Anti-tooth-jamming fastener striking tool

Abstract

An anti-tooth-jamming fastener striking tool, which belongs to the technical field of electric tools. The tool comprises: a striker (Z) which extends in the direction of striking, has an energy storage limit position and a striking stop position, and is provided with side teeth on the side in the direction of length; a lifting wheel (3) which is provided with a set of driving members that are distributed at intervals on a major part of the circumference and respectively correspond to and mesh with the side teeth of the striker (Z); and an electric motor (5) which is in transmission connection with the lifting wheel (3), and is configured to drive the striker (Z) to return from the striking stop position to the energy storage limit position while driving a piston to compress and store energy. Among the side teeth of the striker (Z), starting from the tooth adjacent to the piston end, the tooth pitch between a first tooth (a) and a second tooth (b) is 2+ / -0.5 times the normal tooth pitch of the subsequent teeth distributed at equal intervals. During normal meshing, among the driving members of the lifting wheel (3), a first driving pin (x1) and a second driving pin (x2) for the initial meshing during lifting respectively mesh with the first tooth (a) and the second tooth (b). By means of smart and simple structural improvements, an ideal effect of preventing tooth jamming is achieved, ensuring safe and reliable operations of the fastener striking tool.

Description

Anti-jamming tooth fastener striking tool Technical Field

[0001] The invention relates to a fastener striking tool, in particular to an anti-jamming fastener striking tool, and belongs to the technical field of electric tools. Background Art

[0002] Industries like construction and renovation often require the use of fastener-driving tools like electric nailers to drive nails into the workpiece. When an electric nailer is in operation, as shown in Figure 1, the motor drives the counterclockwise rotation of the lifting wheel D, which moves the striker Z linearly to the energy storage limit position, storing compressed air. Then, as shown in Figure 2, the lifting wheel D rotates to the stop position, disengaging the striker. The compressed air instantly releases energy, causing the striker Z to move linearly to the stop position, driving the nail into the workpiece. The motor then continues to drive the lifting wheel D, and the process repeats. In practice, due to various reasons such as different nail driving resistance, the striking stop position of the firing pin Z often changes each time. In serious cases, as shown in Figure 3, the actual striking stop position of the firing pin Z does not reach the ideal position shown by the dotted line, but is in the blocking position shown by the solid line; as a result, the first tooth a' and the second tooth b' of the side teeth of the firing pin Z fail to be on the rotation trajectory of the driving pin x1 of the lifting wheel D, that is, at the a and b positions shown by the dotted line, so that the driving pin x1 is blocked by the tooth top of the second tooth b' when it rotates counterclockwise to engage, resulting in a tooth jam phenomenon, which not only affects the normal operation but also poses a safety hazard.

[0003] To this end, Chinese patent application number 201680033808.7 discloses a fastener striking tool comprising an ejection portion for supplying a fixing member, a striking member that moves from a first position to a second position and drives the fixing member into a component being struck, and a rack mounted on the striking member. The striking member comprises: a motor; a drive shaft connected to the motor; a rotating element connected to the drive shaft and moving the striking member from the second position to the first position; and a locking member mounted on the rotating element and engaging with the rack. The locking member rotates the rotating element while engaged with the rack to move circumferentially, causing the striking member to move from the second position to the first position. The locking member is capable of moving radially relative to the drive shaft in the rotating element. This technical solution employs an innovative structure in which an elastic element is added between the rack and the drive pin. In the event of a tooth jam, the elasticity of the elastic member can effectively prevent blockage. However, this structure not only increases the number of parts and manufacturing costs, but also increases the probability of failure in the transmission link. Summary of the Invention

[0004] The purpose of the present invention is to provide a tool for striking anti-jamming fasteners with a simple structure, ideal effect, safety and reliability, in view of the shortcomings of the above-mentioned prior art.

[0005] In order to achieve the above-mentioned purpose, the basic technical solution of the anti-jamming fastener striking tool of the present invention is:

[0006] Firing pin: extends along the striking direction, has an energy storage limit position and a striking stop position, and has side teeth on one side of the length direction;

[0007] The lifting wheel has a set of driving members spaced apart on a large half of the circumference and respectively meshing with the side teeth of the striker;

[0008] Motor - connected to the lifting wheel, used to drive the striker to return from the striking stop position to the energy storage limit position to drive the piston to compress and store energy;

[0009] Its characteristics are:

[0010] The pitch between the first and second teeth of the side teeth of the striker, starting from the end adjacent to the piston, is 2±0.5 times (ideally 2±0.2 times, and optimally 2 times) the normal pitch of the subsequent equally spaced teeth;

[0011] During normal engagement, the first driving member and the second driving member of the driving member of the lifting wheel that start engaging with the lifting are respectively engaged with the first tooth and the second tooth.

[0012] The present invention essentially employs the breakthrough concept of "missing tooth avoidance." This means that the firing pin no longer has the second tooth of the conventional uniformly spaced side teeth (the first and second drive members, respectively, meshing with the first and second teeth, meaning the second tooth of the conventional uniformly spaced drive member also no longer exists). Therefore, when the firing pin has not yet reached its ideal striking stop position and is within ±1 normal tooth pitch of the ideal position, the first drive member of the lifting wheel will enter the wide gap between the first and second teeth of the present invention (equivalent to the third tooth of the conventional uniformly spaced side teeth) when it engages, preventing any binding. Subsequently, as the lifting wheel continues to rotate, the first drive member will inevitably engage with the first tooth, forcing the firing pin to automatically move to its proper position, paving the way for the second drive member to engage with the second tooth, and subsequently for the uniformly spaced drive member to engage with the corresponding uniformly spaced teeth.

[0013] By understanding the innovative essence of the present invention, it can be seen that the present invention achieves the ideal effect of avoiding tooth jamming that can only be achieved by the complex structure of the prior art through ingenious and very simple structural improvements, and can ensure the safe and reliable operation of the fastener striking tool.

[0014] A further improvement of the present invention is that the driving member is a driving pin, and the allowable range of the arc length between the center of the first driving pin and the center of the second driving pin in the driving pin of the lifting wheel at the start of lifting engagement is that the minimum value of the arc length is determined as follows: when the first driving pin is engaged with the second tooth and the second driving pin is about to engage with the fourth tooth, the distance between the center of the second driving pin and the fourth tooth is equal to the radius of the second driving pin; the maximum value of the arc length is determined as follows: when the first driving pin is engaged with the second tooth and the second driving pin is about to engage with the fourth tooth, the distance between the center of the second driving pin and the fifth tooth is equal to the radius of the second driving pin.

[0015] In this way, even if an extreme situation occurs - the firing pin stop position is greater than 1 normal tooth pitch from the ideal stop position, the first drive pin will enter the gap between the second tooth and the third tooth and "off-position" engage with the second tooth. At this time, the second drive pin can smoothly "off-position" engage with the fourth tooth, thereby ensuring that the striking tool can continue to operate without mechanical failures such as stuck teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG1 is a schematic diagram of the structure of the prior art firing pin at the energy storage limit position.

[0017] FIG2 is a schematic structural diagram of the prior art firing pin in a striking stop position.

[0018] FIG3 is a schematic structural diagram of the prior art striker in a latching position.

[0019] FIG4 is a schematic structural diagram of an embodiment of the present invention.

[0020] FIG5 is a schematic cross-sectional view of the firing pin in the embodiment of FIG4 at the energy storage limit position.

[0021] FIG6 is a schematic cross-sectional view of the firing pin in the embodiment of FIG4 in a striking stop position.

[0022] FIG. 7 is a schematic structural diagram of the meshing state of the embodiment of FIG. 4 in the “missing tooth avoidance” mode.

[0023] FIG8 is a partial enlarged structural schematic diagram of FIG7 .

[0024] FIG9 is a schematic structural diagram of the embodiment of FIG4 at the start of engagement in an extreme state.

[0025] FIG10 is a structural diagram of the meshing process in an extreme state of the embodiment of FIG4 .

[0026] FIG11 is a schematic structural diagram of the embodiment of FIG4 in an extreme state in which the striker is at the energy storage limit position.

[0027] FIG12 is a schematic diagram of a partially enlarged structure of FIG10. DETAILED DESCRIPTION Example

[0028] The basic structure of the anti-jamming fastener striking tool of this embodiment is shown in Figure 4. The front end of the piston in the energy storage cylinder 1 is connected to the firing pin extending along the striking direction to the nailing seat 2. The firing pin has an energy storage limit position shown in Figure 5 and a striking stop position shown in Figure 6, and one side in the length direction has side teeth corresponding to the drive pin x of the lifting wheel 3. The drive pins x are spaced apart and distributed over the large half circumference of the lifting wheel 3. The rotating shaft of the lifting wheel 3 is connected to the motor 5 through the reduction gear box 4, which is used to drive the piston to compress air and store energy when the firing pin returns from the striking stop position to the energy storage limit position.

[0029] Referring to Figures 7 and 8, the tooth pitch L0 between the first tooth a and the second tooth b in the side teeth of the striker Z starting from the adjacent piston end is twice the tooth pitch L of the subsequent equally spaced teeth (experiments show that the feasible range is 2±0.5 times and the comparative range is 2±0.2 times); the first driving pin x1 and the second driving pin of the lifting wheel D that start engaging are respectively engaged with the first tooth a and the second tooth b.

[0030] Thus, even if the firing pin does not reach the ideal stop position for striking, the first drive pin x1 of the lifting wheel will enter the meshing state. Due to the absence of the second tooth b' of the conventional uniform pitch firing pin, it will enter the wide gap between the first tooth a and the second tooth b (equivalent to the third tooth in the conventional uniform pitch side teeth), completely preventing any jamming. Subsequently, as the lifting wheel continues to rotate, the first drive pin will inevitably engage with the first tooth, causing the firing pin to automatically adjust to the position where the corresponding pin and tooth engage normally.

[0031] Furthermore, this embodiment takes into account that, under extremely specific operating conditions, the striker's stop position may differ from the ideal stop position by more than one tooth pitch. In this case, the first drive pin x1 will initially engage, as shown in Figure 9, by entering the gap between the second tooth b and the third tooth c. This means that the first drive pin x1 will engage the second tooth b. Referring to Figures 10 and 12, even if such an extremely special situation occurs, regardless of whether the pitch of the first tooth a and the second tooth b is actually any specific data within the range of 2±0.5 times the normal pitch of the subsequent equally spaced teeth, the arc length between the center O1 of the first driving pin x1 and the center O2 of the second driving pin x2 in the driving pins of the lifting wheel, which are engaged at the start of lifting, is allowed to vary within a certain range, as long as the minimum value of the arc length (the arc length between O1 and O2 in Figure 12) is determined by the following conditions: when the first driving pin x1 is engaged with the second tooth b and the second driving pin x2 is about to enter into engagement with the fourth tooth d, the distance Sa between the center O2 of the second driving pin x2 and the fourth tooth d is equal to the radius of the second driving pin; and the maximum value of the arc length (the arc length between O1 and O' in Figure 12) is determined by the following conditions: when the first driving pin x1 is engaged with the second tooth b and the second driving pin x2 is about to enter into engagement with the fourth tooth d, the distance Sb between the center O2 of the second driving pin x2 and the fifth tooth e is equal to the radius of the second driving pin. Thus, as long as the arc length is limited to the tolerance range of O2 and O', it can be ensured that after the first drive pin x1 engages the second tooth b, the second drive pin x2 will not interfere with or become stuck with either the preceding fourth tooth or the following fifth tooth when it enters meshing with the fourth tooth d. Alternatively, the arc length can be expressed as a central angle: the minimum value of the central angle between the center of the first drive pin x1 and the center of the second drive pin x2 is equal to the distance Sa between the second drive pin x2 and the second tooth c when the first drive pin x1 is engaged with the second tooth b and the second drive pin x2 is about to enter meshing with the fourth tooth d, which is equal to the radius of the second drive pin; and the maximum value of the central angle is equal to the distance Sb between the second drive pin x2 and the fifth tooth e when the first drive pin x1 is engaged with the second tooth b and the second drive pin x2 is about to enter meshing with the fourth tooth d, which is equal to the radius of the second drive pin. In this way, even when the first drive pin x1 is misaligned and engaged with the second tooth b, the second drive pin x2 can still smoothly engage with the fourth tooth d, and finally reach the energy storage limit position of the striker in the extreme state shown in Figure 11, and the fastener striking tool of this embodiment can still maintain normal operation without the phenomenon of mechanical structure jamming.

[0032] It should be noted that the terms "top," "bottom," "upper," "lower," "front," "back," "inner," and "outer" used above are based on the orientations and positions shown in the accompanying drawings and are for ease of description only and are not intended to be limiting. In addition to the above embodiments, the present invention may also have other implementations. Any technical solutions formed by equivalent substitution or equivalent modification fall within the scope of protection claimed by the present invention.

Claims

1. A tool for striking anti-jamming fasteners, comprising: Firing pin: extends along the striking direction, has an energy storage limit position and a striking stop position, and has side teeth on one side of the length direction; The lifting wheel has a set of driving members spaced apart on a large half of the circumference and respectively meshing with the side teeth of the striker; Motor - connected to the lifting wheel, used to drive the striker to return from the striking stop position to the energy storage limit position to drive the piston to compress and store energy; Its characteristics are: The pitch between the first and second teeth of the side teeth of the striker, starting from the end adjacent to the piston, is 2±0.5 times the normal pitch of the subsequent equally spaced teeth; During normal engagement, the first driving member and the second driving member of the driving member of the lifting wheel that start engaging with the lifting are respectively engaged with the first tooth and the second tooth.

2. The anti-jamming fastener striking tool according to claim 1, characterized in that: The pitch between the first tooth and the second tooth of the side teeth of the striker starting from the end adjacent to the piston is 2±0.2 times the normal pitch of the subsequent equally spaced teeth.

3. The anti-jamming fastener striking tool according to claim 2, characterized in that: The pitch between the first tooth and the second tooth of the side teeth of the striker starting from the end adjacent to the piston is twice the normal pitch of the subsequent equally spaced teeth.

4. The anti-jamming fastener striking tool according to claim 1, 2 or 3, characterized in that: The driving member is a driving pin, and the allowable range of the arc length between the center of the first driving pin and the center of the second driving pin in the driving pin of the lifting wheel that starts lifting engagement is that the minimum value of the arc length is determined as follows: when the first driving pin is engaged with the second tooth and the second driving pin is about to engage with the fourth tooth, the distance between the center of the second driving pin and the fourth tooth is equal to the radius of the second driving pin; the maximum value of the arc length is determined as follows: when the first driving pin is engaged with the second tooth and the second driving pin is about to engage with the fourth tooth, the distance between the center of the second driving pin and the fifth tooth is equal to the radius of the second driving pin.

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