A head locking device for facilitating the replacement of a saw blade on a power saw

Abstract

The present invention discloses a head locking device that facilitates the replacement of a saw blade on a power saw, comprising: a mounting frame, on which a locking piece is provided on the side of the head. The rear end of the locking piece is hinged to the mounting frame. An upward-opening locking groove is provided at the front end of the locking piece. Under the action of a locking piece torsion spring provided on the mounting frame, the locking piece swings upward until its front end abuts against a limit stop bar on the mounting frame. On the head housing, there is a rotatable shaft extending left and right, a locking pin that is reset by a locking pin spring and extends left and right, and a driving member. The inner end of the locking pin is arranged opposite to the inner end of the shaft, and the outer end of the locking pin faces the side where the locking piece is located. A sloping convex platform for pressing the locking pin is provided at the inner end of the shaft, and the outer end of the shaft is fixed to the driving member. The above-mentioned head locking device locks the head when it swings downward to the position for replacing the saw blade, thus facilitating the replacement of the saw blade.

Description

Technical Field

[0001] The present invention relates to the field of power tools, and particularly to a head locking device for facilitating the replacement of a saw blade on a saw. Background Art

[0002] The structure of an existing saw includes: a bottom plate for pressing an object to be sawn during cutting, a mounting bracket, and a head on which a saw blade is mounted. The saw blade is driven to rotate by a motor in the head. The mounting bracket is mounted on the bottom plate, and the rear end of the head is hinged to the mounting bracket so that the head can swing up and down on the mounting bracket. A compression spring is provided between the head and the mounting bracket to push the head upward and make the head reset upward. After the head resets upward and abuts against the limit backstop on the mounting bracket, the saw blade can be located above the bottom plate. Pressing the head downward causes the head to overcome the elastic force of the compression spring and swing downward with the saw blade, and then the saw blade can extend downward out of the bottom plate. The saw blade needs to extend downward out of the bottom plate and be driven to rotate by the motor to cut the object to be sawn. In addition, when the saw blade needs to be replaced, the head also needs to be pressed downward so that the head swings downward against the elastic force of the compression spring to the saw blade replacement position where the mounting screw of the saw blade exposes from the notch on the mounting bracket. During the entire saw blade replacement process, the worker needs to always press the head to keep the head in the saw blade replacement position. Since one hand of the worker needs to press the head, the worker can only use the other hand to replace the saw blade. In this way, replacing the saw blade becomes extremely inconvenient and increases the labor intensity of the worker. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a head locking device for facilitating the replacement of a saw blade on a saw.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows: A head locking device that facilitates the replacement of the saw blade on a saw, comprising: a mounting bracket installed on a base plate, a locking piece located on the side of the head is provided on the mounting bracket, the rear end of the locking piece is hinged to the mounting bracket so that the locking piece can swing up and down, an upwardly opening locking groove is provided at the front end of the locking piece, and the locking piece swings upward under the action of a locking piece torsion spring provided on the mounting bracket until its front end abuts against a limit bar on the mounting bracket. A rotatable shaft extending left and right, a locking pin reset by a locking pin spring and extending left and right, and a driving member are provided on the head housing. The inner end of the locking pin is disposed opposite to the inner end of the shaft, and the outer end of the locking pin faces the side where the locking piece is located. A ramped boss for pressing the locking pin is provided at the inner end of the shaft, and the outer end of the shaft is fixed to the driving member so that the shaft can be driven to rotate by the driving member. After the driving member drives the shaft to rotate forward, the ramped boss can gradually press the locking pin outward through the slope surface, so that the outer end of the locking pin can extend outward to the working position. When the head swings downward, the outer end of the locking pin in the working position can press the locking piece, so that the locking piece can swing downward, so that the outer end of the locking pin can swing downward while abutting against the upper side surface of the locking piece. When the head swings downward to the saw blade replacement position, the outer end of the locking pin just moves above the locking groove. At this time, the locking piece will rotate upward and reset under the action of the locking piece torsion spring, so that the outer end of the locking pin is caught in the locking groove, thereby locking the head by the locking piece. At this time, the head locking mechanism is in the locked state. When unlocking is required, after the driving member drives the shaft to rotate reversely, the ramped boss will gradually release the pressing on the locking pin, so that the locking pin can retract under the action of the locking pin spring and disengage from the locking piece, thereby enabling the head locking mechanism to be in the unlocked state.

[0005] Further, in the above-mentioned head locking device that facilitates the replacement of the saw blade on a saw, the driving member is a handle, the lower end of the handle is fixed to the outer end of the shaft. After the driving handle swings forward, the shaft can be rotated forward, and after the driving handle swings backward, the shaft can be rotated reversely. A front limit convex edge for the forward-swinging handle to abut against to limit the handle forward and a rear limit convex edge for the backward-swinging handle to abut against to limit the handle backward are also provided on the head housing.

[0006] Further, in the above-mentioned head locking device that facilitates the replacement of the saw blade on a saw, a clamping platform is provided at the outer end of the shaft, a clamping groove is provided on the inner side of the lower end of the handle, and the lower end of the handle and the shaft are locked and fixed by screws. When fixing, the clamping platform is caught in the clamping groove, so that the handle can drive the shaft to rotate through the cooperating clamping platform and clamping groove.

[0007] Further, for the above-mentioned head locking device that facilitates the replacement of the saw blade on the electric saw, specifically: on the surface of the head housing opposite to the inner side wall of the handle, there are two elastic sheet holes arranged front and back. In each of the two elastic sheet holes, there is an elastic sheet with one end fixed to the head housing and the other end unfixed. On the outer surface of the unfixed ends of the two elastic sheets, there is a positioning boss protruding outward from the surface of the head housing. The two positioning bosses are respectively a front positioning boss and a rear positioning boss. On the inner side wall of the handle, there is a front positioning hole and a rear positioning hole. When the handle swings back and forth, its inner side wall can respectively squeeze the two positioning bosses. When the positioning boss is squeezed, the elastic sheet where it is located will elastically deform inward, so that the two positioning bosses can move inward and abut against the inner side wall of the handle; when the handle swings forward to abut against the front limiting convex edge, the front positioning boss can just insert into the front positioning hole to perform front positioning on the handle; when the handle swings backward to abut against the rear limiting convex edge, the rear positioning boss can just insert into the rear positioning hole to perform rear positioning on the handle.

[0008] Further, for the above-mentioned head locking device that facilitates the replacement of the saw blade on the electric saw, specifically: above the handle, there is a U-shaped frame straddling the head housing, and one side of the U-shaped frame is fixed to the upper end of the handle.

[0009] The advantages of the present invention are as follows: the head locking device can lock the head when it swings downward to the saw blade replacement position, so that when replacing the saw blade, it is not necessary to manually press the head to keep the head in the saw blade replacement position, which facilitates the replacement of the saw blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a three-dimensional structural schematic diagram of one perspective of the electric saw according to the present invention.

[0011] Figure 2 It is a three-dimensional structural schematic diagram of another perspective of the electric saw according to the present invention.

[0012] Figure 3 It is a three-dimensional structural schematic diagram of the state of the electric saw according to the present invention when replacing the saw blade.

[0013] Figure 4 It is a three-dimensional structural schematic diagram of the head of the electric saw according to the present invention after removing one side of the housing and the handle.

[0014] Figure 5 It is a three-dimensional structural schematic diagram of the electric saw according to the present invention after removing the head.

[0015] Figure 6 It is a structural schematic diagram of the positions of relevant parts when the handle of the electric saw according to the present invention does not swing forward and the motor start button is not pressed.

[0016] Figure 7 This is a schematic structural diagram of the positions of relevant parts when the handle of the present invention swings forward and the motor start button is not pressed.

[0017] Figure 8 is Figure 1 a schematic structural diagram of the handle shown in

[0018] Figure 9 is Figure 1 a schematic structural diagram of the partial housing on the machine head that cooperates with the handle shown in Detailed implementation manners

[0019] The present invention will be further described in detail below in conjunction with specific embodiments and the accompanying drawings.

[0020] Such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7As shown in the figure, the structure of the nose locking mechanism is as follows: A lock piece 43 is arranged on the mounting bracket 9 on the side of the nose 1. The rear end of the lock piece 43 is hinged to the mounting bracket 9, so that the lock piece 43 can swing up and down. An upward-opening lock groove 431 is arranged at the front end of the lock piece 43. Under the action of the lock piece torsion spring arranged on the mounting bracket 9, the lock piece 43 swings upward until its front end abuts against the limit bar on the mounting bracket 9. On the nose 1 housing, a rotatable shaft 41 running left and right, a lock pin 42 running left and right and reset by a lock pin spring, and a driving member 4 are provided. The lock pin spring for resetting the lock pin 42 is located between the lock pin 42 and the nose 1 housing, and the lock pin spring will be compressed when the lock pin 42 is pressed outwards; the inner end of the lock pin 42 is arranged opposite to the inner end of the shaft 41, the outer end of the lock pin 42 faces the side where the lock piece 43 is located, and a sloping convex platform 411 capable of pressing the lock pin 42 is arranged at the inner end of the shaft 41. The outer end of the shaft 41 is fixed to the driving member 4, so that the shaft 41 can be driven to rotate by the driving member 4; moreover, after the shaft 41 is driven to rotate forward by the driving member 4, the sloping convex platform 411 can gradually press the lock pin 42 outwards through the slope surface, so that the outer end of the lock pin 42 can extend outwards to the working position. When the nose 1 swings downward, the outer end of the lock pin 42 in the working position can press the lock piece 43, so that the lock piece 43 can swing downward, so that the outer end of the lock pin 42 can swing downward while abutting against the upper side surface of the lock piece 43. When the nose 1 swings downward to the position for replacing the saw blade, the outer end of the lock pin 42 just moves above the lock groove 431. At this time, the lock piece 43 will rotate upward and reset under the action of the lock piece torsion spring, so that the outer end of the lock pin 42 is caught in the lock groove 431, so that the lock piece 43 can lock the nose 1. At this time, the nose locking mechanism is in the locked state. When unlocking is required, after the shaft 41 is driven to rotate reversely by the driving member 4, the sloping convex platform 411 will gradually release the pressing on the lock pin 42, so that the lock pin 42 can retract under the action of the lock pin spring and disengage from the lock piece 43, so that the nose locking mechanism can be in the unlocked state.

[0021] When the outer end of the locking pin 42 swings downward in the working position, it can press the locking piece 43 because: the movement track of the locking groove 431 is on a small circle with the hinge point of the locking piece 43 as the center, and the movement track of the locking pin 42 is on a large circle with the hinge point of the machine head 1 as the center. The small circle corresponding to the locking groove 431 and the large circle corresponding to the locking pin 42 intersect at two points, and the center of the small circle is inside the large circle. The outer end of the locking pin 42 can be caught in the locking groove 431 because there is an intersection between the two circles, so that the outer end of the locking pin 42 and the locking groove 431 can be caught at the intersection of the two circles. After the outer end of the locking pin 42 is caught in the locking groove 431, the locking piece 43 can lock the machine head 1 because the centers of the movement tracks of the locking pin 42 and the locking groove 431 are not the same. After the locking groove 431 and the locking pin 42 are caught, whether they swing upward or downward, they will limit each other. Thus, the locking pin 42 and the locking groove 431 will be limited at the caught position and cannot swing, so that the locking piece 43 can lock the machine head 1.

[0022] As Figure 1 shown, in this embodiment, the driving member 4 is a handle. The lower end of the handle 4 is fixed to the outer end of the rotating shaft 41. After the driving handle 4 swings forward, it can make the rotating shaft 41 rotate forward. After the driving handle 4 swings backward, it can make the rotating shaft 41 rotate backward. On the shell of the machine head 1, there are also a front limiting convex edge 11 for the forward-swinging handle 4 to abut against to limit the handle 4 forward and a rear limiting convex edge 12 for the backward-swinging handle 4 to abut against to limit the handle 4 backward.

[0023] As Figure 8 shown, a clamping platform 45 is arranged at the outer end of the rotating shaft 41, and a clamping groove 46 is arranged on the inner side of the lower end of the handle 4. The lower end of the handle 4 and the rotating shaft 41 are locked and fixed by screws. When fixed, the clamping platform 45 is caught in the clamping groove 46, so that the handle 4 can drive the rotating shaft 41 to rotate through the matching clamping platform 45 and clamping groove 46.

[0024] As Figure 8 、 Figure 9As shown in the figure, on the surface of the housing of the nose 1 opposite to the inner side wall of the handle 4, there are two elastic sheet holes 7 arranged front and back. In each of the two elastic sheet holes 7, there is an elastic sheet 71 with one end fixed to the housing of the nose 1 and the other end not fixed. On the outer surface of the unfixed ends of the two elastic sheets 71, there is a positioning boss protruding outward from the surface of the housing of the nose 1. The two positioning bosses are respectively a front positioning boss 61 and a rear positioning boss 62. On the inner side wall of the handle 4, there is a front positioning hole 51 and a rear positioning hole 52. When the handle 4 swings back and forth, its inner side wall can respectively squeeze the two positioning bosses. When the positioning bosses are squeezed, the elastic sheet 71 where they are located will elastically deform inward, so that the two positioning bosses can move inward and abut against the inner side wall of the handle 4; when the handle 4 swings forward to abut against the front limit convex edge 11, the front positioning boss 61 can just be inserted into the front positioning hole 51 to perform front positioning on the handle 4; when the handle 4 swings backward to abut against the rear limit convex edge 12, the rear positioning boss 62 can just be inserted into the rear positioning hole 52 to perform rear positioning on the handle 4. Positioning the handle 4 is to prevent the handle 4 from swinging when it is not driven.

[0025] Above the handle 4, there is a U-shaped frame 47 straddling the housing of the nose 1, and one side of the U-shaped frame 47 is fixed to the upper end of the handle 4. Setting the U-shaped frame 47 is on the one hand to more conveniently drive the handle 4 to swing, and on the other hand to guide the forward and backward swing of the handle 4.

Claims

1. A head locking device for facilitating the replacement of a saw blade on a power saw, comprising: a mounting bracket installed on a base plate, a locking piece is arranged on the mounting bracket and located on the side of the head. The rear end of the locking piece is hinged to the mounting bracket, so that the locking piece can swing up and down. An upward-opening locking groove is arranged at the front end of the locking piece. Under the action of a locking piece torsion spring arranged on the mounting bracket, the locking piece swings upward until its front end abuts against a limit stop bar on the mounting bracket. A rotatable shaft running left and right, a locking pin reset by a locking pin spring and running left and right, and a driving member are arranged on the head housing. The inner end of the locking pin is arranged opposite to the inner end of the shaft, and the outer end of the locking pin faces the side where the locking piece is located. A sloping boss for pressing the locking pin is arranged at the inner end of the shaft. The outer end of the shaft is fixed to the driving member, so that the shaft can be driven to rotate by the driving member. After the driving member drives the shaft to rotate forward, the sloping boss can gradually press the locking pin outward through the slope surface, so that the outer end of the locking pin can extend outward to the working position. When the head swings downward, the outer end of the locking pin at the working position can press the locking piece, so that the locking piece can swing downward, so that the outer end of the locking pin can swing downward while abutting against the upper side of the locking piece. When the head swings downward to the saw blade replacement position, the outer end of the locking pin just moves above the locking groove. At this time, the locking piece will rotate upward and reset under the action of the locking piece torsion spring, so that the outer end of the locking pin is caught in the locking groove, so that the locking piece can lock the head. At this time, the head locking mechanism is in the locked state. When unlocking is required, after the driving member drives the shaft to rotate reversely, the sloping boss will gradually release the pressing on the locking pin, so that the locking pin can retract under the action of the locking pin spring and disengage from the locking piece, so that the head locking mechanism can be in the unlocked state.

2. The head locking device for facilitating the replacement of a saw blade on a power saw according to claim 1, characterized in that: The driving member is a handle, the lower end of the handle is fixed to the outer end of the shaft. Driving the handle to swing forward can make the shaft rotate forward, and driving the handle to swing backward can make the shaft rotate reversely. A front limit convex edge for the forward-swinging handle to abut against to limit the handle forward and a rear limit convex edge for the backward-swinging handle to abut against to limit the handle backward are also arranged on the head housing.

3. The head locking device for facilitating the replacement of a saw blade on a power saw according to claim 2, characterized in that: A clamping platform is arranged at the outer end of the shaft, and a clamping groove is arranged on the inner side of the lower end of the handle. The lower end of the handle and the shaft are locked and fixed by screws. When fixed, the clamping platform is caught in the clamping groove, so that the handle can drive the shaft to rotate through the matching clamping platform and clamping groove.

4. The head locking device for facilitating the replacement of a saw blade on a power saw according to claim 2 or 3, characterized in that: On the surface of the machine head housing opposite to the inner side wall of the handle, there are two elastic sheet holes arranged front and back. In each of the two elastic sheet holes, there is an elastic sheet with one end fixed to the machine head housing and the other end unfixed. On the outer surface of the unfixed ends of the two elastic sheets, there is a positioning boss protruding outward from the surface of the machine head housing. The two positioning bosses are respectively a front positioning boss and a rear positioning boss. On the inner side wall of the handle, there is a front positioning hole and a rear positioning hole. When the handle swings forward and backward, its inner side wall can respectively squeeze the two positioning bosses. When the positioning bosses are squeezed, the elastic sheet where they are located will elastically deform inward, so that the two positioning bosses can move inward and abut against the inner side wall of the handle; when the handle swings forward to abut against the front limit convex edge, the front positioning boss can just insert into the front positioning hole to perform front positioning on the handle; when the handle swings backward to abut against the rear limit convex edge, the rear positioning boss can just insert into the rear positioning hole to perform rear positioning on the handle.

5. The machine head locking device for facilitating the replacement of the saw blade on the electric saw according to claim 2 or 3, characterized in that: Above the handle, there is a U-shaped frame straddling the machine head housing, and one side of the U-shaped frame is fixed to the upper end of the handle.

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