Interstitial Ballast Vibrator

The present invention relates generally to railroad track maintenance equipment and more specifically to apparatus used in removing dirty or deteriorated ballast from along the track bed. More particularly, the present invention relates to apparatus for use in conjunction with other apparatus to loosen compacted ballast between the crossties of a railroad track.

Modern railroad track maintenance equipment typically includes a self-propelled unit having an apparatus for trenching alongside the ends of the crossties and an apparatus for removing ballast from beneath the track. The track remains intact and the machinery is supported on the track rails. The removed ballast is replaced by clean ballast such that the track is not left in an unsupported condition. In many instances the ballast between the crossties has been compacted by years of vibration and settling and thus is tightly wedged between the ties such that when the undercutter removes the ballast from beneath the ties, the interstitial ballast remains suspended between the crossties. Obviously if the ballast is not removed it can impair the proper placement of the replacement ballast. In general, however, the condition is a nuisance. In times past crews have manually loosened the interstitial ballast with hammers; in other instances the track is lifted and bowed to allow the ballast to loosen. However, although the rails are somewhat plastic, lifting the rails necessitates repositioning and realigning and is of some concern. Accordingly, there is perceived a need for a simple and efficient attachment for loosening interstitial ballast.

It is the object of the present invention to loosen interstitial ballast from between the crossties of a railroad track for subsequent removal by an undercutter.

It is a further object of the present invention to effect such loosening without deformation of the rails of the railroad track.

Still another object of the invention is to permit proper placement of the replacement ballast beneath and between the crossties.

Each of these objects are advantageously achieved in the present invention through the use of a novel vibrator assembly which utilizes the density of the ties and ballast to its advantage to loosen the ballast without impact or interstitial displacement of a tool. Specifically by apparatus is designed to contact the top of the crossties and the ballast therebetween and to impart vibration to the mass such that the ballast is loosened. A vibrational frequency of 30 to 60 hertz should adequately loosen the ballast. The vibration may be induced in any suitable manner, however, it has been found convenient to mount a rotating eccentrically balanced shaft on an extended plate in the form of a skid. Rotation of the shaft at the desired speed induces vibration in the plate which transmits the vibration to the underlying ballast. The effectiveness of the device is influenced by the effective weight of the vibrating unit. The effective weight of the vibrating unit may be controlled by the mounting structure which is a parallelogram linkage connecting the vibrating unit to a carriage or propulsion unit. A positioning ram is used to urge the linkage laterally to position the vibrating unit at a selected height and to apply a selected downward component of force to achieve a desired "effective weight".

Apparatus embodying features of the invention are depicted in the accompanying drawings which form a portion of this disclosure and wherein:

FIG. 1 is a side elevational view of the type machinery with in the invention may be incorporated; and

FIG. 2 is a detailed elevational view showing the invention as incorporated in the machinery.

FIG. 3 is a sectional view taken along line 3--3 of FIG. 2.

Referring to FIG. 1, it will be noted that a railroad track has three principal components: the rails 11, the crossties 12, and the ballast 13 which forms the bed upon which the crossties 12 and rails 11 are supported and leveled. As is well known in the art, the ballast 13 must be periodically serviced to replenish and restore it to a proper bed which will maintain the track in a safe operating condition. As seen in FIG. 1 this is oftentimes accomplished with a self-propelled track maintenance unit 14 which travels along the track removing and replacing ballast 13 as it goes. Such a unit 14 is typically powered by a diesel engine 16 mounted on an elongated frame or carriage 17 supported on track-engaging wheels 18. An operator compartment 19 contains the controls necessary to operate the engine 16, a trencher 21 which excavates alongside the ends of the crossties 12, an undercutter 22 which removes ballast 13 from beneath the crossties 12, a conveyor system 23 which transports ballast 12 from the undercutter 22 to a cleaning unit 24 which segregates the ballast into a waste portion which is removed from the track and a cleaned portion which is returned to the bed of ballast 13 behind the undercutter. The foregoing is well known in the art and will not be discussed further.

The present invention is a ballast vibrator attachment 26 to be used as a component in the track maintenance unit 14. As may be seen in FIG. 1, the ballast vibrator attachment is preferentially positioned aft of the trencher 21 and forward of the undercutter 22. In this location it will be appreciated that the ballast 13 between the ties 12 are already subject to a degree of vibration due to the lateral action of the trencher 21 and the approaching undercutter 22.

With reference to FIG. 2, it can be seen that the ballast vibrator attachment 26 is supported from the frame or carriage 17 on a mounting flange 27. A pair of parallel support arms 28 and 29 are affixed to the flange 27 with pins 31 and 32 such that the arms 28 and 29 may pivot in a vertical plane aligned with the direction of travel indicated by the arrow. The lower ends of arms 28 and 29 are affixed to a vibrating unit 33 with a set of pins 34 and 36 which pass through an upstanding attachment member 37 which is affixed to a skid plate 38. The skid plate 38 spans the interstice between the crossties 12 and has upturned forward and rear end portions 39 and 41 which prevent entanglement with exposed edges of the crossties 12. Mounted to the top of the skid plate 38 is a vibrator 42 which may be an eccentric shaft or wheel 42' driven for rotation by a hydraulic motor 42 supplied with hydraulic fluid in a conventional manner from the maintenance unit 14 as shown in FIG. 3.

Attached by a pin connected to arm 29 is a linear actuator 43, which is preferentially a double acting cylinder, which is pivotally mounted at 44 to the frame 17 and is also supplied with hydraulic fluid from the maintenance unit 14. The actuator 43 urges the arm 29 laterally, thus changing the angular orientation of the parallelogram and the elevation of the vibrating unit 33.

As will be appreciated the downward component of force on the skid plate 28 may be varied by the force applied by actuator 43, thus the operator may selectively apply greater or lesser or varying force as may be necessary to dislodge the interstitial ballast 13 wedges between the crossties 12.

While I have shown my invention in one form, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit thereof.