Patent Publication Number: US-6666243-B1

Title: Height-adjustable workpiece feeding device for a wood planing machine

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of Taiwanese Application No. 091215803, filed on Oct. 4, 2002. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a height-adjustable workpiece feeding device for a wood planing machine, more particularly to a height-adjustable workpiece feeding device with feed-in and take-out rollers which can be moved synchronously in an upright direction relative to a worktable of the wood planing machine. 
     2. Description of the Related Art 
     Referring to FIG. 1, a conventional wood planing machine is shown to include a mounting frame  11 , a worktable  13  which is movably mounted on the mounting frame  11 , a support carriage  12  which is movably mounted above the worktable  13  to confine a working passage  100  therebetween, and rubber feed-in and take-out rollers  141  (only one is shown) which are rotatably and respectively mounted on two sides of the support carriage  12 . A height-adjusting member includes four sliding blocks  142  (only two are shown) which are respectively disposed on two ends of the rollers  141 , four adjusting rods  143  (only two are shown) which are respectively disposed on top sides of the sliding blocks  142  and which extend outwardly of the mounting frame  11 , four screw nuts  144  (only two are shown) which are respectively disposed on the adjusting rods  143 , and four adjusting nuts  145  (only two are shown) which are respectively disposed on top ends of the adjusting rods  143 . 
     When it is desired to adjust the feed-in and take-out rollers  141  to a desired height, the adjusting nuts  145  are rotated to move the adjusting rods  143  and the rollers  141  upwardly and downwardly. However, since the adjusting rods  143  are moved separately by means of the adjusting nuts  145 , it is difficult to maintain the two ends of each of the feed-in and take-out rollers  141  at a same level, and it is likewise difficult to maintain the feed-in and take-out rollers  141  at a same level, thereby requiring calibration, which is time-consuming and inconvenient. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a height-adjustable workpiece feeding device for a wood planing machine, which permits convenient height adjustment of feed-in and take-out rollers of the device. 
     According to this invention, the height-adjustable workpiece feeding device includes a support carriage for supporting a cutter shaft of a wood planing machine thereon. The support carriage has right and left carriage sides which are respectively mounted on right and left sides of a mounting frame and above a worktable, and feed-in and take-out sides opposite to each other in a transverse direction. The support carriage is movable in an upright direction, and has two guideways which are disposed in the feed-in and take-out sides, respectively. Each of the guideways extends in the upright direction. 
     Two cam follower units are respectively received in the guideways and are respectively slidable along the guideways between upper and lower positions relative to the worktable. Each of the cam follower units has an engaging surface which faces downwardly. 
     Feed-in and take-out rollers are respectively journalled on the cam follower units so as to be rotatable about a first axis parallel to a cutter axis of the cutter shaft. 
     A connecting rod unit has two rod ends which are respectively mounted on the feed-in and take-out sides of the support carriage, and which are rotatable about a second axis transverse to the first axis. 
     Two cam units are respectively secured on the rod ends of the connecting rod. Each of the cam units has a cam surface which includes a first region and a second region that is disposed behind the first region in a clockwise direction about the second axis. As such, the cam units are synchronously rotatable by the connecting rod unit between a first position, where the first regions of the cam units respectively abut against the engaging surfaces of the cam follower units so as to place the cam follower units in the upper position, and a second position, where the second regions of the cam units respectively abut against the engaging surfaces of the cam follower units so as to place the cam follower units in the lower position. 
     Each of two biasing members is disposed to bias each of the cam follower units towards the cam surface of a respective one of the cam units. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which: 
     FIG. 1 is a schematic side view of a conventional wood planing machine; 
     FIG. 2 is a fragmentary perspective view of a preferred embodiment of a height-adjustable workpiece feeding device according to this invention when incorporated in a wood planing machine; 
     FIG. 3 is a schematic side view of the preferred embodiment when incorporated in the wood planing machine; 
     FIG. 4 is a fragmentary perspective view of a portion of the preferred embodiment; 
     FIG. 5 is a fragmentary perspective view of another portion of the preferred embodiment; 
     FIG. 6 is a schematic rear view of the preferred embodiment when incorporated in the wood planing machine; 
     FIG. 7 is a fragmentary, partly sectional schematic view of a retaining member of the preferred embodiment; 
     FIG. 8 is a schematic view of a rotary knob of the retaining member; 
     FIG. 9 is a partly sectional view showing a cam of the preferred embodiment in a first position; 
     FIG. 10 is a partly sectional view showing the cam in a second position; and 
     FIG. 11 is a partly sectional view showing the cam in a third position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 2 and 3, the preferred embodiment of a height-adjustable workpiece feeding device according to the present invention is shown to be mounted on a wood planing machine that includes a mounting frame  22  with two right side columns  23  and two left side columns  23  spaced apart from each other in a longitudinal direction, a worktable  24  mounted on lower portions of the columns  23  for supporting a workpiece (not shown) thereon, and a cutter shaft  25  driven by a motor (not shown) to be rotatable about a cutter axis in the longitudinal direction. 
     The height-adjustable workpiece feeding device is shown to comprise a support carriage  21 , two cam follower units, feed-in and take-out rollers  26 , a connecting rod unit, two cam units, and two biasing members. 
     The support carriage  21  is adapted for supporting the cutter shaft  25  thereon. The support carriage  21  has right and left carriage sides which are adapted to be respectively sleeved on the right and left side columns  23  and to be disposed above the worktable  24 , and feed-in and take-out sides opposite to each other in a transverse direction relative to the longitudinal direction such that the support carriage  21  is movable in an upright direction transverse to the longitudinal and transverse directions. The support carriage  21  has two guideways which are disposed in the feed-in and take-out sides, respectively. Each of the guideways includes right and left guiding grooves  30  which are respectively formed in the right and left carriage sides and each of which extends in the upright direction to terminate at an upper inner wall surface of the support carriage  21 . The upper inner wall surface has an engaging concavity  212 , as shown in FIGS. 3 and 4. 
     Each of the cam follower units includes right and left followers  31  which are respectively received in the right and left guiding grooves  30  of a respective one of the guideways, and which are slidable therealong to a predetermined position relative to the worktable  24 . Each of the right and left followers  31  has an engaging surface  312  which faces downwardly. 
     Each of the feed-in and take-out rollers  26  has right and left roller ends which are respectively journalled on the right and left followers  31  of a respective one of the cam follower units so as to be rotatable about a first axis parallel to the cutter axis. 
     The connecting rod unit includes right and left rods  33  which are respectively and rotatably mounted on the right and left carriage sides of the support carriage  21 . Each of the right and left rods  33  has front and rear rod ends which are respectively mounted on the feed-in and take-out sides of the support carriage  21 , and which are rotatable about a second axis transverse to the first axis. 
     Each of the cam units includes right and left cams  34 . The right cams  34  of the cam units are respectively secured on the front and rear rod ends of the right rod  33 . The left cams  34  of the cam units are respectively secured on the front and rear rod ends of the left rod  33 . With reference to FIG. 4, each of the right and left cams  34  has a cam surface which includes first, second and third regions  341 , 342 , 343  that are disposed one behind another in a clockwise direction about the second axis. As such, when one of the right and left rods  33  is rotated, the cams  34  secured thereon are rotated synchronously therewith among a first position, where the first regions  341  of the cams  34  respectively abut against the engaging surfaces  312  of the respective followers  31  so as to place the followers  31  in an upper position, as shown in FIG. 9, a second position, where the second regions  342  of the cams  34  respectively abut against the engaging surfaces  312  of the respective followers  31  so as to place the followers  31  in an intermediate position, as shown in FIG. 10, and a third position, where the third regions  343  of the cams  34  respectively abut against the engaging surfaces  312  of the respective followers  31  so as to place the followers  31  in a lower position, as shown in FIG.  11 . 
     With reference to FIGS. 3 and 9, each of the biasing members includes two coiled springs  32 , each of which is disposed in a respective one of the right and left guiding grooves  30  of a respective one of the guideways so as to bias the respective follower  31  toward the corresponding cam  34 . Each coiled spring  32  includes an inner compression spring part  321  which has two ends that respectively abut against the respective engaging concavity  212  and an abutting groove  311  in the respective follower  31 , and an outer compression spring part  322  which is disposed to surround the inner compression spring part  321 . The inner and outer compression spring parts  321 , 322  of each coiled spring  32  extend in opposite spiraling directions so as to stabilize the resilient force of the coiled spring  32 . 
     Referring to FIGS. 4,  7  and  8 , a retaining member  35  includes a rotary knob  351  which is secured on the rear rod end of one of the right and left rods  33  adjacent to the take-out side of the support carriage  21  and which has a retaining surface formed with three engaging recesses  355  that are angularly displaced from one another, a mounting slot  352  which is formed in the take-out side, an engaging ball  354  which is received in the mounting slot  352  and which confronts the retaining surface of the rotary knob  351 , and a compression spring  353  which is disposed in the mounting slot  352  to bias the engaging ball  354  toward the retaining surface of the rotary knob  351 . Thus, when the rotary knob  351  is rotated to rotate the respective rod  33 , the engaging ball  354  is pressed inwardly of the mounting slot  352  against the biasing action of the compression spring  353 . The engaging ball  354  can engage a corresponding one of the engaging recesses  355  when the cams  34  are in one of the first, second and third positions, thereby preventing rotation of the rod  33 . 
     Referring to FIGS. 5 and 6, a coupling mechanism  36  includes right and left gears  361  which are respectively mounted on and which are rotated with the rear rod ends of the right and left rods  33 , a first transmitting gear  3621  which is meshed with the left gear  361 , a second transmitting gear  3622  which is meshed with the first transmitting gear  3621 , a third transmitting gear  3631  which is meshed with the right gear  361 , and a transmitting shaft  364  which has right and left shaft ends respectively provided with two worm gears  3641  that are respectively meshed with the second and third transmitting gears  3622 , 3631 . As such, a rotational force applied to rotate one of the right and left rods  33  in one direction will be transmitted to rotate the transmitting shaft  364  so as to rotate synchronously the other one of the right and left rods  33  in the opposite direction. 
     Referring to FIGS. 3,  4  and  9 , in a wood planing operation, a workpiece (not shown) is placed on the worktable  24 . The feed-in and take-out rollers  26  are held in an uppermost position where the cams  34  are in the first position, as shown in FIG.  9 . When it is desired to move the feed-in and take-out rollers  26  to a lower position, a hand tool (not shown) is used to rotate the rotary knob  351  so as to rotate the respective rod  33  until the engaging ball  354  engages an appropriate one of the engaging recess  355 , i.e. the respective cams  34  are in the second or third position as shown in FIG. 10 or  11 , thereby lowering the corresponding roller ends of the feed-in and take-out rollers  26  due to the difference in the distances from the respective rods  33  to the first, second and third regions  341 , 342 , 343 . In addition, since the two rods  33  are rotated synchronously by means of the coupling mechanism  36 , the other roller ends of the feed-in and take-out rollers  26  are lowered synchronously. 
     It is noted that although the cam surface of each cam  34  in this embodiment is shown to include three regions  341 , 342 , 343 , it can be configured to have two or more than three regions according to requirements. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.