1. Field of the Invention
The present invention relates to fixing units. The invention particularly relates to a fixing unit for joining two objects.
2. Description of Related Art
Screws and rivets are commonly used to join two objects. In using screws, a hand tool such as a screwdriver is needed, which can be inconvenient. In using rivets, a special tool is required and the rivets are not reusable.
Referring to
The sleeve assembly 10 includes a first sleeve 12 and a second sleeve 14. The first sleeve 12 defines a through hole 122 along its axis. A thread portion 124 is formed at a lower portion of an inner wall bounding the through hole 122 of the first sleeve 12. A plurality of bar-shaped projections 126 axially extends from a middle portion of the inner wall of the first sleeve 12, and is equably located on the inner wall. A blocking ring 128 extends from a circumference of the inner wall of the first sleeve 12 over the projections 126. The second sleeve 14 defines a through hole 143 along its axis. A thread portion 144 is defined at an upper portion of an outer wall of the second sleeve 14. A lower portion of the second sleeve 14 gradually shrinks down to form a taper portion 142. A blocking ring 148 extends from a circumference of a middle portion of an inner wall bounding the through hole 143 of the second sleeve 14. The first sleeve 12 and the second sleeve 14 are coupled together via engagement of the thread portions 124,144.
The first engaging member 20 includes an rounded base 23, and a pushing pole 22 extending perpendicularly from a central portion of the rounded base 23. A plurality of teeth 24 extends from and is disposed equably along a circumference of the base 23. An engaging groove 26 is formed between every two adjacent teeth 24. The first engaging member 20 defines a through hole 222 along its axis.
The second engaging member 30 includes a pressing part 31, and a sliding pole 32 extending from an end of the pressing part 31. The pressing part 31 and the sliding pole 32 are columns along a same axis. The diameter of the pressing part 31 is greater than the diameter of the sliding pole 32. A teeth part is set on an upper portion of the pressing part 31. An assembly hole (not shown) is defined in a bottom of the pressing part 31. The teeth part includes a plurality of toothed assemblies 34. The toothed assemblies 34 extend from the pressing part 31 and are equably disposed along a circumference of the pressing part 31. Each of the toothed assemblies 34 includes a first tooth 342 and a second tooth 344, wherein the first tooth 342 and the second tooth 344 are connected end-to-end, and each includes a slanted driving surface 346 formed on the top thereof. An engaging groove 36 is formed between every two adjacent toothed assemblies 34.
The splaying member 40 includes a connecting shaft 42, and an elastic claw 44 made up of a plurality of fingers extending from an end of the shaft 42. The elastic claw 44 is expanded in its natural state.
The expandable member 50 is cylinder-shaped with a through hole 52 defined therein. The expandable member 50 is made of flexible materials.
The operating member 60 is discoid-shaped. An assembly hole (not shown) is defined in the bottom of the operating member 60.
The elastic members 70, 80 are coil springs.
Referring also to
Referring also to
In using the fixing unit to join the objects 100, 200, firstly, the expandable member 50 is operated to go through the mounting holes of the objects 100, 200. Secondly, the operating member 60 together with the first engaging member 20 is pressed down. The second engaging member 30 is pushed by the first engaging member 20 to slide down along the projection 126 while the elastic members 70, 80 are compressed, and then rotated left after the top tip of the first tooth 342 passes over the lower end of the projection 126 because of the engagement between the lower tip of the tooth 24 and the slanted driving surface 346 of the first tooth 342, such that the projection 126 is located on the slanted driving surface 346 of the first tooth 342. The splaying member 40 is moved down. Thus, the elastic claw 44 extends out of the taper portion 142 of the second sleeve 14 and expands. The expandable member 50 is expanded by the expanded elastic claw 44. Lastly, the operating member 60 is released. Thus, the elastic member 70 is restored and makes the second and first engaging member 30, 20 rise up. The slanted driving surface 346 of the first tooth 342 engages with the lower end of the projection 126 due to the force of the elastic member 80 to make the second engaging member 30 rotate further, until the projection 126 abuts against a left side of the second tooth 344 of the toothed assembly 34 and cannot move any more. Thus, because the projection 126 engages with the second engaging member 30 preventing vertical movement thereof, the claw 44 is locked in its current extended position. The two objects 100, 200 are sandwiched and joined by the expanded expandable member 50 and the taper portion 142 of the second sleeve 14.
To separate the objects 100, 200, firstly, the operating member 60 is pressed down to drive the first engaging member 20 to slide down along the projection 126 accommodated in the engaging groove 26. The second engaging member 30 is pushed by the first engaging member 20 to move down, and rotated left after the top tip of the second tooth 344 passes over the lower end of the projection 126 because of the engagement between the lower tip of the tooth 24 and the slanted driving surface 346 of the second tooth 344. Secondly, the operating member 60 is released, such that the elastic member 70 is restored and makes the second and first engaging members 30, 20 to rise. The slanted driving surface 346 of the second tooth 344 engages with the lower end of the projection 126 due to the force of the elastic member 80, to make the second engaging member 30 rotate further until the lower end of the projection 126 falls into another engaging groove 36 next to the right side of the second tooth 344 of the toothed assembly 34. The elastic member 80 is restored and makes the first engaging member 20 move up along the projection 126. The elastic member 80 is restored further to make the second engaging member 30 together with the splaying member 40 rise, with the projection 126 accommodating in the another engaging groove 36. Thus, the claw 44 of the splaying member 40 contracts as its retracted back into the second sleeve 14 again, and the expandable member 50 restores to its natural state of contraction. The objects 100, 200 can be easily separated.
Referring to
Certain applications will require more or less retention force by the fixing member. The fixing force of the invention can be adjusted by varying the elasticity of the elastic claw 44. This can be done by altering the size, shape and materials used for the claw 44.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and they will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
Number | Date | Country | Kind |
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200810301507.5 | May 2008 | CN | national |