This invention relates to trench digging apparatus, and, more particularly, relates to portable, motor driven trenchers.
Motorized trenching apparatus are widely utilized in a variety of construction industries for formation of deep, wide, and often extensive trenches. Most such trenchers are dedicated vehicular machinery (see, for example, U.S. Pat. No. 4,195,427) or large complex attachments for plows, tractors, loaders and the like (see, for example, U.S. Pat. No. 7,096,609).
In the field, however, various contractors often need only small, narrow trenches created with a minimum of surface/soil disturbance. For example, electrical and telecommunications contractors often need to install small (½ to ¾ inch) PVC conduits under concrete slabs such as factory, warehouse or store floors and the like. Likewise, plumbers often run small water lines under slabs for waste pipe, supply lines, LP lines, and the like. Usually trenches for such purposes need only be a few inches deep. Larger trenching or digging machinery is thus typically impractical for these installations, and manual trench formation is often made very difficult due to worksite soil compaction (requiring pickaxes and the like to form the trench).
Narrow, shallow but extensive trenching is also utilized by landscape contractors for installation or replacement of sprinkler systems and low voltage landscape lighting. Small trenches can also be utilized by landscaping installers for vinyl edging and erosion cloth installation or replacement. Large trenching units are again typically impractical for use in many such installations (retrofit installations in existing yards and existing installation repair, for example). Heretofore utilized trenchers are not readily maneuverable in small areas and are difficult to utilize when barriers or impediments such as building walls, landscaping and/or fences are near the trench being created. Curved trenches are also difficult for these larger machines to accommodate.
Maintenance of such machinery is involved and extensive, and the ability to perform on-site trenching chain maintenance or replacement is limited by chain size and/or repair tool requirements (the chain being the main wear item in such machinery, maintenance thereof is common). Additionally, the bulk and power of such heretofore known trenching machinery requires trained operators and great care for safe use. The low speed operation of most such machinery means that material removed from the trench is often more difficult to backfill.
Moreover, moving heretofore known trenching machinery from one site to another usually requires trailering, and storage and maintenance of such machinery requires large yard areas, making their maintenance and use impractical for many contractors and/or for smaller jobs. Do-it-yourself and contractor rental facilities would also benefit from smaller and more readily transportable and storable trenching units. Thus, a trencher design for small (narrow and shallow) trench formation that is easy to use and store, and that is readily portable could be utilized.
This invention provides an operator propelled and/or guided portable trencher that is particularly well adapted for formation of narrow and relatively shallow trenches. The trencher is highly maneuverable in small and/or crowded work areas, is capable of tightly curved trench formation, operates at a high speed, and requires little operator training for safe operation. Trencher maintenance and chain replacement are performed quickly and easily, and trencher transport and storage requires little or no extra gear or facilities.
The operator guided portable trencher of this invention includes a wheeled carriage having an operator handle bar mounted thereat. A trenching chain assembly is mounted at the carriage, the assembly including a chain and a multi-sprocket chain guide. A first sprocket of the chain guide is movably mounted and biased to tension the chain while still allowing sprocket movement to partially relieve chain tension during chain use in case of debris entrainment adjacent to the chain guide/chain interface.
The carriage includes a wheel mounting base assembly and a drive frame assembly pivotably connected at first ends to each other, the handle bar mounted adjacent to the first ends. A plurality of wheels is mounted at the mounting base assembly. An operator manipulable support is connected with one or the other of the mounting base assembly and the drive frame assembly, the support spaced from the first ends thereof. The support includes multiple support locations engageable by an engagement structure at the other of the mounting base assembly and the drive frame assembly as may be selected by an operator of the trencher. In this manner, operator selection of pivotable location of the drive frame assembly relative to the wheel mounting base assembly during trencher storage and use is provided.
The trenching chain assembly further includes a chain drive motor at the drive frame assembly operationally associated with the chain guide. The chain guide preferably includes a chain bar and a pivotable sprocket mount with the first sprocket maintained thereat, the chain bar having second and third sprockets mounted adjacent to opposite ends thereof. The sprocket mount is pivotably mounted at the drive frame assembly and biased to selectively tension the chain during chain use as provided above.
It is therefore an object of this invention to provide a compact portable trencher.
It is another object of this invention to provide an easy to use, operator propelled and/or guided trencher.
It is still another object of this invention to provide a relatively small, light weight trencher for small (narrow and shallow) trench formation.
It is yet another object of this invention to provide a trencher having a trenching chain that simply and quickly removable, replaceable and maintainable at a worksite.
It is still another object of this invention to provide an operator propelled and/or guided trencher that is highly maneuverable and thus useful in small areas and adjacent to barriers or other impediments.
It is yet another object of this invention to provide a trencher that can be readily maneuvered to create tightly curved trenches.
It is another object of this invention to provide a trencher that requires little training to utilize and that is relative safe to use.
It is still another object of this invention to provide a trencher that runs at a high speed thus providing removed material with finer particle size that is easier to backfill.
It is yet another object of this invention to provide an operator guided trencher including a wheeled carriage, an operator handle bar mounted with the carriage, and a trenching chain assembly mounted at the carriage, the assembly including a chain and a multi-sprocket chain guide, a first sprocket of the chain guide movably mounted and biased to tension the chain during chain use while allowing sprocket movement to partially relieve chain tension during chain use in case of debris entrainment at the chain.
It is another object of this invention to provide a portable trencher that includes a carriage having a wheel mounting base assembly and a drive frame assembly pivotably connected to each other adjacent to first ends of each, a plurality of wheels mounted at the mounting base assembly, an operator manipulable support connected with one of the mounting base assembly and the drive frame assembly spaced from the first ends thereof and having multiple support locations thereat, the other of the mounting base assembly and the drive frame assembly having engaging means thereat for association with any operator selected one of the support locations of the support thereby providing operator selection of pivotable location of the drive frame assembly relative to the wheel mounting base assembly during trencher storage and use, a trenching chain assembly mounted on the drive frame assembly, the chain assembly including a trenching chain mountable at a chain guide and a chain drive motor operationally associated with the chain guide, and an operator handle bar mounted at the carriage adjacent to the first ends of the mounting base assembly and the drive frame assembly.
It is still another object of this invention to provide an operator propelled and guided portable trencher that includes a carriage having a wheeled mounting base assembly and a drive frame assembly pivotably connected to each other adjacent to first ends of each, a trenching chain assembly mounted at the drive frame assembly of the carriage, the trenching chain assembly including a chain and a chain guide, the chain guide having a chain bar and a pivotable sprocket mount with a first sprocket maintained thereat, the chain bar having second and third sprockets mounted adjacent to opposite ends thereof, the sprocket mount pivotably mounted at the drive frame assembly and biased to tension the chain during chain use while allowing movement of the first sprocket to partially relieve chain tension during chain use in case of debris entrainment adjacent to the chain, and a handle bar mounted at the carriage adjacent to the first ends of the mounting base assembly and the drive frame assembly;
With these and other objects in view, which will become apparent to one skilled in the art as the description proceeds, this invention resides in the novel construction, combination, and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiment of the herein disclosed invention are meant to be included as come within the scope of the claims.
The accompanying drawings illustrate a complete embodiment of the invention according to the best mode so far devised for the practical application of the principles thereof, and in which:
A currently preferred embodiment of the trencher of this invention is illustrated in the FIGURES. Turning to
Spindles 27 are located at the ends of rearward first end frame member 43 and forward second end frame member 45 of a wheel mounting base assembly 47 of carriage 21. Drive frame assembly 49 is pivotably connected at its rearward first end with the rearward first end of assembly 47 using main pivot shaft 51 through journals 53 and 55 at each of assemblies 47 and 49, respectively (see
Mounting base assembly 47 is shown in greater detail in
Drive frame assembly 49 (see
As best shown in
Operator manipulable support 129 includes handle 130 and is pivotably secured on threaded pivot connection 71 of support rod 69 (using a matable nut) and is biased toward engagement with dog 87 by biasing spring 131 connected between support 129 and clip 73 (best shown in
Trenching chain assembly 31 is best illustrated in
Chain guide 137 further includes chain bar 155 having second and third sprockets 157 and 159 rotatably mounted adjacent to opposite ends thereof. Drive sprocket 157 is mounted to drive shaft 103. Idler sprocket 159 is journaled between chain bar mounting plates 161 and 163 through openings 165 thereof receiving opposite facing annular hubs 167 of sprocket 159. Center chain guide plate 169 is made of self lubricating plastic material (for example, ultra-high molecular weight polyethylene) and is mounted between mounting plates 161 and 163 using screws 171 to minimize debris entrainment at the chain and the chain guide interface during trenching operations. The assembled chain bar 155 is mounted to tube 79 using bolt 93 and nut 173.
Turning now to
As trencher 19 moves forward astraddle trench 175 being created (see
Trenching chain 135 includes cutting link combinations 223, each of the cutting link combinations including link body 225 and clip 227. Link body 225 is pivotably joinable with adjacent link bodies at first and second ends in a conventional fashion. At least some of clips 227 include carriage 235 and cutting implement 237. Linkage 239 (herein a welded or press fit linking pin, though other known structures could be utilized both separate from and/or integrated with carriage 235 and/or link body 225) pivotably associates carriage 235 with link body 225 as well, in this configuration, as associating link body 225 with an adjacent link body. Each carriage 235 (and thus clip 227) has end part 241 adapted for pivotable engagement with a link body 225 end (using linkage 239, for example, through openings thereat) so that clip 227 is freely pivotable toward and away from link body 225. Opposite end 243 of carriage 235 is unengaged and freely pivotable.
Carriage 235 includes flat mounting portion 245 between spaced (preferably wedge shaped) sides 246 and 247 each having end part 241 thereat. Cutting implement 237 is secured (welded, bolted or the like, in this embodiment) at the top surface of mounting portion 245, link bearing surface 253 provided opposite the top surface. Sides 246 and 247 are spaced sufficiently to enable freely pivoting movement of link body 225 and adjacent link body or bodies into and out of adjacency and/or contact with link bearing surface 253 of mounting portion 245 therebetween during trenching chain use. Carriage 235 length between opposite ends is preferably greater than link body 225 length (and preferably at least twice the length of body 225 or longer). Cutting implements 237 of clip 227 may be any of various known or conceivable cutting teeth and/or bit (rock/frost, for example) configurations.
Portion 245 is formed (by forging, milling, welding or bending, for example) between wedge shaped spaced sides 246 and 247 along opposite side edges thereof. Clips 227 each have a configuration at opposite end 243 (a broad, flat expanse at the end of the top surface of mounting portion 245, for example) adapted for trench sweeping. While cutting implements 237 are shown herein affixed to every carriage 235 of clips 227, some clips may be provided without cutting implements (“sweeper” clips). Moreover, a sweeper chain can be provided utilizing clips without any cutting implements at all. Trenching chain 135 utilizes a plurality of links 225 joined in an endless chain design together with a plurality of clips 227.
As shown in
The component parts of trenching chain 135 are preferably made of iron or steel and may be cast or milled or otherwise formed (utilizing sheet or angle/channel material, for example). The cutting teeth/bits may include unitary structures or multi-part structures (including, for example, carbide tips). Linkages may be accomplished using steel linking pins (as shown), or may employ linking structure incorporated into any of the linked parts.
Turning now to
Motor 99 is preferably started in this configuration, and the trencher is readied at the location to be trenched. When the operator is ready, engagement of lever 123 causes drive actuation and chain 135 begins rotation on guide 137. The operator then releases assembly 49 by grasping handle 130 of support 129 and moving support 129 against bias while holding handle 89. The operator may thus lower assembly 49 into the earth, and trenching begins (see
As illustrated in
When trenching is completed, drive frame assembly 49 is lifted away from wheel mounting base assembly 77 by an operator grasping hoist handle 89 and pulling while holding support 129 out of engagement with dog 87 by grasping handle 130. When free of the trench, storage support location 133″ of support 129 and dog 87 are brought into engagement (see
As may be appreciated from the foregoing, the trencher of this invention is highly maneuverable in small and/or crowded work areas, requires very little operator training for safe use, and facilitates on-site maintenance. The trencher is highly compact for transport and storage, thus requiring little or no extra gear or facilities. The trencher may utilize any known power source for chain drive. While belt and pulley power transfer is taught herein, other known power transfer systems such as chain/sprocket/clutch, hydraulic pump drive, speed control/centrifugal clutch systems, or the like could be utilized. Alternative trenching depth adjustment systems could also be employed, such as screw/crank systems, gear and rack systems, hydraulic or pneumatics systems, or others. While an articulated handle bar is shown, removable or foldable handle bar systems could be utilized. Instead of relying solely on operator propulsion, belt or chain drive/clutch systems could be provided to transfer drive to one or more of the wheels.
This application is a continuation-in-part of now pending U.S. patent application Ser. No. 12/592,079 filed Nov. 20, 2009 by the inventor herein and entitled “TRENCHING CHAIN”.
Number | Date | Country | |
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Parent | 12592079 | Nov 2009 | US |
Child | 12802900 | US |