Method and apparatus for spraying a tack material from a paving machine having a gravity feed hopper

• US 5,851,085 A
• Filed: 12/30/1996
• Issued: 12/22/1998
• Est. Priority Date: 09/29/1994
• Status: Expired due to Term

• Current Assignee: Roadtec Incorporated
• Original Assignee: Astec Industries Incorporated (Johnson Crushers International)
• Inventors: Campbell, Thomas R.
• Primary Examiner(s): Lisehora, James
• Application Number:
  US08/777,774
• Time in Patent Office: 722 Days
• Field of Search: 404/75, 404/79, 404/82, 404/101, 404/108, 404/110, 404/111
• US Class Current: 404/75
• CPC Class Codes: E01C 19/174 Apparatus with pump-discharge
• CPC Class Codes: E01C 19/405 with spreading-out, levelling or smoothing means other than the tamping or vibrating means for compacting or smoothing, e.g. with screws for spreading-out the previously dumped material, with non-vibratory lengthwise reciprocated smoothing beam E01C19/407 takes precedence
• CPC Class Codes: E01C 19/48 for laying-down the materials and consolidating them, or finishing the surface , e.g. slip forms therefor, forming kerbs or gutters in a continuous operation in situ E01C19/002, E01C23/065 take precedence; devices for guiding or controlling the machines along a predetermined path E01C19/004
• CPC Class Codes: E01C 19/4853 Apparatus designed for railless operation, e.g. crawler-mounted, provided with portable trackway arrangements
• CPC Class Codes: E01C 2301/10 Heated screeds
• CPC Class Codes: E01C 2301/30 Cabin details

Abstract

A paving machine employs in combination a gravity feed HMA hopper and a tack spray assembly and storage tank. Use of the gravity feed hopper permits all HMA or other paving material stored therein to be discharged directly on top of the paving machine'"'"'s distributing auger. Moreover, because the gravity feed hopper takes up a relatively small percentage of the horizontal area of the paving machine, a chassis of standard or near standard dimensions can receive a tack storage tank of sufficient capacity to permit the paving machine to operate an entire day without stopping the machine to refill the storage tank. Therefore, if used in conjunction with an HMA shuttling apparatus, the paving machine can simultaneously coat a surface to be paved with a tack material and pave that surface with HMA for prolonged periods of time without stopping to refill either the HMA hopper of the tack storage tank.

Claims

1. A paving machine comprising:

(A) a chassis having a rear end portion;

(B) a distributing auger mounted on said rear end portion of said chassis and extending transversely across said chassis;

(C) a gravity feed hopper mounted on said rear end portion of said chassis;

(D) discharge means, having an inlet communicating with said gravity feed hopper and an outlet located directly above said distributing auger, for discharging paving materials directly on top of said distributing auger, wherein said gravity feed hopper feeds all paving materials stored therein to said discharge means without employing any internal conveyors and without the aid of any external conveyors;

(E) a screed which is mounted on said chassis behind said distributing auger and which works paving materials into a mat, wherein said distributing auger is located between said gravity feed hopper and said screed;

(F) a storage tank which is mounted on said chassis in front of said gravity feed hopper and which stores a tack material; and

(G) a tack material spray assembly which receives tack material from said storage tank and which sprays tack material onto a surface to be paved at a location in front of said discharge opening.

2. A paving machine as defined in claim 1, wherein said storage tank has a capacity of greater than 1000 gallons.

3. A paving as defined in claim 2, wherein said storage tank has a capacity of between 1500 gallons and 1600 gallons.

4. A paving machine as defined in claim 1, wherein said tack material spray assembly comprises 1) a pump having an inlet in fluid communication with tack material in said storage tank and having an outlet, 2) a conduit having an inlet in fluid communication with said outlet of said pump and having an outlet, 3) a spray bar in fluid communication with said outlet of said conduit, said spray bar being mounted on said paving machine proximate said gravity feed hopper and extending transversely across said paving machine, and 4) a plurality of nozzles which are spaced longitudinally along said spray bar and which spray tack material onto the surface to be paved at said location in front of said discharge opening.

5. A paving machine as defined in claim 4, further comprising a tack material heater assembly supported on said chassis, said tack material heater assembly comprising a burner and a liquid-filled coil which receives heat from said burner and which transfers heat by indirect heat transfer to tack material stored in said storage tank.

6. A paving machine as defined in claim 5, wherein a portion of said coil forms a jacket which surrounds said conduit and said spray bar so as to transfer heat to tack material in said conduit and said spray bar.

7. A paving machine as defined in claim 4, wherein said nozzles are spaced along said spray bar at intervals of about one foot, and wherein each of said nozzles has an orifice that is about 1/32 of an inch in diameter.

8. A paving machine as defined in claim 1, wherein said gravity feed hopper has a storage capacity of over 10 tons.

9. A paving machine as defined in claim 8, wherein said storage tank has a storage capacity of over 1,000 gallons.

10. A paving machine comprising:

(A) a chassis having a rear end portion;

(B) a distributing auger mounted on said rear end portion of said chassis and extending transversely across said chassis;

(C) a gravity feed hopper mounted on said rear end portion of said chassis and having a lower discharge opening which discharges paving materials directly on top of said distributing auger and an upper inlet configured to receive paving materials directly from a paving material delivery device located off board said paving machine, wherein said gravity feed hopper feeds all paving materials stored therein to said discharge opening without employing any internal conveyors and without the aid of any external conveyors, wherein said gravity feed hopper includes

a storage portion for storing paving materials, said storage portion including

     1) an upper section for increasing the capacity of said gravity feed hopper, said upper section having a relatively constant width and terminating at an open top, and

     2) a lower generally frusto-conical section having an upper end of enlarged cross section and a lower end of reduced cross section, said upper end of enlarged cross section being connected to said upper section,

a discharge portion for directing paving materials from said storage portion to said discharge opening, a discharge portion upper end connected to said lower end of reduced cross section and a bottom end in which said discharge opening is formed, and

a gate for selectively closing said discharge opening, said gate being mounted on said discharge portion of said gravity feed hopper, and wherein

     1) said discharge opening is located between said storage portion and said distributing auger and

     2) said discharge portion is inclined downwardly and rearwardly towards said distributing auger so as to direct paving materials towards said distributing auger without the aid of any external conveyors;

(D) a screed which is mounted on said chassis behind said distributing auger and which works paving materials into a mat;

(E) a storage tank which is mounted on said chassis in front of said gravity feed hopper and which stores a tack material; and

(F) a tack material spray assembly which receives tack material from said storage tank and which sprays tack material onto a surface to be paved at a location in front of said discharge opening.

11. A paving as defined in claim 10, wherein said storage tank has a rear wall which is sloped so as to generally complement a slope of a front wall of said lower generally frusto-conical section of said gravity feed hopper.

12. A paving machine comprising:

(A) a chassis having a rear end portion;

(B) a distributing auger mounted on said rear end portion of said chassis and extending transversely across said chassis;

(C) a gravity feed hopper mounted on said rear end portion of said chassis and having a lower discharge opening which discharges paving materials from said paving machine, wherein said gravity feed hopper feeds all paving materials stored therein to said discharge opening without employing any internal conveyors and without the aid of any external conveyors, and wherein said gravity feed hopper has a capacity of over 10 tons;

(D) a screed which is mounted on said chassis and which works paving materials into a mat;

(E) a storage tank which is mounted on said chassis in front of said gravity feed hopper and which stores a tack material, said storage tank having a capacity of over 1000 gallons; and

(F) a tack material spray assembly which receives tack material from said storage tank and which sprays tack material onto a surface to be paved at a location in front of said discharge opening.

13. A paving machine as defined in claim 12, wherein said discharge opening discharges paving materials directly on top of said distributing auger.

14. A paving machine as defined in claim 12, wherein said gravity feed hopper has a capacity of about 12 tons and said storage tank has a capacity of between 1500 gallons and 1600 gallons.

15. A paving machine as defined in claim 12, wherein said tack material spray assembly comprises 1) a pump having an inlet in fluid communication with tack material in said storage tank and having an outlet, 2) a conduit having an inlet in fluid communication with said outlet of said pump and having an outlet, 3) a spray bar in fluid communication with said outlet of said conduit, said spray bar being mounted on said paving machine proximate said gravity feed hopper and extending transversely across said paving machine, and 4) a plurality of nozzles which are spaced longitudinally along said spray bar and which spray tack material onto the surface to be paved at said location in front of said discharge opening, wherein each of said nozzles has an orifice that is about 1/32 of an inch in diameter;

and further comprising

a source of heated oil and a jacket which is connected to and receives oil from said source of heated oil, said jacket surrounding said conduit and said spray bar so as to transfer heat to tack material in said conduit and said spray bar.

16. A method comprising:

(A) feeding paving materials directly into a gravity feed hopper of a paving machine from a paving material delivery device located off-board said paving machine, said paving materials including hot mix asphalt, said gravity feed hopper being mounted at a rear end portion of a mobile chassis of said paving machine;

(B) storing said paving materials in said gravity feed hopper, wherein the steps (A) and (B) comprise feeding over 10 tons of paving materials into said gravity feed hopper and storing over 10 tons of paving materials in said gravity feed hopper;

(C) storing a tack material in a storage tank mounted on said chassis in front of said gravity feed hopper;

(D) feeding tack material from said storage tank to a tack spray assembly mounted on said chassis;

(E) spraying a layer of tack material onto a surface to be paved using said tack spray assembly;

(F) discharging said paving materials from a discharge opening of said gravity feed hopper directly on top of a distributing auger extending transversely across said mobile chassis, wherein all of the paving materials stored in said gravity feed hopper are fed out of said gravity feed hopper and onto said distributing auger without employing any internal conveyors and without the aid of any external conveyors;

then

(G) distributing said paving materials onto said layer of tack material using said distributing auger; and

then

(H) working said paving materials into a mat using said paving machine.

17. A method as defined in claim 16, further comprising propelling said paving machine along the surface to be paved at a rate of 20 feet per minute to 40 feet per minute during said steps (C) through (G).

18. A method as defined in claim 16, wherein said spraying step forms a tack material layer having a volume of about 0.05 gallons per square yard.

19. A method as defined in claim 16, wherein the step (C) comprises storing over 1,000 gallons of said tack material in said storage tank.

20. A method as defined in claim 19, wherein the step (C) comprises storing over 1,500 gallons of said tack material in said storage tank.