HIGH ENERGY SCREED FOR A PAVER OR THE LIKE

• US 3,838,933 A
• Filed: 11/21/1972
• Issued: 10/01/1974
• Est. Priority Date: 11/21/1972
• Status: Expired due to Term

• Current Assignee: Caterpillar Paving Products Inc (Caterpillar Incorporated)
• Original Assignee: Fred T. Smith, Herbert A. Lehman
• Inventors: Lehman, Herbert A., Smith, Fred T.
• Primary Examiner(s): Byers, Jr., Nile C.
• Application Number:
  US05/308,535
• Time in Patent Office: 679 Days
• Field of Search: 404/114,106,118,84,113,102,108,101
• US Class Current: 404/114
• CPC Class Codes: E01C 19/4853 Apparatus designed for railless operation, e.g. crawler-mounted, provided with portable trackway arrangements

Abstract

The trailing portion of the screed is connected to the draft arms by leaf springs contained in a vertical transverse plane. The upper ends of the springs are rigidly secured to the draft arms; the lower ends of the springs are connected to the screed by a horizontal, transverse pivot. Vibrators are mounted on the screed adjacent the leading portion thereof. Vertically disposed coil springs have their lower ends engaged with the vibrators for imparting a downward force thereto. The upper ends of these springs support weights, which weights are freely supported by vertical walls mounted from the draft arms.

Claims

1. In a vibratory screed assembly for a paver or the like, the improvement comprising:

a. a frame;

b. a screed having leading and trailing portions;

c. mounting means connecting the trailing portion of the screed with the frame for relative vibratory movement therebetween, said mounting means being defined by spring means which serve as the sole means for transferring draft forces from the frame to the screed;

d. vibrating means connected to the leading portion of the screed;

e. said mounting means and said vibrating means cooperating with each other to impart vibratory motion to the screed characterized by;

1. at least vertical oscillatory movement of the leading portion of the screed;

2. predominantly horizontal longitudinal movement of the trailing portion of the screed;

whereby the amount of vertical vibratory movement of the screed progressively decreases from the leading portion to the trailing portion thereof.

2. orbital movement of the trailing portion of the screed as considered in a vertical longitudinal plane, the amount of vertical vibratory movement of the trailing portion of the screed being substantially less than the amount of vertical vibratory movement of the leading portion of the screed;

whereby the amount of vertical vibratory movement of the screed progressively decreases from the leading portion to the trailing portion thereof.

3. The improvement according to claim 2 wherein said vibrating means includes a vibratory mechanism mounted on the leading portion of the screed and including an eccentric elemenT supported for rotation about a horizontal transverse axis, and spring means engaged with said vibrating mechanism for transferring a vertical downward force to the latter.

4. The improvement according to claim 3 wherein said vibrating means further includes a weight engaged with said spring, said weight being carried by said frame for vertical movement relative thereto.

5. The improvement according to claim 2 wherein said yieldable means include plural leaf springs generally disposed in a vertical transverse plane, said springs having their upper ends fixed to said frame and their lower ends connected to the trailing portion of the screed by transverse horizontal pivot means.

6. In a vibratory screed assembly for a paver or the like, the improvement comprising:

a. a frame;

b. a screed having leading and trailing portions;

c. mounting means connecting the trailing portion of the screed to the frame and permitting at least rocking movement of the screed about a horizontal transverse axis disposed adjacent said trailing portion, said mounting means being defined by spring means which serve as the sole means for transferring draft forces from the frame to the screed;

d. vibrating means connected to the leading portion of the screed;

e. said mounting means and said vibrating means cooperating with each other to impart vibratory rocking movement of said screed about said axis, whereby the amount of vertical vibratory movement of the screed progressively decreases from the leading portion to the trailing portion thereof.

7. The improvement according to claim 6 wherein said mounting means engages said screed adjacent only the trailing portion thereof and constitutes the sole means through which longitudinal draft forces are transferred from said frame to said screed.

8. The improvement according to claim 7 wherein said vibratory means engages said screed adjacent only the leading portion thereof.

9. The improvement according to claim 8 wherein said vibrating means includes a vibratory mechanism mounted on the leading portion of the screed and including an eccentric element supported for rotation about a horizontal transverse axis, and spring means engaged with said vibrating mechanism for transferring a vertical downward force to the latter.

10. The improvement according to claim 9 wherein said vibrating means further includes a weight engaged with said spring, said weight being carried by said frame for vertical movement relative thereto.