GB2543515A

GB2543515A - Screw

Info

Publication number: GB2543515A
Application number: GB1518500.2A
Authority: GB
Inventors: Yang Hui-Ju
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-10-20
Filing date: 2015-10-20
Publication date: 2017-04-26
Also published as: GB201518500D0

Abstract

A screw comprises a circular rod or shank (10), a tip (11), a tool connecting part (12), a thread part (13), and multiple protruding ribs (14). The circular rod (10) has a centre line (101), a tail end (102), and a head end (103). The tip (11) is formed on the tail end (102). The tool connecting part (12) is formed on the head end (103). The thread part. (13) helically extends from the tip (11) to the circular rod (10), The multiple protruding ribs (14) are formed on an outer surface around the tail end (102). The multiple protruding ribs (14) extend on the circular rod (10) and are parallel to the centerline (101), and are adapted to provide a reaming effect to reduce resistance when the tip (11) of the screw is screwed into the workpiece.

Description

1. Field of the Invention

The present invention relates to a screw, especially a screw for screwing wooden workpiece. 2, Description of the Prior Arts

Multiple types of screws are designed according to various applications and functions. Taking a screw for screwing wooden workpiece for example, said screw has a circular rod, a tip, a tool connecting part, and a thread. The tip is formed on a tail end of the circular rod. The tool connecting part is formed on a head end of the circular rod. The thread helically extends from an outer surface of the tip to an outer surface of the circul ar rod. A hand too! or electric tool is connected to the tool connecting part of the screw by a user, and the tip of the screw is disposed towards the wooden workpiece. The screw' is applied with twisting force by the hand tool or the electric tool to make the tip and the thread of the screw bore a hole and tap in the workpiece to be securely screwed with workpiece.

Though the conventional screw is an element for securely fastening the workpiece, the chips produced from the boring and tapping processes are obstructed by thermal expansion caused by the friction acting between the workpiece and the screw'.

In addition, an inclined angle of a thread wall towards the tip is greater than an inclined angle of the other thread wall, so the tapping process of the saw needs a large twisting force and is laborious for user.

To overcome the shortcomings, the present invention provides a screw to mitigate or obviate the aforementioned problems.

The main ob jective of the present invention is to provide a screw to eliminate obstruction of discharging chips of the conventional screw,

The screw in accordance with the present invention comprises a circular rod, a tip, a tool connecting pail, a thread part, and multiple protruding ribs. The circular rod has a centerline, a tail end, and a head end. The tip is formed on the tail end of the circular rod. The tool connecting part is formed on the head end of the circular rod. The thread part helically extends from an outer surface of the tip to an outer surface of the circular rod. The multiple protruding ribs are formed on an outer surface around the tail end of the circular rod and are disposed in multiple thread pitches of the thread part from the tip. The multiple protrading ribs straightly extend on the circular rod and are parallel to the centerline of the circular rod, and a rib depth of each protruding rib is smaller than a thread depth of the thread part.

The conventional screw is applied with twisting force by the hand tool or the electric tool to make the tip and the thread of the screw bore a hole and tap in the workpiece, and the chips produced from the boring and tapping processes of the screw are discharged from the thread part to make the conventional screw' securely fastened with workpiece. The screw in accordance with the present utility model has the multiple protrading ribs. The multiple protruding ribs provi de a reaming effect to reduce resistance of discharging the chips after the tip of the screw' is screwed into the workpiece. So the chips produced from the workpiece are smoothly discharged from the workpiece.

In addition, an inclined angle of a thread wall of the thread part towards tlie tip is smaller than an inclined angle of the other thread wall of the thread, so twisting force applied to the tapping process of the screw is reduced and screwing of the screw is laborsaving for users.

Other objectives, advantages and novel features of the; invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, IN THE DRAWINGS:

Fig. 1 is a perspective view of a preferred embodiment of a screw in accordance with the present invention;

Fig. 2 is a side view' of the screw in Fig. 1;

Fig, 3 is a cross-sectional side view' of the screw along line 3~3 in Fig. 2;

Fig. 4 is an implementing operational view of the screw in Fig. 1, screwed with a workpiece; and

Fig. 5 is another implementing operational view of the screw in Fig. 1, screwed with the workpiece.

With reference to Fig. 1, an embodiment of a screw in accordance with the present utility model comprises a circular rod 10, a tip 11, a tool connecting part 12, a thread part 13, and multiple protruding ribs 14,

With reference to Figs. 1 to 2, the circular rod 10 has a centerline 101, a tail end 102, and a head end 103. The tail end 102 and the head end 103 are respectively formed on two ends of the circular rod 10 relative to the centerline 101 of the circular rod 10. The tip 11 is formed on the tail end 102 of the circular rod 10. The tool connecting part 12 is formed on the head end 103 of the circular rod 10 and a diameter of the tool connecting part 12 is bigger than a diameter of the circular rod 10. The tool connecting part 12 has a tool recess formed on a top surface of the tool connecting part 12. In a preferred embodiment, the tool recess is slotted, cross, polygonal or in any other shape for connecting a hand tool or an electric tool. The thread part 13 helically extends from an outer surface of the tip 11 to an outer surface of the circular rod 10.

With reference to Figs, 1 to 3, the multiple protruding ribs 14 are formed on an outer surface around the tail end 102 of the circular rod 10 and are disposed in multiple thread pitches L of the thread part 13 from the tip 11. The multiple protruding ribs 14 straightiy extend on the circular rod 10 and are parallel to the centerline 101 of the circular rod 10. The multiple protruding ribs 14 are two protruding ribs 14 or four protruding ribs 14 formed straightiy at equal angles to each other on the circular rod 10. In the preferred embodiment, the multiple protruding ribs 14 are disposed and straightiy arranged in a range of two pitches L to four pitches L of the thread part 13 from the tip 1L A rib depth h (the depth that the protruding rib 14 protrudes in a direction of the outer diameter of the circular rod 10) of each protruding rib 14 is smaller than a thread depth H of the thread part 13. In the preferred embodiment, the rib depth h of each protruding rib 14 is from one third to half of the thr ead depth H.

With reference to Figs. 1 to 3, the thread part 13 is a V thread and is triangular viewed from the cross section. The thread part 13 has a first thread wall 131 and a second thread wall 132 respectively formed on two sides of the thread part 13, The first thread wall 131 is disposed on a portion of the thread part 13 that is towards the tip 1 L The second thread wall 132 is disposed on a portion of the thread part 13 that is towards the tool connecting part 12, In the preferred embodiment, the included angle θ 1 between the first thread wall 13 i and a perpendicular 104 of the centerline 101 of the circular rod 10 is smaller than the included angle Θ 2 between the second thread wall 132 and the perpendicular 104 of the centerline 101 of the circular rod 10. The included angle Θ 1 is an angle of 5 to 20 degrees. The included angle Θ 2 is an angle of 25 to 45 degrees.

With reference to Figs. 4 and 5, when the present invention is applied to fasten the workpieces 20, 30, the tool connecting part 12 of the screw is connected to a hand tool or an electric tool by a user, and the screw is rotated by the hand tool or the electric tool. The screw is screwed into the workpieces 20, 30, and the tip 11 and the thread part 13 of the screw start boring a hole and tapping in the workpieces 20, 30. The chips produced from the boring and tapping processes of the screw to the w'orkpieces 20,30 are discharged along the space formed in the thread part 13 and the circular rod 10. Besides, the multiple protruding ribs 14 provide a reaming effect to reduce resistance of discharging the chips when the tip 11 of the screw' is screwed into the wOrkpieces 20, 30. So the chips produced from the workpiece 20,30 are smoothly discharged from the workpieces 20, 30.

Furthermore, when the screw is screwed into the workpieces 20, 30, an inclined angle of the first thread wall 131 of the thread part 13 towards the tip 11 is smaller than an inclined angle of the second thread wall 132 of the thread 13, thereby reducing twisting force applied to the boring and tapping process of the screw to save labor for user.

Claims

CLAIMS:

1. A screw comprising: a circular rod (10) having a centerline (101); and a tail end (102) and a head end (103) respectively formed on two ends of the circular rod (10) relative to the centerline (101) of the circular rod (10); a tip (11) formed on the tail end (102) of the circular rod (10); a tool connecting part (12) formed on the head end (103) of the circular rod (10); and a thread part (13) helically extending from an outer surface of the tip (11) to an outer surface of the circular rod (10); and multiple protruding ribs (14) formed on an outer surface around the tail end (102) of the circular rod (10) and disposed in multiple thread pitches of die thread part (13) from the tip (11). the multiple ribs straightly extending on tire circular rod (10) and parallel to the centerline (101) of the circular rod (10). and a rib depth (h) of each protruding rib (14) being smaller than a thread depth (H) of the thread part (13).

2. The screw as claimed in claim 1, wherein the multiple protruding ribs (14) are two protruding ribs (14) formed straightly on the circular rod (10), and the two protruding ribs (14) are disposed in a range of two pitches to four pitches of the thread part (13) from the tip (11).

3. The screw' as claimed in claim 1, wherein the multiple protruding ribs (1.4) are four protruding ribs (14) formed straightly on the circular rod (10), and the four protruding ribs (14) are disposed in a range of two pitches to four pitches of the thread part (13) from the tip (11).

4. The screw as claimed in any one of claims 1 to 3, wherein the rib depth (h) of each protruding rib (14) is from one third to half of the thread depth (H) of the thread part (13).

5. The screw as claimed in any one of claims 1 to 4. wherein the thread part (13) is a V thread and has a first thread wall (131) disposed on the thread part (13) toward the tip (11); and a second thread wail (132) disposed on the thread part (13) towards the tool connecting part (12); wherein an included angle (Θ 1) between the first thread wall (131) and a perpendicular (104) of the centerline (101) of the circular rod (10) is smaller than an included angle (Θ 2) between the second thread wall (132) and the perpendicular (104) of the centerline (101) of the circular rod (10).

6. The screw as claimed in claim 5, wherein the included angle (Θ 1) between the first thread wall (131) and the perpendicular (104) of the centerl ine (101) of the circular rod (10) is 5 to 20 degrees, and the included angle (0 2} between the second thread wall (132) and the perpendicular (104) of the centerline (101) of the circular rod (10) is 25 to 45 degrees.