Claims
- 1. A driven feed assembly for an abrasive surfacer having at least one pair of vertically spaced apart upper and lower abrasive heads, the feed assembly comprising:
- (a) feedworks means including opposed upper and lower conveying assemblies each mounted to a frame and relative to a reference center plane between said upper and lower abrasive heads for substantially centering the upper and lower surfaces of workpieces relative to the center plane and for conveying the workpieces longitudinally past said upper and lower abrasive heads so as to cause each workpiece to simultaneously and substantially equally engage the upper and lower abrasive heads as they are conveyed thereby;
- (b) said upper conveying assembly comprising a plurality of resilient and passive upper pinch rollers, each pinch roller comprising a generally transverse row of upper pinch wheels mounted to contacting workpieces passing thereunder, wherein each of said pinch wheels includes inner and outer annular layers of different hardness, each inner annular layer comprising a relatively soft and resilient material, each outer annular layer comprising a relatively harder material said wheels independently contacting and, by elastic deformation of their respective inner and outer layers, applying a corrective downward force to the opposed upper surface portion of the workpieces along contact lines as the workpieces pass thereunder;
- (c) said lower conveying assembly comprising an endless driven conveyor belt having a pluraity of passive and resilient idler rollers mounted between an associated drive conveyor roller and an idler conveyor roller and contacting the inside upper surface of said conveyor belt in opposed relationship to said upper pinch rollers and substantially parallel to the contact lines of said upper pinch rollers, whereby said idler rollers, acting through said conveyor belt, apply corrective upward forces to the workpieces as they are conveyed thereover by said conveyor belt; and
- (d) a pneumatic spring means for independently biasing each of said upper pinch wheels downward against its associated one of said workpieces, and for permitting upward movement of said upper pinch wheels in response to a portion of unusual thickness of warpage in said workpiece.
- 2. The driven feed assembly of claim 1 wherein: the radial dimension of each said inner annular layer is greater than the radial dimension of its associated outer annular layer.
- 3. The driven feed assembly of claim 2 wherein: each of said inner annular layers comprises a material of approximately 20 durometer, and each of said outer annular layers comprises a material of a durometer of between about 70 and 80.
- 4. The driven feed assembly of claim 2 wherein: each of said passive and resilient idler rollers of said lower conveying assembly comprises a generally transverse row of lower pinch wheels, each lower pinch wheel including inner and outer annular layers of different hardness, each inner annular layer comprising a relatively soft and resilient material, and each outer annular layer comprising a relatively harder material.
- 5. The driven feed assembly of claim 4 including a lower pneumatic spring means for independently biasing each of said lower pinch wheels upward against said conveyor belt as the conveyor belt carries an associated one of said workpieces thereover, ad for permitting downward movement of said lower pinch wheel in response to a portion of unusual thickness or warpage in said workpiece.
- 6. The driven feed assembly of claim 1 wherein: the upper pinch wheels in each pinch roller are transversely spaced apart from one another, and transversely offset from the pinch wheels in each adjacent pinch roller.
- 7. The driven feed assembly of claim 1 wherein: said pneumatic spring means includes an air mount associated with each upper pinch wheel, and wherein a support means for supporting each of said upper pinch wheels relative to said frame comprises:
- (a) a first mounting member fixedly mounted to said frame;
- (b) first and second side plates transversely spaced apart from one another via an intermediate orthogonal second mounting member;
- (c) a first axle passing through said first and second side plates and means clamping said first axle between said side plates such that said side plates may rotate about said first axle;
- (d) a second axle contained between said first and second side plates for mounting one of said upper pinch wheels rotatably relative to said first and second side plates; and
- (e) one of said air mounts positioned between said frame and said first and second side plates and overlying said upper pinch wheel, whereby said pinch wheel may resiliently rise and fall while said air mount applies a corrective vertical force whenever said upper pinch wheel encounters unusual warpage of the like in the workpieces.
- 8. The driven feed assembly of claim 1 further including:
- (a) a first and second pair of links, each link pivotally mounted at one end with respect to said frame and at the other end with respect to an upper shroud located above said center plane, and an upper contact shoe mounted to said upper shroud downstream from said feedworks means and proximate said center plane;
- (b) a third and fourth pair of links, each link pivotally mounted at one end with respect to said frame and at the other end with respect to a lower shroud located below said center plane, and a lower contact shoe mounted to said lower shroud in opposed relation to said upper contact shoe;
- (c) an upper biasing means for urging said upper shroud and contact shoe downwardly toward said center plane, and a lower biasing means for biasing said lower shroud and contact shoe upwardly toward said center plane;
- (d) said first and second pairs of links being substantially equal in length, and said third and fourth pairs of links being substantially equal in length;
- (e) said upper and lower biasing means providing substantially equal mechanical bias to said upper and lower contact shoes, respectively, whereby said shoes, when moved apart by workpieces against the force of their respective biasing means, tend to center the workpieces on said center plane.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 509,793, filed July 1, 1983, now abandoned, which in turn was a continuation of application Ser. No. 258,613, filed Apr. 29, 1981, now abandoned.
US Referenced Citations (17)
Foreign Referenced Citations (1)
Number |
Date |
Country |
190266 |
Jun 1957 |
ATX |
Continuations (2)
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Number |
Date |
Country |
Parent |
509793 |
Jul 1983 |
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Parent |
258613 |
Apr 1981 |
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