US3596608A

US3596608A - Hopper door actuating mechanism

Info

Publication number: US3596608A
Application number: US777430A
Authority: US
Inventors: Herman A Aquino; Ernest J Nagy; William R Shaver
Original assignee: Pullman Inc
Current assignee: Pullman Standard Inc; Pullman Inc
Priority date: 1968-11-20
Filing date: 1968-11-20
Publication date: 1971-08-03
Anticipated expiration: 1988-08-03

Abstract

This invention relates to a vehicle discharge arrangement for hoppers which may be carried by a railway car or other type of vehicle. Bottom doors are pivoted about a generally horizontal axis to open lowered and closed raised positions and are provided at their lower ends with edge portions positioned in overlapping closed positions. One door is operated by a transversely extending arm which in turn is moved by means of a vertical lever pivoted on a supporting sill extending longitudinally of the vehicle. The other door is interconnected to move with the first door by means of a linkage and bellcrank mechanism which permits the first door to move initially out of the closed position before any substantial movement of the second door occurs. In a partially opened position the overlapping edge portion of the first door is out of the way of the second door which then can pivot to its open position. The linkage and bellcrank mechanism, as well as the transverse arm and vertical lever means, are arranged to be positioned in overcenter locking configurations to positively secure the doors in their closed positions.

Description

United States Patent [72] Inventors Herman A. Aquino Hobart; Ernest J. Nagy, Munster; William R. Shaver, Mumer, all of, Ind. [21 Appl. No. 777,430 [22] Filed Nov. 20, 1968 (45] Patented Aug. 3, 1971 [73] Assignee Pullman incorporated Chicago, Ill.

[54] HOPPER DOOR ACTUA'I'ING MECHANISM 22 Claims, 7 Drawing Fig.

Primary Examiner-Arthur L. La Point Assistant Examiner-Howard Beltran Attorneys-J-lilmond O. Vogel and Wayne Morris Russell ABSTRACT: This invention relates to a vehicle discharge arrangement for hoppers which may be carried by a railway car or other type of vehicle. Bottom doors are pivoted about a generally horizontal axis to open lowered and closed raised positions and are provided at their lower ends with edge portions positioned in overlapping closed positions. One door is operated by a transversely extending arm which in turn is moved by means of a vertical lever pivoted on a supporting sill extending longitudinally of the vehicle. The other door is interconnected to move with the first door by means of a linkage and bellcrank mechanism which permits the first door to move initially out of the closed position before any substantial movement of the second door occurs. In a partially opened position the overlapping edge portion of the first door is out of the way of the second door which then can pivot to its open position. The linkage and bellcrank mechanism, as well as the transverse arm and vertical lever means, are arranged to be positioned in overcenter locking configurations to positively secure the doors in their closed positions.

PATENTEU AUG 3 I97! SHEET 1 BF 4 0 WWM X m AV N W Jmw W MM MR y REL PATENIEnms 3:911 3,596, 0

sum 2 or 4 INVENTORS HERMAN A. AOUINO ERNESTJ. NAGY WILLIAM R. SHAVER BY 40. 0M

M ATT'Y.

PATENTED AUG 3 l9?! SHEET 3 OF 4 INVENTORS HERMAN A.AOUINO ERNEST J. NAGY WILLIAM R. SHAVER ATT Y.

PATENTED M18 3 I971 SHEET '4 BF 4 IN VENTORS HERMAN A. AQUINO ERNEST J. NAGY WILLIAM R. SHAVER M (9/ ATTY.

HOPPERIJOOR ACTUA'IING MECHANISM SUMMARY The primary object of the invention is to provide an improved door opening mechanism for bottom discharge of a hopper which permits quick positive opening and closing of the doors with an improved door actuating mechanism and door configuration. In the closed position overlapping edge portions of the doors provide an effective closure and are securely retained against opening by overcenter linkage and DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a railway hopper car;

FIG. 2 is an enlarged sectional view of a door-operating mechanism taken substantially along line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is a side elevational view, partially in section, taken along the line 4-4 of FIG. 3;

FIG. 5 is a cross-sectional view taken along the line 5-5 of FIG. 3;

FIG. 6 is a perspective view of a portion of a hopper car showing a door-operating mechanism; and

FIG. 7 is a cross-sectional view taken substantially along the line 7-7 of FIG. 2.

DETAILED DESCRIPTION FIG. 1 discloses a railway hopper car 10, supported on a wheeled underframe 11 which includes a longitudinally extending center sill 12 formed of channel members 13 connected at their upper ends by top plates 14 and bottom plates 15 extending longitudinally along said center sill. Theplates l4 and 15 are spaced to provide four openings 16 aloiig said center sill 12, one of said openings 16 being best shown in FIGS. 2, 3, and 6. As best shown in FIG. 1, the hopper car 10 is provided with conventional vertical side walls 17. In the disclosure shown in FIG. 1 the hopper car 10 includes hopper structures designated generally at 18. A pair of these identical hopper structures 18 are provided on each side of the center sill 12, the said hopper structures 18 as best shown in FIG. 1 being in longitudinally spaced and aligned relation. Each hopper structure 18 includes

end slope sheets

19 and 20 with a partition wall 21, as shown in FIG. 1, separating each pair of hopper structures 18. EAch hopper structure 18 also includes, as best shown in FIG. 3, an inner slope sheet 22 adjacent the center sill 12. The hopper structures 18 are supported on the wheeled underframe 11 in a suitable manner not disclosed in detail.

A pair of door-actuating mechanisms 23 are supported on the center sill 12 in longitudinally spaced relation. Each actuating mechanism 23 comprises two vertical levers 24 which are pivotally connected as indicated at 25 to angle brackets 26 suitably supported on the center sill 12. The vertical levers 24 extend through the openings 16 in the center sill l2 and project downwardly with respect thereto. Guide angles 27 suitably connected to the center sill I2 guide the lower ends of the levers 24, as best shown in FIG. 3. Longitudinally extending actuating means 28 are pivotally connected'as indicated at 29 to the levers 24 and in tum are connected to piston assemblies 28', as shown in FIG. 1, of pneumatic cylinders 29 supported at opposite ends of the car 10 as best shown in FIG. 1. Pneumatic cylinders 29 may be suitably connected to a source of pressure for moving the beams 28 in a longitudinal direction, thereby actuating pivotal movement of the levers 24 which actuate door operating mechanisms 52 at respectively opposite sides of center sill 12 to open or close pairs of

doors

38 and 39 at each side of the center sill.

The lower ends of the levers 24 are provided with pivot brackets 30 disposed on opposite sides of said levers 24. Each pivot bracket 30 includes a socket 31 in which a ball 32 is swiveled. Each ball 32 is suitably connected to an arm 33 as best shown in FIG. 3, extending laterally outwardly in opposite directions with respect to the center sill 12. A ball 34 is connected to the other end of each arm 33 and is suitably swiveled in a socket 35 provided in pivot brackets 36. The pivot brackets 36 are secured to a pair of connecting structures 37 which in turn are suitably connected to the bottom side of each bottom door generally designated at 38. Each hopper structure 18 is provided with a bottom master door 38 and a bottom slave door each of which is vertically pivotal with respect to an opening 40 designated in FIG. 3, at the lower end of each hopper structure 18. The

doors

38 and 39 are provided with hinge elements 41 hingedly connected by means of hinge pins 42 to brackets 43. The brackets 43 for the door 38 are suitably connected to the center sill structure 12 and the brackets 43 for the door 39 are suitably connected to a horizontally extending angle structure 44 suitably connected to the outer surface of the side walls 17 as best shown in FIG. 3. The

doors

38 and 39 also include upwardly extending end flanges 45 and the end slope sheets 19 adjacent the opening 40 are provided with outwardly projecting flanges 46.

As best shown in FIG. 3, the

doors

38 and 39 are disposed in relative V-shaped relation and include inner converging

bottom sheets

47 and 48 which as best shown in FIG. 7 are provided at their lower edges with

horizontal flanges

49 and 50 respectively on said

bottom sheets

47 and 48. The flat

horizontal edge portions

49 and 50 are in the closed position of the

doors

38 and 39 in overlapping relation as indicated. A longitudinally extending reinforcing member 51 is connected to the flat portion 49 and to the outer surface of the door 38 as indicated in FIG. 7.

The hopper structure 18 at each side of the center sill 12 includes at opposite ends thereof a pair of linkage and bellcrank mechanisms generally designated at 52. Each such actuating mechanism 52 for the hopper structure 18 at respectively opposite sides of the center sill is actuated by means of the dooractuating mechanisms 23. Each mechanism 52, as best shown in FIGS. 3 and 6, actuates a pair of doors and comprises a first link 53 which is pivotally connected as indicated at 54 to a pivot bracket 55 suitably attached to the door 38. The first link 53 includes at its upper end a curved end portion 56 which in turn is pivotally connected, as indicated at 57, to a bellcrank 58. The bellcrank 58 Includes a pivot fulcrum 59 including a spacer 60 supported on the outer side of each of the end slope sheets 19. A second link 61 is pivotally connected at 62 to another end of the bellcrank 58. A pivotal connection 63 pivotally connects the link 61 to a pivot bracket 64 each being disposed on opposite ends of the door 39.

THE OPERATION In the closed position of the

doors

38 and 39, as best shown in FIGS. 1, 2 and 3, the door-actuating mechanisms 23 are disposed in a locked overcenter position. The piston assemblies 28' are at the outer ends of the cylinder 29 and the actuating beams 28 have pivoted the vertical levers 24 so that the ms 33 are positioned transversely and slightly in an overposition relative to a vertical plane extending transversely through the ball connections 32-34 which are secured to the bottom of the door 38. Thus in this position the

doors

38 and 39 are firmly locked by the overcenter positioning of the arms 33. As best shown in FIG. 3, a centerline A though the pivotal connections 62 and pivot pins 63 is disposed overcenter with respect to the center of the pivot fulcrum 59 so that the said link 61 is also in an overcenter position which securely locks the bellcrank 58 and link 53 in the closed position further assuring that the

gates

38 and 39 are positively closed.

It should be noted that when the links 61 at the opposite ends of door 39 are disposed in the overcenter position, the product of the force occurring in the links acting on a line extending through the end

pivotal connections

62 and 63 and the perpendicular distance from this line to the center of the bellcrank fulcrum pivot 59, is greater than the product of the force occurring in links 53 acting on a line extending through the end

pivotal connections

57 and 54 and the perpendicular distance from this latter line to the center of the pivot. The force in the links 61 created by the weight of the door 39 or this weight combined with the weight of the lading thereon. The force in links 53 is created by the weight of the door 38 or this weight combined with that of the lading thereon. Thus under the force conditions described the doors will tend to remain closed and when such force conditions are reversed the doors will open.

As shown in FIG. 7, the horizontal flat edge 50 is in overlapping and seating relation on the flange 49 of the door 38 and thus with the overcenter action of the arms 33 and the links 61 a positive locking means for the

doors

38 and 39 is provided. This of course is extremely desirable in view of the heavy loads which the hopper must carry.

In the discharge operation of material from the hopper structures 18, it of course is desired that a rapid discharge is effected so that the

doors

38 and 39 must open quickly. The discharge operation is as follows:

The pneumatic cylinders 29 are charged with air to cause the piston assemblies 28 to move the beams 28 in a direction longitudinally inwardly from the ends of the car which in turn causes the levers 24 to pivot. The pivotal action of the levers 24 moves the arms 33 as shown in FIG. 2 in a substantially clockwise direction which in turn causes movement of all of the doors 38 downwardly about their pivotal connections. As each door 38 moves downwardly the link 53 of each mechanism 52 causes swinging movement of the bellcrank 58 about the pivot fulcrum 59. This also of course causes the upper end of the link 61 to move from the overcenter position shown in FIG. 3 wherein the centerline A moves beyond the pivot fulcrum center. During this movement to the position of the line designated at B there is only a slight downward movement of the associated door 39. On the other hand, the door 38 has during this movement moved to the dotted line position shown in FIG. 3 wherein the flat edge 49 is disposed out of the way of the path of movement of the flat edge 50 of the door 39. Thus there is a timed delay or time sequence provided by the

links

53 and 61 and bellcrank 58 which act as a guide means for the links so that the doors 39 do not open until the doors 38 are each in an out-of-the-way position. Thus the positioning of the

links

53 and 61 is critical to provide a sequential or timed operation of the

doors

38 and 39. As indicated, the bellcrank 58 in each mechanism acts as a guide for the links so that such sequence is effective. Due to the heavy weight of the material in each hopper structure 18 at each side of the center sill l2 movement of the

doors

38 and 39 is of course very rapid and such sequence of operation occurs in a fraction of time. It is of course understood that each door 39 operates completely in response to the movement of the associated door 38 as determined by the linkage and bellcrank mechanism and that the pairs of doors on opposite sides of the center sill are actuated simultaneously by the mechanisms 23 operatively connected with the doors 38. The bellcranks 58 guide the movement of the

linkages

53 and 61 so that the movement of the gate 39 is retarded or delayed until the gate 38 has moved to an out-of-the-way position toward full opening.

The structure disclosed and described thus permits the quick opening of the

doors

38 and 39 and the effective locking and positioning of the doors in their closed position. In the closed position the doors are effectively sealed by means of their overlapping engagement of the

flat edges

49 and 50 and the door 38 which is effectively supported by the arms 33 on the center sill, in turn also effectively assist in supporting of the weight on the doors 39. An efi'ective and simplified structure is thus achieved which meets the objectives of the invention.

What I claim is:

l. A vehicle bottom discharge arrangement for discharging a load from a vehicle having a hopper, comprising:

first and second doors pivotally connected to said vehicle, below said hopper for vertical swinging movement from closed to open positions,

said doors having adjacent edge portions in closing overlapping engagement in the closed position wherein said first door overlaps said second door door-operating mechanism including force-transmitting means connected to said first door for transmitting a force applied exteriorly of said hopper to move said first door between said positions,

second force-transmitting means pivotally connected between said doors, said second force-transmitting means being responsive to said movement of said first door to swing said second door to open and closed positions, and

means guiding movement of said second force-transmitting means during movement of said first door to provide for sequential movement of the second door with respect to the first door to retard movement of said second door until said edge portion of said first door is disposed out of the path of movement of said edge portion of said second door.

2. The invention in accordance with claim 1,

said doors in the closed position being positioned in V- shaped relation and converging downwardly from said hopper.

3. The invention in accordance with claim 2,

said edge portions of said doors extending substantially horizontally and being disposed in relative overlapping relation at the convergence of said doors.

4. The invention in accordance with claim 2,

said second force transmitting means comprising a first link pivotally connected to said first door,

a second link pivotally connected to said second door,

said guide means being pivotally interconnected between said links, and

means movably connecting said guide means to said vehicle.

5. The invention in' accordance with claim 1,

said second force transmitting means comprising a first link pivotally connected to said first door, I

a second link pivotally connected to said second door,

said guide means being pivotally interconnected between said links, and

means movably connecting said guide means to said vehicle.

6. The invention in accordance with claim 5,

said guide means including a bellcrank having at one end a fulcrum pivotally connected to said vehicle, and

means respectively pivotally connecting said links to the other ends of said bellcrank.

7. A vehicle bottom discharge arrangement for discharging a load from a vehicle having a hopper: comprising:

first and second doors pivotally connected to said vehicle for vertical swinging movement from closed to open positions,

door-operating mechanism including a horizontal movable arm having one end connected to said first door for moving the same between said positions,

a first link pivotally connected to said first door,

a second link pivotally connected to said second door, and

guide means pivotally mounted on said vehicle and pivotally connected to said links whereby said second door is moved sequentially relative to said first door between said positions in response to movement of said first door,

said doors having edge portions in the closed position being positioned in overlapping relation wherein said first door overlaps said second door, and

said first door being initially moved out of the path of movement of said second door whereby said second door is free to move to its open position.

8. The invention in accordance with claim 7,

said guide means comprising a bellcrank.

9. The invention in accordance with claim 8,

said bellcrank having its fulcrum supported on said vehicle,

said second link extending vertically and being pivotally connected to an end of said bellcrank disposed above said fulcrum,

said first link extending above said fulcrum and having an end pivotally connected to an end of said bellcrank disposed laterally to one side of said fulcrum, whereby during movement of said first door to an open position the movement of said second door is retarded until said first door is partially opened.

10. The invention in accordance with claim 7,

said guide means including a bellcrank having its fulcrum supported on said vehicle,

11. The invention in accordance with claim 10,

said doors having edge portions in the closed position being positioned in overlapping relation, and

12. The invention in accordance with claim 10,

said second link in the closed position having a vertical centerline through the pivotal connections of said second link to said second door and to said guide means and bellcrank being disposed to one side of said fulcrum in an overcenter position.

13. The invention in accordance with claim 7,

said second link in the closed position having a vertical centerline through the pivotal connections of said second link to said second door and to said guide means and bellcrank having a fulcrum on the vehicle and being disposed to one side of said fulcrum in an overcenter position.

14. The invention in accordance with claim 13,

said other end of said first arm being movable with said vertical arm to an overcenter position in the closed position of said doors.

15. The invention in accordance with claim 7,

said vehicle including a longitudinally extending support disposed laterally with respect to said doors,

a vertical arm pivotally connected to said support,

means for pivotally moving said vertical arm,

means pivotally connecting the other end of said first mentioned arm to said vertical arm whereby during longitudinal movement of said vertical arm said other end of said first arm is moved longitudinally to exert a transverse force for moving said doors.

16. The invention in accordance with claim 15,

17. The invention in accordance with claim 7,

said doors being disposed in V-shaped relation having inner surfaces converging downwardly relative to said hopper and having said overlapping edge portions extending horizontally with the edge portion of said first door being disposed below the edge portion of said second door.

18. The invention in accordance with claim 7,

a vertical arm pivotally connected to said support,

means for pivotally moving said vertical arm,

means pivotally connecting the other end of said horizontal movable arm to said vertical arm whereby during longitudinal movement of said vertical arm said other end of said horizontal movable arm is moved longitudinally to exert a transverse force for moving said doors.

19. A vehicle bottom discharge arrangement for discharging a load from a vehicle having a hopper, comprising:

first and second doors extendinglongitudinally of the vehicle and pivotally connected to said vehicle, below said for transmitting a force appliedexteriorly of said hopper to move said doors between said positions, said forcetransmitting means extending substantially the length of the hopper for transmitting drive to the doors along the lengths of the doors for uniformly opening them from a locked position to an open position,

second force-transmitting means pivotally connected between said doors,

said second force-transmitting means being responsive to said movement of said first door to swing said second door to open and closed positions, and

said second force transmitting means having means for guiding movement of said second force transmitting means during movement of said one door to retard movement of said other door moving sequentially relative to said first door until said edge portion of said one door is disposed out of the path of movement of said edge portion-of said other door.

20. A vehicle bottomdischarge arrangement for discharging a load from the hopper of a vehicle, comprising:

a pair of interconnected master and slave doors extending longitudinally of the vehicle and pivotally connected to said vehicle for swinging movement from a door closed and locked position to a door open and unlocked position,

said doors having adjacent longitudinally extending lateral edge portions in closing overlapping load-supporting interengagement with one another in the door closed position, the edge portion of the master door overlapping in load-supporting relation underneath the edge portion of the slave door preventing opening movement of the slave door from the locked position,

dooroperating mechanism including movable arm means including a pair of longitudinally spaced lateral extending door arms each having one end connected to said master door for moving the same between said positions and preventing opening of the master door and thereby the slave door in the locked position, said door-operating mechanism further having longitudinally extending forcetransmitting means extending substantially the length of the hopper and connecting with the door arms for transmitting drive to the doors along the lengths of the doors for-uniformly opening then from the locked closed position to the unlocked open position,

first link means including a pair of longitudinally spaced laterally extending links each being connected with said master door and with a respective door arm, and extending upwardly from the master door,

second link means including a pair of longitudinally spaced laterally extending links each being pivotally connected to said slave door and extending upwardly therefrom, and

each link meansbeing so pivotally interconnected with one another above the doors with said master door being first moved by said arm means to retard and subsequently move said slave door between said positions.

21. A vehicle bottom discharge arrangement for discharging a load from the hopper of a vehicle comprising:

a pair of interconnecting master and slave doors extending longitudinally of the vehicle and pivotally connected to door-operating mechanism including laterally extending movable arm means and longitudinally extending forcetransmitting means extending substantially the lengthof the hopper and connecting with the arm means for transmitting drive to the master door, said longitudinally extending force transmitting means connecting with said arm means in an overcenter locked position in the closed position of the doors attendant to holding the doors in the closed and locked position,

first link means being connected with said master door,

second link means being connected with said slave door and pivotally connecting with said first link means,

said master door being moved first by said arm means to retard and subsequently move said slave door between said locked and unlocked positions.

22. The invention according to claim 21, and

said force-transmitting means having means for providing an overcenter locking of the door operating mechanism attendant to keeping the master door in load-supporting relation against the slave door.

Claims

1. A vehicle bottom discharge arrangement for discharging a load from a vehicle having a hopper, comprising: first and second doors pivotally connected to said vehicle, below said hopper for vertical swinging movement from closed to open positions, said doors having adjacent edge portions in closing overlapping engagement in the closed position wherein said first door overlaps said second door door-operating mechanism including force-transmitting means connected to said first door for transmitting a force applied exteriorly of said hopper to move said first door between said positions, second force-transmitting means pivotally connected between said doors, said second force-transmitting means being responsive to said movement of said first door to swing said second door to open and closed positions, and means guiding movement of said second force-transmitting means during movement of said first door to provide for sequential movement of the second door with respect to the first door to retard movement of said second door until said edge portion of said first door is disposed out of the path of movement of said edge portion of said second door.

2. The invention in accordance with claim 1, said doors in the closed position being positioned in V-shaped relation and converging downwardly from said hopper.

3. THe invention in accordance with claim 2, said edge portions of said doors extending substantially horizontally and being disposed in relative overlapping relation at the convergence of said doors.

4. The invention in accordance with claim 2, said second force transmitting means comprising a first link pivotally connected to said first door, a second link pivotally connected to said second door, said guide means being pivotally interconnected between said links, and means movably connecting said guide means to said vehicle.

5. The invention in accordance with claim 1, said second force transmitting means comprising a first link pivotally connected to said first door, a second link pivotally connected to said second door, said guide means being pivotally interconnected between said links, and means movably connecting said guide means to said vehicle.

6. The invention in accordance with claim 5, said guide means including a bellcrank having at one end a fulcrum pivotally connected to said vehicle, and means respectively pivotally connecting said links to the other ends of said bellcrank.

7. A vehicle bottom discharge arrangement for discharging a load from a vehicle having a hopper: comprising: first and second doors pivotally connected to said vehicle for vertical swinging movement from closed to open positions, door-operating mechanism including a horizontal movable arm having one end connected to said first door for moving the same between said positions, a first link pivotally connected to said first door, a second link pivotally connected to said second door, and guide means pivotally mounted on said vehicle and pivotally connected to said links whereby said second door is moved sequentially relative to said first door between said positions in response to movement of said first door, said doors having edge portions in the closed position being positioned in overlapping relation wherein said first door overlaps said second door, and said first door being initially moved out of the path of movement of said second door whereby said second door is free to move to its open position.

8. The invention in accordance with claim 7, said guide means comprising a bellcrank.

9. The invention in accordance with claim 8, said bellcrank having its fulcrum supported on said vehicle, said second link extending vertically and being pivotally connected to an end of said bellcrank disposed above said fulcrum, said first link extending above said fulcrum and having an end pivotally connected to an end of said bellcrank disposed laterally to one side of said fulcrum, whereby during movement of said first door to an open position the movement of said second door is retarded until said first door is partially opened.

10. The invention in accordance with claim 7, said guide means including a bellcrank having its fulcrum supported on said vehicle, said second link extending vertically and being pivotally connected to an end of said bellcrank disposed above said fulcrum, said first link extending above said fulcrum and having an end pivotally connected to an end of said bellcrank disposed laterally to one side of said fulcrum, whereby during movement of said first door to an open position the movement of said second door is retarded until said first door is partially opened.

11. The invention in accordance with claim 10, said doors having edge portions in the closed position being positioned in overlapping relation, and said first door being initially moved out of the path of movement of said second door whereby said second door is free to move to its open position.

12. The invention in accordance with claim 10, said second link in the closed position having a vertical centerline through the pivotal connections of said second link to said second door and to said guide means and bellcrank being disposed to one side of said fulcruM in an overcenter position.

13. The invention in accordance with claim 7, said second link in the closed position having a vertical centerline through the pivotal connections of said second link to said second door and to said guide means and bellcrank having a fulcrum on the vehicle and being disposed to one side of said fulcrum in an overcenter position.

14. The invention in accordance with claim 13, said other end of said first arm being movable with said vertical arm to an overcenter position in the closed position of said doors.

15. The invention in accordance with claim 7, said vehicle including a longitudinally extending support disposed laterally with respect to said doors, a vertical arm pivotally connected to said support, means for pivotally moving said vertical arm, means pivotally connecting the other end of said first mentioned arm to said vertical arm whereby during longitudinal movement of said vertical arm said other end of said first arm is moved longitudinally to exert a transverse force for moving said doors.

16. The invention in accordance with claim 15, said other end of said first arm being movable with said vertical arm to an overcenter position in the closed position of said doors.

17. The invention in accordance with claim 7, said doors being disposed in V-shaped relation having inner surfaces converging downwardly relative to said hopper and having said overlapping edge portions extending horizontally with the edge portion of said first door being disposed below the edge portion of said second door.

18. The invention in accordance with claim 7, said vehicle including a longitudinally extending support disposed laterally with respect to said doors, a vertical arm pivotally connected to said support, means for pivotally moving said vertical arm, means pivotally connecting the other end of said horizontal movable arm to said vertical arm whereby during longitudinal movement of said vertical arm said other end of said horizontal movable arm is moved longitudinally to exert a transverse force for moving said doors.

19. A vehicle bottom discharge arrangement for discharging a load from a vehicle having a hopper, comprising: first and second doors extending longitudinally of the vehicle and pivotally connected to said vehicle, below said hopper for swinging movement from closed to open positions, said doors having adjacent longitudinally extending lateral edge portions in closing overlapping load supporting interengagement in the closed position, the edge portion of one door overlapping the edge portion of the other door preventing opening movement of the other door with respect to the one door, door-operating mechanism including longitudinally extending force transmitting means connected to said one door for transmitting a force applied exteriorly of said hopper to move said doors between said positions, said force-transmitting means extending substantially the length of the hopper for transmitting drive to the doors along the lengths of the doors for uniformly opening them from a locked position to an open position, second force-transmitting means pivotally connected between said doors, said second force-transmitting means being responsive to said movement of said first door to swing said second door to open and closed positions, and said second force transmitting means having means for guiding movement of said second force transmitting means during movement of said one door to retard movement of said other door moving sequentially relative to said first door until said edge portion of said one door is disposed out of the path of movement of said edge portion of said other door.

20. A vehicle bottom discharge arrangement for discharging a load from the hopper of a vehicle, comprising: a pair of interconnected master and slave doors extending longitudinally of the vehicle and pivotally connected to said vehicle for swingIng movement from a door closed and locked position to a door open and unlocked position, said doors having adjacent longitudinally extending lateral edge portions in closing overlapping load-supporting interengagement with one another in the door closed position, the edge portion of the master door overlapping in load-supporting relation underneath the edge portion of the slave door preventing opening movement of the slave door from the locked position, door-operating mechanism including movable arm means including a pair of longitudinally spaced lateral extending door arms each having one end connected to said master door for moving the same between said positions and preventing opening of the master door and thereby the slave door in the locked position, said door-operating mechanism further having longitudinally extending force-transmitting means extending substantially the length of the hopper and connecting with the door arms for transmitting drive to the doors along the lengths of the doors for uniformly opening then from the locked closed position to the unlocked open position, first link means including a pair of longitudinally spaced laterally extending links each being connected with said master door and with a respective door arm, and extending upwardly from the master door, second link means including a pair of longitudinally spaced laterally extending links each being pivotally connected to said slave door and extending upwardly therefrom, and each link means being so pivotally interconnected with one another above the doors with said master door being first moved by said arm means to retard and subsequently move said slave door between said positions.

21. A vehicle bottom discharge arrangement for discharging a load from the hopper of a vehicle comprising: a pair of interconnecting master and slave doors extending longitudinally of the vehicle and pivotally connected to the vehicle for swinging movement from a door closed and locked position to a door open and unlocked position, said doors having adjacent longitudinally extending lateral edge portions in closed overlapping engagement with one another in the door-closed position, the edge portion of the master door overlapping in load-supporting relation with the edge portion of the slave door preventing opening of the slave door from the locked position, door-operating mechanism including laterally extending movable arm means and longitudinally extending force transmitting means extending substantially the length of the hopper and connecting with the arm means for transmitting drive to the master door, said longitudinally extending force transmitting means connecting with said arm means in an overcenter locked position in the closed position of the doors attendant to holding the doors in the closed and locked position, first link means being connected with said master door, second link means being connected with said slave door and pivotally connecting with said first link means, said master door being moved first by said arm means to retard and subsequently move said slave door between said locked and unlocked positions.

22. The invention according to claim 21, and said force-transmitting means having means for providing an overcenter locking of the door operating mechanism attendant to keeping the master door in load-supporting relation against the slave door.