1. Field of Invention
The invention relates to the driving axis of a puller and, in particular, to an improved structure of the driving axis of a puller to prevent the driving axis from causing safety problems due to damage.
2. Related Art
As shown in
However, when the object is engages in the axle part of the machine too tightly, it is usually difficult to rotate the rotating part 71 of the driving axis 7. The user may naturally exert an even larger force in hope of rotating the driving axis 7. If the torque imposed by the user on the driving axis 7 is greater than that sustainable by the driving axis 7, the stress at the junction between the driving axis 7 and the rotating part 71 becomes so large that they break up. What is even worse is that the sudden breakdown of the driving axis 7 may call for a replacement of the entire puller, as it is the primary component thereof. The maintenance is thus higher. Moreover, if the breaking happens during the tightening process of turning the rotating part 71 of the driving axis 7, the user may lose his/her center of gravity and hit the surrounding machines next to the puller, resulting in serious injuries.
An objective of the invention is to provide an improved structure of the driving axis of a puller. With a rotating element to rotate a screw bar and a positioning element to fix the rotating element on the screw bar, only the positioning element will be damaged when the screw bar receives a large torque. This achieves the effect of reducing the maintenance cost.
To achieve the above-mentioned objective, the disclosed improved structure of the driving axis of a puller includes a screw bar, a driving assembly, and a driven assembly. The screw bar has a top end and a bottom end. The driving assembly has a through hole. The driven assembly has a screw hole and is provided with several connecting arms along the radial direction. The driven assembly is underneath the driving assembly. The bottom end of the screw bar goes through the through hole of the driving assembly and the screw hole of the driven assembly.
The invention is further characterized in that the top end of the screw bar has a rotating element for a tool to mount thereon for rotating the screw bar, that the rotating element has a corresponding space to mount on the top end, that one end of the rotating element is formed with a connecting hole connecting to the space, that the screw bar has a positioning hole corresponding to the connecting hole with a positioning element going through the connecting hole and being positioned in the positioning hole, thereby fixing the rotating element on the screw bar to rotate with the screw bar concurrently.
These and other features, aspects and advantages of the invention will become apparent by reference to the following description and accompanying drawings which are given by way of illustration only, and thus are not limitative of the invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
Please refer to
The improved screw bar is combined with the driving assembly and the driven assembly to form a puller. The driving assembly 2 has an accommodating recess 21 for the pivotal connection of a special-shaped nut 22. The top edge of the accommodating recess 21 has an annular groove 23 for embedding a C-shaped buckle, thereby positioning the special-shaped nut 22 in the accommodating recess 21. The driving assembly 2 is formed with a through hole 25. The special-shaped nut 22 has a screw hole 221. The screw bar 1 is screwed through the screw hole 221 of the special-shaped nut 22 and through the through hole 25 of the driving assembly 2. The driving assembly 2 is extended downward with several extension arms 26.
The driven assembly 3 is provided underneath the driving assembly 2. It includes a screw base 31 and a connecting base 32. The connecting base 32 is under the screw base 31. The center of the screw base 31 has a screw hole 311. The center of the connecting base 32 has a connecting hole 321. The screw bar 1 penetrates in sequence through the screw hole 311 of the screw base 31 and the connecting hole 321 of the connecting base 32. The outer part of the screw base 31 is extended outward with several fixing arms 312. The outer part of the connecting base 32 is extended outward with several connecting arms 322. The fixing arms 312 on the screw base 31 and the fixing arms 312 of the screw base 31 alternate in space. The end of each of the extension arms 26 is fixed to the connecting base 32. In this embodiment, each of the extension arms is screw-locked onto the connecting base 32. Moreover, the length of each of the fixing arms 321 of the screw base 31 is greater than that of each of the connecting arms 322 of the connecting base 32. The outer edge of each of the fixing arms 312 of the screw base 31 is pivotally connected with a claw 34. The middle section of each of the claws 34 is pivotally connected with an action arm 35. In this embodiment, the action arm 35 consists of two pieces and pivotally connects to the corresponding connecting arm 322 of the connecting base 32. The end of each of the claws 34 far from the corresponding fixing arm 312 has a hook part 341.
When the invention is in use, as shown in
However, suppose the object is so firmly stuck in the axle part that it is difficult to urge the axle part with a force. If one exerts a force that is not sustainable by the positioning element 13 to rotate the rotating element 11, the positioning element 13 will break. The rotation of the rotating element 11 and the screw bar 1 stops. In comparison with the conventional puller, the maintenance cost of the positioning element 13 is lower. The invention thus has better replaceability. When the exerted force is too large, the positioning element 13 breaks to protect the screw bar 1 from damages. The invention can thus reduce its cost.
When this embodiment is in use, the claws 34 can be adopted to fit various environments. When the claws 34 are installed as shown in
The screw bar 1 is provided with an adjusting element 5 for adjusting and positioning the connecting base 4 under the connecting base 4. The outer edge of one end of the adjusting element 5 has an outer thread section 51 for correspondingly connecting to the screw hole 42 of the connecting base 4. The other end is a rotation section 52 for adjustment and rotation. The adjusting element 5 further has a screw hole 53 that rotates and slides along the screw bar 1. Therefore, the outer thread section 51 of the adjusting element 5 can be fixed in or departed from the screw hole 42 of the connecting base 4.
The bottom end of the screw bar 1 is pivotally connected with a pulling assembly 6 via a connecting element 61. The other end of the connecting element 61 is connected with a pushing bar 62, which in turn is connected with a positioning bar 63 for positioning. Both ends of the positioning bar 63 have a deep cut 631, respectively. Both sides of each of the deep cuts 631 are provided with a sliding hole 632. Each of the deep cuts 631 has a pulling bar 64 protruded outward with a hook part 641. A positioning element 65 goes through each of the sliding hole 632 to limit and position the corresponding pulling bar 64 within the corresponding deep cut 631. Each of the pulling bars 64 can slide along the corresponding deep cut 631.
The end of each of the pulling bar 64 far from the corresponding hook part 641 is connected with an adjusting bar 66 for adjusting the relative distance of the hook parts 641 of the pulling bars 64. Both ends of the adjusting bar are connected with an adjusting element 67 respectively to link with the corresponding pulling bar 64, so that the pulling bars 64 are fixed on the adjusting bar 66.
Afterwards, the user first rotates the adjusting element 5 under the connecting base 4 upwards. The adjusting element 5 is locked via the outer thread section 51 inside the screw hole 42 at the bottom of the connecting base 4, so that the connecting base 4 foes not slide downward. The user then turn the rotating element 11 to drive the screw bar 1, making the connecting base 4 to urge against the axle element downward. At the same time, the pulling assembly 6 and the screw bar 1 displace upwards. This then achieves the goal of departing the bearing R from the axle element.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to people skilled in the art. Therefore, it is contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.