Powered fastener driver

Abstract

A powered fastener driver is disclosed that includes a piston movable within an inner cylinder from a top dead center (TDC) position to a driven position or a bottom dead center (BDC) position. The piston has a reduced stroke length between a TDC position and a BDC position.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 464,215 filed on May 5, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The utility model relates to a power fastener driver, and more particularly to a gas spring power fastener driver. Background Art

[0004] Various 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 generated by an air compressor, electrical energy, flywheel mechanisms, etc.), but these designs typically encounter power, size, and cost limitations. Utility Model Content

[0005] In some aspects, the technology described herein relates to a powered fastener driver comprising: a housing; an inner cylinder located within the housing; a piston capable of moving within the inner cylinder from a top dead center (TDC) position to a driven position or a bottom dead center (BDC) position, the piston having a stroke length between the TDC position and the BDC position measuring 73 mm or less; a driver blade attached to the piston for moving therewith along a drive axis from the TDC position toward the BDC position to drive a fastener into a workpiece, the driver blade comprising: a first end; a second end opposite the first end and attached to the piston; a first set of drive teeth extending from a first side of the driver blade between the first end and the second end, adjacent drive teeth within the first set being separated from each other by a first distance; and a second set of drive teeth extending from the first side of the driver blade, adjacent drive teeth within the second set being separated from each other by a second distance equal to the first distance, wherein adjacent drive teeth in the first and second sets are respectively separated from each other by a third distance less than each of the first and second distances; a lifter operable to move the piston and the driver blade from the BDC position toward the TDC position, the lifter engaging the first set of drive teeth during a first rotation to move the piston and the driver blade from the BDC position to an intermediate position between the BDC position and the TDC position, and engaging the second set of drive teeth during a second rotation to move the piston from the intermediate position toward the TDC position; and a drive unit operably connected to the lifter to provide torque to the lifter to rotate the lifter.

[0006] In some aspects, the technology described herein relates to a powered fastener driver comprising: a housing; an inner cylinder located within the housing; a piston capable of moving within the inner cylinder from a top dead center (TDC) position to a driven position or a bottom dead center (BDC) position, the piston having a diameter of less than 50 mm and a stroke length of the piston between the TDC position and the BDC position measuring 60 mm and 74 mm; a driver blade attached to the piston for moving along the driving position with the piston; The axis moves from the TDC position toward the BDC position so as to drive a fastener into a workpiece; a lifter operable to move the piston and the driver blade from the BDC position toward the TDC position, the lifter comprising a plurality of drive pins configured to engage the driver blade, the drive pins being positioned along an imaginary circle coaxial with the axis of rotation of the lifter and having a diameter less than 60 mm; and a drive unit operably coupled to the lifter to provide torque to the lifter to rotate the lifter.

[0007] In some aspects, the technology described herein relates to a powered fastener driver comprising: a housing; an inner cylinder located within the housing; a piston capable of moving within the inner cylinder from a top dead center (TDC) position to a driven position or a bottom dead center (BDC) position, the piston having a stroke length between the TDC position and the BDC position measuring 73 mm or less; a driver blade attached to the piston for moving therewith along a drive axis from the TDC position toward the BDC position to drive a fastener into a workpiece, the driver blade comprising: a first end; a second end opposite the first end and attached to the piston; a first set of drive teeth extending from a first side of the driver blade between the first end and the second end, adjacent drive teeth within the first set being separated from each other by a first distance; and a second set of drive teeth extending from the first side of the driver blade, adjacent drive teeth within the second set being separated from each other by a second distance equal to the first distance, wherein wherein adjacent drive teeth in the first group and the second group are respectively separated from each other by a third distance less than each of the first distance and the second distance; a lifter operable to move the piston and the driver blade from the BDC position toward the TDC position, the lifter engaging the first group of drive teeth during a first rotation to move the piston and the driver blade from the BDC position to an intermediate position between the BDC position and the TDC position, and engaging the second group of drive teeth during a second rotation to move the piston from the intermediate position toward the TDC position, the lifter comprising a body and a plurality of drive pins supported on the body, wherein each of the drive pins is configured to engage one of the drive teeth in the first group and one of the drive teeth in the second group, and wherein the drive pins are positioned on the body along an imaginary circle coaxial with the rotation axis of the lifter and having a diameter less than 60 mm; and a drive unit operably connected to the lifter to provide torque to the lifter to rotate the lifter.

[0008] Other features and aspects of the present invention will become apparent by considering the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a three-dimensional view of a gas spring powered fastener driver according to an embodiment of the utility model.

[0010] Figure 2 yes Figure 1 Another perspective view of the gas spring powered fastener driver.

[0011] Figure 3A yes Figure 1Another perspective view of a gas spring powered fastener driver with various portions removed for clarity.

[0012] Figure 3B yes Figure 1 Another perspective view of a gas spring powered fastener driver with various portions removed for clarity.

[0013] Figure 4 yes Figure 1 The gas spring powered fastener driver is along Figure 1 A cross-sectional view taken along line 4--4 is shown.

[0014] Figure 5 yes Figure 1 The gas spring powered fastener driver is along Figure 1 A cross-sectional view taken along line 5--5 is shown.

[0015] Fig. 6A yes Figure 1 A perspective view of a piston of a gas spring powered fastener driver.

[0016] Figure 6B yes Fig. 6A The piston moves along Fig. 6A A cross-sectional view taken along line 6B--6B is shown in FIG.

[0017] Fig. 7A is a perspective view of another piston and another driver blade.

[0018] Figure 7B yes Fig. 7A The piston and drive blades move along Fig. 7A A cross-sectional view taken along line 7B--7B.

[0019] Figure 8 yes Figure 1 A perspective view of a drive blade of a gas spring powered fastener driver.

[0020] Fig. 9 yes Figure 8 Detailed view of the drive blades.

[0021] Fig.10 yes Figure 1 A top view of the lifter of a gas spring powered fastener driver.

[0022] Before explaining any embodiment of the utility model in detail, it should be understood that the application of the utility model is not limited to the details of the component construction and arrangement set forth in the following description or shown in the following drawings. The utility model can have other embodiments and can be practiced or executed in a variety of different ways. In addition, it should be understood that the words and terms used herein are for descriptive purposes and should not be considered as limiting. DETAILED DESCRIPTION

[0023] refer to Figure 1 to Figure 2 , the gas spring powered fastener driver 10 is operable to drive fasteners (e.g., nails, tacks, staples, etc.) held within the magazine 14 into a workpiece. The driver 10 includes a housing 18 having a cylinder support portion 22, a drive unit support portion 26, and a handle portion 30. In the illustrated embodiment, the cylinder support portion 22 extends between the drive unit support portion 26 and the handle portion 30. Accordingly, the drive unit support portion 26 and the handle portion 30 are spaced apart from each other. In the illustrated embodiment, the cylinder support portion 22, the drive unit support portion 26, and the handle portion 30 are integrally formed as a single piece with each other (e.g., using a casting process or a molding process, depending on the materials used). The battery pack 34 is received and supported by the battery pack attachment interface of the handle portion 30.

[0024] refer to Figure 2 In some embodiments, the driver 10 further includes a nose bridge assembly 50 supported by the housing 18 and extending from the housing. The nose bridge assembly 50 is positioned at the end of the magazine 14. The magazine 14 includes a magazine body 60 that is configured to receive fasteners to be driven into a workpiece by the powered fastener driver 10. The magazine body 60 ( Figure 1 ) has a first end 64 coupled to the nose bridge assembly 50 and a second end 68 opposite the first end 64. The cassette body 60 defines a fastener channel (not shown) extending from the first end 64 of the cassette body 60 to near the second end 68. The fastener channel is configured to receive a fastener. The cassette 14 further includes a pusher assembly 72 positioned within the fastener channel 448 of the cassette body 60. The pusher assembly 72 is slidably coupled to the cassette 14 and is configured to bias the fasteners in the cassette 14 toward the nose bridge assembly 50.

[0025] The nose bridge assembly 50 generally includes a first base portion 80 coupled to the first end 64 of the cassette body 60 and a second cover portion 84 coupled to the base portion 80. The base portion 80 of the nose bridge assembly 50 is fixed to the cassette body 60. The cover portion 84 of the nose bridge assembly 50 substantially covers the base portion 80. In the illustrated embodiment, the cover portion 84 is pivotally coupled to the base portion 80 by a latch mechanism 88. The nose bridge assembly 50 cooperatively defines a firing channel 92 (at Figure 5Only a portion of the firing channel is shown in FIG. 1 ). The firing channel 92 is connected to the fastener channel of the cassette body 60 for receiving the fastener from the cassette body 60. The nosepiece assembly 50 further has a distal end portion ( Figure 5 ).

[0026] refer to Figures 1 to 3B In some embodiments, the driver 10 includes a workpiece contact assembly 100 extending along a side of the nose assembly 50. The workpiece contact assembly 100 is configured to move from an extended position toward a retracted position when the workpiece contact assembly 100 is pressed against the workpiece. The workpiece contact assembly 100 includes a drive depth adjustment mechanism 104 that adjusts the effective length of the workpiece contact assembly 100. The drive depth adjustment mechanism 104 adjusts the depth to which the fastener is driven into the workpiece. Although not shown, the powered fastener driver 10 further includes a blank-fire lockout assembly. The blank-fire lockout assembly prevents the powered fastener driver 10 from operating when the number of fasteners remaining in the magazine 14 drops below a predetermined value.

[0027] like Figures 4 to 5 As shown, the fastener driver 10 includes a storage chamber cylinder 120 positioned within the cylinder support portion 22. An inner cylinder or driver cylinder 124 is positioned within the storage chamber cylinder 120, and a movable piston 128 is positioned within the inner cylinder 124. The fastener driver 10 further includes a driver blade 132, which is attached to the piston 128 and can move therewith. The fastener driver 10 does not require an external air pressure source, but rather the storage chamber cylinder 120 encloses a pressurized gas in fluid communication with the inner cylinder 124. In the illustrated embodiment, the inner cylinder 124 and the movable piston 128 are positioned within the storage chamber cylinder 120. The driver 10 further includes a filling valve 136 ( Figure 4 ). When connected to a source of compressed gas, the filling valve 136 allows the storage chamber cylinder 120 to be refilled with compressed gas if any leaks previously occurred. For example, the filling valve 136 can be configured as a Schrader valve.

[0028] The inner cylinder 124 and the driver blade 132 define a drive axis 150. During a drive cycle, the driver blade 132 and the piston 128 can move between a top dead center (TDC) position and a driven position or a bottom dead center (BDC) position. As shown in FIG. 3 , the fastener driver 10 further includes a lift assembly 170, a transmission 174, and a motor 178. The transmission 174 and the motor 178 are positioned within the drive unit support portion 26 of the housing 18. In the illustrated embodiment, the driver blade 132 has a stroke length L1 ( Figure 4) is measured to be about 73 mm or less, which is less than a conventional driver. In some embodiments, the stroke length L1 can be measured to be between about 60 mm and about 74 mm. In some embodiments, the stroke length L1 can be about 66.5 mm. The term "about" as used herein means plus or minus 5% of the value. As discussed in more detail below, a reduced stroke length L1 can be achieved for a variety of reasons. As discussed in more detail below, the lifting assembly has a lifter 182 (FIG. 3) that is powered by the motor 178 and moves the driver blade 132 from the driven position to the TDC position. Moreover, the transmission 174 provides torque from the motor 178 to the lifter 182.

[0029] In operation, the lift assembly 170 drives the piston 128 and the driver blade 132 toward the TDC position by energizing the motor 178. As the piston 128 and the driver blade 132 are driven toward the TDC position, the gas above the piston 128 and the gas within the reservoir cylinder 120 are compressed. Before reaching the TDC position, the motor 178 is deactivated and the piston 128 and the driver blade 132 are held in a ready position between the TDC position and the BDC position until the user activates the trigger 186 ( Figure 1 ) and was released. Figure 5 In some embodiments, the driver 10 further includes a latch assembly having a pawl or latch 190 for selectively retaining the driver blade 132 in the ready position. When released, the compressed gas above the piston 128 and within the reservoir cylinder 120 drives the piston 128 and the driver blade 132 to the driven position, thereby driving the fastener into the workpiece. Specifically, the driver blade 132 is received in the firing channel 92 for driving the fastener from the firing channel 92 out of the distal end of the nosepiece assembly 50 and into the workpiece. The illustrated fastener driver 10 thus operates on the principle of a gas spring using the lifting assembly 170 and the piston 128 to further compress the gas within the inner cylinder 124 and the reservoir cylinder 120.

[0030] Further references Figure 4, the inner cylinder 124 is configured to guide the piston 128 and the driver blade 132 along the drive axis 150 to compress the gas in the storage chamber cylinder 120. Therefore, the size and shape of the inner cylinder 124 are determined according to the size and shape of the piston 128. The inner cylinder 124 includes an inner annular wall 200, which has a first end 204 and a second end 208 opposite the first end 204. The inner cylinder defines a substantially uniform inner diameter D1. In the illustrated embodiment, the inner cylinder 124 defines an inner diameter D1 of about 20 mm to about 50 mm. Preferably, the inner cylinder 124 defines an inner diameter D1 of less than about 51 mm. The piston 128 is positioned adjacent to the second end 208 at the TDC position, and the piston 128 is positioned between the first end 204 and the second end 208 at the BDC position.

[0031] Continue to refer Figure 4 , the storage chamber cylinder 120 has an annular outer wall 220 that circumferentially surrounds the inner wall 200. More specifically, the storage chamber cylinder 120 extends from a first end 224 to a second end 228. Each of the illustrated first end 224 and second end 228 of the storage chamber cylinder 120 is circular, respectively. The first end 204 of the inner cylinder 124 is attached to the first end 224 of the storage chamber cylinder 120. The first ends 204, 224 may be attached in any suitable manner (e.g., press fit, threaded, etc.). A seal 232 is disposed between the first end 204 of the inner cylinder 124 and the first end 224 of the storage chamber cylinder 120. The seal 232 prevents pressurized gas from escaping between the storage chamber cylinder 120 and the inner cylinder 124.

[0032] The storage chamber cylinder 120 includes a first portion 236 and a second portion 240 adjacent to the first portion 236. The first portion 236 is adjacent to the first end 224 and has a substantially constant second inner diameter D2. The first portion 236 defines a first longitudinal axis 244 that is colinear with the drive axis 150. The second portion 240 is adjacent to the second end 228. The second portion 240 extends from the first portion 236 toward the second end 228. The second end 228 has a third inner diameter D3 that is variable along the length of the second portion 240 between the first portion 236 and the second end 228. As shown, the third diameter D3 generally increases from the first portion 236 to the second end 228. The second portion 240 defines a second longitudinal axis 248 that is coaxial with the second end 228. In other words, the second end 228 defines a second longitudinal axis 248 that extends through the center of the second end 228. The second longitudinal axis 248 extends parallel to the drive axis 150 and is spaced apart from the drive axis (e.g., from Figure 4The second longitudinal axis 248 is radially below the first longitudinal axis 244 / drive axis 150 as viewed in the reference system of the housing 18). The first longitudinal axis 244 and the second longitudinal axis 248 are offset, respectively. Accordingly, the storage chamber cylinder 120 is not concentric with the inner cylinder 124. Moreover, as shown, the storage chamber cylinder defines a volume. A first portion 120' of the volume of the storage chamber cylinder 120 is generally defined on a first side of the drive axis 150, while a second portion 120" of the storage chamber cylinder 120 is generally defined on an opposite second side of the drive axis 150. The second portion 120" is at least partially positioned between the drive unit support portion 26 of the housing 18 and the handle portion 30 of the housing 18. The second portion 120" has a larger volume than the first portion 120'. The driver 10 further includes an end cap 252 positioned at the second end 228. The end cap 252 fluidly seals the inner cylinder 124 and the storage chamber cylinder 120 relative to the external atmosphere.

[0033] The second longitudinal axis 248 is spaced apart from the first longitudinal axis 244 by an offset distance H. The offset distance H between the first longitudinal axis 244 and the second longitudinal axis 248 is between about 5% and about 25% of the second diameter D2. In some embodiments, the offset distance H is between about 5% and about 20% of the second diameter D2. In further embodiments, the offset distance H is between about 5% and about 15% of the second diameter D2. In still further embodiments, the offset distance H is between about 5% and about 10% of the second diameter D2. In still further embodiments, the offset distance H is greater than about 25% of the second diameter D2. In the illustrated embodiment, the offset distance H is about 21% of the second diameter D2.

[0034] The non-concentric configuration of the inner cylinder 124 and the reservoir cylinder 120 can reduce the overall size of the driver 10 and can facilitate positioning of the driver 10 in a small space during use of the driver 10. Specifically, the overall height of the driver 10 can be reduced compared to conventional drivers. In addition, this configuration shifts the center of mass of the cylinders 120, 124 closer to the second end 228 (where the handle portion 30 of the driver 10 is located). Figure 1 to Figure 2 ), which can improve the balance and / or handling of the actuator 10 when in use. Moreover, the length L2 of the reservoir cylinder 120 can be less than the length of the reservoir cylinder of a conventional actuator. In the illustrated embodiment, the length L2 ( Figure 4 ) is measured to be about 100 mm. In other embodiments, the length L2 ( Figure 4) is measured to be approximately 173 mm. In other embodiments, the length L2 of the reservoir chamber cylinder 120 between the first end 224 and the second end 228 can be in the range of approximately 98 mm to 175 mm. In other embodiments, the length L2 of the reservoir chamber cylinder 120 between the first end 224 and the second end 228 can be in the range of approximately 90 mm to 190 mm. Additionally, the non-concentric configuration of the inner cylinder 124 and the reservoir chamber cylinder 120 is one of the factors that can reduce the stroke length L1 of the driver blade 132. This is because, although the footprint of the driver 10 is small, the reservoir chamber cylinder 120 can still accommodate the necessary amount of gas. The amount of pressurized gas can be approximately 60 cm 3 About 300cm 3 In the illustrated embodiment, the amount of pressurized gas may be about 100 cm 3 Thus, while the stroke length L1 is reduced and the footprint of the actuator 10 is reduced, the volume of the reservoir cylinder 120 still enables the 118 lbf to 125 lbf impact force that can be generated at TDC. This allows for a favorable compression ratio of no more than about 1.6. In some embodiments, the compression ratio can be between about 1.4 and about 1.6. The low compression ratio reduces the lifting shear stress experienced by the lifter 182 during operation to, for example, 1220 MPa.

[0035] Reference FIG. 6A to FIG. 6B In the illustrated embodiment, the piston 128 includes a first portion 310 and a second portion 314 that is integrally formed with the first portion 310 or otherwise coupled to the first portion. The first portion 310 defines a plurality of grooves 318a, 318b, 318c (e.g., circumferential grooves) that each extend around its circumference. In the illustrated embodiment, the second groove 318b has a greater depth than the first groove 318a and the third groove 318c. In the illustrated embodiment, the second portion 314 is integrally formed with the first portion 310. In some embodiments, the second portion 314 can be coupled to the first portion 310 via a threaded engagement or via a fastener (e.g., FIG. 7A to FIG. 7B The second portion 314 is coupled to the driver blade 132. In the illustrated embodiment, the driver blade 132 is positioned within the slot 320 of the second portion 314 and is secured to the driver blade 132 via a fastener 322 (e.g., a pin, Figures 4 to 5 and FIG. 7A to FIG. 7B ) is coupled to the piston 128. In other embodiments, the driver blade 132 can be coupled to the piston in other ways (e.g., threaded engagement).

[0036] exist FIG. 7A to FIG. 7B In the embodiment of the present invention, the configuration of the piston 128 is similar to that mentioned above. FIG. 6A to FIG. 6B The configuration of the piston 128 is different. Only FIG. 7A to FIG. 7B The difference between the piston 128 of FIG. 6 and the piston 128 of FIG. 7 is shown in FIG. FIG. 7A to FIG. 7B In the embodiment of, the first part 310 and the second part 314 are different components that are threadedly connected to each other. To this end, the first part 210 includes a recess 311a positioned at one end and a threaded hole 311b extending from the recess 311a at least partially through the first part 310. The recess 311a surrounds the threaded hole 311b. The second part 314 has a threaded protrusion 312 extending from it. The second part 314 is connected to the first part 310 via a threaded engagement therebetween. Specifically, the threaded protrusion 312 is configured to be matingly connected to the threaded hole 311b. After connection, the second part 314 is seated in the recess 34a of the first part 310. FIG. 7A to FIG. 7B In the embodiment of the present invention, the first portion 310 of the piston 128 is constructed of a first material (e.g., aluminum), while the second portion 314 of the piston 128, the driver blade 132, and the pin 322 are constructed of a second material (e.g., steel). In other embodiments, both the first and second portions 310, 314 of the piston 128, the driver blade 132, and the pin 322 are constructed of the same second material (e.g., steel). In the illustrated embodiment, the central longitudinal axis extending through the threaded hole 311b is aligned with the central longitudinal axis of the first portion 310. In addition, the central longitudinal axis extending through the second portion 314 (which extends through the center of the slot 320) is aligned with the central longitudinal axis of the first portion 310 and the central longitudinal axis of the threaded hole 311b. In other embodiments, the central longitudinal axis extending through the threaded hole 311b may be offset relative to the central longitudinal axis of the first portion 310. In this case, the central longitudinal axis extending through the second portion 314 may also be offset relative to the central longitudinal axis of the first portion 310, so that the central longitudinal axis of the first portion 310 does not extend through the center of the slot 320.

[0037] In the illustrated embodiment, the piston 128 comprises a smaller diameter than pistons in other gas spring powered fastener drivers. The first portion 310 defines a maximum diameter D4 of the piston 128. In the illustrated embodiment, the diameter D4' ( Figure 7B ) is typically smaller than the diameter of the first portion 310. Due to the reduced size of the piston 128 (e.g., the first portion 310 thereof), the pressure of the compressed gas required to move the piston 128 and the driver blade 132 from the TDC position to the BDC position with sufficient force to fully drive the nail into the workpiece increases.

[0038] The second groove 318b of the first part 310 receives therein a sealing ring 326b, which seals the piston 128 relative to the inner cylinder 124. As shown, the sealing ring 326b is configured as a "quad ring". When configured as a quad ring, the sealing ring 326b includes a cross-sectional shape with four protrusions 326b', wherein adjacent protrusions 326b' are equidistantly spaced. In other embodiments, the sealing ring 326b can be an O-ring with a conventional cylindrical cross section. Whether using a quad ring or an O-ring, the sealing ring 326b is made of an elastomer or a plastic material having a material component for reducing friction with the inner wall during sliding contact with the inner wall of the inner cylinder 124. Each of the O-ring and the quad ring preferably has a thickness of 2.5mm to 5.6mm. Additionally, each of the first groove 318a and the third groove 318c also includes a guide ring 326a, 326c. In the illustrated embodiment, the guide rings 326a, 326c contact the inner surface of the inner cylinder. The guide rings 326a, 326c create a low friction contact and prevent wear between the piston and the inner surface of the inner cylinder. In the illustrated embodiment, the guide rings 326a, 326c are formed of polyoxymethylene (POM) plastic, but other materials may be used in other embodiments.

[0039] In the illustrated embodiment, the maximum diameter D4 measures approximately 25.3 mm (eg, 1.0 inch). Thus, the total surface area of ​​the piston 128 is approximately 502.7 mm 2 In other embodiments, the maximum diameter D4 of the piston 128 is less than about 50 mm, and the total surface area exposed to the compressed gas in the inner cylinder 124 is less than about 1965 mm 2 In other embodiments, the maximum diameter D4 of the piston 128 is less than about 37 mm, and the total surface area exposed to the compressed gas in the inner cylinder 124 is less than about 1075 mm 2Additionally, the pressure of the compressed gas required to move the piston 128 and the driver blade 132 from the TDC position to the BDC position with sufficient force to fully drive the nail into the workpiece is at least about 123 psi, which is greater than the pressure of a conventional gas spring driver when the piston is in the TDC position. In other embodiments, the pressure of the compressed gas required to move the piston 128 and the driver blade 132 from the TDC position to the BDC position with sufficient force to fully drive the nail into the workpiece is at least about 331 psi, which is greater than the pressure of a conventional gas spring driver when the piston is in the TDC position. In other embodiments, the pressure of the compressed gas required to move the piston 128 and the driver blade 132 from the TDC position to the BDC position with sufficient force to fully drive the nail into the workpiece can be about 120 psi to about 335 psi, which is greater than the pressure of a conventional gas spring driver when the piston is in the TDC position. Despite the reduced overall size of the driver 10, the non-concentric configuration of the reservoir cylinder 120 and the inner cylinder 124 and the smaller diameter D4 of the piston 128 enable sufficient pressure to drive the piston 128. Additionally, the thickness of the sealing ring 326b and the use of the guide rings 326a, 326c help reduce penetration caused by increased internal pressure. That is, the thickness of the sealing ring 326b and the guide rings 326a, 326c increases the compression of the seal to about 10%, which is at least twice that of the seals used in conventional drives.

[0040] refer to Figures 4 to 5 , the actuator 10 includes a buffer 330 positioned below the piston 128 to stop the piston 128 in the driven position or BDC position ( Figure 5 ) and absorbs the impact energy from the piston 128. The buffer 330 is configured to evenly distribute the impact force of the piston 128 across the buffer 330 when the piston 128 is rapidly decelerated upon reaching the BDC position. The buffer 330 may be formed of any suitable elastic material (e.g., rubber).

[0041] Figures 8 to 9 Details of the driver blade 132 are shown. As shown, the driver blade 132 includes a first end 338 and a second end 342 opposite the first end 338. The first end 338 is a free end and the second end 342 is coupled to the piston 128. The second end 342 includes a hole 346 that is sized and shaped to receive the pin 322 therethrough to attach the driver blade 132 to the piston 128. The driver blade 132 further includes a driver tip at the first end 338 of the driver blade 132. The driver tip is configured to strike and drive a fastener.

[0042] The driver blade 132 includes a plurality of axially spaced drive teeth 350 on a first side of the driver blade 132 between a first end 338 and a second end 342 of the driver blade 132. As described in more detail below, the drive teeth 350 are configured to engage the lifter 182 of the lift mechanism 140 to move the driver blade 132 to a TDC (i.e., retracted or ready) position. As will be discussed in more detail below, the lifter 182 is configured to rotate twice to lift the driver blade 132 from the BDC position to the TDC position. Thus, the drive teeth 335 include a first set of drive teeth 350a' to 350d' that engage the lifter 182 during a first rotation and a second set of drive teeth 350e" to 350h". that engage the lifter 182 during a second rotation. In the illustrated embodiment, the distances between adjacent drive teeth 350 are not the same. In other words, the distances between adjacent drive teeth 350 are variable. Moreover, in the illustrated embodiment, the distances (e.g., DT4, DT6) between some of the adjacent drive teeth (e.g., the distance between drive teeth 350c' and 350d' and the distance between 350g" and 350h") may be the same, but different from the distances between other adjacent drive teeth (e.g., the distance between drive teeth 350a' and 350b' and the distance between drive teeth 350e" and 350f"). Moreover, the distances (e.g., DT4) between adjacent drive teeth within the first group of drive teeth (e.g., the distance between drive teeth 350c' and 350d') may be the same as the distances (e.g., DT6) between adjacent drive teeth within the second group of drive teeth (e.g., the distance between drive teeth 350c' and 350d'). Further, in the illustrated embodiment, the distance (e.g., DT7) between adjacent teeth (e.g., 350d', 350e") ​​of the first group of drive teeth and the second group of drive teeth is smaller than the distance (e.g., DT4, DT6) between adjacent teeth within the first group of drive teeth and the second group of drive teeth. Finally, the distance DT7 between adjacent teeth (e.g., 350d', 350e") ​​of the first group of drive teeth and the second group of drive teeth is smaller than the distance DT1 to DT6 between adjacent teeth within each of the first group of drive teeth and the second group of drive teeth. The distances described herein are measured from the lowest end of each tooth to the lowest end of the adjacent tooth.

[0043] like Fig. 9As shown, the distances between adjacent drive teeth 350a' to 350d' within the first group are not the same. In other words, the distances between adjacent drive teeth 350a' to 350d' within the first group are variable. That is, the first group has a distance DT1 between the first drive tooth 350a' and the second drive tooth 350b', a distance DT2 between the second drive tooth 350b' and the third drive tooth 350c', and a distance DT3 between the third drive tooth 350c' and the fourth drive tooth 350d'. In the illustrated embodiment, the distance DT3 is different from the distances DT1 and DT2, and the distances DT1 and DT2 are the same. In other words, the distances DT1 and DT3 are different, and in the illustrated embodiment, the distance DT3 is greater than DT1. In the illustrated embodiment, the distance DT1 is measured to be approximately 8.5 mm, the distance DT2 is measured to be approximately 8.5 mm, and the distance DT3 is measured to be approximately 8.32 mm. In other embodiments, the distance DT1 may measure from about 6 mm to about 16 mm, the distance DT2 may measure from about 6 mm to about 16 mm, and the distance DT3 may measure from about 5 mm to about 13 mm. In other embodiments, the distances DT1, DT2, and DT3 may be different from each other. In other embodiments, the distance DT2 may be the same as DT3, and DT3 may be different from DT1. In other embodiments, the distances DT1, DT2, and DT3 may be the same.

[0044] Moreover, if Fig. 9 As shown, the distances between adjacent drive teeth 350e" to 350h" in the second group are not the same. In other words, the distances between adjacent drive teeth 350e" to 350h" in the second group are variable. That is, the second group has a distance DT4 between the first drive tooth 350e" and the second drive tooth 350f', a distance DT5 between the second drive tooth 350f" and the third drive tooth 350g", and a distance DT6 between the third drive tooth 350g" and the fourth drive tooth 350h". In the embodiment shown, the distance DT6 is different from the distances DT4 and DT5, and the distances DT4 and DT5 are the same. In other words, the distances DT4 and DT6 are different, and in the embodiment shown, the distance DT6 is greater than DT4. In the embodiment shown, the distance DT4 is measured In other embodiments, the distance DT4 may be measured from about 6 mm to about 16 mm, the distance DT5 may be measured from about 6 mm to about 16 mm, and the distance DT6 may be measured from about 5 mm to about 13 mm. In other embodiments, the distances DT4, DT5, and DT6 may be different from each other. In other embodiments, the distance DT5 may be the same as DT6, and DT6 may be different from DT4. In other embodiments, the distances DT4, DT5, and DT6 may be the same.

[0045] Additionally, a distance DT7 is provided between the first set of drive teeth 350a' to 350d' and the second set of drive teeth 350e" to 350h". That is, the distance DT7 is measured between the last drive tooth 350d' (e.g., the lowermost tooth) of the first group and the first drive tooth 350e" (e.g., the uppermost tooth) of the second group. In the illustrated embodiment, the distance DT7 is less than both the distance DT3 of the first group and the distance DT6 of the second group. Moreover, the distance DT7 is less than the distance DT4 of the second group. In the illustrated embodiment, the distance DT7 measures approximately 6.42 mm. In other embodiments, the distance DT7 can measure between approximately 5 mm and approximately 13 mm. The distance DT7 relative to the distances DT3, DT4, and DT6 as discussed above is necessary to achieve the reduced stroke length L1. Specifically, DT7 being less than all three distances DT3, DT4, and DT6 achieves a smaller diameter D5 of the drive pin 396 of the lifter 182, as will be discussed below. Conversely, if DT7 were greater than or equal to the distances DT3, DT4, and DT6, the diameter D5 of the lifter 182 would need to be larger, which in turn would increase the stroke length L1.

[0046] The driver blade 132 also includes a plurality of axially spaced locking tabs 354 on a second side of the driver blade 132 opposite the first side of the driver blade 132 and opposite the drive teeth 350, between the first end 338 and the second end 342 of the driver blade 132. As described in more detail below, the locking tabs 354 are configured to engage the latch 190 to hold the driver blade 132 in the TDC (i.e., retracted or ready) position before being released to the BDC (i.e., extended or driven) position.

[0047] Lifter 182 Figure 3A and Figure 3B The lifter 182 has a central hub 384 having an upper disc 388 and a lower disc 392 extending radially outward from the central hub 384 and axially spaced from each other. Each of the upper disc 388 and the lower disc 392 is formed with a peripheral recess 394 ( Fig.10). When the fastener driver 10 is fired and the driver blade 132 moves to the BDC (i.e., extended or driven) position into the nosepiece 54 to force the fastener out of it and into the workpiece, the peripheral recess 394 provides clearance for the driver blade 132. The lift mechanism 140 includes a plurality of drive pins 396 mounted within the lifter 182. Each drive pin 396 is coupled to both the upper disc 388 and the lower disc 392. The drive pin 396 includes a drive pin 396' configured to engage a drive tooth 350h" (e.g., the lowest tooth) that is closest to the first end 338 of the driver blade 132 in the ready position. In this case, the lowest drive tooth 350h" is also the fourth drive tooth 350h" in the first group of drive teeth. The drive pin 396 also includes a drive pin 396' configured to engage a first drive tooth 350a' in the first group (which is also the tooth (e.g., the highest tooth) that is closest to the second end 342 of the driver blade 132) in the BDC position when the lifter 182 begins a first rotation. The drive pin 396' is also configured to engage a first drive tooth 350e" in the second group of drive teeth when the lifter 182 begins a second rotation. Fig.10 , the drive pin 396 is oriented along an imaginary circle that is coaxial with the axis of rotation of the lifter 182 and has a fifth diameter D5, which in this case is about 18.75 mm. In other embodiments, the fifth diameter D5 can be in the range of about 16 mm to about 60 mm. In other embodiments, the fifth diameter D5 can be in the range of about 16 mm to about 30 mm. Due to the reduced stroke length L1, the diameter D5 of the lifter 182 is also reduced relative to the lifter of a conventional driver. In other embodiments, the drive pin 396' can be oriented on a first imaginary circle that is coaxial with the axis of rotation, while the other drive pins 396, 396" can be oriented on a different second imaginary circle that is coaxial with the axis of rotation and larger than the first imaginary circle.

[0048] As described in further detail below, the transmission 174 raises the driver blade 132 from the driven position to the ready position. Figure 3B , the transmission 174 provides torque from the motor 178 to the lifter 182. The transmission 174 includes an input shaft 410 and a first output shaft 414 extending along a first output shaft axis 414'. The first output shaft rotates a drive gear 418, which is operable to drive a driven gear 422. In the illustrated embodiment, the gears 418, 422 are meshing spur gears. A second output shaft 426 extends from the driven gear 422 ( Figure 5). The second output shaft 426 is operable to drive the lifter 182, which in turn is operable to move the driver blade 132 from the driven position to the ready position, as explained in more detail below. In the illustrated embodiment, the second output shaft 426 is arranged along a second output shaft axis 426' ( Figure 3B ) extends from the first output shaft axis 426'. The second output shaft axis 426' is the axis of rotation of the lifter 182. As shown, the second output shaft axis 426' is laterally offset from the drive axis 150. In the illustrated embodiment, the first output shaft axis 414' intersects the drive axis 150. In other embodiments, the first output shaft axis 414' may be positioned between the drive axis 150 and the second output shaft axis 426'. Although not shown, the transmission 174 is configured as a planetary transmission having a first planetary gear stage (not shown) and a second planetary gear stage (not shown). In alternative embodiments, the transmission may be a single-stage planetary transmission, or a multi-stage planetary transmission including any number of planetary gear stages. Moreover, the drive 10 further includes a one-way clutch mechanism (not shown) incorporated in the transmission 174. The one-way clutch mechanism allows rotation in a single (i.e., first) direction of rotation (i.e., in Figure 5 The torque is transmitted to the first output shaft 414 of the transmission 174 in the reference frame of , while preventing the motor 178 from responding to the torque in the opposite second rotational direction (e.g., in the reference frame of ). Figure 3B The one-way clutch mechanism is coupled to the first planetary gear stage of the transmission 174. In an alternative embodiment, for example, the one-way clutch mechanism may be coupled to the second planetary gear stage.

[0049] Although not shown, in some embodiments, the driver 10 further includes a torque limiting electronic clutch mechanism that limits the amount of torque transmitted to the first output shaft 414 and the lifter 182 .

[0050] refer to Figure 5 As described above, in some embodiments, the latch 190 selectively holds the driver blade 132 in the ready position, and a solenoid (not shown) is used to release the latch 190 from the driver blade 132. In other words, the latch assembly can move between a latched state, in which the driver blade 132 is held in the ready position against a biasing force (i.e., the pressurized gas in the reservoir cylinder 120), and a released state, in which the driver blade 132 is allowed to be driven from the ready position to the driven position by the biasing force. The latch 190 is rotated about a latch axis 430 (shown in FIG. 3 ) by a shaft (not shown) on the base portion 80, and as shown in FIG. Figure 5The latch axis 430 is parallel to the second output shaft axis 426 ′ of the second output shaft 426 .

[0051] refer to Figure 5 , the latch assembly is positioned adjacent to the side of the driver blade 132 opposite the lift assembly 170. In addition, the latch 190 is configured to rotate about an axis relative to the latch axis 430 via actuation of the solenoid, such that a tip of the latch 190 is configured to engage a stop surface (not shown) of the nose assembly 50 when the latch 190 moves toward the driver blade 132.

[0052] The latch 190 can be moved between a latched position (consistent with the latched state of the latch assembly) and a released position (consistent with the released state of the latch assembly), in which the latch 190 engages with one of the locking protrusions 354 on the driver blade 132 to resist the biasing force of the compressed gas and hold the driver blade 132 in the ready position, and in which the driver blade 132 is allowed to be driven from the ready position to the driven position by the biasing force of the compressed gas. In addition, when the solenoid is de-energized, the stop surface against which the latch 190 can engage limits the movement of the latch 190 when returning to the latched state. Figure 5 The degree of rotation about the latch axis 430 in the counterclockwise direction in the reference frame.

[0053] The operation of the firing cycle of the driver 10 is described in detail below. Prior to initiating the firing cycle, the driver blade 132 is held in the ready position with the piston 128 near top dead center within the inner cylinder 124. More specifically, the drive pin 396' on the lifter 182 engages the lowermost drive tooth 350h" ("drive teeth 350") of the axially spaced teeth (drive teeth 350) on the driver blade 132. Figure 5 ) is engaged, and the rotational position of the lifter 182 is maintained by the one-way clutch mechanism. In other words, as previously described, when the lifter 182 maintains the driver blade 132 in the ready position, the one-way clutch mechanism prevents the motor 178 from being driven in reverse by the transmission 174. In addition, in the ready position of the driver blade 132, the latch 190 may engage with the lowermost locking protrusion 354' on the driver blade 132, but does not necessarily contact the driver blade 132 and play a role in maintaining the driver blade in the ready position. More specifically, at this time, the latch 190 provides a safety function to prevent the driver blade 132 from accidentally firing when the one-way clutch mechanism fails.

[0054] When the trigger 186 is pulled to initiate the firing cycle, the solenoid is energized to pivot the latch 190 from the latched position to the released position, thereby repositioning the latch 190 so that it can no longer engage the locking projection 354 (thus defining the released state of the latch assembly). At about the same time, the motor 178 is activated to cause the first output shaft 414 and the lifter 182 to move along the Figure 5 's reference frame, thereby slightly shifting the driver blade 132 upward beyond the ready position before the lowest drive tooth 350h' on the driver blade 132 slides off the drive pin 396' (at the TDC position of the driver blade 132). Thereafter, the piston 128 and the driver blade 132 are pushed downward toward the driven position by the expanding gas in the inner cylinder 124 and the storage chamber cylinder 120. When the driver blade 132 shifts toward the driven position, the motor 178 remains activated to cause the lifter 182 to continue to rotate counterclockwise.

[0055] refer to Figure 5 In some embodiments, as the fastener is driven into the workpiece, the piston 128 strikes the bumper 330 to rapidly decelerate the piston 128 and the driver blade 132 , ultimately stopping the piston 128 in the driven position or bottom dead center position.

[0056] Shortly after the driver blade 132 reaches the driven position, the lifter 182 begins a first rotation. Specifically, the drive pin 396" on the lifter 182 engages the first drive tooth 350a' in the first set of drive teeth 350 on the driver blade 132, and as the drive pin 396 engages subsequent drive teeth 350b', 350c', 350d' in the first set, continued counterclockwise rotation of the lifter 182 raises the driver blade 132 and the piston 128 toward the ready position. Shortly thereafter and before the lifter 182 completes a full rotation, the solenoid is de-energized, allowing the latch 190 to reengage the driver blade 132 and ratchet around the locking protrusion 354 (thereby defining the latched state of the latch assembly) as the driver blade 132 continues to shift upward.

[0057] After one full rotation of the lifter 182 occurs, the latch 190 holds the driver blade 132 in an intermediate position between the driven position and the ready position while the lifter 182 continues (in Figure 5's reference frame) counterclockwise rotation until the drive pin 396' reengages another of the lifting drive teeth 350 on the driver blade 132. Specifically, as the lifter 182 begins its second rotation, the drive pin 396' on the lifter 182 engages the first drive tooth 350e' of the second set of drive teeth 350 on the driver blade 132, and as the drive pin 396 engages subsequent drive teeth 350f', 350g', 350h' in the first set, continued counterclockwise rotation of the lifter 182 raises the driver blade 132 and the piston 128 toward the ready position. After the second complete rotation, the driver blade 132 is again in the ready position such that the drive pin 396' is again positioned adjacent to and engaged with the lowermost drive tooth 350h'.

[0058] As described above, the reduced stroke length L1 of the driver blade 132 achieves a reduced size of the lifter 182. That is, the drive pin 396 can be oriented on an imaginary circle with a reduced diameter D5. The reduced size of the lifter 182 allows more operations of the motor 178 to be more efficient. That is, the reduced size of the lifter 182 reduces the required motor torque and gear train load while maintaining the effectiveness of the fastener driver 10. For example, in the illustrated embodiment, the motor torque from the BDC position to the TDC position is 0.1 Newton meter (Nm) to 0.2Nm. Additionally, the drive cycle of the fastener 10 is also shorter. The driver blade 132 is configured to reciprocate between the TDC position and the BDC position at a frequency of at least about 2.5 hertz (Hz). In other embodiments, the driver blade 132 is configured to reciprocate between the TDC position and the BDC position at a frequency of about 1 Hz to 8 Hz. In other embodiments, the driver blade 132 is configured to reciprocate between the TDC position and the BDC position at a frequency of about 1 Hz to 4 Hz. Moreover, when reciprocating at a frequency of at least 2.5 Hz, the stroke length L1 of the piston 128 between the TDC position and the BDC position is 73 mm or less. Because the motor 178 is more efficient, the motor 178 requires less energy per cycle. This means that more fasteners can be driven before the battery pack is exhausted. For example, in the embodiment shown, the driver 10 can drive 725 fasteners using a single battery pack. The drive unit is configured to maintain continuous activation for more than about 290 seconds when the driver blade is reciprocated at a frequency of at least about 2.5 Hz. The drive unit is configured to maintain continuous activation for about 250 seconds to about 350 seconds when the driver blade is reciprocated at a frequency of at least about 2.5 Hz.

[0059] Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention described.

[0060] Various features of the invention are set forth in the appended claims.

Claims

1. A powered fastener driver, characterized in that: The powered fastener driver includes: case; an inner cylinder, the inner cylinder being located within the housing; a piston movable within the inner cylinder from a top dead center position to a driven position or a bottom dead center position, the piston having a stroke length measuring 73 mm or less between the top dead center position and the bottom dead center position; a driver blade attached to the piston for moving with the piston along the drive axis from the top dead center position toward the bottom dead center position to drive a fastener into a workpiece, the driver blade comprising: The first end, a second end, the second end being opposite the first end and attached to the piston, a first set of drive teeth extending from a first side of the driver blade between the first end and the second end, adjacent drive teeth within the first set being separated from one another by a first distance, and a second set of drive teeth extending from the first side of the driver blade, adjacent drive teeth within the second set being separated from one another by a second distance equal to the first distance, wherein adjacent drive teeth in the first group and the second group are respectively separated from each other by a third distance that is less than each of the first distance and the second distance; a lifter operable to move the piston and the driver blade from the bottom dead center position toward the top dead center position, the lifter engaging the first set of drive teeth during a first rotation to move the piston and the driver blade from the bottom dead center position to an intermediate position between the bottom dead center position and the top dead center position, and engaging the second set of drive teeth during a second rotation to move the piston from the intermediate position toward the top dead center position; and A drive unit is operably coupled to the lifter to provide torque to the lifter, thereby rotating the lifter.

2. The powered fastener driver of claim 1, wherein: The powered fastener driver further includes a reservoir cylinder positioned within the housing and including pressurized gas in fluid communication with the inner cylinder, wherein the reservoir cylinder includes a first end and a second end opposite the first end, and wherein the second end of the reservoir cylinder is not concentric with the first end of the reservoir cylinder.

3. The powered fastener driver of claim 2, wherein: The inner cylinder includes a first end and a second end opposite the first end, and wherein the first end of the inner cylinder is coupled to the first end of the reservoir cylinder.

4. The powered fastener driver of claim 3, wherein: The reservoir cylinder defines a volume, wherein a first portion of the volume is defined on a first side of the drive axis and a second portion of the volume is defined on a second side of the drive axis, and wherein the second portion is larger than the first portion.

5. The powered fastener driver of claim 4, wherein: The housing defines a cylinder support portion, a drive unit support portion, and a handle portion spaced apart from the drive unit support portion, and wherein the second portion of the volume is at least partially positioned between the drive unit support portion and the handle portion.

6. The powered fastener driver of claim 1, wherein: The piston comprises a circumferential groove, wherein a sealing ring is positioned within the circumferential groove, and wherein the sealing ring has a thickness of 2.5 mm to 5.5 mm.

7. The powered fastener driver of claim 6, wherein: The sealing ring is a star-shaped ring.

8. The powered fastener driver of claim 1, wherein: The distance between the lowest tooth and the adjacent tooth in the first set of drive teeth defines the first distance, and the distance between the lowest tooth and the adjacent tooth in the second set of drive teeth defines the second distance.

9. The powered fastener driver of claim 1, wherein: In response to continued activation of the drive unit to rotate the lifter, the driver blade is configured to reciprocate between the top dead center position and the bottom dead center position at a frequency of at least 2.5 Hertz.

10. The powered fastener driver of claim 9, wherein: The drive unit is configured to remain continuously activated while reciprocating the driver blade at a frequency of at least 2.5 Hz for more than 290 seconds.

11. A powered fastener driver, characterized in that: The powered fastener driver includes: case; an inner cylinder, the inner cylinder being located within the housing; a piston movable within the inner cylinder from a top dead center position to a driven position or a bottom dead center position, the piston having a diameter of less than 50 mm and a stroke length of the piston measuring 60 mm and 74 mm between the top dead center position and the bottom dead center position; a driver blade attached to the piston for moving with the piston along the drive axis from the top dead center position toward the bottom dead center position to drive a fastener into a workpiece; a lifter operable to move the piston and the driver blade from the bottom dead center position toward the top dead center position, the lifter comprising a plurality of drive pins configured to engage the driver blade, the drive pins being positioned along an imaginary circle coaxial with the axis of rotation of the lifter and having a diameter less than 60 mm; and A drive unit is operably coupled to the lifter to provide torque to the lifter, thereby rotating the lifter.

12. The powered fastener driver of claim 11, wherein: The powered fastener driver further includes a pressurized gas in fluid communication with the inner cylinder, wherein a pressure of the pressurized gas acting on the piston at the top dead center position is at least 123 psi.

13. The powered fastener driver of claim 11, wherein: The powered fastener driver further includes a reservoir cylinder positioned within the housing and including pressurized gas in fluid communication with the inner cylinder, wherein the reservoir cylinder includes a first end and a second end opposite the first end, and wherein the second end of the reservoir cylinder is not concentric with the first end of the reservoir cylinder.

14. The powered fastener driver of claim 13, wherein: The inner cylinder includes a first end and a second end opposite the first end, and wherein the first end of the inner cylinder is coupled to the first end of the reservoir cylinder.

15. The powered fastener driver of claim 14, wherein: The reservoir cylinder defines a volume, wherein a first portion of the volume is defined on a first side of the drive axis and a second portion of the volume is defined on a second side of the drive axis, and wherein the second portion is larger than the first portion.

16. The powered fastener driver of claim 15, wherein: The housing defines a cylinder support portion, a drive unit housing portion, and a handle portion spaced apart from the drive unit housing portion, and wherein the second portion of the volume is at least partially positioned between the drive unit housing portion and the handle portion.

17. A powered fastener driver, characterized in that: The powered fastener driver includes: case; an inner cylinder, the inner cylinder being located within the housing; a piston movable within the inner cylinder from a top dead center position to a driven position or a bottom dead center position, the piston having a stroke length measuring 73 mm or less between the top dead center position and the bottom dead center position; a driver blade attached to the piston for moving with the piston along the drive axis from the top dead center position toward the bottom dead center position to drive a fastener into a workpiece, the driver blade comprising: The first end, a second end, the second end being opposite the first end and attached to the piston, a first set of drive teeth extending from a first side of the driver blade between the first end and the second end, adjacent drive teeth within the first set being separated from one another by a first distance, and a second set of drive teeth extending from the first side of the driver blade, adjacent drive teeth within the second set being separated from one another by a second distance equal to the first distance, wherein adjacent drive teeth in the first group and the second group are respectively separated from each other by a third distance that is less than each of the first distance and the second distance; a lifter operable to move the piston and the driver blade from the bottom dead center position toward the top dead center position, the lifter engaging the first set of drive teeth during a first rotation to move the piston and the driver blade from the bottom dead center position to an intermediate position between the bottom dead center position and the top dead center position, and engaging the second set of drive teeth during a second rotation to move the piston from the intermediate position toward the top dead center position, the lifter comprising a body and a plurality of drive pins supported on the body, wherein each of the drive pins is configured to engage one of the drive teeth in the first set and one of the drive teeth in the second set, and wherein the drive pins are positioned on the body along an imaginary circle coaxial with an axis of rotation of the lifter and having a diameter less than 60 mm; and A drive unit is operably coupled to the lifter to provide torque to the lifter, thereby rotating the lifter.

18. The powered fastener driver of claim 17, wherein: The powered fastener driver further includes a pressurized gas in fluid communication with the inner cylinder, wherein a pressure of the pressurized gas acting on the piston at the top dead center position is at least 123 psi.

19. The powered fastener driver of claim 18, wherein: The powered fastener driver further includes a reservoir cylinder positioned within the housing and including pressurized gas in fluid communication with the inner cylinder, wherein the reservoir cylinder includes a first end and a second end opposite the first end, and wherein the second end of the reservoir cylinder is not concentric with the first end of the reservoir cylinder.

20. The powered fastener driver of claim 19, wherein: The reservoir cylinder defines a volume, wherein a first portion of the volume is defined on a first side of the drive axis and a second portion of the volume is defined on a second side of the drive axis, and wherein the second portion is larger than the first portion, and The housing defines a cylinder support portion, a drive unit housing portion, and a handle portion spaced apart from the drive unit housing portion, and wherein the second portion of the volume is at least partially positioned between the drive unit housing portion and the handle portion.

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