Field of Search:
175/122,170,175 173/57,147,152-160,163,164 299/55,56
Claims:
I claim
1. A portable earth boring machine comprising, in combination, base means including spaced track members; a carriage means mounted for movement along said track members; a fluid motor for driving said carriage means along said track members; an engine mounted on said carriage means and including an engine drive shaft; a gear reduction unit mounted on said carriage means and including a gear reduction input shaft driven by said engine drive shaft and a gear reduction output shaft; a thrust plate mounted on said carriage means forwardly of said gear reduction unit and including a radially disposed thrust absorbing surface ; thrust bearing means mounted on said thrust plate and including a radially disposed thrust transmitting surface, said surface being normal to the direction of thrust abutting said thrust bearing means and a coupling portion in driven connection with said gear reduction output shaft , said auger connecting shaft means being isolated from said above-mentioned power units by said radially disposed surfaces ; and a casing pusher ring mounted on the forward end of said thrust plate in surrounding relationship with said auger connecting shaft means.
2. The apparatus defined in claim 1 wherein said auger connecting shaft means includes an overload protection slip clutch.
3. A portable earth boring machine comprising, in combination, base means including spaced track members; a carriage means mounted for movement along said track members; a fluid motor for driving said carriage means along said track members; an engine mounted on said carriage means and including an engine drive shaft; a gear reduction unit mounted on said carriage means and including a gear reduction input shaft driven by said engine drive shaft and a gear reduction output shaft; a thrust plate mounted on said carriage means forwardly of said gear reduction unit and including a radially disposed thrust absorbing surface ; thrust bearing means mounted on said thrust plate and including a radially disposed thrust transmitting surface, said surface being normal to the direction of thrust application of said fluid motor ; auger connecting shaft means including a front end for connection with an earth boring auger and a rear end including a bearing engaging shoulder application of said fluid motor; and auger connecting shaft means including a front end for connection with an earth boring auger and a rear end including a bearing engaging shoulder abutting said thrust bearing means and a coupling portion in driven connection with said gear reduction output shaft , said auger connecting shaft means being isolated from said above-mentioned power units by said radially disposed surfaces .
4. The apparatus defined in claim 3 wherein said auger connecting shaft means includes an overload protection slip clutch.
5. A portable earth boring machine comprising, in combination, base means including spaced track members; a carriage means mounted for movement along said track members, including an upper carriage frame portion removably mounted on said carriage means; an engine mounted on said carriage frame portion and including an engine drive shaft; a gear reduction unit mounted on said carriage frame portion and including a gear reduction input shaft driven by said engine drive shaft and a gear reduction output shaft; a thrust plate mounted on said carriage frame portion forwardly of said gear reduction unit and including a radially disposed thrust absorbing surface ; thrust bearing means mounted on said thrust plate and including a radially disposed thrust transmitting surface, said surfaces being normal to the direction of thrust application of said fluid motor ; and auger connecting shaft means including a front end for connection with an earth boring auger and a rear end including a bearing engaging shoulder abutting said thrust bearing means and a coupling portion in driven connection with said gear reduction output shaft , said auger connecting shaft means being isolated from said above-mentioned power units by said radially disposed surfaces .
6. The apparatus defined in claim 5 wherein said auger connecting shaft means includes an overload protection slip clutch.
7. A portable earth boring machine comprising, in combination, base means including spaced track members; a carriage means mounted for movement along said track members including an upper carriage frame portion removably mounted on said carriage means; an engine mounted on said carriage frame portion and including an engine drive shaft; a gear reduction unit mounted on said carriage frame portion and including a gear reduction input shaft driven by said engine drive shaft and a gear reduction output shaft; a thrust plate mounted on said carriage frame portion forwardly of said gear reduction unit and including a radially disposed thrust absorbing surface ; thrust bearing means mounted on said thrust plate and including a radially disposed thrust transmitting surface, said surfaces being normal to the direction of thrust application of said fluid motor ; auger connecting shaft means including a front end for connection with an earth boring auger and a rear end including a bearing engaging shoulder abutting said thrust bearing means and a coupling portion in driven connection with said gear reduction output shaft , said auger connecting shaft means being isolated from said above-mentioned power units by said radially disposed surfaces ; and a casing pusher ring mounted on the forward end of said thrust plate in surrounding relationship with said auger connecting shaft means.
8. The apparatus defined in claim 7 wherein said auger connecting shaft means includes an overload protection slip clutch.
Description:
This invention relates to portable earth boring machines and more particularly to a machine adapted for horizontal boring of shafts for the insertion of pipelines at installations where excavation from the surface is undesirable.
In general, the machine of the present invention comprises a base means that includes spaced track members which are disposed in a trench adjacent the hill to be bored. The machine further includes a carriage means mounted for movement along the track means and such carriage supports a power train for rotating connected sections of auger shafts and an earth boring auger. The carriage further supports a pusher ring for driving sections of casings into the bored hole.
The present earth boring machine is of the same general type disclosed in my co-pending application, Ser. No. 867,816 filed Oct. 20, 1969, and in accordance with the present invention includes an improved power train for driving the sectional augers.
With machines of this general type, a problem has been encountered where the ground conditions make horizontal boring difficult. For example, in the New England states where the earth includes a high content of hard rock, the axial thrust on the power train caused by augers encountering rock has imposed axial thrust of high magnitude on the auger shaft and hence upon the gear reduction units located between the engine and the auger sections. Such high axial stresses have on occasion caused failure of such gear reduction units with resulting delay and an expense in replacing same.
In accordance with the present invention, the above mentioned problem has been solved by providing, along the power train, a novel rugged thrust plate assembly and thrust bearing arranged to transmit the axial thrust from the auger directly to the carriage frame as it is advanced along the track means thereby isolating the gear reduction unit from excessive damaging axial thrust forces.
As another aspect of the present invention, the above mentioned thrust plate is also utilized to provide a rugged mount for the above mentioned casing pusher ring whereby the thrust encountered in pushing casings into the bored hole is more efficiently transmitted to the carriage frame.
It is therefore an object of the present invention to provide an improved earth boring machine of the type described wherein the power train includes a novel thrust plate and bearing assembly adapted to isolate elements of the power train from high axial thrust forces.
It is another object of the present invention to provide an earth boring machine of the type described wherein the thrust plate assembly is utilized to more efficiently transmit axial thrust from a casing pusher ring to the carriage means on which it is mounted.
Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodiment of the invention is clearly shown.
In the drawings:
FIG. 1 is a side elevational view of an earth boring machine constructed in accordance with the present invention;
FIG. 2 is a front elevational view of the earth boring machine of FIG. 1;
FIG. 3 is a side sectional view of the thrust plate and bearing assembly comprising a portion of the machine of the preceding figures, the section being taken along the line 3--3 of FIG. 2; and
FIG. 4 is a partial side sectional view partially in section of a portion of the thrust plate and bearing assembly of FIG. 3, the section being taken along the line 4--4 of FIG. 2.
Referring in detail to the drawings, FIGS. 1 and 2 illustrate the complete horizontal earth boring machine of the present invention which comprises a base means indicated generally at 20. Such base means includes spaced longitudinally extending track means 22 which support a carriage means indicated generally at 24.
The machine further includes an upper carriage frame portion 26 which is removably mounted on a lower carriage frame portion 28. Lower carriage frame portion 28 is provided with wheels 30 which roll along the tracks 22 and the upper carriage portion 26 can be removed from lower carriage portion 28 by opening clamp and guide key assemblies 32. Such assemblies are disclosed and described in detail in my co-pending application, Ser. No. 867,816 filed Oct. 20, 1969.
The carriage means 24 is advanced and retracted along track 22 by a hydraulic power cylinder, a portion of which is seen at 34 in FIG. 1. With such power cylinder being operatively connected between a power cylinder base 36 and the carriage means 24.
Details of the power cylinder 34 and power cylinder base 36 are disclosed and described in detail in my co-pending application, Ser. No. 867,816 filed Oct. 20, 1969.
It will further be seen that pressurized fluid for actuating power cylinder 34 is provided by a fluid power system including a pump 38 driven by an engine 40. The fluid power circuit further includes a control valve mechanism 42 and conduits 44 and 46 such that when control valve mechanism 42 is actuated the pushing cylinder 34 is extended or retracted so as to move carriage 24 forwardly or rearwardly along the track means.
Referring again to FIG. 1, the boring machine further includes a pusher ring 50 including a front annular surface 52 for engaging the sections of pipe casing for pushing such sections into the bored hole. Such pusher ring 50 includes the transverse pusher ring plate 60 and 92 which are backed up by a thrust plate 51 mounted on the carriage means with such thrust plate 51 serving as a mount for a thrust bearing assembly indicated at 72. The mechanism comprising the thrust plate 51, the thrust bearing assembly 72 mounted thereon, and the back up plates 90 which transmit the thrust from the auger connecting shaft 64 to the carriage means 24 and thereby isolate gear reduction unit 54 from the thrust.
It should further be mentioned, with particular reference to FIGS. 1 and 4, that a slip clutch assembly 62 is provided between gear reduction unit 54 and the auger connecting shaft 64 such that in the event an overloaded condition occurs, then slip clutch 64 will permit the power train to function with the auger means on shaft 64 in a stalled condition without overloading and damaging the elements of the power train.
Reference is next made to FIG. 4 which illustrates in detail the above mentioned thrust transmitting assembly which includes the thrust plate 51 and the thrust bearing assembly mounted thereon and indicated generally at 72.
This assembly includes a base means bolted to thrust plate 51 by a plurality of bolts 86. A rotary shaft base 82 is welded to the rear end of auger connecting shaft 64 at a weld 84 with a conventional slip clutch assembly indicated generally at 62 being interposed between rotary shaft base 82 and auger connecting shaft 64.
A plurality of roller bearings 80 are mounted between roller bearings 74 which are pressed into a recess in the thrust bearing base, FIG. 4, such that rotary shaft base 82 is free to be driven by an output shaft 78 of gear reduction unit 54 with such shaft 78 being keyed by its hexagonal shape within the bore 76 of rotary shaft base 82.
It should be mentioned that the rearwardly extending annular flange of rotary shaft base 82 is extended freely through the hole in thrust plate 72.
Referring next to FIG. 3, the previously mentioned thrust plate 51 is rigidly mounted on upper carriage portion 26 of carriage means 24 by the generally triangular gusset plates 90. The forward ends of such gusset plates are welded to thrust plate 51 and the base edges of such gusset plates are welded to the top surface of the upper carriage portion.
It will now be understood that with thrust bearing assembly 72 being mounted on thrust plate 51 the entire thrust reaction from an auger connecting shaft 64 being transmitted to the base 20 via thrust bearing base means, thrust plate 51, gusset plates 90, upper carriage portion 26, carriage means 24, and energized carriage driving cylinder 34, the latter being connected to base means 20 by power cylinder base 36.
It should be mentioned that auger connecting shaft 64 is preferably provided with a hexagonal socket 66 for receiving the hexagonal end of the rearmost auger section.
A typical auger construction for connection with the machine of the present invention is disclosed and described in detail in my co-pending application, Ser. No. 85,614 filed Oct. 30, 1970.