is different from the first width. The second width defines a plurality of guide surfaces spaced from the common plane and extending parallel to the drive axis. The plurality of guide surfaces may slide against corresponding guide surfaces of the channel.

In another aspect, the present invention provides a gas spring power fastener driver, comprising: a cylinder; a movable piston positioned within the cylinder; and a driving vane attached to the piston and movable with the piston between a Top Dead Center (TDC) position and a driving position or a Bottom Dead Center (BDC) position. The drive blade includes a body and a plurality of teeth extending from the body. The drive blade defines a drive axis. The drive blade includes: a body having a first side and an opposing second side, the drive axis passing between the first side and the opposing second side; and a plurality of projections extending from the first side of the body. The body and the projection are bisected by a common plane. The gas spring powered fastener driver further includes a latch assembly movable between a locked condition in which the drive blade is held in the ready position against the biasing force of the compressed gas and a released condition in which the drive blade is permitted to be driven toward the drive position by the biasing force. The latch assembly includes a latch engageable with the plurality of tabs. The gas spring powered fastener driver further includes a nosepiece guide having a channel in which the drive blade is slidably received. The body has a first width in a direction perpendicular to the common plane. The protrusion has a second width in a direction perpendicular to the common plane. The second width is different from the first width. The second width defines a plurality of guide surfaces spaced from the common plane and extending parallel to the drive axis. The plurality of guide surfaces may slide against corresponding guide surfaces of the channel.

In yet another aspect, the present invention provides a gas spring power fastener driver comprising: a cylinder; a movable piston positioned within the cylinder; a drive vane attached to the piston and movable with the piston between a Top Dead Center (TDC) position and a drive or Bottom Dead Center (BDC) position. The drive vane is configured to be positioned at a ready position intermediate the TDC position and the BDC position. The lifter is operable to move the drive vane from the BDC position towards the TDC position. The lifter is supported by the lifter housing. The lifter includes: a body rotatably supported about a rotational axis; and a plurality of drive pins engageable with the drive blade when moving the drive blade from the BDC position to the TDC position. A motor and transmission are provided to provide torque to the lifter. The magnet is positioned at a predetermined location on the body of the riser. The magnet is coupled with the body for common rotation about an axis of rotation. The sensor is positioned on the riser housing. The sensor is configured to detect the magnet to stop the driving blade at the intermediate position. A horizontal plane extends through the axis of rotation. One of the drive pins is at a first angle relative to a horizontal plane when the drive blade is in the ready position. One of the drive pins is at a second angle relative to horizontal when the drive blade is in the TDC position. The predetermined position of the magnet is selected based on a difference between the first angle and the second angle. The difference between the first angle and the second angle is between 7 degrees and 14 degrees.

Other features and aspects of the present invention will become apparent by consideration of the following detailed description and accompanying drawings.

Drawings

Fig. 1 is a perspective view of a gas spring powered fastener driver according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the gas spring powered fastener driver of FIG. 1.

FIG. 3 is a partial cross-sectional view, with portions removed for clarity, of the gas spring powered fastener driver of FIG. 1.

FIG. 4 is another partial cross-sectional view of the gas spring powered fastener driver of FIG. 1 with portions removed for clarity.

FIG. 5 is a partial cross-sectional view of the gas spring powered fastener driver taken along line 5-5 in FIG. 1.

FIG. 6A is a schematic view of the gas spring powered fastener driver of FIG. 1 showing the drive blade in a drive or bottom dead center position.

FIG. 6B is a schematic view of the gas spring powered fastener driver of FIG. 1, showing the drive blade in a top dead center position prior to actuation.

FIG. 7 is a cross-sectional view of the gas spring powered fastener driver of FIG. 1, taken along line 7-7 in FIG. 1, illustrating a motor and transmission for providing torque to the riser.

FIG. 8 is an exploded view of the one-way clutch mechanism of the transmission of FIG. 7.

FIG. 9 is an assembled cross-sectional view of the one-way clutch mechanism of FIG. 8.

FIG. 10 is an exploded view of the torque limiting clutch mechanism of the transmission of FIG. 7.

FIG. 11 is an assembled partial cross-sectional view of the torque-limiting clutch mechanism of FIG. 10 with portions of the gas spring powered fastener driver of FIG. 1 added for clarity.

Fig. 12 is an exploded view of the riser of fig. 7.

FIG. 13 is an enlarged view of the gas spring powered fastener driver of FIG. 5 showing the drive blade in the ready position and the latch in the latched condition.

FIG. 14 is an enlarged view of the gas spring powered fastener driver of FIG. 5, showing the drive blade in a top dead center position and the latch in a released condition.

Fig. 15A is a perspective view of the drive blade.

Fig. 15B is an enlarged plan view of the drive blade of fig. 15A.

FIG. 16 is a bottom view of the fastener driver of FIG. 1, showing the drive blade supported within the nosepiece guide.

FIG. 17 is a perspective view of a bumper of the gas spring power fastener driver of FIG. 1.

FIG. 18 is a partial cross-sectional view of the gas spring powered fastener driver of FIG. 1, showing the phase change material adjacent the bumper.

Fig. 19 is a graph showing the temperature of the buffer of fig. 17 over multiple firing cycles, with a phase change material proximate the buffer.

FIG. 20 is a partial cross-sectional view of a portion of the cylinder assembly of the gas spring powered fastener driver of FIG. 1, illustrating another embodiment of the connection between the inner and outer cylinders of the cylinder assembly.

FIG. 21 is a partial cross-sectional view of a portion of the nose piece assembly of the gas spring powered fastener driver of FIG. 3.

FIG. 22 is a partial cross-sectional view of the gas spring powered fastener driver of FIG. 1, showing a portion of an alternative embodiment of the cylinder assembly of the gas spring powered fastener driver of FIG. 1.

FIG. 23 is a side view of the gas spring powered fastener driver of FIG. 1 with portions removed for clarity and showing a plurality of damping elements.

Fig. 24 is a schematic diagram of another embodiment of a motor and transmission embodying the present invention, illustrating an alternative position of the torque limiting clutch mechanism of fig. 10.

FIG. 25A is a bottom view of a portion of the fastener driver of FIG. 1 showing a drive blade supported in another embodiment of a nose piece guide of the gas spring powered fastener driver of FIG. 1.

FIG. 25B is a bottom view of a portion of the fastener driver of FIG. 1 illustrating a drive blade supported in yet another embodiment of the nosepiece guide of the gas spring powered fastener driver of FIG. 1.

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

Detailed Description

Referring to fig. 1-4, a gas spring powered fastener driver 10 is operable for driving fasteners (e.g., nails, tacks, staples, etc.) held within a magazine 14 into a workpiece. The fastener driver 10 includes an inner cylinder 18 and a movable piston 22 (fig. 5) positioned within the cylinder 18. Referring to fig. 5, the fastener driver 10 further includes a driver blade 26 attached to the piston 22 and movable therewith. Fastener driver 10 does not require an external air pressure source, but rather includes an external storage chamber cylinder 30 of pressurized gas in fluid communication with cylinder 18. In the illustrated embodiment, the cylinder 18 and the movable piston 22 are positioned within the reservoir cylinder 30. Referring to fig. 2, the drive 10 further includes a fill valve 34 (shown exploded from the cylinder 30) coupled to the reservoir cylinder 30. When connected to a source of compressed gas, the fill valve 34 allows the reservoir cylinder 30 to be refilled with compressed gas if any leakage previously occurred. For example, the fill valve 34 may be configured as a schrader valve.

Referring to fig. 4-6, the cylinder 18 and the drive blade 26 define a drive axis 38 (fig. 5). During a drive cycle, the driver blade 26 and piston 22 may move between a Top Dead Center (TDC) position (fig. 6B) and a drive or Bottom Dead Center (BDC) position (fig. 6A). The fastener driver 10 further includes a lift assembly 42 (fig. 4) powered by a motor 46 (fig. 4) and operable to move the drive blade 26 from the drive position to the TDC position.

In operation, the lift assembly 42 drives the piston 22 and the drive vane 26 toward the TDC position by energizing the motor 46. As the piston 22 and driver blade 26 are driven toward the TDC position, the gas above the piston 22 and the gas within the storage chamber cylinder 30 are compressed. Before reaching the TDC position, the motor 46 is deactivated and the piston 22 and drive vane 26 are held in a ready position between the TDC position and the BDC or drive position until released by a user actuating the trigger 48 (fig. 3). When released, the compressed gas above the piston 22 and within the reservoir cylinder 30 drives the piston 22 and drive blade 26 to a driving position, thereby driving a fastener into a workpiece. The illustrated fastener driver 10 thus operates on the gas spring principle with the lift assembly 42 and piston 22 to further compress the gas within the cylinder 18 and reservoir cylinder 30. Further details regarding the structure and operation of fastener driver 10 are provided below.

Referring to fig. 5 and 6A-6B, the reservoir cylinder 30 is concentric with the cylinder 18. The cylinder 18 has an annular inner wall 50 configured to guide the piston 22 and the drive vane 26 along the drive axis 38 to compress the gas in the reservoir cylinder 30. The reservoir cylinder 30 has an annular outer wall 54 that circumferentially surrounds the inner wall 50. The cylinder 18 has a threaded section 58 (fig. 5). The reservoir cylinder 30 has corresponding threads at the lower end 60 of the reservoir cylinder 30 such that the lower end 60 of the cylinder 18 is threadedly coupled to the reservoir cylinder 30. In this way, the cylinder 18 is configured to be axially fixed to the reservoir cylinder 30. The threaded coupling may facilitate and simplify assembly of the driver 10. Further, the reservoir cylinder 30 is rotatably movable relative to the cylinder 18 such that a marking area 62 (fig. 1) displaying indicia, such as logos, images, trademarks, text, logos, and other markings, on a tip 64 of the reservoir cylinder 30 may be arrayed about the drive axis 38.

The storage chamber cylinder 30 and the cylinder 18 define a first total volume in which gas is located when the driver blade 26 is in the TDC position (fig. 6B). The reservoir cylinder 30 and the cylinder 18 define a second total volume that is greater than the first total volume in which gas is located when the drive vane 26 is in the drive position (fig. 6A). The compression ratio is defined as the ratio of the second total volume to the first total volume. In one embodiment, the compression ratio is 1.7. For example, in the illustrated embodiment, the compression ratio is 1.61. In another embodiment, the compression ratio is 1.6. A lower compression ratio may reduce the forces and/or stresses on the actuator 10 (i.e., the reservoir cylinder 30, the piston 22), which may extend the useful life of the actuator 10. In particular, as the piston 22 and drive vane 26 move toward the TDC position, force (from the lift assembly 42 and the gas compressed by the piston 22 in the cylinder 18 and the reserve chamber cylinder 30) acts on the drive vane 26. The force is at a maximum when the piston 22 and driver blade 26 reach the TDC position. In this way, the lower compression ratio reduces the reaction force exerted by the lift assembly 42 and/or the stress on the driver blade 26 when in the TDC position, thereby reducing wear on the driver blade 26 and extending the life of the drive 10.

In one embodiment, the force acting on the drive blade 26 when in the TDC position does not exceed 450 pounds-force (lbf). In another embodiment, the force acting on the driver blade 26 when in the TDC position is no more than 435lbf. In yet another embodiment, the force acting on the driver blade 26 when in the TDC position is about 433lbf. In some embodiments, in addition to exerting a maximum force of 450lbf or less on the driver blade 26 when in the TDC position, a minimum force of 85lbf must be exerted on the driver blade 26 when in the TDC position. Similarly, a lower compression ratio may reduce the force and/or stress on the drive blade 26 when in the ready position. In one embodiment, the force acting on the drive blade 26 when in the ready position does not exceed 430 pounds-force (lbf). In another embodiment, the force acting on the driver blade 26 when in the ready position does not exceed 415lbf. In yet another embodiment, the force acting on the driver blade 26 when in the ready position is about 410lbf.

While in some embodiments it is desirable to maintain the force acting on the driver blade 26 at no more than 450lbf when in the TDC position, it is also desirable to maintain a relatively high average force on the driver blade between the TDC and BDC positions of the driver blade 26 to adequately drive the fastener into the workpiece. For example, in one embodiment, the average force on the drive blade 26 is between 302lbf and 362lbf, and the force acting on the drive blade 26 when in the drive or BDC position is no less than 225lbf. In another embodiment, the average force acting on the driver blade 26 is between 327lbf and 337lbf, and the force acting on the driver blade 26 when in the drive position or BDC position is no less than 250lbf. In yet another embodiment, the average force on the drive blade 26 is about 332lbf, and the force acting on the drive blade 26 when in the drive or BDC position is about 252lbf.

The stroke length 76 (fig. 6B) of the piston 22/driver blade 26 is defined as the distance traveled by the piston 22/driver blade 26 between the TDC position and the driving position (fig. 6B and 6A, respectively). The stroke length 76 determines the pressure exerted on the piston 22 when the piston 22 is at the TDC position. In the illustrated embodiment, the stroke length 76 is between 4.1 inches and 5.1 inches. In another embodiment, the stroke length 76 is between 4.4 inches and 4.8 inches. In yet another embodiment, the stroke length 76 is about 4.6 inches.

Referring to fig. 6A, the reservoir cylinder 30 has a first diameter D1. The cylinder 18 has a second diameter D2 that is smaller than the first diameter D1 of the reservoir cylinder 30. In one embodiment, the second diameter D2 is about 1.732 inches. In conjunction with a stroke length 76 of the piston 22 of about 4.6 inches, the volume that the piston 22 displaces between the TDC position and BDC position of the driver blade 26 is about 10.8 cubic inches.

For the above-described range of stroke lengths 76 and the above-described range of average forces applied to the drive vane 26 as it moves between its TDC and BDC positions, in some embodiments, the fastener driver 10 is capable of performing up to 120 joules (J) of work on the fastener during a fastener driving operation. This impact energy is sufficient to drive nails up to 3.5 inches in length into the workpiece during, for example, a framing operation. Further, in some embodiments, the fastener driver 10 is capable of performing at least 15J of work on the fastener during a fastener driving operation.

The pressure of the reservoir cylinder 30 varies depending on the positions of the drive vane 26 and the piston 22. For example, when the compression ratio is about 1.61 and the stroke length 76 is about 4.6 inches, the reservoir cylinder 30 has a pressure of about 108 pounds per square inch (psi) when the piston 22/driver blade 26 is in the driven position, and about 174psi when the piston 22/driver blade 26 is in the TDC position (i.e., when the gas inside the reservoir cylinder 30 is 70 degrees fahrenheit). In other embodiments, the pressure of the reservoir cylinder 30 is between 98psi and 118psi when the piston 22/driver blade 26 is in the driven position, and between 164psi and 184psi when the piston 22/driver blade 26 is in the TDC position (i.e., when the gas within the reservoir cylinder 30 is 70 degrees fahrenheit).

Referring to fig. 1, the driver 10 includes a housing 80 having: a cylinder support portion 84 in which the storage chamber cylinder 30 is at least partially positioned; and a motor support portion 88 in which the motor 46 and the transmission 92 are at least partially positioned. In the illustrated embodiment, the cylinder support portion 84 is integrally formed as one piece with the motor support portion 88 (e.g., using a casting or molding process depending on the material used). As described in further detail below, the transmission 92 lifts the drive blade 26 from the drive position to the ready position. Referring to fig. 7, the motor 46 is positioned within the transmission housing portion 88 for providing torque to the transmission 92 when activated. A battery pack 90 (fig. 1) may be electrically connected to the motor 46 for supplying electrical power to the motor 46. In alternative embodiments, the drive may be powered by an alternative power source, such as an AC voltage input (i.e., from a wall outlet), or by an alternative DC voltage input (e.g., an AC/DC converter).

Referring to fig. 7, the transmission 92 includes an input 94 (i.e., a motor output shaft) and includes an output shaft 96 that extends to a lifter 100 operable to move the drive blade 26 from the drive position to the ready position, as explained in more detail below. In other words, the transmission 92 provides torque from the motor 46 to the lifter 100. The transmission 92 is configured as a planetary transmission having a first planetary stage 104, a second planetary stage 106, and a third planetary stage 108. In alternative embodiments, the transmission may be a single stage planetary transmission, or a multi-stage planetary transmission including any number of planetary stages.

With continued reference to fig. 7, the first planetary stage 104 includes a ring gear 112, a planet carrier 116, a sun gear 120, and a plurality of planet gears 124 that are coupled to the planet carrier 116 for relative rotation therewith. The sun gear 120 is drivingly coupled to the motor output shaft 94 and is meshed with the planet gears 124. Ring gear 112 includes a toothed inner peripheral portion 128. In the illustrated embodiment, the ring gear 112 in the first planetary stage 104 is fixed to a transmission housing 132 positioned adjacent the motor 46, thereby preventing the ring gear from rotating relative to the transmission housing 132. A plurality of planet gears 124 are rotatably supported on the planet carrier 116 and are engageable (i.e., meshingly engaged) with a toothed inner peripheral portion 128.

The second planetary stage 106 includes a ring gear 136, a planet carrier 142, and a plurality of planet gears 146 coupled to the planet carrier 142 for relative rotation therewith. The ring gear 136 includes a first toothed inner peripheral portion 138 and a second inner peripheral portion 140 adjacent the toothed inner peripheral portion 138. The planet carrier 116 of the first planetary stage 104 further includes an output pinion gear 150 that meshes with the planet gears 146, which in turn are rotatably supported on the planet carrier 142 of the second planetary stage 106 and mesh with the toothed inner peripheral portion 138 of the ring gear 136. Similar to the ring gear 112 of the first planetary stage 104, the ring gear 136 of the second planetary stage 106 is fixed relative to the transmission housing 132.

Referring to fig. 7-9, the drive 10 further includes a one-way clutch mechanism 154 incorporated in the transmission 92. More specifically, the one-way clutch mechanism 154 includes the carrier 142, which is also a component of the third planetary stage 108. The one-way clutch mechanism 154 allows torque to be transmitted to the output shaft 96 of the transmission 92 in a single (i.e., first) rotational direction (i.e., counterclockwise in the frame of reference of fig. 9), while preventing the motor 46 from being driven in the opposite direction in response to torque being applied to the output shaft 96 of the transmission 92 in a second, opposite rotational direction (e.g., clockwise in the frame of reference of fig. 9). In the illustrated embodiment, the one-way clutch mechanism 154 is coupled with the second planetary stage 106 of the transmission 92. In an alternative embodiment, for example, the one-way clutch mechanism 154 may be incorporated into the first planetary stage 104.

With continued reference to fig. 7-9, the one-way clutch mechanism 154 further includes a plurality of lobes 158 (fig. 8) defined on the outer periphery of the planet carrier 142. Further, the one-way clutch mechanism 154 includes: a plurality of rolling elements 166 engageable with respective bosses 158; and a ramp 170 (fig. 9) adjacent each boss 158 along which the rolling element 166 is movable. The rolling elements 166 are shown extending from a disc 174. As the rolling elements 166 move away from the respective bosses 158, each ramp 170 tilts in a manner that causes the rolling elements 166 to displace away from the rotational axis 178 (fig. 8) of the planet carrier 142. Referring to fig. 7, the carrier 142 of the one-way clutch mechanism 154 is at the same planetary stage of the transmission 92 (i.e., the second planetary stage 106) as the ring gear 136. In response to applying torque on the transmission output shaft 96 in the second rotational direction (i.e., as the rolling elements 166 move along the ramps 170 away from the respective lobes 158), the rolling elements 166 may engage the second inner peripheral portion 140 of the ring gear 136. The plate spring 182 is positioned adjacent the carrier 142. The leaf spring 182 includes an arm 186 for biasing the rolling element 166 toward the second inner peripheral portion 140 (and away from the boss 158).

In operation of the one-way clutch mechanism 154, the rolling elements 166 are held in close proximity to the respective lobes 158 in a first rotational direction of the transmission output shaft 96 (i.e., counterclockwise in the frame of reference of fig. 9). However, when the piston 22/drive vane 26 has reached the ready position, the rolling elements 166 move away from the respective bosses 158 in response to applying a torque on the transmission output shaft 96 in a second, opposite rotational direction (i.e., clockwise in the frame of reference of fig. 9). More specifically, when the transmission output shaft 96 rotates a small amount (e.g., 1 degree) in the second rotational direction, the rolling elements 166 roll off the respective lobes 158 along the ramps 170 and engage the second inner peripheral portion 140 on the ring gear 136, thereby preventing further rotation of the transmission output shaft 96 in the second rotational direction. The corresponding arms 186 of the leaf springs 182 exert additional force on the rolling elements 166 to hold the rolling elements 166 against the second inner peripheral portion 140 of the ring gear 136, where the rolling elements snap or wedge against the second inner peripheral portion 140. Thus, the one-way clutch mechanism 154 prevents the transmission 92 from applying torque to the motor 46 in response to applying torque on the transmission output shaft 96 in the opposite second rotational direction (i.e., when the piston 22 and drive blade 26 have reached the ready position), which might otherwise back drive or cause the motor 46 to rotate in the opposite direction.

Referring to fig. 7, the third planetary stage 108 includes a ring gear 190, a planet carrier 194, and a plurality of planet gears 198 that are coupled to the planet carrier 194 for relative rotation therewith. The planet carrier 142 of the second planetary stage 106 further includes an output pinion 202 that meshes with the planet gears 198, which are in turn rotatably supported on the planet carrier 194 of the third planetary stage 108 and mesh with a toothed inner peripheral portion 206 of the ring gear 190. Unlike the ring gears 112, 136 of the first and second

planetary stages

104, 106, the ring gear 190 of the third planetary stage 108 is rotatable relative to a transmission cover 210 adjacent the transmission housing 132. The carrier 194 is coupled to the output shaft 96 for relative rotation therewith.

Referring to fig. 7, 10 and 11, the drive 10 further includes a torque limiting clutch mechanism 214 incorporated into the transmission 92. More specifically, the torque limiting clutch mechanism 214 includes a ring gear 190, which is also a component of the third planetary stage 108. The torque limiting clutch mechanism 214 limits the amount of torque transferred to the transmission output shaft 96 and the lifter 100. In the illustrated embodiment, the torque limiting clutch mechanism 214 is engaged with the third planetary stage 108 of the transmission 92 (i.e., the last of the planetary transmission stages), and the one-way clutch mechanism 154 and the torque limiting clutch mechanism 214 are coaxial (i.e., aligned with the axis of rotation 178).

Referring to fig. 10 and 11, the ring gear 190 of the torque limiting clutch mechanism 214 includes an annular front end 218 having a plurality of lobes 222 defined thereon. The torque limiting clutch mechanism 214 further includes a plurality of stop members 226 supported within a collar 230 fixed to the cover 210. The stop members 226 engage with the respective bosses 222 to inhibit rotation of the ring gear 190, and the torque limiting clutch mechanism 214 further includes a plurality of springs 234 for biasing the stop members 226 toward the annular front end 218 of the ring gear 190. The springs 234 are seated within corresponding cylindrical pockets 236 in the cover 210 between the collar 230 and the disc 238. The disc 238 is positioned outside of the cover 210 and circumferentially surrounds a section 242 of the cover 210. A retaining ring 246 axially secures the disc 238 to the cap 210. In response to a reaction torque applied to the transmission output shaft 96 above a predetermined threshold, torque from the motor 46 is transferred from the transmission output shaft 96 to the ring gear 190, causing the ring gear 190 to rotate and the stop member 226 to slip on the boss 222.

With continued reference to fig. 7, 10, and 11, the gears (i.e., the first, second, and third

planetary stages

104, 106, 108) may be assembled from the front of the transmission housing 132, and the torque limiting clutch mechanism 214 may be inserted through the rear of the cover 210 adjacent the transmission housing 132. The stop member 226 and spring 234 may then be inserted through a corresponding cylindrical recess 236 located forward of the collar 230, and the disc 238 positioned against the spring 234 to preload the spring 234. Subsequently, a retaining ring 246 is positioned within a circumferential groove 248 in the cap segment 242 and against the disk 238 to axially secure the disk 238. This may simplify assembly of the transmission 92, reduce required assembly time, and reduce part cost.

Fig. 24 illustrates a schematic diagram of the motor 46 and transmission 92 of fig. 7, wherein the transmission 92 includes an alternate location for the torque limiting clutch mechanism 214. In particular, instead of the torque limiting clutch mechanism 214 being integrated with the ring gear 190 of the third planetary stage 108, the torque limiting clutch mechanism 214 is integrated with the second planetary stage 106 (including the second stage ring gear 136). Since the torque output by the second planetary stage 106 is lower than the third planetary stage 108, the preload force of the spring 234 of the torque limiting clutch mechanism 214 may be reduced, thereby reducing the force or load applied to the transmission 92 and reducing the likelihood that the transmission 92 will break under the applied load.

Referring to fig. 4 and 12, the riser 100, which is a component of the riser assembly 42, is coupled for common rotation with the transmission output shaft 96, which in turn is coupled for common rotation with the third stage planet carrier 194 through a spline-fit arrangement (fig. 11). The riser 100 includes a hub 260 having an opening 264. An end of the transmission output shaft 96 extends through the opening 264 and is rotatably secured to the riser 100. With continued reference to fig. 12, the hub 260 is formed from two

plates

272A, 272B and includes a plurality of drive pins 276 (fig. 13) extending between the

plates

272A, 272B. The illustrated lifter 100 includes seven drive pins 276; however, in other embodiments, the lifter 100 may include three or more drive pins 276. The drive pin 276 may in turn engage the drive blade 26 to lift the drive blade 26 from the drive position to the ready position. The riser assembly 42 further includes a bearing 280 positioned adjacent the upper plate 272A. The bearing 280 is configured to rotatably support the transmission output shaft 96.

The illustrated lifter 100 further includes a disc member 282 positioned adjacent the lower plate 272B (fig. 12). The disc member 282 is coupled for common rotation with the transmission output shaft 96 and the riser 100. The disk member 282 supports a magnet 300 positioned within an aperture 306 defined by an outer peripheral portion 304 of the disk member 282, as discussed further below. Specifically, the disc member 282 may be considered a retaining member for inhibiting the drive pin 276 and the magnet 300 from moving axially relative to the rotational axis 178 (i.e., to the right in the frame of reference of fig. 12). The lifter 100 further includes a second retaining member 283. The second retaining member 283 is positioned between the bearing 280 and the top surface of the upper plate 272A of the hub 260. More specifically, the second retaining member 283 is adjacent the top surface (i.e., positioned to the left of the frame of reference of fig. 12). In the illustrated embodiment, the second retaining member 283 is a washer. In other embodiments, the second retaining member 283 may be a plate member, a disc member, or the like. The second retaining member 283 is configured to inhibit axial movement of the drive pin 276 relative to the rotational axis 178 (i.e., to the left in the frame of reference of fig. 12).

Referring to fig. 12, the lifter 100 further includes a roller bushing 284 positioned on each drive pin 276. The roller bushing 284 is configured to facilitate rolling movement between the drive pin 276 and the drive blade 26 when lifting the drive blade 26 from the drive position to the ready position. This may reduce wear on the drive blade 26 (i.e., teeth) and/or the lifter 100, which may increase the life of the drive 10.

Referring to fig. 2 and 13-14, the drive 10 further includes a lifter housing portion 292 positioned adjacent the storage chamber cylinder 30 (fig. 2). The riser housing portion 292 substantially encloses the riser assembly 42. In addition, the riser housing portion 292 includes a sensor 296 (e.g., a hall effect sensor) positioned proximate the riser 100 (fig. 13). As discussed above, the lift 100 includes a magnet 300 supported by a disk member 282. The sensor 296 and the magnet 300 are configured to indicate the position (i.e., the ready position) of the drive blade 26, as discussed further below.

Referring to fig. 4, 15A and 15B, the drive blade 26 includes teeth 310 along its length, and the respective roller bushing 284 can engage the teeth 310 when the drive blade 26 is returned from the drive position to the ready position. Referring to fig. 15A, the teeth 310 extend from a first side 314 of an elongated body 312 of the drive blade 26 in a non-perpendicular direction relative to the drive axis 38 defined by the drive blade 26. For example, the illustrated teeth 310 extend in a direction at an angle a of about 115 degrees relative to the drive axis 38 (fig. 15B). In other embodiments, angle a may be between about 105 degrees and 125 degrees. Still further, in other embodiments, the angle a may be between about 110 degrees and 120 degrees. The non-perpendicular direction in which the teeth 310 extend may facilitate contact between the roller bushings 284. This may reduce the stress applied to the teeth 310, thereby extending the life of the driver 10. The illustrated drive blade 26 includes eight teeth 310 such that two revolutions of the lift 100 move the drive blade 26 from the drive position to the ready position. Furthermore, because the roller bushings 284 are rotatable relative to the respective drive pins 276, sliding movement between the roller bushings 284 and the teeth 310 is inhibited when the lifter 100 moves the drive blade 26 from the drive position to the ready position. As a result, friction and concomitant wear on the teeth 310 that may be caused by sliding movement between the drive pin 276 and the teeth 310 is reduced.

The drive blade 26 further includes axially spaced projections 318 (fig. 15A) formed on a second side 322 of the body 312 opposite the teeth 310, the purpose of which is described below. The illustrated drive blade 26 is manufactured such that the body 312, each tooth 310, and each tab 318 are bisected by a common plane 316 (fig. 16). This may simplify the manufacture of the driver blade 26 and reduce the stress applied to the driver blade 26 (i.e., the teeth 310, the protrusions 318, etc.).

Referring to fig. 2, 5 and 13-14, the drive 10 further includes a nose piece guide 330 positioned at an end of the cassette 14. The nose piece guide 330 forms a firing channel 334 (fig. 5) that communicates with a fastener channel 336 (fig. 13-14) in the cassette 14. The firing channel 334 is configured to continuously receive fasteners from the collated fastener strip within the fastener channel 336 of the cassette 14. As described above, the lifter assembly 42 moves the drive blade 26 from the drive position to the ready position. The sensor 296 determines the position of the drive blade 26 in response to detecting the magnet 300, which is positioned on the disk member 282 and rotates in unison with the lift 100. Specifically, when the drive blade 26 reaches the ready position, the magnet 300 aligns with the sensor 296, deactivating the motor 46 in response to the output from the sensor 296 to stop the drive blade 26 at the ready position (fig. 13). In the ready position of the drive blade 26, the drive blade 26 is positioned above the fastener channel 336 so that fasteners can be received within the firing channel 334 prior to the firing cycle being initiated. For example, in the illustrated embodiment, the drive blade 26 is positioned about 0.63 inches above the fastener passage 336. This may allow sufficient time to load subsequent fasteners and reduce the likelihood of the driver 10 jamming.

Referring to fig. 13 and 14, the position of the magnet 300 is positioned on the lifter 100 such that the roller bushing 284 of the drive pin 276A contacts the lowest tooth 310A of the drive blade 26 when the drive blade 26 is in the ready position. The position of the magnet 300 on the lift 100 may be selected based on: the lifter 100 needs to rotate by how much to move the drive blade 26 up from the ready position (which is slightly below TDC; fig. 13) to the TDC position (fig. 14) (i.e. when the lowest tooth 310 on the drive blade 26 slides off the roller bushing 284 of the drive pin 276A and the drive blade 26 fires). In other words, the angular distance traveled by drive pin 276A and its roller bushing 284 corresponds to the linear distance traveled by drive blade 26 from the ready position to the TDC position. In this way, reducing the angular distance traveled by drive pin 276A and its roller bushing 284 after the user pulls trigger 48 will also reduce the time it takes to drive blade 26 to fire after the user initiates a firing cycle (by pulling trigger 48). For example, in the illustrated embodiment, the drive pin 276A (and its roller bushing 284) is at an angle A1 relative to a horizontal plane 332 that extends through the rotational axis of the lifter 100 (i.e., the rotational axis 178 of fig. 8) when the drive blade 26 is in the ready position. As shown in fig. 14, the drive pin 276A (and its roller bushing 284) is at an angle A2 relative to the horizontal plane 332 when the drive blade 26 is in the TDC position. The magnet 300 is positioned such that the lifter 100 must be rotated by the difference Δ A between angle A2 and angle A1 after the drive blade 26 is moved from the ready position to the TDC position (i.e., after the user pulls the trigger 48). In the illustrated embodiment, the magnet 300 is located on the elevator 100 such that the elevator 100 must rotate by a difference Δ A of about 7 degrees to about 14 degrees before the drive blade 26 is fired, thereby causing the fasteners to be rapidly fired after the user pulls the trigger 48 (discussed in more detail below).

The drive 10 also includes an activation sequence that utilizes the relationship between the sensor 296 and the magnet 300. More specifically, after the user pulls the trigger 48, the motor 46 is configured to be activated to begin rotation of the lifter 100 to lift the drive blade 26 from the ready position to the TDC position. The controller of the drive 10 controls the motor 46 to operate in multiple stages based on the angular distance of the magnet 300 relative to the sensor 296, the magnet being coupled to the riser 100 for common rotation. For example, in some embodiments, the controller may control the operation of the motor 46 to operate in three phases. In the first phase, the controller begins driving the motor at a 100% Pulse Width Modulation (PWM) duty cycle for a first period of time (i.e., the controller ignores the inrush current in the first period of time). In the second phase, once the magnet 300 is rotated relative to the sensor 296 by the first predetermined angular distance, the controller drives the motor at a PWM duty cycle of 50% for a second period of time. The second stage is configured to avoid damage to the drive pin 276 or teeth 310 if they happen to be misaligned when the firing cycle is initiated. In the third stage, once the magnet 300 has rotated a second predetermined angular distance relative to the sensor 296, the controller again drives the motor at 100% pwm for a third period of time (i.e., after a time when the drive pin 276 or teeth 310 may be misaligned) until the drive blade 26 is lifted to the TDC position. The second predetermined angular distance may be based on how much the motor 46 needs to rotate to ensure that the lifter 100 (i.e., drive pin 276) has engaged the teeth 310. This start sequence may be used in conjunction with an electronic clutch that stops driving the motor 46 in response to no hall transition for a certain period of time (e.g., 20 ms) indicating a motor stall/jam. Accordingly, the start-up sequence is configured to inhibit or prevent the drive 10 from jamming.

The controller of the drive 10 further includes a relay electrically connected between the battery pack 90 and the motor 46. The relay is configured to be adjustable between an open state in which power cannot be transferred from the battery pack 90 to the motor 46, and a closed state in which power can be transferred from the battery pack 90 to the motor 46. The controller is configured to send a control signal to determine whether the relay is in an open state or a closed state. This may be referred to as a relay check. The relay check may be enabled when the user pulls and presses the trigger 48 to begin the firing cycle. In the illustrated embodiment, if the controller determines during the relay check that the relay is in the open state, the controller determines that the driver 10 is not ready to fire fasteners and the motor 46 will remain deactivated. Subsequently, the controller sends another control signal to energize the coil of the relay, thereby switching the relay from the open state to the closed state. If the controller determines during the relay check that the relay is in the closed state, the controller determines that the driver 10 is ready to fire the fastener.

The drive 10 may be operated in a variety of modes utilizing the trigger 48 and the workpiece contact arm or arm member 410. In the illustrated embodiment, the driver 10 is operable in a sequential actuation mode, in which both the trigger 48 and the arm member 410 must be sequentially actuated (i.e., when the arm member 410 is pressed against a workpiece) to initiate a firing cycle, and a contact actuation mode (i.e., impact firing), in which the trigger 48 may remain depressed and only the arm member must be actuated to initiate a continuous firing cycle. The controller is configured to perform a relay check immediately after the user pulls the trigger 48 in each of the plurality of modes. In particular, for the contact actuation mode, a relay check may be performed prior to actuation of the arm member 410. This may further reduce the time taken from the user pulling the trigger 48 until the motor 46 is activated to lift the drive vane 26 from the ready position to the TDC position. For example, in the illustrated embodiment, the time period is between 5 milliseconds and 10 milliseconds. In another embodiment, the time period is 6 milliseconds. This period of time may be referred to as the "electrical firing time".

Further, the time period between the user actuating the trigger 48 and the drive blade 26 beginning to move from the TDC position to the BDC position may be referred to as the "tool firing time". The combination of the predetermined position of the magnet 300 on the lift 100 and the adjustment of the electrical firing time (i.e., the adjustment of the relay check performed prior to actuation of the arm member 410) may reduce the overall tool firing time. In the illustrated embodiment, repositioning the magnet 300 as described above reduces the total tool firing time by between 3 milliseconds and 7 milliseconds, and more particularly by about 5 milliseconds. In the illustrated embodiment, with both of the above modifications, the total tool firing time is between 60 milliseconds and 40 milliseconds. In another embodiment, the total tool firing time is between 50 milliseconds and 40 milliseconds. In yet another embodiment, the total tool firing time is between 45 milliseconds and 40 milliseconds.

Referring to fig. 15A and 15B, the drive blade 26 includes a slot 338 extending along the drive axis 38. The slots 338 are configured to receive ribs 342 (fig. 16) extending from the nose piece guide 330. The ribs 342 are configured to facilitate movement of the drive blade 26 along the drive axis 38 and to inhibit off-axis movement of the drive blade 26. (i.e., left or right in the frame of reference in fig. 16.)

Referring to fig. 2-3 and 13-14, the driver 10 further includes a latch assembly 350 having a pawl or latch 354 for selectively retaining the drive blade 26 in the ready position and a solenoid 358 for releasing the latch 354 from the drive blade 26. In other words, the latch assembly 350 is movable between a latched state (fig. 13) in which the drive blade 26 is held in the ready position against the biasing force (i.e., pressurized gas in the reservoir 30) and a released state (fig. 14) in which the drive blade 26 is permitted to be driven from the ready position to the drive position by the biasing force. The latch 354 is pivotally supported about a latch axis 366 (fig. 3) by a shaft 362 on the nose piece guide 330. The latch axis 366 is parallel to the axis of rotation 368 of the lift 100 (fig. 3). Specifically, the latch 354 is positioned between two bosses 370 of the nose piece guide 330 such that both sides of the shaft 362 are supported by the nose piece guide 330. This may reduce stress on the latch 354.

Referring to fig. 2 and 3, the latch assembly 350 is positioned adjacent the side 322 of the drive blade 26. The solenoid 358 is supported by a boss 374 (fig. 2) extending from the riser housing portion 292. As such, the solenoid 358 defines a solenoid axis 398 that extends parallel to the drive axis 38 (i.e., parallel to the lifter housing portion 292). In addition, the latch 354 is configured to rotate about the axis 362 relative to the latch axis 366 such that the tip 378 of the latch 354 is configured to engage the stop surface 382 (fig. 13) of the nose piece guide 330 when the latch 354 is moved toward the drive blade 26, as discussed further below.

Referring to fig. 2 and 3, the solenoid 358 includes a solenoid plunger 386 to move the latch 354 out of engagement with the drive blade 26 when transitioning from the locked state (fig. 13) to the released state (fig. 14). The plunger 386 includes a first end positioned within the solenoid 358 and a second end coupled to the latch 354 (fig. 3). In the illustrated embodiment of the driver 10, the plunger 386 includes a slot 360 that receives a corresponding radially extending tab 364 on the latch 354 (fig. 2). The tab 364 fits loosely within the slot 360 to allow the tab 364 to translate and pivot within the slot 360 relative to the plunger 386.

Displacement of the plunger 386 pivots the latch 354 about the latch axis 366. Specifically, when the solenoid 358 is energized, the plunger 386 retracts into the body of the solenoid 358 along the solenoid axis 398 (fig. 3), pivoting the latch 354 about the latch axis 366 in a clockwise direction in the frame of reference of fig. 2, thereby disabling the latch 354 from engagement with the drive blade 26 (fig. 14). In other words, the latch 354 is spaced from the protrusion 318 of the drive blade 26, thereby ending the transition of the latch assembly 350 to the released state. When the solenoid 358 is de-energized, an internal spring bias within the solenoid 358 extends the plunger 386 of the solenoid 358 along the solenoid axis 398 causing the latch 354 to pivot in an opposite direction about the latch axis 366. Specifically, as the plunger 386 extends, the latch 354 rotates about the latch axis 366 toward the drive blade 26, ending the transition to the locked state shown in fig. 13. In an alternative embodiment, one or more springs may be used to individually bias the plunger 386 and/or the latch 354 to assist the internal spring bias within the solenoid 358 in returning the latch assembly 350 to the locked state.

The latch 354 is movable between a latched position (consistent with the latched condition of the latch assembly 350 shown in fig. 13) in which the latch 354 engages one of the tabs 318A on the drive blade 26 to hold the drive blade 26 in the ready position against the biasing force of the compressed gas, and a released position (consistent with the released condition of the latch assembly 350 shown in fig. 14) in which the drive blade 26 is permitted to be driven from the ready position to the drive position by the biasing force of the compressed gas. Further, when the solenoid 358 is de-energized, the stop surface 270 against which the latch 354 may engage limits the extent to which the latch 354 may rotate about the latch axis 366 in a counterclockwise direction in the frame of reference of fig. 2 when returning to the latched state.

Referring to fig. 2 and 3, the driver 10 further includes an arm member 410 positioned on the end 406 of the nose piece guide 330. The arm member 410 includes a first end 414 and a second end 418 located opposite the first end 414 along the drive axis 38. The first end 414 is proximate the end 406 and is configured to engage a workpiece. Second end 418 may be coupled to a depth-of-actuation adjustment mechanism 422. In particular, the depth to which the arm portion 410 extends relative to the end 406 of the nose piece guide 330 may be adjusted using the depth-of-actuation adjustment mechanism 422. In addition, the illustrated drive 10 includes a bracket member 426 (fig. 2) positioned between the riser housing portion 292 and the nose piece guide 330. The support member 426 is configured to support the arm 410 and the driving depth adjustment mechanism 422. The bracket member 426 may be secured to the drive 10 by the riser housing portion 292 and the nose piece guide 330. The bracket member 426 may reduce additional mounting brackets, fasteners such as screws, and/or assembly time.

More specifically, as shown in fig. 21, the bracket member 426 is mounted between the end portion 516 of the lifter housing portion 292 and the nose piece guide 330. The end portion 516 of the riser housing portion 292 includes a cutout or window 520. The flange portion 524 of the bracket member 426 extends through the window 520. The flange portion 524 is connected to the depth-of-drive adjustment mechanism 422. The bracket member 426 is securely coupled between the riser housing portion 292 and the nose piece guide 330. As such, during assembly of the drive 10, the bracket member 426 is mounted between the riser housing portion 292 and the nose piece guide 330, and the depth-of-drive adjustment mechanism 422 is mounted to the flange portion 524 of the bracket member 426 that extends through the window 520. In turn, the arm member 410 (i.e., the second end 418) is rotatably coupled to the driven depth adjustment mechanism 422.

Referring to fig. 5, the driver 10 includes a bumper 442 located below the piston 22 to stop the piston 22 at the driving position (fig. 6A) and absorb impact energy from the piston 22. The buffers 442 are configured to uniformly distribute the impact force of the piston 22 over the buffers 442 when the piston 22 rapidly decelerates upon reaching the driving position (i.e., the bottom dead center position).

Referring to fig. 5, the bumper 442 is received within the cylinder 18 and is held in place by a lifter housing portion 292 that is threaded into the bottom end of the cylinder 18. The bumpers 442 are received within cutouts 454 formed in the riser housing portion 292. The cutouts 454 coaxially align the bumpers 442 with respect to the drive blade 26. In alternative embodiments, the riser housing portion 292 and the bumpers 442 may be supplemented with additional structure (e.g., a key and keyway arrangement) for inhibiting relative rotation between the bumpers 442 and the recesses 446.

Referring to fig. 5 and 17, the buffer 442 has a volume. The volume is limited by the size of the cylinder 18. The volume of the buffer 442 may be maximized to fit within the cylinder 18, so that the thermal capacity of the buffer 442 may be increased. In particular, the bumpers 442 may experience high temperatures during successive firing cycles due to gas expansion within the cylinder 18. In addition, the contact surface area of the bumper 442 with its surrounding structure may be increased, thereby increasing the rate of heat transfer that occurs between the bumper 442 and its surrounding structure (e.g., the cylinder 18, etc.).

Referring to fig. 5 and 18, the driver 10 further includes an annular pocket 460 surrounding the cylinder 18. A heat sink 462 (fig. 18) can be positioned within the pocket 460 and in thermal contact with the bumpers 442 (e.g., by conduction, convection, or a combination thereof). The heat sink 462 is formed of a thermally conductive material to further increase heat transfer from the buffer 442, thereby cooling the buffer 442. In one embodiment of the drive 10, the material is a Phase Change Material (PCM) that slowly absorbs heat from the buffer 442 during operation of the drive 10, thereby keeping the temperature of the buffer 442 relatively low without significantly increasing the weight of the drive 10. This can suppress the bumper failure and extend the service life of the driver 10.

For example, as shown in fig. 19, the temperature increase of the bumper 442 is significantly inhibited by about 900 firing cycles of the driver 10 having the phase change material relative to a bumper in a similar fastener driver without the phase change material positioned immediately adjacent the bumper. Further, as shown in fig. 19, the phase change material is configured to maintain the buffer 442 at a temperature of 150 degrees fahrenheit or less for at least 600 firing cycles. In this way, the temperature rise of the buffer 442 can be significantly suppressed for a longer period of time than a fastener driver without phase change material positioned proximate the buffer. In particular, the phase change material may be configured to change phase at a predetermined temperature limit. The predetermined temperature limit may be determined based on the temperature reached by the buffer 442 at which permanent damage to the buffer 442 may otherwise occur. Further, the amount of phase change material positioned in the pockets 460 may be determined based on the desired overall weight and/or size of the actuator 10 while maximizing thermal protection of the buffer 442.

Referring to fig. 6A-6B and 13-14, the operation of the firing cycle of the driver 10 is described and detailed below. Referring to fig. 6B and 13, prior to initiating the firing cycle, the drive blade 26 remains in the ready position with the piston 22 near top dead center within the cylinder 18. More specifically, the bushings 284 associated with the drive pins 276A (fig. 13) on the lifter 100 engage the lowest teeth 310A of the axially spaced teeth 310 on the drive blade 26, and the rotational position of the lifter 100 is maintained by the one-way clutch mechanism 154. In other words, as previously described, the one-way clutch mechanism 154 prevents the motor 46 from being back driven by the transmission 92 when the lifter 100 holds the drive blade 26 in the ready position. Further, in the ready position of the drive blade 26 (fig. 13), the latch 354 may engage with the lowest tab 318A on the drive blade 26, but does not necessarily contact the drive blade 26 and act to hold the drive blade in the ready position. Conversely, at this time, the latch 354 provides a safety function to prevent the drive blade 26 from being accidentally fired in the event of a failure of the one-way clutch mechanism 154.

Referring to FIG. 14, when the trigger 48 is pulled to initiate the firing cycle, the solenoid 358 is energized to pivot the latch 354 from the locked position shown in FIG. 13 to the released position shown in FIG. 14, thereby repositioning the latch 354 so that it can no longer engage the tab 318A (thereby defining the released state of the latch assembly 350). At about the same time, the motor 46 is activated to rotate the transmission output shaft 96 and the lifter 100 in a counterclockwise direction in the frame of reference of fig. 4, thereby slightly displacing the drive blade 26 upward past the ready position (at the TDC position of the drive blade 26) before the lowermost tooth 310 on the drive blade 26 slides off the drive pin 276A. Because the roller bushings 284 are rotatable relative to the drive pins 276 that support them, subsequent wear of the drive pins 276 and teeth 310 is reduced. Thereafter, the piston 22 and the drive vane 26 are pushed downward toward the drive position (fig. 6A) by the expanding gas in the cylinder 18 and the reservoir cylinder 30. As the drive blade 26 is displaced toward the drive position, the motor 46 remains activated to continue the counterclockwise rotation of the lifter 100.

Referring to FIG. 5, as the fastener is driven into a workpiece, the piston 22 strikes the bumper 442 to rapidly decelerate the piston 22 and drive blade 26, eventually stopping the piston 22 at the drive or bottom dead center position.

Referring to fig. 16, shortly after the drive blade 26 reaches the drive position, the first drive pin 276 on the lifter 100 engages one of the teeth 310 on the drive blade 26 and continued counterclockwise rotation of the lifter 100 lifts the drive blade 26 and piston 22 toward the ready position. Shortly thereafter and before the lifter 100 completes one full rotation, the solenoid 358 is de-energized, allowing the latch 354 to re-engage the drive blade 26 and ratchet around the tab 318 (thereby defining the locked state of the latch assembly 350) as the drive blade 26 continues to be displaced upwardly.

After one full rotation of the lifter 100 occurs, the latch 218 holds the drive blade 26 in an intermediate position between the drive position and the ready position while the lifter 100 continues to rotate counterclockwise (in the frame of reference of fig. 4) until the first drive pin 276A reengages another tooth 310 on the drive blade 26. Continued rotation of the lifter 100 raises the drive vane 26 to the ready position, which is detected by the sensor 296 as described above. If the drive blades 26 become stuck during their return stroke (i.e., due to a jam caused by foreign debris), the torque limiting clutch mechanism 214 slips, transferring torque from the motor 46 to the ring gear 138 in the second planetary stage 86 and causing the ring gear 190 of the third planetary stage 108 to rotate within the cover 210. As a result, excessive force is not applied to the drive blade 26, which may otherwise cause the lifter 100 and/or the teeth 310 on the drive blade 26 to break.

Fig. 20 illustrates an alternative embodiment of the coupling between the cylinder 18 and the reservoir cylinder 30 shown in fig. 5. More specifically, instead of providing threads (i.e., threaded section 58) on the

cylinders

18, 30, the cylinder 18 includes a retaining member 504 that is received in a groove 508 of the cylinder 18. Retaining member 504 is securely attached to groove 508. The reservoir cylinder 30 includes a corresponding recess 512 to receive the retaining member 504. As such, the cylinder 18 is configured to be axially secured to the reservoir cylinder 30 by the retaining member 504. In the illustrated embodiment, the retaining member 504 has an annular shape. Similar to the embodiment shown in fig. 5, the reservoir cylinder 30 is rotatably movable relative to the cylinder 18 for displaying the indicia area 62 in a desired orientation. Furthermore, the retaining member 504 may reduce or inhibit angular stacking of the reservoir cylinder 30, and may simplify assembly of the actuator 10.

Referring to fig. 5, as the driver blade 26 approaches the BDC position, an intermediate chamber 530 is formed between the bottom portion 534 of the cylinder 18 and the bumper 442/piston 22. More specifically, when the piston 22 strikes the bumper 442, the intermediate chamber 530 is completely sealed (i.e., not fluidly connected with the external atmosphere). If the pressure within the intermediate chamber 530 being sealed at this time exceeds the gas pressure within the cylinder 18, some of the gas within the intermediate chamber 530 being sealed may partially unseat the sealing element (e.g., O-ring 538) between the piston 22 and the inner cylinder 18, creating a path for the higher pressure gas within the intermediate chamber 530 to leak into the cylinder 18 containing the low pressure gas. Any additional gas "pumped" into the inner cylinder 18 over multiple firing cycles in this manner can increase the gas pressure acting on the driver piston 22 and affect the desired performance of the driver 10.

As shown in fig. 22, in an alternative embodiment of the fastener driver 10, a lifter housing portion 292 is threaded to the bottom end of the cylinder 18, and a slot 542 (i.e., through the threaded connection of the lifter housing portion and the inner cylinder) is provided between the lifter housing portion 292 and the inner cylinder 18, such that the intermediate chamber 530 cannot be sealed when the piston 22 strikes the bumper 442. More specifically, the intermediate chamber 530 is fluidly connected to the external atmosphere by the slot 542 at any position of the piston 22/driver blade 26 between the TDC and BDC positions. In the illustrated embodiment, slots 542 are machined into the inner circumference of inner cylinder 18 and are oriented parallel to drive vanes 26. The groove 542 prevents or inhibits pressure buildup in the intermediate chamber 530 when the piston 22/driver blade 26 approaches the BDC position and the cushion 442 is being compressed by the piston 22. In this way, the pressure in the intermediate chamber 530 cannot exceed the pressure within the inside cylinder 18, preventing the O-ring 538 from unseating in the manner described above, such that the cylinder 18 is prevented from fluidly connecting to the intermediate chamber 530.

Referring to fig. 23, the actuator 10 includes a plurality of cushion or damping elements 550A-550C positioned between the housing 80 and the

internal components

18, 46, 92 of the actuator 10. In the illustrated embodiment, the first damping element 550A is positioned between the cylinder 18 and the cylinder support portion 84 of the housing 80. In other embodiments, the first damping element 550A may be positioned in other locations, such as between the storage chamber cylinder 30 and the cylinder support portion 84. Further, the illustrated driver 10 includes: a second damping element 550B positioned between the transmission 92 and the motor support portion 88 of the housing 80; and a third damping element 550C positioned between the motor 46 and the motor support portion 88. First damping element 550A and second damping element 550B each have an annular shape. The damping elements 550A-550C are formed from a resilient material, such as rubber, to absorb energy that may be transferred from the gas springs to the housing 80 of the driver 10 during a firing operation. For example, if the lifter housing portion 292 is rigidly coupled to the housing of the transmission 92, the force of the gas spring may cause a pivoting force to be applied to the motor 46/transmission 92 at the point where the lifter housing portion 292 is rigidly coupled to the transmission 92 when the drive blade 26 is driven to the BDC position. The position of the third damping element 550C is specifically configured to dampen pivotal movement of the motor 46/transmission 92 relative to the rigid connection point. In this way, the cylinder 18 and/or the motor 46/transmission 92 are not rigidly mounted within (movable within) the housing 80. In the illustrated embodiment, driver 10 includes three damping elements 550A-550C. In other embodiments, the driver 10 may include one or more damping elements (e.g., two, four, etc.) positioned anywhere within the housing 80.

Referring to fig. 15A to 15B, the driving blade 26 may have a portion having a first hardness and another portion having a greater hardness than the first portion. More specifically, the body 312 of the driver blade 26 and at least some of the teeth 310 and projections 318 of the driver blade 22 are formed from a first material, such as a metal, such that a first portion of the driver blade 22 has a first hardness. One or more of the remaining teeth 310 may be formed of a different material or subjected to a post-manufacturing process such that the teeth have a second hardness that is greater than the first hardness. For example, during lifting of the driving blade 26 to the TDC position by the lifter assembly 42, the lowest tooth 310A of the driving blade 26 is subjected to a greater force than the other teeth 310, the lowest tooth being formed of a harder material or having a greater hardness than the remaining teeth 310 to reduce premature wear. In one embodiment, the lowest tooth 310A is formed of carbide. In another embodiment, the lowest teeth 310A are coated with a carbide layer. Further, in another embodiment, the lowermost tooth 310A is hardened by an induction hardening process. In other embodiments, one or more of the teeth 310 and/or the projections 318 may have a second, greater hardness.

Fig. 25A-25B illustrate an alternative embodiment of the drive blade 26 shown in fig. 15A-16. In particular, as shown in fig. 16, the body 312 of the drive blade 26, as well as each tooth 310 and each tab 318, are bisected by a common plane 316. Body 312 includes a first width W relative to plane 316. The protrusion 318 and the tooth 310 in fig. 16 each have the same width W as the body 312. In an alternative embodiment of the drive blades 26', 26 "(as shown in fig. 25A and 25B), the bodies 312', 312" have a first width W1, and the width W2 of the projections 318', 318 "and/or the width W3 of the teeth 310', 310" may have a different width (i.e., smaller, larger) than the width W1 of the bodies 312', 312 "in a direction perpendicular to the common plane 316', 316", respectively. For example, as shown in fig. 25A, the width W2 of the projection 318' is less than the width W1 of the body 312' of the drive blade 26 '. In another example, as shown in FIG. 25B, the width W3 of the tooth 310 "is greater than the width W1 of the body 312" of the drive blade 26 ". In other embodiments, the width of the tab 318 may be greater than the width of the body 312 of the driver blade 26, or the width of the tooth 310 may be less than the width of the body 312 of the driver blade 26. The different sizes or stepped widths W2, W3 of the drive lobes 26', 26 "define

guide surfaces

572A, 572B, 576A, 576B on the drive lobes 26', 26" that are spaced from the common plane 316', 316 "and extend parallel to the drive axis 38.

With continued reference to fig. 16 and 25A-25B, the nose piece guide 330 (fig. 16) includes a channel 560 configured to receive the drive blade 26. As shown in fig. 25A-25B, the channels 560', 560 "may have multiple widths to match the widths W1, W2, W3 of the different sizes of the drive lobes 26, such that

multiple guide surfaces

564A, 564B, 568A, 568B that match or correspond to the guide surfaces 572A, 572B, 576A, 576B of the drive lobes 26', 26" are formed within the channels 560', 560 ". For example, in the embodiment shown in fig. 25A, the plurality of guide surfaces 564A, 564B, 568A, 568B include a first guide surface 564A and a second guide surface 568A, respectively, that are formed proximate the intersection between the protrusion 318 'and the body 312'. In the illustrated embodiment of fig. 25B, the plurality of guide surfaces 564A, 564B, 568A, 568B include first and second guide surfaces 564B, 568B, respectively, formed proximate the intersection between the tooth 310 "and the body 312". Similar to the ribs 342, the plurality of guide surfaces 564A, 564B, 568A, 568B facilitate movement of the drive blade 26', 26 "along the drive axis 38 and inhibit off-axis movement of the drive blade 26', 26". More specifically, the guide surfaces 572A, 572B, 576A, 576B of the drive blades 26', 26 "are slidable relative to the guide surfaces 564A, 564B, 568A, 568B of the channels 560', 560". Further, the plurality of guide surfaces 564A, 564B, 568A, 568B, 572A, 572B, 576A, 576B may inhibit the drive blade 26', 26 "from pivoting or twisting within the channel 560', 560" about the rib 342 of the nosepiece guide 330', 330 "as the drive blade 26', 26" returns from the BDC position toward the TDC position. This may further maintain the orientation of the teeth 310' relative to the drive pins 276 in a desired orientation (i.e., the teeth 310', 310 "remain orthogonal to the roller bushings 284 on the respective drive pins 276), such that the distribution of the load caused by contact between the drive pins 276 and the teeth 310', 310" is across the width of the teeth 310', 310", thereby reducing stress on the teeth 310', 310".

Various features of the invention are set forth in the following claims.

Claims

1. A gas spring powered fastener driver, comprising:

an outer cylinder;

an inside cylinder positioned inside the outside cylinder;

a movable piston positioned within the inner cylinder;

a drive vane attached to the piston and movable with the piston between a top dead center, TDC, position and a drive position or a bottom dead center, BDC, position; and

a holding member fixed to the inside cylinder, the holding member coupling the inside cylinder to the outside cylinder,

wherein the inner cylinder is axially fixed to the outer cylinder relative to a drive axis defined by the drive vane, an

Wherein, the outer cylinder can rotate relative to the inner cylinder.

2. The gas spring powered fastener driver according to claim 1 wherein the inner cylinder defines a first recess; the outer cylinder defining a second groove that mates with the first groove; the retaining member is received within each of the first and second grooves.

3. A gas spring powered fastener driver according to claim 1 and wherein said retaining member has an annular shape.

4. A gas spring powered fastener driver, comprising:

a cylinder;

a movable piston positioned within the cylinder;

a drive vane attached to the piston and movable with the piston between a top dead center, TDC, position and a drive position or a bottom dead center, BDC, position;

a lifter operable to move the drive vane from the bottom dead center, BDC, position towards the top dead center, TDC, position;

a transmission for providing torque to the riser;

a buffer positioned in the cylinder and configured to absorb impact energy from the piston when the driving blade is driven toward the bottom dead center BDC position;

a chamber defined between the piston, the cylinder and the buffer when the drive blade reaches the bottom dead center BDC position; and

a plurality of slots defined by the cylinder, the slots fluidly communicating the chamber with an external atmosphere.

5. A gas spring powered fastener driver according to claim 4 and wherein said grooves are machined into the inner periphery of said cylinder.

6. A gas spring powered fastener driver, comprising:

a housing having a first portion and a second portion;

an outer cylinder supported by the first portion;

an inside cylinder positioned within the outside cylinder;

a movable piston positioned within the inner cylinder;

a lifter operable to move the drive vane from the bottom dead centre, BDC, position towards the top dead centre, TDC, position;

a motor and transmission for providing torque to the lifter, the motor and transmission being supported by the second part; and

a plurality of damping elements positioned between the housing and at least one of the inner cylinder, the transmission, or the motor,

wherein the damping elements are positioned such that at least one of the inside cylinder, the transmission or the motor is mounted within the housing but is movable relative to the housing to damp the force exerted on the housing by the inside cylinder, the transmission or the motor.

7. A gas spring powered fastener driver as set forth in claim 6 wherein one of said plurality of damping elements is positioned between the end of said inner cylinder and said first portion of said housing.

8. A gas spring powered fastener driver as set forth in claim 6 wherein one of said plurality of damping elements is positioned between said transmission and said second portion of said housing.

9. The gas spring powered fastener driver as set forth in claim 6, wherein one of said plurality of damping elements is positioned between a portion of said motor and said second portion of said housing.

10. A gas spring powered fastener driver as claimed in claim 6, wherein one of said damping elements has an annular shape.

11. A gas spring powered fastener driver according to claim 6 and wherein said damping elements are formed of an elastomeric material.

12. A gas spring powered fastener driver, comprising:

a cylinder;

a movable piston positioned within the cylinder; and

a drive vane attached to the piston and movable with the piston between a Top Dead Center (TDC) position and a drive position or a Bottom Dead Center (BDC) position, the drive vane including a body and a plurality of teeth extending from the body,

wherein the body has a first hardness,

wherein at least one of the teeth has a second hardness greater than the first hardness.

13. The gas spring powered fastener driver as set forth in claim 12, wherein said at least one of said teeth is hardened to said second hardness by induction hardening.

14. The gas spring powered fastener driver as set forth in claim 13, wherein the drive lobe includes a first end attached to the piston and an opposite second end, and wherein at least one of the teeth having the second hardness is the lowest tooth proximate the second end of the drive lobe.

15. A gas spring powered fastener driver, comprising:

a cylinder;

a movable piston positioned within the cylinder;

a driver blade attached to the piston and movable with the piston between a Top Dead Center (TDC) position and a drive or Bottom Dead Center (BDC) position, the driver blade including a body and a plurality of teeth extending from the body, the driver blade defining a drive axis, the driver blade including

A body having a first side and an opposite second side between which the drive axis passes, and

a plurality of teeth extending from the first side of the body,

wherein the body and the teeth are bisected by a common plane;

a lifter operable to move the drive vane from the bottom dead center BDC position towards the top dead center TDC position, the lifter being configured to engage with the teeth of the drive vane when moving the drive vane from the bottom dead center BDC position towards the top dead center TDC position; and

a nose piece guide having a channel in which the drive blade is slidably received,

wherein the body has a first width in a direction perpendicular to the common plane,

wherein the teeth have a second width in a direction perpendicular to the common plane, the second width being different from the first width, an

Wherein the second width defines a plurality of guide surfaces spaced from the common plane and extending parallel to the drive axis, the plurality of guide surfaces being slidable against respective guide surfaces of the channel.

16. The gas spring powered fastener driver as set forth in claim 15, wherein said second width is greater than said first width.

17. The gas spring powered fastener driver as set forth in claim 15, wherein said nose piece guide further includes a rib extending therefrom; the drive blade includes a slot extending along a drive axis of the drive blade, the slot configured to receive the rib; the second width inhibits rotation of the drive blade within the channel about the rib relative to the drive axis.

18. The gas spring powered fastener driver of claim 15 further including a latch assembly movable between a locked condition in which the drive blade is held in a ready position against the biasing force of compressed gas and a released condition in which the drive blade is permitted to be driven toward the drive position by the biasing force, the latch assembly including a latch engageable with a plurality of projections extending from the second side of the body, and wherein the plurality of projections are bisected by the common plane and have a third width equal to the first width.

19. A gas spring powered fastener driver, comprising:

a cylinder;

a movable piston positioned within the cylinder;

a drive vane attached to the piston and movable with the piston between a Top Dead Center (TDC) position and a drive or Bottom Dead Center (BDC) position, the drive vane including a body and a plurality of teeth extending from the body, the drive vane defining a drive axis, the drive vane including

a plurality of projections extending from a first side of the body,

wherein the body and the projections are bisected by a common plane;

a latch assembly movable between a latched state in which the drive blade is held in a ready position against a biasing force of compressed gas and a released state in which the drive blade is permitted to be driven toward the drive position by the biasing force, the latch assembly including a latch engageable with the plurality of projections; and

wherein the protrusions have a second width in a direction perpendicular to the common plane, the second width being different from the first width, an

20. The gas spring powered fastener driver as set forth in claim 19, wherein said second width is less than said first width.

21. The gas spring powered fastener driver as defined in claim 19 wherein, the nosepiece guide further includes a rib extending from the nosepiece guide; the drive blade includes a slot extending along a drive axis of the drive blade, the slot configured to receive the rib; the second width inhibits rotation of the drive blade within the channel about the rib relative to the drive axis.

22. The gas spring powered fastener driver of claim 19 further including a lifter operable to move the drive vane from the bottom dead center, BDC, position toward the top dead center, TDC, position, the lifter configured to engage a plurality of teeth extending from the first side of the body when moving the drive vane from the bottom dead center, BDC, position toward the top dead center, TDC, position, and wherein the plurality of teeth are bisected by a common plane and have a third width equal to the first width.

23. A gas spring powered fastener driver, comprising:

a cylinder;

a movable piston positioned within the cylinder;

a drive vane attached to the piston and movable with the piston between a top dead center, TDC, position and a drive position or a bottom dead center, BDC, position, the drive vane configured to be positioned at a ready position intermediate the top dead center, TDC, position and the bottom dead center, BDC, position;

a lifter operable to move the driving vane from the bottom dead center BDC position toward the top dead center TDC position, the lifter supported by a lifter housing, the lifter including

A body rotatably supported about an axis of rotation, an

A plurality of drive pins engageable with the drive blade as the drive blade is moved from the Bottom Dead Center (BDC) position to the Top Dead Center (TDC) position;

a motor and transmission for providing torque to the lifter;

a magnet positioned at a predetermined location on the body of the riser, the magnet coupled for common rotation with the body about the axis of rotation; and

a sensor positioned on the lifter case, the sensor configured to detect the magnet to stop the drive blade at the intermediate position,

wherein a horizontal plane extends through the axis of rotation,

wherein one of the drive pins is at a first angle relative to the horizontal plane when the drive blade is in the ready position,

wherein one of the drive pins is at a second angle relative to the horizontal when the drive blade is at the top dead center, TDC, position,

wherein the predetermined position of the magnet is selected based on a difference between the first angle and the second angle, an

Wherein the difference between the first angle and the second angle is between 7 degrees and 14 degrees.

24. The gas spring powered fastener driver set forth in claim 23 and further comprising

A nosepiece guide and an arm member movably supported on the nosepiece guide, an end of the arm member being configured to contact a workpiece;

a power source operable to provide power to the motor;

a controller; and

a relay electrically connected between the power source and the motor, the relay adjustable between an open state in which power cannot be transmitted from the power source to the motor and a closed state in which power can be transmitted from the power source to the motor,

wherein prior to actuating the arm member, the relay is adjusted to the closed state and the controller issues a control signal to activate the motor.

25. The gas spring powered fastener driver as set forth in claim 23 further including a trigger operable by a user to initiate fastener driving operations wherein the period of time between user actuation of the trigger and the start of movement of the drive blade from the top dead center, TDC, position toward the bottom dead center, BDC, position is between 40 milliseconds and 45 milliseconds.