FIELD OF THE INVENTION
The present invention relates to powered fastener drivers, and more specifically to gas spring-powered fastener drivers.
BACKGROUND OF THE INVENTION
There are various fastener drivers known in the art for driving fasteners (e.g., nails, tacks, staples, etc.) into a workpiece. These fastener drivers operate utilizing various means known in the art, such as by compressed air.
SUMMARY OF THE INVENTION
The present invention provides, in one aspect, a gas spring-powered fastener driver including an outer cylinder configured to contain a pressurized gas therein, an inner cylinder disposed within the outer cylinder, a piston disposed within the inner cylinder and moveable along the inner cylinder, a driver blade attached to the piston and moveable therewith between a top-dead-center (TDC) position and a bottom-dead-center (BDC) position, the driver blade configured to drive a fastener when moved from the TDC position toward the BDC position, and a two-way valve coupled to the outer cylinder. The two-way valve configured to selectively permit a first flow of gas into the outer cylinder and to selectively permit a second flow of gas from the outer cylinder.
The present invention provides, in another aspect, a gas spring-powered fastener driver including an outer cylinder configured to contain a pressurized gas therein, an inner cylinder disposed within the outer cylinder, a piston disposed within the inner cylinder and moveable along the inner cylinder, a driver blade attached to the piston and moveable therewith between a top-dead-center (TDC) position and a bottom-dead-center (BDC) position, the driver blade configured to drive a fastener when moved from the TDC position toward the BDC position, and a valve coupled to the outer cylinder. The valve including a first seal configured to selectively permit a first flow of gas into the outer cylinder and a second seal configured to selectively permit a second flow of gas from the outer cylinder.
The present invention provides, in yet another aspect, a gas spring-powered fastener driver including an outer cylinder configured to contain a pressurized gas therein, an inner cylinder disposed within the outer cylinder, a piston disposed within the inner cylinder and moveable along the inner cylinder, a driver blade attached to the piston and moveable therewith between a top-dead-center (TDC) position and a bottom-dead-center (BDC) position, the driver blade configured to drive a fastener when moved from the TDC position toward the BDC position, and a valve coupled to the outer cylinder. The valve including a plunger moveable between a sealed position, a filling position in which a first flow of gas is permitted into the outer cylinder, and an exhausting position in a second flow of gas is permitted from the outer cylinder.
Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view of a gas spring-powered fastener driver in accordance with an embodiment of the invention.
FIG. 2 is a partial section view of the gas spring-powered fastener driver of FIG. 1.
FIG. 3 is a section view of an integrated fill and pressure release valve according to one embodiment of the present disclosure.
FIG. 4 illustrates the valve of FIG. 3 in a filling position.
FIG. 5 illustrates the valve of FIG. 3 in an exhausting position, with certain components hidden for clarity.
FIG. 6 is an exploded perspective view of the valve of FIG. 3.
FIG. 7 is a section view of an integrated fill and pressure release valve according to another embodiment of the present disclosure.
FIG. 8 illustrates the valve of FIG. 7 in a filling position.
FIG. 9 illustrates the valve of FIG. 7 in an exhausting position.
FIG. 10 is a section view of an integrated fill and pressure release valve according to yet another embodiment of the present disclosure.
FIG. 11 illustrates the valve of FIG. 10 in a filling position.
FIG. 12 illustrates the valve of FIG. 10 in an exhausting position.
FIG. 13 is a section view of an integrated fill and pressure release valve according to yet another embodiment of the present disclosure.
FIG. 14 illustrates the valve of FIG. 13 in a filling position.
FIG. 15 illustrates the valve of FIG. 13 in an exhausting position.
FIG. 16 is a section view of an integrated fill and pressure release valve according to yet another embodiment of the present disclosure.
FIG. 17 illustrates the valve of FIG. 16 in a filling position.
FIG. 18 illustrates the valve of FIG. 16 in an exhausting position.
FIG. 19 is an exploded perspective view of the valve of FIG. 16.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION
With reference to FIGS. 1 and 2, a gas spring-powered fastener driver 10 is operable to drive fasteners (e.g., nails, tacks, staples, etc.) held within a magazine 14 into a workpiece. The fastener driver 10 includes a housing 12 having a cylinder support portion 13 in which an inner cylinder 18 is disposed. A piston 22 is positioned within the inner cylinder 18 (FIG. 2) and moveable along the cylinder 18. The fastener driver 10 further includes a driver blade 26 that is attached to the piston 22 and moveable therewith. The fastener driver 10 does not require an external source of air pressure, but rather includes an outer cylinder or storage chamber cylinder 30 of pressurized gas in fluid communication with the cylinder 18. In the illustrated embodiment, the cylinder 18 and moveable piston 22 are positioned within the storage chamber cylinder 30. In some embodiments, the cylinder 18 may be positioned adjacent the storage chamber cylinder 30 and in fluid communication with the storage chamber cylinder 30. With reference to FIG. 2, the driver 10 further includes a valve 34 coupled to the storage chamber cylinder 30. As will be described in greater detail herein, the valve 34 regulates a pressure of the gas within the storage chamber cylinder 30. And, when connected with a source of compressed gas, the valve 34 also permits the storage chamber cylinder 30 to be refilled with compressed gas if any prior leakage has occurred. Accordingly, a bi-directional flow of compressed gas is selectively permitted through the valve 34, making the valve 34 operable as both a gas inlet valve and a pressure-regulating valve.
Together, the cylinder 18 and the driver blade 26 define a driving axis. During a driving cycle, the driver blade 26 and piston 22 are moveable between a top-dead-center (TDC) position and a driven or bottom-dead-center (BDC) position along the driving axis. The fastener driver 10 further includes a lifting assembly (not shown), which is operable to move the driver blade 26 from the driven position toward the TDC position.
In operation, the lifting assembly drives the piston 22 and the driver blade 26 toward the TDC position. As the piston 22 and the driver blade 26 are driven toward the TDC position, the gas above the piston 22 and within the storage chamber cylinder 30 is compressed. Prior to reaching the TDC position, the piston 22 and the driver blade 26 are held in a ready position, which is located between the TDC and the BDC or driven positions, until being released by user activation of a trigger 48 (FIG. 1). When released, the compressed gas above the piston 22 and within the storage chamber cylinder 30 drives the piston 22 and the driver blade 26 to the driven position, thereby driving a fastener into the workpiece. The illustrated fastener driver 10 therefore operates on a gas spring principle utilizing the lifting assembly and the piston 22 to repeatedly compress the gas within the cylinder 18 and the storage chamber cylinder 30 for consecutive fastener driving operations.
With reference to FIG. 2, the storage chamber cylinder 30 is concentric with the cylinder 18. The cylinder 18 has an annular inner wall 50 configured to guide the piston 22 and driver blade 26 along the driving axis to compress the gas in the cylinder 18 and the storage chamber cylinder 30. The storage chamber cylinder 30 has an annular outer wall 54 circumferentially surrounding the inner wall 50. The cylinder 18 has a connecting section 58. The storage chamber cylinder 30 has corresponding connecting section at a lower end 60 of the storage chamber cylinder 30 such that the cylinder 18 is coupled to the storage chamber cylinder 30 at the lower end 60. In the illustrated embodiment, the connecting section 58 is a securement ring. In other embodiments, the connecting section 58 is a threaded connection. As such, the cylinder 18 is configured to be axially secured to the storage chamber cylinder 30. A threaded coupling may facilitate and simplify assembly of the driver 10.
Gas spring-powered fastener drivers such as those described herein must be able to accommodate for overpressure and/or high temperature conditions. An overpressure situation is when the pressure in the storage chamber cylinder 30 exceeds a threshold value that denotes an upper limit of an operating range. Traditionally, the storage chamber cylinder 30 is designed to crack as a controlled failure if pressure in the cylinder 30 exceeds the threshold value. The crack allows pressurized air to escape, which renders traditional gas-spring powered fastener driver unusable after the over-pressure situation. In the gas spring-powered fastener driver 10 disclosed herein, the storage chamber cylinder 30 can be re-filled after exhausting gas through the valve 34 due to an overpressure condition. As will be described in greater detail below, the valve 34 of the present disclosure is a two-way valve. The two-way valve allows pressurized air, when above the threshold value, to be exhausted through the valve 34 in a first direction and allows compressed air to flow through the valve 34 in a second direction to refill the storage chamber cylinder 30 with pressurized air.
FIGS. 3-6 illustrate the valve 34 according to one embodiment of the present disclosure. The valve 34 includes a cylindrical valve body 100 having an interior end 104 and an exterior end 108. The interior end 104 is disposed within the storage chamber cylinder 30, while the exterior end 108 extends beyond the storage chamber cylinder 30 (FIG. 2). The interior end 104 includes at least one aperture 112 that allows for fluid communication between a storage chamber 52 defined between the cylinders 18, 30 and an interior of the valve body 100. In the illustrated embodiment, the interior end 104 includes two opposing apertures 112. However, the interior end 104 may include more or fewer apertures 112. The exterior end 108 includes an opening 114 in an axial end face 116 of the body 100 that allows for fluid communication between the interior of the valve body 100 and the atmosphere.
The interior of the valve body 100 extends along a length of the valve body 100 and includes a sealed portion 120 and an atmospheric portion 124. The sealed portion 120 corresponds to the interior end 104 and is in fluid communication with the storage chamber 52 via the apertures 112. The atmospheric portion 124 corresponds to the exterior end 108 and is in fluid communication with the atmosphere via the opening 114. A sealing area 128 separates the sealed portion 120 from the atmospheric portion 124. In the illustrated embodiment, the sealed portion 120 is smaller in diameter than the atmospheric portion 124. Therefore, a tapered wall 132 is formed at the sealing area 128 to transition between the sealed portion 120 and the atmospheric portion 124. Disposed within the sealing area 128 are an inlet seal 136 and an outlet seal 140. The inlet seal 136 selectively allows compressed gas to flow into the storage chamber 52 through the valve 34, and the outlet seal 140 selectively allows compressed gas to flow out of the storage chamber 52 through the valve 34. In the illustrated embodiment, the outlet seal 140 is annular and includes a tapered radially outer edge 144 engageable with the tapered wall 132. The engagement between the outlet seal 140 and the wall 132 forms a first sealing surface. In some embodiments, an outer seal member 148, such as an O-ring, is disposed on the tapered radially outer edge 144 of the outlet seal 140 or the tapered wall 132 to assist in sealing the outlet seal 140 and the wall 132.
In the illustrated embodiment, the inlet seal 136 includes a stem 152 having a protrusion 156 at one end of the stem 152. The stem 152 extends through a central aperture 160 in the annular outlet seal 140, and the protrusion 156 is shaped to engage the outlet seal 140 to selectively seal the central aperture 160. Engagement between the protrusion 156 and the outlet seal 140 forms a second sealing surface. In some embodiments, an inner seal member 164, such as an O-ring, is disposed on the protrusion 156 or the outlet seal 140 to assist in sealing between the central aperture 160 of the outlet seal 140 and the protrusion 156.
The valve 34 further includes a sealed portion biasing member 168 disposed within the sealed portion 120 and an atmospheric portion biasing member 172 disposed within the atmospheric portion 124. The sealed portion biasing member 168 of the illustrated embodiment is a compression spring seated between the valve body 100 and the protrusion 156 of the inlet seal 136. The sealed portion biasing member 168 applies a biasing force F1 on the inlet seal 136 in a direction that maintains the seal between the protrusion 156 and the central aperture 160 of the outlet seal 140. The atmospheric portion biasing member 172 of the illustrated embodiment is also a compression spring. The atmospheric portion biasing member 172 is seated at one end to the valve body 100, proximate the opening 114 in the axial end face 116, and at another end to the outlet seal 140. The atmospheric portion biasing member 172 applies a biasing force F2 on the outlet seal 140 in a direction that maintains the seal between the outlet seal 140 and the tapered wall 132. The sealed portion biasing member 168 and the atmospheric portion biasing member 172 apply biasing forces in opposite directions.
To fill the storage chamber 52, compressed gas is allowed to flow through the valve 34 by moving the inlet seal 136 against the biasing force F1 of the sealed portion biasing member 168, thereby breaking the seal between the protrusion 156 and the outlet seal 140 (FIG. 4). When filled, the inlet seal 136 is moved back into sealing engagement with the outlet seal 140 by the sealed portion biasing member 168. In an overpressure situation, the compressed gas within the sealed portion 120 applies a force on the outlet seal 140 that overcomes the biasing force F2 of the atmospheric portion biasing member 172, breaking the seal between the outlet seal 140 and the tapered wall 132 and allowing pressurized gas to escape the storage chamber 52 through the valve 34, thereby decreasing the pressure within the storage chamber 52 (FIG. 5). When the pressure decreases to a point below the threshold value (e.g., no longer in overpressure), the biasing force F2 from the atmospheric portion biasing member 172 re-engages the outlet seal 140 with the tapered wall 132. The valve 34 of the above-described embodiment is a double spring, dual-action valve capable of independently controlling inlet and exhaust gas flow.
FIGS. 7-9 illustrate a valve 34b according to another embodiment of the present disclosure, with like parts having like reference numerals plus the letter “b” appended thereon, and the following differences explained below. The valve 34b is a ball-seat valve. Therefore, the inlet seal 136b is formed as a sphere or ball 176, rather than a stem and protrusion. The ball 176 is sized to seal the central aperture 160b within the outlet seal 140b, and the ball 176 is held in place due by the pressure of the compressed gas in the storage chamber 52b. In other words, the inlet seal 136b is biased towards a sealed position due to the gas pressure within the system, and the valve 34b does not include a sealed portion biasing member. Furthermore, the sealed portion 120b and the atmospheric portion 124b have similar diameters. Rather than a tapered wall forming a transition, the valve 34b includes a radially inward-extending circumferential protrusion 180 to engage the outlet seal 140b. Like the double-spring dual-action valve 34, when pressure in the storage chamber 52b exceeds a threshold value, the outlet seal 140b and the ball 176 move in unison against the biasing force of the atmospheric portion biasing member 172b to allow pressurized gas to be exhausted (FIG. 9).
FIGS. 10-12 illustrate a valve 34c according to yet another embodiment of the present disclosure, with like parts having like reference numerals plus the letter “c” appended thereon, and the following differences explained below. The sealed portion biasing member 168c is a tension spring acting on the outlet seal 140c. Like the ball-seat valve 34b, the inlet seal 136c is held in place due to pressure in the storage chamber 52c. The valve 34c does not include an atmospheric portion biasing member. Unlike the ball-seat valve 34b, the inlet seal 136c includes a stem 152c and protrusion 156c, like the double spring dual-action valve 34.
FIGS. 13-15 illustrate a valve 34d according to yet another embodiment of the present disclosure, with like parts having like reference numerals plus the letter “d” appended thereon, and the following differences explained below. The valve 34d includes a single plunger 186 movable within the valve body 100d to control both gas flow into the storage chamber 52d and gas flow out of the storage chamber 52d. The plunger 186 is moveable between a sealing position (FIG. 13), a filling position (FIG. 14), and an exhausting position (FIG. 15). The plunger 186 is coupled to a biasing member 190, illustrated as a spring, on its interior end. The plunger 186 includes a sealing piston or disk 194 to sealingly engage the inner walls of the valve body 100d and separate the sealed portion 120d from the atmospheric portion 124d. In some embodiments, the sealing disk 194 includes a seal 200, such as an O-ring, disposed on a radially outer edge. The interior end 104d of the valve 34d includes at least one aperture 112d that allows for fluid communication between the storage chamber 52d and the interior of the valve body 100d. Similarly, the exterior end 108d includes at least one aperture 204 that allows for fluid communication between the atmosphere and the interior of the valve body 100d.
When the plunger 186 is located between the interior end and exterior end apertures 112d, 204, the valve 34d is sealed. To fill the storage chamber cylinder 30d with pressurized gas, the plunger 186 is moved toward the interior end 104d until it passes at least a portion of the interior end aperture 112d (FIG. 14). The storage chamber cylinder 30d is then in fluid communication with the atmosphere. In an overpressure situation, the pressure of the compressed gas moves the plunger 186 against the force of the spring 190 to a position beyond the aperture 204 of the exterior end 108d (FIG. 15), fluidly communicating the storage chamber 52d with the atmosphere to exhaust excessed compressed gas to atmosphere.
When the valve 34d is sealed (FIG. 13), the spring 190 is approximately at its natural length. Therefore, to fill the storage chamber cylinder 30, the compressed gas must overcome the biasing force F3 of the spring 190 in a first direction. Similarly, to exhaust gas from the storage chamber cylinder 30, the compressed gas must overcome the biasing force F3 of the spring 190 in a second direction opposite the first direction.
FIGS. 16-19 illustrate a valve 34e according to yet another embodiment of the present disclosure, with like parts having like reference numerals plus the letter “e” appended thereon, and the following differences explained below. The valve body 100e includes an aperture 112e in fluid communication with the storage chamber 52e. The exterior end 108e includes an opening 114e that allows for fluid communication between the interior of the valve body 100e and the atmosphere. The plunger 186e includes a sealing disk 194e and a guide disk 208. The sealing disk 194e is solid and sealingly engages the inner walls of the valve body 100e. The guide disk 208 is disposed within the sealed portion 120e and includes an aperture 212 to allow gas to pass through the guide disk 208 (FIG. 19). The biasing member 190e is between the guide disk 208 and the valve body 100e.
To fill the storage chamber cylinder 30, the plunger 186e is depressed so that the sealing disk 194e exposes at least a portion of the aperture 112e (FIG. 17). To exhaust compressed gas from the cylinder 30, the plunger 186e is moved toward the exterior end 108e so the sealing disk 194e disengages from the interior walls (FIG. 18). In other words, the sealing disk 194e is positioned outside of the valve body 100e when the plunger 186e is in the exhausting position. The guide disk 208 remains within the valve body 100e to support the plunger 186e relative to the valve body 100e. Exhausted compressed gas flows out of the valve 34e though the aperture 212 in the guide disk 208.
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 as described.
Various features of the invention are set forth in the following claims.
Patent Application
20230356375
