US 3177004 A
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Description (OCR text may contain errors)
April 1965 G. A. SCHMIDT 3,177,004
LOAD EQUALIZER FOR SINGLE AXLE BOGIES Filed March 15, 1965 3 Sheets3heet 1.
6.5014 615 ,4. SCHMIDT April 6, 1965 G. A. SCHMIDT LOAD EQUALIZER FOR SINGLE AXLE BOGIES 3 Sheets-Sheet 2 Filed March 15, 1963 INVENTOR. GEO/96E A. SCH/W07 WWW ATTORNEY- 1 G. A. SCHMIDT LOAD EQUALIZER FOR SINGLE AXLE BOGIES April 6, 1965 3 Sheets-Sheet 5 Filed March 15, 1963 INVENTOR. GzE'O/PGF A. SCH/W07 United States Patent 3,177,904 LQAD EQUALIZER F012 SENGLE AXLE BOGIKE George A. Schmidt, Langhorne, Pa, assignor to Strick Traiiers, a division of Frnehaul Trailer (30., Philadelphia, Pa, a corporation of Michigan Filed Mar. 15, 1963, er. No. 265,537 8 Claims. (Cl. 289-1045) This invention relates to over-the-road vehicles, such as trailers. It is advantageous from the standpoint of economy and operation to removably couple wheeled units or bogies individually to the trailer body adjacent each other. Such a construction is desirable to carry out the system disclosed in the Bohlen et al. Patent No. 3,004,772 where a tandem axle semi-trailer is connected to single axle semitrailers and vice versa, and to enable the load to be shifted relative to the bogie axles, as in the Sheppard et al. iatent No. 2,841,411.
The primary object of the invention is to provide a readily and easily operable means to efiect load equalization between two or more bogies which are removably but separately connected to the vehicle body.
Another object is to provide a load equalizer for two or more single axle bogies wherein conventional leaf spring suspensions and rocker arms are employed and a pneumatic means is provided to raise one end of the rocker arm to a position of alignment with one end of the spring of one bogie while the adjacent end of the spring of the next bogie is in engagement with the rocker arm so that movement of the bogies relative to each other thereafter will positively effect connection between said one end of the spring and the rocker arm thereby equalizing the load on the axles through the rocker arm.
Another object of the invention is to provide means mounted on each of a plurality of single axle bogies so that the operator can readily make connection when he so desires between the adjacent ends of the springs of the bogies and the rocker arm and thus effect load equalization on the axles or break the connection when he no longer wants the equalization.
Another object is to provide a load equalizer 0f the character described which is applicable to a single vehicle body with multiple single axle slide bogies or to a plurality of removably connected bodies, with multiple single axle slide bogies.
These and other objects of the invention will become more apparent as the following description proceeds in conjunction with the accompanying drawings, wherein:
FIG. 1 is a fragmentary perspective view of the equaL izer means of the instant invention in its inoperative conditiOn;
FIG. 2 is a view similar to FIG. 1 showing the equalizer in its operative condition wherein one end of the rocker arm of one bogie raised to a position of alignment with the spring of the adjacent bogie;
FIG. 3 is a view similar to FIG. 1 showing the joining of the adjacent ends of the springs with the rocker arm to elfect load equalization;
FIG. 4 is a diagrammatic view of a single axle bogie equipped with a means to removably couple it to a vehicle body;
FIG. 5 is a side elevational view of the bogie some parts being excluded and others shown in section;
FIG. 6 is a schematic diagram of the air system for operating the brakes and the equalizer of tandem axle units.
Specific reference is now made to the drawings wherein similar reference characters are used for corresponding elements throughout.
The instant invention is applicable primarily to a vehicle construction of the type in which two or more sin- 3,177,94 Patented Apr. 6, 1965 gle axle wheeled units 10 known in the art as a bogie, are slidably or removably coupled by a mechanism of the type illustrated in the Sheppard et al. Patent No. 2,841, 411 to a vehicle body. The bogie comprises longitudinal beams 13 which are connected as by gussets 14 to transverse beams 15 to whose ends are secured plates 16 each having an aperture 17, the plates being connected by longitudinal angle members 18. The upper surfaces of the plates 16 and members 18 are in substantially the same horizontal plane and are slidably engaged by the hori zontal flange of angulated side rails 19 longitudinally beneath the trailer body 20. The side rail 19 includes a vertically extending flange with spaced apertures adapted to register with aperture 17.
The coupling mechanism is carried by the bogie and includes a rotatable shaft 21 (see FIG. 4) having a handle 22 at one of its ends, the shaft mounting spaced plates 23 to which are pivoted the inner ends of coupling rods or pins 24. The rods at their outer ends extend slidably through the bogie apertures 17 and through one or more of the spaced body rail apertures, there being springs 26 normally urging the rods or pins through the rail apertures in the coupling position. Upon rotation of the handle in a clockwise direction, the pins are retracted out of the rail apertures, there being a latch mechanism 28 to releasably hold the pins in the retracted position, at which time the bogie is uncoupled and slidable relative to the body. Reverse rotation of the handle and release of the latch mechanism will recouple the bogie to the body.
Depending from the bogie beams 13 are longitudinally spaced front and rear hanger brackets 30 and 32. Transversely spaced longitudinally extending leaf springs 34 mount by means of U-bolts 3/6 a transversely extending axle 38 equipped with wheels 40. The rear end 42 of the spring extends through the rear bracket 32 whereas the front end 44 of the spring extends into one end of a rocker arm 46. The rocker arm is substantially channel in cross-section and is pivoted around a horizontal axis as at 48 to the front bracket 30 and includes front and rear open ends or throats 5t) and 52. Above the rear throat of the rocker arm, the bogie beam is provided with a stop 54 and the front throat may be provided with a pad 56 for a purpose later to appear.
Integral with or secured to the front spring bracket 30 beneath the rocker arm is a generally angulated member 58 of channel cross section. Secured as to 60 to the leg 62 of the member 58 beneath the front throat 59 of the rocker arm is an air cylinder or chamber 54 having a piston therein (not shown) at the inner end of a piston rod as which is movable through an aperture provided in the leg 62 in the direction of and away from the pad 56.
As will be seen in FIG. 6, each bogie mounts an air reservoir 68 one side of which is connected to each of the air cylinders 64 via a three-way valve 70 and a protection valve 72. The other side of the reservoir is operatively connected to a relay valve 74 which is in turn connected to two lines 76 and 78. The lines '76 and 78 of one bogie can be quickly connected to the corresponding lines of the next bogie by means of normally closed couplers 869 which open upon coupling. The line 78 by a coupler 82 connects to the emergency line 84 whereas the line '76 connects by a coupler 86 to the service line 88. The emergency and service lines are appropriately connected to a source of air under pressure at the tractor (not shown), the latter being the line through which air is admitted by foot pedal operation to apply the trailer or bogie brakes, the former being employed as an air pressure supply and fail-safe mechanism to permit automatic brake application should the supply pressure or connection fail. The protection valves 72 are merely employed to insure that the reservoirs 68 will not fall below a predetermined required pressure due to the use of the air cyli way valves 70 of the bogies are then turned to a position where air from the reservoirs 58 will be admitted into the cylinders 64 urging the piston rods es outwardly against the pads 56 thereby raising the frontthroats 5d of the rocker arms until each is in substantial horizontal alignment with the rear end 42 of the spring of the front bogie as seen in FIG. 2. The front bogie is then uncoupled from the body and the brakes are applied to that bogie. This is automatically accomplished via the relay valve 74 by disconnecting the service and emergency airlines or hoses of the front bogie. The brakes on the rear bogie are then released and the vehicle is moved forward whereupon the rear ends 42 of the springs of the front bogie enter the front throats 54B of the rocker arms 26. Then the front bogie is recoupled to the body and the three-way valves 74 'areactuated to release air from the cylinders 64 (via exhaust ports in the valves 70) to retract the piston or push rods 66 to the position shown in FIG. 3. This allows the front ends or throats 50 of the rocker arms to lower onto the rear ends 42 of the front springs which are urged downwardly away from contact with the top of the hanger bracket 32. This is the load equalized road position wherein the vertical load from the rear ends 42 of the front springs are shifted from their hangers 32 to the front ends 50 of the rocker arms and balance the loads on the rear ends 52.0f the rocker arms from the front ends 44 of the rear bogie. It is to be noted that in FIG. 1 there is shown a clearance between pad 55 and rod 66 in the extreme rocking position whereas, in FIG. 3, the undersurface of the rear end. 42 of the spring will engage the upper surface of the pad 55 prior to contacting the retainer bolt 90 of the hanger bracket 32 in the event that the front axle should drop into a depression.
It will thus be seen that each of the single axle units.
because of the combination and arrangement of parts is interchangeable with the next and capable of use separately or in load equalized tandem or multiple axle rela tion. The invention has particular utility in the coupling and uncoupling of two or more vehicle bodies and the positioning one single axle bogie under each body when the bodies are uncoupled or in tandem under the rear body when the bodies are coupled as described in the Bohlen et a1. Patent No. 3,004,772.
While a preferred embodiment has here been shown and described, skilled artisans may make variations without departing from the spirit of the invention and th scope of the appended claims. 1
1. In a vehicle having a body and front and rear bogies separately and slidably coupled thereto, each bogie ineluding a frame, a transverse axle adapted to mount wheels, longitudinally extending springs supporting said axle, means suspending the front and rear ends of said springs from said frame, the means suspending the front end of each rear bogie spring including a rocker arm pivoted intermediate its ends to said rear bogie frame for movement in a vertical plane, the end portion of said rocker arm to the rear of its pivot engaging the front end of the rear bogie spring, and pneumatic retractable means operative upon and beneath the end portion of said rocker arm infront of its pivot to raise the same to a position of substantial horizontal alignment with the rear end of the front bogie spring whereby upon relative movement between the bogies towards each other the rear end of the front bogie spring will engage the said front end portion ofsaid rocker arm and remain thus engaged after said pneumatic retractable means has been retracted to an inoperative position to effect load equalization on the axles. 2. The combination of claim 1 wherein the front end portion of said rocker arm includes a throat opening forwardly and adapted to receive the rear end of thefront bogie spring therethrough.
3. The combination of claim 2 wherein the means to suspend the rear end of each front bogie spring includes a hanger through which said rear end extends for subsequent insertion through said throat of said rocker arm.
4. In a vehicle having a body and a plurality of interchangeable bogies separately and slidably coupled thereto in front to rearrelationship, each bogies including a frame, a transverse axle adapted to mount wheels, longitudinally extending springs supporting said axle, means suspending the front and rear ends of said springs from said frame, the means suspending the front end of each spring including a rocker arm pivoted intermediate its ends to saidframe for movement in a vertical plane, the end portion of said rocker arm to the rear of its pivot engaging the front end of the spring, and pneumatic retractable means'carried by said frame and operative on the end portion of said rocker arm in front of its pivot to raise the same to a position where upon relative movement between said adjacent bogies towards each other the rear end of the spring of said next front bogies will engage said front end portion of said rocker arm and remain thus engaged after said pneumatic retractable means has been retracted to an inoperative position to thereby efiect load equalization on the axles.
5. The combination of claim 4 wherein the front end portion of said rocker arm includes an open throat into which said rear end of the spring of said next front bogie extends in the load equalization position.
6. The combination of claim 5 wherein said retractable means includes a source of air under pressure on said bogie frame, a cylinder mounted on said frame beneath said rocker arm, valved means connecting said cylinder to said source and a piston rod slidable in said cylinder, said rod being extended to engage the front end portion of said rocker arm to raise the latter upon admission of air intosaid cylinder and to retract said rod upon exhausting of air therefrom.
7. In a vehicle having a body and front and rear bogies separately and slidably coupled thereto, each bogie including a frame, a transverse axle adapted to mount wheels, longitudinally extending springs supporting said axle, means suspending the front and rear ends of said springs from said frame, the means suspending the front end of each rear bogie spring including a rocker arm pivoted intermediate its ends to said rear bogie frame for movement in a vertical plane, the end portion of said rocker arm to the rear of its pivot engaging the front end of the rear bogie spring, a cylinder mounted beneath said rocker arm, a piston rod extending through one end of said cylinder and slidable toward and away from the end portion of said rocker arm extending in front of its pivot, a source of air under pressure and valved means interconnecting said source and said cylinder so that said rod can be extended to engage said front end portion of said'rockor arm and raise it to a position whereby upon relative movement between said bogies, said rear end of said front bogie'spring will engage said front end portion of said rocker arm and-remain thus engaged after said rod has been retracted out of engagement with said front end portion of said rocker arm to thereby effect load equalization on the axles. I
8. A bogie adapted to be slidably coupled to a vehicle body andincluding a frame, a transverse axle adapted to mount wheels and longitudinally extending springs supporting said axle intermediate their ends, each spring including a front and rear end, means suspending said rear end of said spring from said frame, a rocker arm pivoted intermediate its ends to said frame about a horizontal pivot, said front end of said spring engaging the portion of said rocker arm extending rearwardly from its pivot, and means adapted to effect connection between the portion of said rocker arm extending forwardly from its pivot with the rear end of a corresponding spring of a similar bogie which is adapted to be slidably connected to the vehicle body and thereby to equalize the loads on the axles, said last-named means including an air cylinder mounted on said frame beneath said rocker arm and adapted for connection to a source of air under pressure and a piston rod slidable through one end of said cylinder so that said rod 5 can be selectively extended to engage and raise said for- Ward portion of said rocker arm for connection to the front end of the spring of a similar bogie and retracted from said forward portion of said rocker arm after said connection has been effected.
References Cited by the Examiner UNITED STATES PATENTS 2,912,252 11/59 Bohlen 280104.5
1.0 3,108,822 10/63 Tantlinger 280-104.5
A. HARRY LEVY, Primary Examiner.