EP3984703A1

EP3984703A1 - Tool for striking fastener

Info

Publication number: EP3984703A1
Application number: EP19932313.0A
Authority: EP
Inventors: Aiguo Wang; Fengzhi CHANG; Dongsheng GAO; Qinghua Zhu
Original assignee: Nanjing Toua Hardware & Tools Co Ltd
Current assignee: Nanjing Toua Hardware & Tools Co Ltd
Priority date: 2019-06-11
Filing date: 2019-11-29
Publication date: 2022-04-20
Also published as: CN110253503B; CN110253503A; JP2022535984A; EP3984703A4; JP7366158B2; WO2020248531A1

Abstract

Disclosed is a tool for striking a fastener, belonging to the technical field of electric tools, the tool comprising an energy storage mechanism (2), composed of a cylinder (2-2) and a piston (2-1), in a housing (1), wherein the piston (2-1) is connected to a striker (4) extending to a gun nozzle (3), a holding handle (5) is provided on one side of the cylinder (2-2), a nail box (6) is provided on one side of the gun nozzle (3), and a lifting mechanism (7) is provided between the holding handle (5) and the nail box (6); the lifting mechanism (7) includes the striker (4) having meshing teeth distributed at intervals, and a driving wheel (9) having meshing cylinders circumferentially distributed at intervals, with the driving wheel (9) being in transmission connection with an electric motor (8); gear shifting fingers (9-3) radially extend out of opposite sides of the driving wheel (9) at a preset arc length; and a side surface, opposite the meshing teeth, of the striker (4) is provided with an advance convex pin (4-1) capable of meshing with the gear shifting fingers (9-3). Before the meshing cylinder is in lifting engagement with the meshing teeth, the gear shifting fingers (9-3) turn to a meshing and gear shifting position in front of the advance convex pin (4-1); and when the meshing cylinder is in lifting engagement with the meshing teeth, the gear shifting fingers (9-3) turn to shift the advance convex pin (4-1) in order to enable the meshing teeth to be located at a position meshing with the meshing cylinder. The tool has a simple structure, and effectively prevents interference between the re-lifting meshing of the driving wheel and the meshing of the striker.

Description

TECHNICAL FIELD

The present disclosure relates to tools for striking a fastener, and in particular to an electric gas spring nail gun, which belongs to the technical field of electric tools.

BACKGROUND

According to the applicant, for a long time, tools for fixing one object to another by means of nail fasteners are mainly actuated by air, including high-pressure gas, gas combustion and so on, which not only are expensive, but also have potential safety hazards. Therefore, in recent years, an electric gas spring nail gun appears, of which a typical structure is as revealed by American patents US8011441 and US8267296 . This type of nail gun employs an electric motor to drive a toothless avoiding driving wheel to rotate, thereby lifting a striker meshing with the driving wheel, and accumulates energy by compressing the air in the cylinder through a piston. Then, when the driving wheel reaches the toothless avoiding state and disengages from the striker, the compressed air enables the piston to drive the striker released by the driving wheel to move quickly to complete the nailing action. After that, the driving wheel enters the lifting and meshing state again, to start a next cycle of nailing. Since the energy comes from electrical power, the electric gas spring nail gun has good operation performance and is safe.
However, during practices, when this type of nail gun occasionally has a nail jam due to some reasons, as shown in FIG 6, since the striker is blocked and does not move to a normal limit position indicated by a dotted line, the teeth of the driving wheel may interfere with the striker when lifting and meshing again, that is, they are blocked and cannot enter the meshing state; at this time, not only the transmission element may be damaged because the electric motor is stuck, but since the air inside the cylinder still has certain pressure, once the nail jam is removed, the striker will be out of control to cause safety hazard. Therefore, the above patent also provides a ratchet locking structure, to prevent the striker being out of control; however, this design increases the complexity of elements and assembling.

SUMMARY

In view of the above defects existing in the prior art, the present disclosure aims to provide a tool for striking a fastener, which has a simple structure and is capable of avoiding a nail jam, so as to ensure a convenient and safe usage.
In order to achieve the above aim, the basic technical scheme of the tool for striking a fastener according to the present disclosure is as follows. The tool for striking a fastener includes: an energy storage mechanism, composed of a cylinder and a piston, in a housing, wherein the piston is connected to a striker extending to a gun nozzle, a holding handle having a battery pack is provided on one side of the cylinder, a nail box is provided on one side of the gun nozzle, and a lifting mechanism is provided between the holding handle and the nail box;
the lifting mechanism includes the striker having meshing teeth distributed at intervals in a length direction, and a driving wheel having meshing cylinders distributed at intervals by a preset arc length, and the driving wheel is in transmission connection with an electric motor to which the battery pack supplies electric power;
gear shifting fingers radially extend out of opposite sides of the driving wheel at a preset arc length; and a side surface, opposite the meshing teeth, of the striker is provided with an advance convex pin capable of meshing with the gear shifting fingers; before the meshing cylinder is in lifting engagement with the meshing teeth, the gear shifting fingers turn to a meshing and gear shifting position in front of the advance convex pin; and when the meshing cylinder is in lifting engagement with the meshing teeth, the gear shifting fingers turn to shift the advance convex pin in order to enable the meshing teeth to be located at a position meshing with the meshing cylinder.
In this way, no locking mechanism is needed, and the structure is simple; moreover, when the meshing cylinder is in lifting engagement with the meshing teeth, the gear shifting fingers actually have shifted the advance convex pin, which effectively prevents interference of meshing between the driving wheel and the striker during a re-lifting.
To further improve the present disclosure, the driving wheel includes two symmetrical wheel pieces, and the meshing cylinders are supported between the two symmetrical wheel pieces.
To further improve the present disclosure, gear shifting fingers radially extend out of opposite sides of the two symmetrical wheel pieces at a preset arc length respectively, and two side surfaces, opposite the meshing teeth, of the striker are provided with an advance convex pin capable of meshing with the gear shifting finger respectively.
To further improve the present disclosure, the gear shifting finger is provided with a uniform lifting curve flange which forms a cam pair with the advance convex pin.
To further improve the present disclosure, two ends of the uniform lifting curve flange are provided with a transition arc respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is described below in further detail in conjunction with drawings.

FIG. 1 is a perspective view of Embodiment 1 of the present disclosure.
FIG. 2 is a sectional view of the embodiment shown in FIG. 1.
FIG. 3 is a perspective view of a lifting mechanism of the embodiment shown in FIG. 1.
FIG. 4 is a diagram of a meshing start position of a lifting mechanism shown in FIG. 3.
FIG. 5 is a diagram of a meshing end position of a lifting mechanism shown in FIG. 3.
FIG. 6 is a diagram of meshing interference in the prior art.

DETAILED DESCRIPTION

Embodiment

1

The basic structure of the tool for striking a fastener provided in the present embodiment is as shown in FIG. 1 and FIG. 2, a rear end of a shell 1 is provided with an energy storage mechanism 2 composed of a cylinder 2-2 and a piston 2-1, and the piston 2-1 is fixedly connected to a striker 4 extending to a gun nozzle 3. A holding handle 5 having a battery pack 5-1 is provided on a lower side of the cylinder 2-2, a nail box 6 for placing strip nails is provided on a lower side of the gun nozzle 3, and a lifting mechanism 7 is provided on an upper part between the holding handle 5 and the nail box 6, an electric motor 8 and a deceleration transmission mechanism 8-1 are provided on a lower part between the holding handle 5 and the nail box 6.
As shown in FIG. 3, the lifting mechanism 7 includes a striker 4 having meshing teeth distributed at intervals in a length direction, and a driving wheel 9 meshing with the striker 4; the driving wheel 9 is composed of two symmetrical wheel pieces 9-1 and meshing cylinders 9-2 supported between the two symmetrical wheel pieces and distributed at intervals by a preset arc length; the driving wheel 9 is in transmission connection with an electric motor 8 to which the battery pack 5-1 supplies electric power.
Gear shifting fingers 9-3 radially extend out of opposite sides of the two symmetrical wheel pieces of the driving wheel 9 at a preset arc length respectively, and two side surfaces, opposite the meshing teeth, of the striker 4 are provided with a cylindrical advance convex pin 4-1 capable of meshing with the gear shifting finger 9-3 respectively. The symmetrical wheel pieces in the present embodiment not only change the cantilever meshing cylinders in the prior art into a two end supported structure, but also form on that basis a symmetrical meshing structure between the gear shifting finger 9-3 and the advance convex pin 4-1 at two sides, thus the bearing capacity is higher and the transmission is more stable. The gear shifting finger 9-3 is provided with a uniform lifting curve flange C which forms a cam pair with the advance convex pin 4-1; two ends of the uniform lifting curve flange C are provided with a transition arc respectively, to ensure a stable and reliable lifting movement.
During operation, as shown in FIG. 4, before the meshing cylinder 9-2 is in lifting engagement with the meshing teeth, the gear shifting fingers 9-3 turn to a meshing and gear shifting position in front of the advance convex pin 4-1; even if the striker deviates from the initial position due to a nail jam and other reasons, the gear shifting finger 9-3 can also play a blocking function when starting meshing with the advance convex pin 4-1, thereby effectively preventing an incontrollable action of the striker and ensuring safety; then, through transmission, the striker is shifted in order to enable meshing cylinder 9-2 to be located at a position normally meshing with the meshing teeth, that is, when the meshing cylinder 9-2 is in lifting engagement with the meshing teeth, the gear shifting fingers 9-3 turn to shift the advance convex pin 4-1 in order to enable the meshing teeth to be located at a position meshing with the meshing cylinder, thereby preventing the nail jam shown in FIG. 6. Then, the driving wheel continues rotating, the meshing cylinder 9-2 is in lifting engagement with the meshing teeth, until reaching the meshing disengaged position shown in FIG. 5, and the striker will be released suddenly to shoot a nail.
Experiences show that, whether or not the striker deviates from the initiating position due to a nail jam and other reasons, the gear shifting fingers have turned to a meshing and gear shifting position in front of the advance convex pin before the meshing cylinder is in lifting engagement with the meshing teeth, even if there is residual pressure air in the cylinder, the striker will also be unlikely to lose control due to the gear shifting finger, moreover, when the meshing cylinder is in lifting engagement with the meshing teeth, the gear shifting fingers actually have shifted the advance convex pin, which not only enables lifting, but also has shifted the advance convex pin in order to enable the meshing teeth to be located at a position meshing with the meshing cylinder, thereby ensuring accurate meshing, and effectively preventing interference of meshing between the driving wheel and the striker during a re-lifting
Besides the above embodiments, the present disclosure can also have other changes. For example, during the rotation process of the driving wheel, in order to enable the convex pin on the striker to be stressed by a force along the movement direction of the striker only, the gear shifting finger can also be designed as a lifting flange of other curves. Any technical scheme employing equivalent substitutes or equivalent transformations shall be included in the scope of protection of the present disclosure.

Claims

A tool for striking a fastener, comprising an energy storage mechanism, composed of a cylinder and a piston, in a housing, wherein the piston is connected to a striker extending to a gun nozzle, a holding handle having a battery pack is provided on one side of the cylinder, a nail box is provided on one side of the gun nozzle, and a lifting mechanism is provided between the holding handle and the nail box; the lifting mechanism comprises the striker having meshing teeth distributed at intervals in a length direction, and a driving wheel having meshing cylinders distributed at intervals by a preset arc length, and the driving wheel is in transmission connection with an electric motor to which the battery pack supplies electric power; wherein
gear shifting fingers radially extend out of opposite sides of the driving wheel at a preset arc length; and a side surface, opposite the meshing teeth, of the striker is provided with an advance convex pin capable of meshing with the gear shifting fingers; before the meshing cylinder is in lifting engagement with the meshing teeth, the gear shifting fingers turn to a meshing and gear shifting position in front of the advance convex pin; and when the meshing cylinder is in lifting engagement with the meshing teeth, the gear shifting fingers turn to shift the advance convex pin in order to enable the meshing teeth to be located at a position meshing with the meshing cylinder.
The tool for striking a fastener according to claim 1, wherein the driving wheel comprises two symmetrical wheel pieces, and the meshing cylinders are supported between the two symmetrical wheel pieces.
The tool for striking a fastener according to claim 2, wherein gear shifting fingers radially extend out of opposite sides of the two symmetrical wheel pieces at a preset arc length respectively, and two side surfaces, opposite the meshing teeth, of the striker are provided with a cylindrical advance convex pin capable of meshing with the gear shifting finger respectively.
The tool for striking a fastener according to claim 3, wherein the gear shifting finger is provided with a uniform lifting curve flange which forms a cam pair with the advance convex pin.
The tool for striking a fastener according to claim 4, wherein two ends of the uniform lifting curve flange are provided with a transition arc respectively.