Patent Application
20190211861
The present invention is related to a screw, in particular, to an expansion screw capable of being installed into a pre-drilled preparatory hole on a wall surface.
Presently, it is known that a conventional expansion screw mainly comprises a sleeve, a screw shaft for penetrating into the sleeve and a nut fastened on the screw shaft. The edge of the screw shaft is formed of an expanded end portion. After the screw shaft penetrates into a preparatory hole pre-drilled on a wall, the nut can be rotated to allow the screw shaft to move outward, and the expanded end portion of the screw shaft is able to expand the bottom end of the sleeve in order to be abutted against the internal of the preparatory hole such that the expansion screw can be secured inside the preparatory hole.
However, before the use of the aforementioned expansion screw, it is necessary to pre-drill the preparatory hole at the desired fastening location by using the tool of an electrical drill etc. In addition, the hole diameter of the preparatory hole needs to match with the outer diameter and length of the expansion screw such that the size thereof cannot be too large or too small. As a result, the installation process of such conventional expansion screw can be tedious and time consuming.
Furthermore, since the drill head is required to perform the drilling operation, it is constantly worn out and may become slim in size overtime. Consequently, in actual operations, the drill head needs to be replaced with new ones from time to time in order to prevent unfit hole diameter of the preparatory hole such that the expansion screw cannot be inserted into the hole or may be jammed inside the preparatory hole.
Finally, to place the expansion screw into the preparatory hole, hammer or rigid object is often required for impacting the expansion screw in order to allow the expansion screw to be completely inserted into the preparatory hole. Nevertheless, the situation of erroneous angles of impact due to difficulties of hammering often occurs, leading to unstable or incomplete installation process.
In view of the above, there is a need to overcome the aforementioned drawbacks. Accordingly, the inventor seeks to resolve the technical difficulties and successfully completes the novel design of the present invention with advantageous technical effects after years of researches and developments along with extensive experience in relevant fields and industries.
In view of the aforementioned drawbacks, the present invention provides a screw apparatus comprising a shaft unit and a sleeve unit. The shaft unit is fastened at the internal of the sleeve unit. The shaft unit includes a first end portion and a second end portion. The second end portion is of a tapered shape such that an outer diameter of the second end portion is greater than an outer diameter of the first end portion. The sleeve unit comprises a holding portion, a locking portion and an expansion portion. The holding portion is attached onto one side of the locking portion opposite thereto. An outer diameter of the holding portion is configured to be greater than an outer diameter of the locking portion. An outer side of the locking portion includes a plurality of locking members formed to circumference thereon. The locking portion and the expansion portion are integrally formed as one piece. The expansion portion includes a plurality of slots formed thereon, and each one of the slots extends to an end surface of the expansion portion. The shaft unit is fastened onto the inner threaded portion of the sleeve unit via the outer threaded portion thereof. The sleeve unit is configured to lock onto an internal of an object via the locking members. In addition, the screw apparatus of the present invention also comprises a fastening unit, which is fastened onto the first end portion of the shaft unit in order to allow the second end portion of the shaft unit to move toward the expansion portion of the sleeve unit; thereby, the second end portion forces the expansion portion to expand outward in order to secure the sleeve unit inside the object.
The primary objective of the screw apparatus of the present invention relies in that: the outer side of the sleeve unit is formed of outer threads such that the sleeve unit is able to attach onto the object more firmly and stably.
To facilitate the understanding of the technical features and the technical effects of the present invention, the following provides a detailed description of exemplary embodiments of the present invention along with the accompanied drawings.
Please refer to
The shaft unit 10 includes a first end portion 11 and a second end portion 12. An outer side of the first end portion 11 includes an outer threaded portion 111 formed to circumference thereon. The second end portion 12 is of a tapered shape such that an outer diameter of the second end portion 12 is greater than an outer diameter of the first end portion 11.
As shown in
The outer diameter of the holding portion 22 is greater than the outer diameter of locking portion 23. An outer side of the locking portion 23 includes a plurality of locking members 231 formed to circumference thereon. In this exemplary embodiment, the locking members 231 are outer threads; however, the present invention is not limited to such configuration only.
The locking portion 23 and the expansion portion 24 are integrally formed as one piece. The expansion portion 23 includes a plurality of slots 241 formed thereon, and each one of the slots 241 extends to the end surface of the expansion portion 24. The shaft unit 10 is fastened onto the inner threaded portion 21 of the sleeve unit 20 via the outer threaded unit 111 thereof. The sleeve unit 20 is locked onto an internal of an object (not shown in the drawings) via the locking member 231; wherein the object can be a wall, cabinet or door plank etc.; however, the present invention is not limited to such objects only, and the user can install the screw apparatus onto any objects according to his or her needs.
As shown in
Please refer to
In the screw apparatus according to the second exemplary embodiment of the present invention, the shaft unit 10 is fastened inside the sleeve unit 20, and the sleeve unit 20 uses the locking member 231 for locking onto an object (not shown in the drawings). The end surface of the first end portion 11 of the shaft unit 10 is formed of a flat-shape slot or a cross-shape slot 40 thereon. As shown in
