1. Field of the Invention
The present invention relates to a staple gun; and more particularly to a staple gun with a safety device and its safety device which can prevent the staples from being discharged by mistake.
2. Description of the Prior Art
Commonly, all staple guns applicable for U-shaped staples are almost light and operated in such a way that the staple exit is made to abut against a plane first, and then the control handle will be pressed to discharge a staple. In recent years, in order to be applicable to the planes with other objects (for example, wire), a conventional staple gun with a staple-floating function was developed on the market, such as the staple gun disclosed in U.S. Pat. No. 6,131,788.
The staple gun disclosed in U.S. Pat. No. 6,131,788 is interiorly provided with a guide device to be operated to guide a guide element toward a staple exit to extend out of the staple gun a predetermined distance. The guide element is defined with a U-shaped notch at a distal end thereof to surround an object like wire, so that a control handle can be used to discharge the staple to surround the wire in such a manner that the two legs of the staple are pressed into the plane where the wire abuts, thus making the staple stand on the plane in a reverse U manner, which is called the staple-floating function. If the staple-floating function is unneeded, the guide device can be operated to retract the guide element into the staple exit of the staple gun.
Although the conventional staple gun has a staple-floating fixing function, such a staple gun having both a staple-floating function and a flat-stapling function (the flat-stapling function means that when a staple is fixed into a pre-determined plane by the staple gun, the staple will abut against the predetermined plane) lacks of a safety structure to ensure the staple to be discharged safely and prevent the staples from being discharged by mistake.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.
The primary objective of the present invention is to provide a staple gun with a safety device, which utilizes the safety device to prevent the staples from being discharged by mistake.
In order to achieve the above objective, a staple gun with a safety device in accordance with the present invention comprises a housing combined by two symmetrical half-housing bases. The housing is defined with a staple exit in a bottom surface thereof and an inner chamber adjacent to the staple exit. The staple exit is in communication with the inner chamber. The inner chamber is provided with a safety device and a staple-floating unit.
The safety device includes a safety push sheet and a switch, a lower end of the safety push sheet extends out of the staple exit, in a middle portion of the safety push sheet is defined an engaging slot along a staple-discharging direction, the safety push sheet is further provided with a triggering sheet at an upper end thereof, the inner chamber is provided with a switch corresponding to the triggering sheet in such a manner that the contact moves upwards with the safety push sheet to turn on the switch to transmit a staple-discharging signal.
The staple-floating unit includes a guide sheet, a control knob, a positioning pin, one end of the guide sheet extends out of the staple exit, a middle portion of the guide sheet is provided with a linkage sheet for penetrating the engaging slot, the other end of the guide sheet cooperates with the safety push sheet to pull both ends of an elastic element in such a manner that the safety push sheet is movably connected to the guide sheet, the guide sheet is provided with a pair of fins above the elastic element, each of the fins includes an elongated transverse hole for penetration of the positioning pin.
The housing is defined with an insertion hole corresponding to the staple-floating unit in such a manner that the control knob is elastically installed in the insertion hole to advance/retreat along the elongated hole, the control knob is located between the two fins, the control knob is defined with a through hole in alignment with the elongated hole for penetration of the positioning pin, both ends of the positioning pin, which penetrate the guide sheet, are limited by the housing, so that the control knob is guided to advance/retreat along the elongated hole, and the positioning pin drives the safety push sheet and the guide sheet to move up and down to enable the safety push sheet and the guide sheet to protrude out of the staple exit, so that the staple gun is able to apply a floating staple.
Further analysis shows that the present invention has the following advantages:
1. The present invention utilizes the safety push sheet to contact the appointed surface first, and then a counter-acting force of contacting the appointed surface will turn on the switch to transmit a disc-discharging signal, thus effectively improving the safety and preventing the staples from being discharged by mistake.
2. The staple-floating unit is movably connected to the safety device of the present invention, so that when the staple gun is used to drive staples into a plane, the guide sheet keeps in a static state without being driven by the safety device to move, in addition, if the staple gun is used to exert the staple-floating function, through the cooperation of the positioning pin and the limiting grooves, the control knob will perform three segments of movement: first, guiding the positioning pin to the start position of the synchronous movement of the safety push sheet and the guide sheet, namely the control knob drives the positioning pin to one end of the elongated hole; second, the positioning pin will linearly move downwards along the limit grooves to cause the safety push sheet and the guide sheet to move synchronously; third, when the guide sheet protrudes out of the staple exit and the staple gun is ready to exert the staple-floating function, the control knob will be pushed back to move transversely to ensure the guide sheet to be positioned, and the safety push sheet is still brought into contact with the appointed surface earlier than the guide sheet to exert the safety function. The staple-floating unit and the safety device of the present invention have no influence on each other and both are installed in the limit space in the staple gun to make the safety device to exert the safety function substantially.
The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.
Referring to
As shown in
The safety device 200 includes a safety push sheet 20 and a switch 25. As shown in
The staple-floating unit 300 includes a guide sheet 30, a control knob 40, a positioning pin 35 and two limit grooves 50 in the inner chamber 11. One end of the guide sheet 30, which is U-shaped in cross section, is defined with an arc notch toward the staple exit 12. The guide sheet 30 is provided with a linkage sheet 32 transversely protruding from a middle portion thereof and a pull hook 33 on the other end thereof for hooking at the other end of the elastic element 23. The guide sheet 30 is further provided with two opposite fins 34 above the pull hook 33 in such a manner that the two fins 34 are located opposite the two housing bases 101, 102. Each of the fins 34 is transversely defined with an elongated slot 341 for penetration of the positioning pin 35, so that the staple-floating unit 300 can be movably connected to the safety device 200.
The control knob 40 installed in the insertion hole 13 includes an elliptic disc portion 41 and a knob portion 42 protruding from a center of the disc portion 41. The disc portion 41 is located on the inner side wall of the inner chamber 11 while only the knob portion 42 extends out of the insertion hole 13. The knob portion 42 can move up and down along the insertion hole 13. The disc portion 41 is further provided with a lateral portion 43 protruding from one side thereof opposite the guide sheet 30, and the lateral portion 43 is defined with a transverse through hole 431 in alignment with the elongated slots 341 for penetration of the positioning pin 35. The disc portion 41 of the control knob 40 is provided with a pillar portion 441 protruding toward a back side of the guide sheet 30, so that the pillar portion 441 and the back side of the guide sheet 30 can hook at both ends of a spring 44, so that the control knob 40 can elastically advance and retreat with respect to the guide sheet 30.
The limit grooves 50 are located in the inner walls of the respective two half-housing bases 101, 102. As shown in
Referring to
Referring to
Further as shown in
While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.