CN118003289A

CN118003289A - Fastener delivery mechanism for fastener driver

Info

Publication number: CN118003289A
Application number: CN202311473364.7A
Authority: CN
Inventors: S·A·萨瑟兰; C·A·劳夫; E·L·沃森; E·A·波默罗伊
Original assignee: Techtronic Cordless GP
Current assignee: Techtronic Cordless GP
Priority date: 2022-11-09
Filing date: 2023-11-07
Publication date: 2024-05-10

Abstract

A powered fastener driver comprising: a housing; a nose piece extending from the housing; a driver blade movable within the nose piece between a Top Dead Center (TDC) position and a Bottom Dead Center (BDC) position; a piston coupled to the driver blade to move therewith; an actuator cylinder within which the piston is movable and which is in fluid communication with the pressurized gas acting on the piston; a magazine coupled to the nose piece, in which a chain type fastener can be received; a fastener delivery mechanism for loading individual fasteners from the magazine into the nosepiece; and a lifter assembly, the lifter assembly comprising: a lifter housing; a drive shaft rotatably disposed within the elevator housing; a lifter sprocket disposed on the drive shaft for moving the driver blade from the BDC position toward the TDC position; and a cam rotatable in response to rotation of the drive shaft to actuate the fastener delivery mechanism.

Description

Fastener delivery mechanism for fastener driver

Cross Reference to Related Applications

The present application claims priority from U.S. provisional patent application No. 63/501,016, filed on day 5 and 9 of 2023, U.S. provisional patent application No. 63/383,178, filed on day 11 and 10 of 2022, and U.S. provisional patent application No. 63/383,027, filed on day 11 and 9 of 2022, each of which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates to fastener drivers, and more particularly to fastener delivery mechanisms for fastener drivers.

Background

Powered fastener drivers are used to drive fasteners (e.g., nails, tacks, staples, etc.) into workpieces. Such fastener drivers typically include a magazine in which fasteners are stored and a pusher mechanism for individually delivering fasteners from the magazine to a fastener driving channel, wherein the fasteners are impacted by a driver blade during a fastener driving operation.

Disclosure of Invention

In one aspect, the present disclosure provides a powered fastener driver comprising: a housing; a nose piece extending from the housing; a driver blade movable within the nose piece between a Top Dead Center (TDC) position and a Bottom Dead Center (BDC) position; a piston coupled to the driver blade to move therewith; an actuator cylinder within which the piston is movable and which is in fluid communication with the pressurized gas acting on the piston; a magazine coupled to the nose piece, in which a chain type fastener can be received; a fastener delivery mechanism for loading individual fasteners from the magazine into the nosepiece; and a lifter assembly, the lifter assembly comprising: a lifter housing; a drive shaft rotatably disposed within the elevator housing; a lifter sprocket disposed on the drive shaft for moving the driver blade from the BDC position toward the TDC position; and a cam rotatable in response to rotation of the drive shaft to actuate the fastener delivery mechanism.

The fastener delivery mechanism can include a spring-loaded pusher support post slidably disposed within a bracket at least partially disposed on the nose piece.

The fastener delivery mechanism may further include a pusher disposed on an end of the pusher support post.

The pusher is movable along a set of chain fasteners to load individual fasteners from the set of chain fasteners into the nose piece one at a time.

The fastener delivery mechanism may further include a rocker arm having a proximal end that follows the cam.

The rocker arm may include a forked distal end that fits around and engages a transverse post on the propeller support post.

As the cam rotates the rocker arm, the fork-shaped distal end may move the pusher support post into the cradle and move the pusher along the set of chain-type fasteners to engage the next fastener from the set of chain-type fasteners.

In response to continued rotation of the cam, the distal end of the rocker arm can move past the cam and the pusher support post is biased to a ready position to move the pusher toward the nosepiece to deliver the next fastener into the nosepiece.

In another aspect, the present disclosure provides a powered fastener driver comprising: a housing; a nose piece extending from the housing; a driver blade movable along a fastener delivery axis within the nose piece between a Top Dead Center (TDC) position and a Bottom Dead Center (BDC) position; a piston coupled to the driver blade to move therewith; an actuator cylinder within which the piston is movable and which is in fluid communication with the pressurized gas acting on the piston; a magazine coupled to the nose piece, in which a chain type fastener can be received; a lifter assembly for moving the driver blade from the BDC position toward the TDC position, the lifter assembly including a drive shaft; and a fastener delivery mechanism configured to load individual fasteners from the magazine into the nosepiece, the fastener delivery mechanism comprising: a cam rotatable in response to rotation of the drive shaft to actuate the fastener delivery mechanism; and a rocker arm having a rounded proximal end following the cam.

The rocker arm may further include a distal end, and the pusher support post engages the distal end of the rocker arm.

The fastener delivery mechanism may further comprise a pusher disposed on the pusher support post.

The pusher may be movable away from the nose piece when the rocker arm is driven by the cam.

The rocker arm is rotatable by the cam to move the pusher along the set of chain fasteners to engage a next fastener from the set of chain fasteners.

In response to continued rotation of the cam, the rocker arm may move past the cam and the pusher is biased toward the nosepiece to deliver the next fastener into the nosepiece.

In yet another aspect, the present disclosure provides a powered fastener driver comprising: a housing; a nose piece extending from the housing; a driver blade movable within the nose piece between a Top Dead Center (TDC) position and a Bottom Dead Center (BDC) position; a piston coupled to the driver blade to move therewith; an actuator cylinder within which the piston is movable and which is in fluid communication with the pressurized gas acting on the piston; a magazine coupled to the nose piece, in which a chain type fastener can be received; a riser assembly, the riser assembly comprising: a lifter housing; a drive shaft rotatably disposed within the elevator housing; a first lifter sprocket disposed on the drive shaft to move the driver blade from the BDC position toward the TDC position; and a fastener delivery mechanism configured to load individual fasteners from the magazine into the nosepiece, the fastener delivery mechanism comprising: a cam rotatable in response to rotation of the drive shaft to actuate the fastener delivery mechanism; a rocker arm driven by the cam; and a pusher movable by the rocker arm.

The pusher is movable along a set of chain type fasteners to load individual fasteners into the nose piece.

In response to continued rotation of the cam, the rocker arm moves past the cam and the pusher is biased toward the nose piece to deliver the next fastener into the nose piece.

Drawings

FIG. 1 is a perspective view of a gas spring powered fastener driver.

FIG. 2 is a first side plan view of the gas spring powered fastener driver of FIG. 1 with a portion of the housing removed.

FIG. 3 is a second side plan view of the gas spring powered fastener driver of FIG. 1 with the housing removed.

Fig. 4 is a top plan view of the gas spring powered fastener driver of fig. 1.

FIG. 5 is a cross-sectional view of the gas spring powered fastener driver of FIG. 1, taken along line 5-5 of FIG. 3.

FIG. 6 is a cross-sectional view of the gas spring powered fastener driver of FIG. 1, taken along line 6-6 of FIG. 4.

FIG. 7 is a perspective view of a lifter assembly for the gas spring powered fastener driver of FIG. 1.

Fig. 8 is a perspective view of a riser sprocket for the riser assembly of fig. 7.

Fig. 9 is a side plan view of the elevator sprocket of fig. 8.

Fig. 10 is a rear plan view of a pair of elevator sprockets for the elevator assembly of fig. 7.

Fig. 11 is a perspective view of an actuator for the elevator assembly of fig. 7.

Fig. 12 is a top view of the pair of elevator sprockets of fig. 10 in a first position on either side of the actuator of fig. 11.

Fig. 13 is a top view of the pair of elevator sprockets of fig. 10 in a second position on either side of the actuator of fig. 11.

Fig. 14 is a plan view of a fastener delivery mechanism for the gas spring powered fastener driver of fig. 1.

Fig. 15 is another plan view of the fastener delivery mechanism of fig. 14.

Fig. 16 is yet another plan view of the fastener delivery mechanism of fig. 14.

Fig. 17 is yet another plan view of the fastener delivery mechanism of fig. 14.

Fig. 18 is yet another plan view of the fastener delivery mechanism of fig. 14.

FIG. 19 is a perspective view of a safety latch assembly for the gas spring powered fastener driver of FIG. 1.

Fig. 20 is another perspective view of the safety latch assembly of fig. 19.

Fig. 21 is yet another perspective view of the safety latch assembly of fig. 19.

FIG. 22 is a perspective view of another elevator sprocket for the gas spring powered fastener driver of FIG. 1.

Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure 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 disclosure 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

Fig. 1-6 illustrate an embodiment of a gas spring powered fastener driver 100. The fastener driver 100 includes a housing 102 having a first housing shell 104 and a second housing shell 106 joined. The housing 102 includes a head portion 108 having a handle portion 110 and a drive unit housing portion 112 attached thereto. The housing 102 also includes a battery receptacle portion 114 extending from the handle portion 110 that is sized and shaped to receive a removable battery pack 116 therein.

Fastener driver 100 further includes a fastener delivery portion 120 extending along drive unit housing portion 112 from a front end piece 122 to a magazine receptacle portion 124 adjacent drive unit housing portion 112. The cassette receptacle portion 124 is generally cylindrical and is sized and shaped to receive a coiled arrangement of fasteners therein. A cassette cover 126 is rotatably disposed on the housing 102 and provides access to a cassette 128 that is removably disposed within the cassette receptacle portion 124. The cassette 128 is a can-type cassette containing a coiled arrangement of chain-type staple strips. During operation of the fastener driver 100, individual fasteners are sequentially loaded from the magazine 128 to the nosepiece 122 via the fastener delivery portion 120.

As shown, the fastener driver 100 further includes a trigger 130 extending outwardly from the handle portion 110 of the housing 102. In a particular aspect, the housing 102 of the fastener driver 100 includes one or more vents 132 formed in the first housing shell 104 and/or the second housing shell 106 to provide airflow to and from the interior of the housing 102 to help cool the internal electrical components contained therein.

As illustrated in fig. 2-6, the fastener driver 100 also includes several internal components. Specifically, the fastener driver 100 includes a reservoir cylinder 140 disposed within the head portion 108 of the housing 102 and attached to a lifter housing 142. The elevator housing 142 includes an air-filled valve 144 in fluid communication with the interior of the reservoir cylinder 140. For example, the air-packing valve 144 may be configured as a Schrader valve, a Presta valve, a Dunlop valve, or some other similar valve. When connected to a source of compressed gas, the air-filled valve 144 enables the reservoir cylinder 140 to be filled with compressed gas or refilled with compressed gas in the event of any leakage.

The fastener driver 100 further includes a transmission 146 coupled to the elevator housing 142. A motor 148 is coupled to the transmission 146. The elevator assembly l50 is rotatably disposed in the elevator housing 142 adjacent the reservoir cylinder 140. During operation, motor 148 drives transmission 146, and transmission 146 rotates elevator assembly 150. Specifically, the transmission includes an output shaft 152 having a first bevel gear 154 disposed thereon. The elevator assembly 150 includes a drive shaft 156 having a second bevel gear 158 disposed thereon. The second bevel gear 158 is engaged with the first bevel gear 154 at a right angle such that the output shaft 152 of the transmission 146 is perpendicular to the drive shaft 156 of the elevator assembly 150. As best depicted in fig. 5, the drive shaft 156 extends along a drive shaft axis 157 that is perpendicular to a fastener delivery axis 159 of the fastener driver 100.

The fastener driver 100 includes a circuit board 160 that controls the operation of the fastener driver 100. The user interface 162 is connected to the circuit board 160 and extends through the housing 102 into an area near the handle portion 110. The user interface 162 provides user controls for the fastener driver 100 and includes, for example, an on/off switch, a mode selector button, a remaining charge indicator, a charge indicator, and other additional buttons and indicators as necessary. The circuit board 160, when engaged with the battery receptacle portion 114 and the removable battery pack 116, is electrically connected thereto and provides DC power to the motor 148, which is operatively coupled to the elevator assembly 150 through the transmission 146 and bevel gears 154, 158.

The reservoir cylinder 140 includes a driver cylinder 170 disposed therein. Further, a movable piston 172 is slidably disposed within the driver cylinder 170. The driver blade 174 is connected to the movable piston 172 and moves back and forth along the fastener delivery axis 159 between a Top Dead Center (TDC) (i.e., retracted or ready) position and a Bottom Dead Center (BDC) (i.e., extended or driven) position. As shown, the driver blade 174 includes a proximal end 176 and a distal end 178. The proximal end 176 of the driver blade 174 is connected to the movable piston 172 by a pin or other type of fastener. The driver blade 174 includes a plurality of first posts 180 extending from the driver blade 174 in a first direction perpendicular to the driver blade 174 and the fastener delivery axis 159, and a plurality of second posts 182 extending from the driver blade 174 in a second direction perpendicular to the driver blade 174 and the fastener delivery axis 159 opposite the first direction. The first and second posts 180, 182 may be fixed posts, in other words, they do not rotate with in place. Instead, the first and second posts 180, 182 may include outer bearings that rotate on the center post to help smooth the driver blade 174 as the elevator assembly 150 returns the driver blade to the TDC position.

In a particular aspect, as shown, there are five pairs of opposing (and laterally aligned) first and second posts 180, 182 equidistantly spaced along a lifter engagement section 184 defined along a portion of the length of the driver blade 174. It should be appreciated that the driver blade 174 may include more than five pairs of first and second posts 180, 182 or fewer than five pairs of first and second posts 180, 182, depending on the stroke length of the driver blade 174, the number of teeth on one or more lifter sprockets that are selectively engaged with the driver blade 174, or a combination thereof. As illustrated, when the piston 172 moves to a Top Dead Center (TDC) (i.e., retracted or ready) position within the driver cylinder 170 and the fastener driver 100 is ready to be fired, the distal end 178 of the driver blade 174 is positioned adjacent the nose piece 122. Upon firing, the distal end 178 of the driver blade 174 is moved into the nosepiece 122 to drive the fastener from within the nosepiece 122 and into the workpiece until the piston 172 reaches a Bottom Dead Center (BDC) (i.e., extended or driven) position within the driver cylinder 170.

The lifter assembly 150 selectively engages the driver blade 174 and the lifter assembly 150 is driven by the motor 148 to move the driver blade 174 from the post-firing position to the ready position and in the process move the piston 172 from the BDC position to the TDC position. As the elevator assembly 150 rotates, it also engages and actuates the fastener delivery mechanism 188 so that the fastener driver 100 loads fasteners to be driven into the workpiece into the nosepiece 122.

Fig. 7-13 show details of the elevator assembly 150 and its components. The elevator assembly 150 includes a drive shaft 156 having a second bevel gear 158 disposed thereon for rotation therewith. A first lifter sprocket 190 and a second lifter sprocket 192 are provided on the drive shaft 156. A first elevator sprocket 190 is disposed on the drive shaft 156 on a first side of the driver blade 174 or fastener delivery axis 159 and a second elevator sprocket 192 is disposed on the drive shaft 156 on a second side of the driver blade 174 or fastener delivery axis 159 opposite the first side. The elevator sprockets 190, 192 are keyed to the drive shaft 156 and rotate therewith. Further, the elevator sprockets 190, 192 are slidable along the drive shaft 156 as described below. An actuator 194 is disposed between the elevator sprockets 190, 192. The actuator 194 is stationary or fixed relative to the drive shaft 156 and does not rotate. A first spring 196 is compressively mounted adjacent the first elevator sprocket 190 and a second spring 198 is compressively mounted adjacent the second elevator sprocket 190. Springs 196, 198 bias the elevator sprockets 190, 192 inwardly along the drive shaft 156 toward the actuator 194.

Fig. 8-10 show details of the elevator sprockets 190, 192. As illustrated in fig. 8, the first elevator sprocket 190 includes a disc-shaped body 200 that includes a central hub 202 formed with a central aperture 204 that is keyed to the drive shaft 156 of the elevator assembly 150 to allow the first elevator sprocket 190 to rotate with the drive shaft 156. As shown, the first elevator sprocket 190 includes a first elevator tooth 210, a second elevator tooth 212, a third elevator tooth 214, a fourth elevator tooth 216, and a fifth elevator tooth 218 extending radially outward from the body 200 of the first elevator sprocket 190. As best shown in fig. 9, the first elevator tooth portion 210, the second elevator tooth portion 212, the fourth elevator tooth portion 216, and the fifth elevator tooth portion 218 are sized and shaped to be identical to one another. However, the third elevator tooth 214 is sized and shaped differently than the first elevator tooth 210, the second elevator tooth 212, the fourth elevator tooth 216, and the fifth elevator tooth 218.

Specifically, the tooth area A3 of the third lifter tooth 214, measured from the outer periphery of the disc-shaped body 200 (indicated by the dashed circle) to the outer wall of the third lifter tooth 214, is greater than the tooth area a of each of the other lifter teeth 210, 212, 216, 218. For example, the area A3 is greater than or equal to 1.100 times the area a. Further, area A3 is greater than or equal to 1.125 times area a, such as greater than or equal to 1.150 times area a, greater than or equal to 1.175 times area a, greater than or equal to 1.200 times area a, greater than or equal to 1.225 times area a, or greater than or equal to 1.250 times area a. In another aspect, the area A3 is less than or equal to 1.400 times the area a, such as less than or equal to 1.375 times the area a, less than or equal to 1.350 times the area a, less than or equal to 1.325 times the area a, less than or equal to 1.300 times the area a, or less than or equal to 1.275 times the area a. On the other hand, the area A3 is equal to 1.26 times the area a. It should be appreciated that the area A3 may be within a range between and include any of the maximum and minimum values of A3 described herein. It should further be appreciated that the increased size of the third elevator tooth 214 relative to the first, second, fourth and fifth elevator teeth 210, 212, 216, 218 allows for the placement of the magnet 219 within the third elevator tooth 214 of the second elevator sprocket 192. The magnet 219 is detected by a sensor (e.g., a hall sensor) to determine the position of the elevator assembly 150 during operation of the fastener driver 100. The magnet 219 is disposed within a bore 221 formed in the third elevator tooth 214 of the second elevator sprocket 192.

To further house the magnet 219 within the third elevator tooth 214 of the second elevator sprocket 192, the third elevator tooth 214 of the second elevator sprocket 192 is wider than the first elevator tooth 210, the second elevator tooth 212, the fourth elevator tooth 216, and the fifth elevator tooth 218 of the second elevator sprocket 192. In particular, the third elevator tooth 214 of the second elevator sprocket 192 has a first width W1, while the first elevator tooth 210, the second elevator tooth 212, the fourth elevator tooth 216, and the fifth elevator tooth 218 of the second elevator sprocket 192 have a second width W2. The first width W1 is greater than the second width W2. In particular aspects, the first width W1 is greater than or equal to 1.3 times the second width W2, such as greater than or equal to 1.4 times the second width W2, greater than or equal to 1.5 times the second width W2, or greater than or equal to 1.6 times the second width W2. In another aspect, the first width W1 is less than or equal to 2.0 times the second width W2, such as less than or equal to 1.9 times the second width W2, less than or equal to 1.8 times the second width W2, or less than or equal to 1.7 times the second width W2. It should be appreciated that the first width W1 may be within a range between and include any of the minimum and maximum values of W1 disclosed herein. It should further be appreciated that all of the elevator teeth 210, 212, 214, 216, 218 on the first elevator sprocket 190 have the same width, and that this width is substantially the same as the second width W2.

As further shown, the first elevator sprocket 190 includes an elevator outer ramp 220 adjacent the outer periphery of the disc-shaped body 200 and an elevator inner ramp 222 adjacent and contiguous with the central hub 202 of the first elevator sprocket 190.

Fig. 11 shows that actuator 194 includes an elongated body 230 formed with a central bore 232. The drive shaft 156 extends through the central bore 232 of the actuator 194. The actuator 194 maintains a stationary position between the first and second elevator sprockets 190 and 192 and does not rotate with the drive shaft 156 or translate on the drive shaft 156 relative to the first and second elevator sprockets 190 and 192. The actuator 194 includes an actuator first exterior ramp 240 and an actuator second exterior ramp 242 adjacent the outer periphery of the elongate body 230. The actuator first exterior ramp 240 and the actuator second exterior ramp 242 are aligned with one another and are located on opposite sides of the elongate body 230 of the actuator 194. The actuator 194 further includes an actuator first inner ramp 250 and an actuator second inner ramp 252 adjacent the central bore 232 of the elongate body 230. The actuator first inner ramp 250 and the actuator second inner ramp 252 are aligned with each other and are located on opposite sides of the elongate body 230 of the actuator 194. Moreover, the actuator outer ramps 240, 242 are diametrically opposed to the actuator inner ramps 250, 252.

During operation of the fastener driver 100, the lifter outer ramps 220 of the lifter sprockets 190, 192 engage the actuator outer ramps 240, 242 on the actuator 194 and the lifter inner ramps 222 of the lifter sprockets 190, 192 engage the actuator inner ramps 250, 252 on the actuator 194. As the elevator assembly 150 rotates, the teeth on the elevator sprockets 190, 192 engage the posts on the driver blade 174 to move the driver blade 174 to the TDC position. When the lifter ramps 220, 222 engage the actuator ramps 240, 242, 250, 252, the lifter sprockets 190, 192 are driven outwardly along the drive shaft 156 away from the actuator 194 to clear the driver blade 174 for subsequent engagement with the driver blade 174 to begin the lifting sequence. Springs 196, 198 then bias the elevator sprockets 190, 192 inwardly along the drive shaft 156 back toward the actuator 194. Thereby, the elevator sprockets 190, 192 move between a first position shown in fig. 12, in which the sprockets 190, 192 are spaced apart a first distance D1 and the driver blade 174 is engaged, and a second position shown in fig. 13, in which the sprockets 190, 192 are spaced apart a second distance D2 and clear the driver blade 174 for later re-engagement.

In a particular aspect, the second distance D2 is longer than the first distance D1. Specifically, D2 is greater than or equal to 1.50 times the first distance D1, such as greater than or equal to 1.75 times the first distance D1, greater than or equal to 2.00 times the first distance D1, or greater than or equal to 2.25 times the first distance D1. In another aspect, the second distance D2 is less than or equal to 3.50 times the first distance D1, such as less than or equal to 3.25 times the first distance D1, less than or equal to 3.00 times the first distance D1, less than or equal to 2.75 times the first distance D1, or less than or equal to 2.50 times the first distance D1. It should be appreciated that the second distance D2 may be within a range between and any of the minimum and maximum values of the second distance D2 described herein.

Fig. 14-18 show details of the fastener delivery mechanism 188 for the fastener driver 100. As shown, the fastener delivery mechanism 188 includes a spring loaded pusher support post 302 slidably disposed within a bracket 304 on the nosepiece 122, adjacent the cartridge receptacle portion 124, or extending partially into the cartridge receptacle portion 124. The pusher support column 302 includes a proximal end 308 and a distal end 310. The spring is compressively mounted adjacent the proximal end 308 of the pusher support column 302 to bias the pusher support column 302 toward the barrel 312 of the nose piece 122. The pusher 314 is mounted on the distal end 310 of the pusher support column 302 by a hinge pin 316. A torsion spring 318 is provided on the hinge pin 316 to bias the pusher 314 about the hinge pin 316 toward the nose piece 122.

The fastener delivery mechanism 188 further includes a rocker arm 320 rotatably mounted to the nose piece 122 or the lifter housing 142 (not shown in fig. 14-18 for clarity) by a post 322 (e.g., a threaded fastener, a hardened pin, or the like). The rocker arm 320 includes a rounded proximal end 324 and a forked distal end 326 that fits around a transverse post 328 on the distal end 310 of the pusher support post 302. As shown, the fastener delivery mechanism 188 includes a cam 332 disposed on the drive shaft 156 proximate the second elevator sprocket 192. The cam 332 selectively engages the rounded proximal end 324 of the rocker arm 320 such that the rounded proximal end 324 of the rocker arm 320 acts as a cam follower. As previously described, the elevator sprocket 192 is part of the elevator assembly 150 that rotates to return the driver blade 174 to a Top Dead Center (TDC) (i.e., retracted or ready) position during operation of the fastener driver 100 in which the fastener delivery mechanism 188 is installed.

When the driver blade 174 is fired or moved to a Bottom Dead Center (BDC) (i.e., extended or driven) position, the driver blade 174 moves into the barrel 312 of the nosepiece 122 to drive a fastener therefrom. Initially, when the driver blade 174 is fired, as depicted in fig. 15, the cam 332 does not engage the rounded proximal end 324 of the rocker arm 320. Thereafter, as the elevator sprocket 192 rotates counterclockwise, as seen in fig. 15-18, the cam 332 engages the rounded proximal end 324 of the rocker arm 320 and pushes the rounded proximal end 324 of the rocker arm 320 upward to rotate the rocker arm 320 clockwise about the post 322 and move the fork distal end 326 in a downward direction away from the nose piece 122. As the forked distal end 326 moves in a downward direction, the pusher 314 moves down the chain type fastener to engage the next ready fastener, as shown in fig. 17.

Before the elevator sprocket 192 stops at the end of the firing sequence and returns the driver blade 174 to the TDC (i.e., retracted or ready) position, the rounded proximal end 324 of the rocker arm 320 clears the cam 332 and moves past the cam 332 while the pusher support post 302 is biased to the ready position and moves the pusher 314 upward to deliver the next fastener into the barrel 312 of the nosepiece 122.

Fig. 19-20 depict a safety latch assembly 400, the safety latch assembly 400 including a latch 402 having a front end 403 and a driver blade support roller 404 disposed thereon. As described below, the driver blade support roller 404 contacts the driver blade 174 as the front end of the latch 402 disengages from the driver blade 174 and provides support for the driver blade 174 as it moves back and forth between the TDC and BDC positions to maintain proper alignment of the driver blade 174 within the powered fastener driver 100. A solenoid 406 having a plunger 408 is coupled to the latch 402 via a latch actuation rod 410. As shown in fig. 20, when the solenoid 406 is energized, the plunger 408 moves downward into the solenoid 406 to pivot the latch actuation lever 410 upward and, in turn, also pivot the front end 403 of the latch 402 to a position yielding one or more teeth 411 on the driver blade 174 such that the front end 403 of the latch 402 does not interfere with the movement of the driver blade 174 when it moves to the BDC position. When the solenoid 406 is de-energized, the first spring 412 returns the plunger 408 to the ready position and the second spring 414 returns the front end 403 of the latch 402 to the ready position (fig. 21) to engage the one or more teeth 411 to prevent movement of the driver blade 174 toward the BDC position.

Fig. 22 depicts another embodiment of a lifter sprocket 500 that can be paired with a similarly configured lifter sprocket and mounted within a lifter assembly 150. The elevator sprocket 500 includes a body 502 having a central hub 504 with a plurality of elevator teeth 506 extending radially outward from the central hub 504. The body 502 includes a central bore 508 that is keyed to the drive shaft 156 to prevent rotation of the elevator sprocket 500 on the drive shaft 156. The elevator sprocket 500 further includes an elevator outer chamfer 510 adjacent the outer periphery of the body 502 and an elevator inner chamfer 512 adjacent and spaced from the central hub 504. As described herein, the elevator ramps 510, 512 cooperate with the actuator ramps 240, 242, 250, 252 to urge a pair of opposing elevator sprockets 500 axially along the drive shaft 156 against the springs 196, 198, thereby allowing the elevator sprockets 500 to clear the driver blade 174 for later engagement with the driver blade 174 to begin the lifting sequence.

Although the disclosure 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 disclosure as described.

Various features of the invention are set forth in the appended claims. The terms "comprises" and "comprising," and variations thereof, when used in the specification and claims, are intended to include the specified features, steps or integers. These terms should not be interpreted to exclude the presence of other features, steps or components.

Claims

1. A powered fastener driver comprising:

a housing;

A nose piece extending from the housing;

a driver blade movable within the nose piece between a Top Dead Center (TDC) position and a Bottom Dead Center (BDC) position;

a piston coupled to the driver blade to move therewith;

an actuator cylinder within which the piston is movable and which is in fluid communication with the pressurized gas acting on the piston;

A magazine coupled to the nose piece, the chain type fastener being receivable in the magazine;

A fastener delivery mechanism for loading individual fasteners from the magazine into the nosepiece; and

A riser assembly, the riser assembly comprising:

A lifter housing;

A drive shaft rotatably disposed within the elevator housing;

A lifter sprocket disposed on the drive shaft for moving the driver blade from the BDC position toward the TDC position; and

A cam rotatable in response to rotation of the drive shaft to actuate the fastener delivery mechanism.

2. The powered fastener driver of claim 1 wherein the fastener delivery mechanism includes a spring-loaded driver support post slidably disposed within a bracket at least partially disposed on the nose piece.

3. The powered fastener driver of claim 2 wherein the fastener delivery mechanism further comprises a pusher disposed on an end of the pusher support post.

4. The powered fastener driver of claim 3 wherein the driver moves along a set of chain-type fasteners to load individual fasteners from the set of chain-type fasteners into the nose piece one at a time.

5. The powered fastener driver of claim 3 wherein the fastener delivery mechanism further comprises a rocker arm having a proximal end that follows the cam.

6. The powered fastener driver of claim 5 wherein the rocker arm includes a forked distal end that fits around and engages a transverse post on the pusher support post.

7. The powered fastener driver of claim 6 wherein the forked distal end moves the pusher support post into the cradle and moves the pusher along the set of chain-type fasteners to engage a next fastener from the set of chain-type fasteners as the cam rotates the rocker arm.

8. The powered fastener driver of claim 7 wherein in response to continued rotation of the cam, the distal end of the rocker arm moves past the cam and the driver support post is biased to a ready position to move the driver toward the nosepiece to deliver the next fastener into the nosepiece.

9.A powered fastener driver comprising:

a housing;

A nose piece extending from the housing;

a driver blade movable within the nosepiece along a fastener delivery axis between a Top Dead Center (TDC) position and a Bottom Dead Center (BDC) position;

a piston coupled to the driver blade to move therewith;

A lifter assembly for moving the driver blade from the BDC position toward the TDC position, the lifter assembly comprising:

A drive shaft; and

A cam rotatable in response to rotation of the drive shaft; and

A fastener delivery mechanism actuated by the cam to load individual fasteners from the magazine into the nosepiece, the fastener delivery mechanism including a rocker arm having a rounded proximal end following the cam.

10. The powered fastener driver of claim 9 wherein the rocker arm further comprises a distal end and the pusher support post engages the distal end of the rocker arm.

11. The powered fastener driver of claim 10 wherein the fastener delivery mechanism further comprises a pusher disposed on the pusher support post.

12. The powered fastener driver of claim 11 wherein the pusher moves away from the nose piece when the rocker arm is driven by the cam.

13. The powered fastener driver of claim 12 wherein the driver moves along a set of chain-type fasteners to load individual fasteners from the set of chain-type fasteners into the nose piece one at a time.

14. The powered fastener driver of claim 11 wherein the cam rotates the rocker arm to move the driver along the set of chain-type fasteners to engage a next fastener from the set of chain-type fasteners.

15. The powered fastener driver of claim 14 wherein in response to continued rotation of the cam, the rocker arm moves past the cam and the pusher is biased toward the nosepiece to deliver the next fastener into the nosepiece.

16. A powered fastener driver comprising:

a housing;

A nose piece extending from the housing;

a piston coupled to the driver blade to move therewith;

A riser assembly, the riser assembly comprising:

A lifter housing;

A drive shaft rotatably disposed within the elevator housing;

A first lifter sprocket disposed on the drive shaft to move the driver blade from the BDC position toward the TDC position; and

A cam rotatable in response to rotation of the drive shaft; and

A fastener delivery mechanism actuated by the cam to load individual fasteners from the magazine into the nosepiece, the fastener delivery mechanism comprising:

a rocker arm driven by the cam; and

A pusher that is movable by the rocker arm.

17. The powered fastener driver of claim 16 wherein the pusher moves away from the nose piece when the rocker arm is driven by the cam.

18. The powered fastener driver of claim 17 wherein the pusher moves along a set of chain type fasteners to load each fastener into the nose piece.

19. The powered fastener driver of claim 18 wherein the cam rotates the rocker arm to move the driver along the set of chain-type fasteners to engage a next fastener from the set of chain-type fasteners.

20. The powered fastener driver of claim 19 wherein in response to continued rotation of the cam, the rocker arm moves past the cam and the pusher is biased toward the nosepiece to deliver the next fastener into the nosepiece.