Patent Application
20050109425
1. Field of the Invention
This invention relates to a worktable-elevating device for the planing table of a planer, particularly to one able to move the worktable up and down with quickness.
2. Description of the Prior Art
A conventional planer usually has its worktable moved up and down by manually turning around a hand wheel, wasting labor and time and unable to quickly elevate a planing table. Another conventional planer is provided with an electrically elevating device to drive a planing table to move up and down, having complicated structure and increasing producing cost.
The objective of this invention is to offer a worktable-elevating device for a planer, able to quickly move the worktable up and down by pulling a control rod and automatically actuate the worktable to atop moving by releasing the control rod.
This invention will be better understood by referring to the accompanying drawings, wherein:
A preferred embodiment of a worktable elevating device for a planer in the present invention, as shown in
The bottom base 10 has its four corners respectively fixed with a guide column 11 and has a worm 12 secured at a preset location on one side.
The worktable 20 is slidably fitted on the four guide columns 11 of the bottom base 10 and threadably assembled with the worm 12 of the bottom base 10, able to be moved up and down. The worktable 20 is provided with an actuating shaft 21 on a preset side, a knife shaft 22 for planing and a motor 23 for driving the actuating shaft 21 and the knife shaft 20. The actuating shaft 21 is provided with an actuating chain wheel 24 having an endless chain 25 engaged thereon.
The worktable-elevating device 30, as shown in
The input gear unit 32 consists of a bearing 321, a transmission shaft 323 and a bevel gear 326. The bearing 321 is positioned in the bearing groove 3112 of the vertical bearing holding plate 311 of the base body 31 by a C-shaped lock washer 322. The transmission shaft-323 is pivotally inserted through the bearing 321 and has one end extending-out of the shaft hole 3111 of the vertical bearing holding plate 311 and having a driven chain wheel 325 fixed thereon by a C-shaped lock washer 324, with the drive chain wheel 325 driven to rotate together with the actuating chain wheel 24 of the worktable 20 by means of the endless chain 25, which meshes with the two chain wheels 24 and 325. The bevel gear 326 has its central shaft hole 3261 fitted with the transmission shaft 323 at the inner side of the base body 31 and secured thereon by a C-shaped lock washer 327, letting the bevel gear 326 actuated to rotate with the transmission shaft 323.
The two output gear units 33 are respectively assembled on the upper and the lower horizontal bearing holding plate 314 of the base body 31. Each output gear unit 33 is composed of a bearing 331 and a bevel gear 333. The bearing 331 is positioned in the bearing position groove 3142 of the horizontal bearing holding plate 314 by a C-shaped lock washer 332. The bevel gear 333 is bored with a central shaft hole 3331 to be fitted around the worm 12 of the bottom base 10, with a proper gap formed between the shaft hole 3331 and the worm 12. A shaft tube 3332 extends outward from one side of the shaft hole 3331 of the bevel gear 333 to be pivotally inserted through the bearing 331. In addition, the two bevel gears 333 of the two output gear units 33 and the bevel gear 326 of the input gear unit 32 respectively have their rotation axes inter crossing at 90 degrees so that they can be meshed with each other and driven to rotate reversely. Further, each bevel gear 333 of the two output gear units 33 has the other side, opposite to the shaft tube 3332, annularly provided with four projecting block-shaped engaging teeth 3333.
The worm holder 34 is screwed with the worm 12 between the two output gear units 33 and separated from the two bevel gears 333 at a proper distance. The worm holder 34 is bored with a center threaded hole 341 in the center to be screwed with the worm 12 and has its intermediate outer edge formed with two annular flanges 342 extending outward horizontally, with an annular position groove 343 formed between the two annular walls 342. Further, the worm holder 34 has its upper and lower side respectively provided with four projecting block-shaped engaging teeth 344 to mesh with the block-shaped engaging teeth 3333 of the two bevel gears 333 of the two output gear units 33.
The control rod 35 shaped as an elongate plate has one end pivotally assembled at an intermediate position of one side of the plate cover 315, opposite to the pivotal members 3151, and has a position stud 351 fixed at a preset position near its pivotal fulcrum to be inserted in the annular position groove 343 of the worm holder 34. Thus, when the control rod 35 is pulled upward or downward, the position stud 351 will actuate the worm holder 34 to move up or down to engage with one of the two output gear units 33.
The two elastic compressing units 36 respectively consists of a compressing bolt 361, a compression spring 362 and two locking nuts 363. The pressing bolt 361 is fitted around by the compressing spring 362 and vertically inserted through the pivotal member 3151 of the plate cover 315 to be fixedly positioned thereon by the two locking nuts 363. Thus, two heads 3611 of the two pressing bolts 361 can elastically compress a preset portion of the control rod 35 so as to enable the control rod 35 to automatically recover its original position by the elastic compressing unit 36 after the control rod 35 is pulled upward or downward and then released.
When the worktable elevating device 30 is in a motionless condition, as shown in
In operating and using, as shown in
On the contrary, as shown in
Evidently, the worktable 20 can easily and quickly be moved up or down only by pulling the control rod 35 upward or downward and can be stopped moving up or down by releasing the control rod 35 to let it automatically recover its original position by the recovering resilience of the two elastic pressing units 36, easy in handling and practical worth and industrial profitability.
In addition, a backlash of a preset size between the worm holder 34 of the elevating device 30 and the worm 12 of the bottom base 10 can be set in advance, and the size of this backlash is approximately equivalent to the total of two engaging gaps formed between the worm holder 34 and the two output gear units 33. Thus, when the control rod 35 actuates the worm holder 34 to move upward or downward, the backlash or the engaging gap enables the worm holder 34 to be moved up and down, and when the backlash or the engaging gap is eliminated, the worm holder 34 can closely and smoothly be engaged with the worm 12 or the output gear unit 33.
While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.
