Referring to FIG. 1, a fastener 101 is commonly fastened to a surface 100 of a workpiece in a perpendicular manner. Though it is a fast and easy way to fasten to the surface 100 of the workpiece, the surface 100 of the workpiece is formed with a hole and burrs that are obvious, so that the fastener 101 is unsuitable for use on the surface of a workpiece with higher quality.
To overcome the aforesaid drawback, a fastener installation tool 1, as disclosed in European Patent Publication No. EP2517834 and as shown in FIG. 2, is developed. The fastener installation tool 1 comprises a hollow frame body 11, two positioning mechanisms 12 respectively disposed at two opposite sides of the frame body 11, a handle 13 connected to the frame body 11, and a drive mechanism 14 for driving a left one of the positioning mechanisms 12 as viewed from FIG. 2. Each of the positioning mechanisms 12 includes a positioning block 121 that is movable relative to the frame body 11, a clamping arm 123 connected to and extending downward from the positioning block 121 for clamping and positioning a workpiece (A), and an angled guide passage 124 extending obliquely through the positioning block 121 and the clamping arm 123. The positioning block 121 is formed with a discharge hole 122 communicating with the angled guide passage 124. The drive mechanism 14 includes a spring 141, and a drive handle 142 pivoted to the frame body 11. The spring 141 has one end hooked to the frame body 11, and the other end movable along with the left positioning mechanism 12.
In practice, the drive handle 142 is operated to move in the direction of an arrow 15 so as to drive the positioning block 121 of the left positioning mechanism 12 to move in the direction of an arrow 16. Through cooperation of the clamping arms 123 of the positioning mechanisms 12 and the resilient restoring force of the spring 141, the workpiece (A) is clamped and positioned between the clamping arms 123. Thereafter, two fasteners (B) can be respectively inserted into the angled guide passages 124 and screwed to the workpiece (A).
From the aforesaid structure of the fastener installation tool 1, it is apparent that the fastener installation tool 1 cannot cooperate with a readily available clamping tool for driving, but has to depend only on the drive mechanism 14 which is a special tool. Therefore, the use thereof is limited. Furthermore, the discharge hole 122 is formed in the positioning block 121 of each positioning mechanism 12 such that the chips generated when each fastener (B) is driven into the workpiece (A) must pass through the clamping arm 123 and a portion of the positioning block 121 of a respective positioning mechanism 12 before the chips can be discharged via the corresponding discharge hole 122. As such, the distance moved by the chips is rather long, and the chips are prone to be stuck in the corresponding angled guide passage 124. Moreover, the strength and stability for clamping the workpiece (A) using the resilient restoring force of the spring 141 are insufficient, so that each fastener (B) is likely to deviate when driven into the workpiece (A). This results in bulging and splitting of the workpiece (A).