Patent Application
20060272184
The present invention generally relates to a material handling apparatus and, in a preferred embodiment thereof, more particularly relates to an excavating machine, representatively a tracked excavator, having operatively attached to the stick portion of its boom a specially designed combination bucket and breaker structure which uniquely permits the excavator operator to selectively carry out either digging or refusal material breaking tasks without having to change out equipment on the stick.
Large scale earth excavation operations are typically performed using a powered excavating apparatus, such as a tracked excavator, having an articulated, hydraulically pivotable boom structure with an elongated, pivotal outer end portion commonly referred to as a “stick.” Secured to the outer end of the stick is an excavating bucket which is hydraulically pivotable relative to the stick between “closed” and “open” positions. By pivotally manipulating the stick, with the bucket swung to a selected operating position, the excavator operator uses the bucket to forcibly dig into the ground, scoop up a quantity of dirt, and move the scooped up dirt quantity to another location, such as into the bed of an appropriately positioned dump truck.
A common occurrence during this conventional digging operation is that the bucket strikes refusal material (in excavation parlance, a material which “refuses” to be dug up) such as rock which simply cannot be broken and scooped up by the bucket. When this occurs it is typical practice to stop the digging operation, remove the bucket from the stick, and install a hydraulically operated “breaker” on the outer end of the stick in place of the removed bucket. The breaker has, on its outer end, an oscillating tool portion which rapidly hammers the refusal material in a manner breaking it up into portions which can be subsequently dug up. After the breaker has been utilized to break up the refusal material, the operator removes the breaker from the stick, replaces the breaker with the previously removed bucket, and resumes the digging operation with the bucket.
While this procedure is easy to describe, it is a difficult, laborious and time-consuming task for the operator to actually carry out due to the great size and weight of both the bucket and breaker which must be attached to and then removed from the stick, and the necessity for the operator to climb into and out of the high cab area of the excavator (often in inclement weather) to effect each bucket and breaker change-out on the stick. This sequence of bucket/breaker/bucket change-out, of course, must be laboriously repeated each time a significant refusal area is encountered in the overall digging process.
A previously utilized alternative to this single excavator sequence is to simply provide two excavators for each digging project—one excavator having a bucket attached to its boom stick, and the second excavator having a breaker attached to its boom stick. When the bucket-equipped excavator encounters refusal material during the digging process, it is simply moved away from the digging site, and the operator climbs down from the bucket-equipped excavator, walks over to and climbs up into the breaker-equipped excavator, drives the breaker-equipped excavator to the digging site, and breaks up the encountered refusal material. Reversing the process, the operator then switches to the bucket-equipped excavator and resumes the digging process to scoop up the now broken-up refusal material.
While this digging/breaking technique is easier on the operator, it is necessary to dedicate two large and costly excavators to a given digging task, thereby substantially increasing the total cost of a given excavation task. A modification of this technique is to use two operators—one to operate the bucket-equipped excavator, and one to operate the breaker-equipped excavator. This, of course, undesirably increases both the manpower and equipment cost for a given excavation project.
Another attempt to solve this problem is disclosed in U.S. Pat. No. 6,085,446 and U.S. Pat. No. 4,100,688 for an excavating machine having a motorized milling tool attached to the back of the bucket. A primary disadvantage of these devices is complexity, cost, and reliability. Another disadvantage is the weight that must be continuously carried by the bucket. The additional weight substantially reduces the carrying capacity and mobility of the bucket. Another disadvantage to the device of U.S. Pat. No. 6,085,446 is that the back of the bucket cannot be used to smooth or pad the soil, as is a well-known practice in the industry. Another disadvantage is that surface rock is not subject to an overburden pressure, so it generally fails faster under compression and impact forces than by the shearing forces of a scraping and gouging rotary drilling tool.
Another attempt to solve this problem is disclosed in U.S. Pat. No. 4,070,772 for an excavating machine having a hydraulic breaker housed inside, or on top of, the boom stick. A primary disadvantage of this device is that it is extremely complex and expensive. Another disadvantage of this device is that it cannot be retrofit to existing excavators. Another disadvantage of this device is that the size of the breaker is limited. Another disadvantage of this device is that the bucket must be fully stowed to access the breaker and vice versa, making simultaneous operation impractical.
Another attempt to solve this problem is disclosed in U.S. Pat. No. 5,689,905 for another excavating machine having a hydraulic breaker housed inside, or on top of, the boom stick. In this device, the chisel portion of the breaker is removed when not in use. A primary disadvantage of this device is that it fails to permit immediate, unassisted switching from breaker to bucket, and thus simultaneous operation is impossible. Another disadvantage of this device is that it requires manual handling of the extremely heavy chisel tool each time the operator desires to convert to a breaker or bucket operation. Another disadvantage of this device is that it is extremely complex and expensive. Another disadvantage of this device is that it cannot be retrofit to existing excavators.
A more recent attempt to solve this problem is disclosed in U.S. Pat. No. 6,751,896 for an excavating machine having a boom stick portion on which both an excavating bucket and a hydraulic breaker are mounted for hydraulically driven pivotal movement between first and second positions. A deployment system is disclosed having a bracket for closely aligned pivotal support of both the breaker and a single hydraulic cylinder on a single bracket. While this design is a marked improvement over the prior art, its primary disadvantage is that it lacks the desired level of durability at the first pivot and extension limiting (stop) mechanisms to tolerate the massive reciprocating loads of operation over time. Another disadvantage is that it is difficult to disassemble the first pivot to replace tool components. Another disadvantage is that the means for lubricating the bearing surface of the first pivot was ineffective and weakened the first pivot assembly. Another disadvantage is that it suffers durability loss from exposure of mechanical fasteners to the excavated material.
As can be readily appreciated from the foregoing, a need exists for an improved design for carrying out the requisite digging and refusal material-breaking portions of an overall excavation operation in a manner eliminating or at least substantially eliminating the above-mentioned problems, limitations and disadvantages commonly associated with conventional digging and breaking operations. It is to this need that the present invention is directed. In particular, there is a need for a new design with superior durability to the designs disclosed in U.S. Pat. No. 6,751,896.
The present invention is a marked improvement over the designs disclosed in U.S. Pat. No. 6,751,896. In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, an excavating machine, representatively a tracked excavator, is provided with a specially designed pivotable boom stick assembly that includes a boom stick having first and second excavating tools secured thereto for movement relative to the boom stick. Illustratively, the first excavating tool is an excavating bucket secured to the boom stick for pivotal movement relative thereto between a first position and a second position, and the second tool is a breaker secured to the boom stick for pivotal movement relative thereto between a stowed position and an operative position.
A hydraulically operable drive apparatus is interconnected between the boom stick and the bucket and breaker and is usable to pivotally move the bucket between its first and second positions, and to pivotally move the breaker between its stowed and operative positions. Representatively, the drive apparatus includes a plurality of hydraulic cylinder assemblies operatively interconnected between the boom stick and the bucket and breaker.
The bucket, when the breaker is in its stowed position, is movable by the drive apparatus to the second bucket position and is usable in conjunction with the boom stick, and independently of the breaker, to perform a digging operation. The breaker, when the bucket is in its first position, is movable by the drive apparatus to the breaker's operative position and is usable in conjunction with the boom stick, and independently of the bucket, to perform a breaking operation. Accordingly, the excavating machine may be advantageously utilized to perform both digging and breaking operations without equipment change-out on the boom stick.
A primary advantage of the present invention's various embodiments is that it provides an extremely durable trunnion assembly for pivotal connection of the tool to the bracket. Another advantage is that it provides a new and durable stop mechanism, configured to avoid distortion of the side plates. Another advantage is that it is easy to disassemble the trunnion assembly to replace or service tool components. Another advantage is that it provides a reliable and effective means for lubricating the bearing surface of the trunnion assembly to ensure reliable operation of the tool.
In accordance with a preferred embodiment thereof, an excavating tool system for use on an excavating machine is provided. A bracket is located on the underside of a boom stick. The bracket has a first pivot and a second pivot. The first pivot is a trunnion. An excavating tool is pivotally secured at one end to the trunnion. The excavating tool has a third pivot located thereon between its one end and its opposite end. A hydraulic cylinder is pivotally secured at one end to the second pivot and pivotally secured on its opposite end to the third pivot. In the preferred embodiment, the pivotal attachment of the excavating tool to the bracket is bifurcated, thus comprising a pair of coaxial trunnions.
In the preferred embodiment, the centers of the trunnions are located coaxially on the bracket sides slightly further from base than the location of the second pivot.
In a preferred embodiment of the present invention, each trunnion comprises an outer plate and a cylindrical bearing extending from the outer plate. A plurality of bolt holes extends through the outer plate and the sleeve bearing. In a more preferred embodiment, a hub extends from the sleeve bearing. In the more preferred embodiment, the outer plate and hub are also cylindrical.
The mounting bracket further comprises a base and a pair of parallel bracket sides extending upward from the base, each having a hub socket and a plurality of threaded holes arranged generally symmetrically around the hub sockets. The threaded holes are aligned with the bolt holes for receiving threaded fasteners (such as bolts) for attaching the trunnions to the mounting bracket sides.
In a more preferred embodiment, the trunnion further comprises a lubrication system. In the preferred embodiment, the lubrication system comprises a bore in the outer plate. A fluid channel extends from the bore to the outer surface of the bearing. A lubrication connection, such as a grease cert, is attached to the fluid channel inside the bore.
In another preferred embodiment of the present invention, a stop is formed on each bracket side. A stop bar is located on one end of the excavating tool such that the stop bar engages the stop members to limit the pivotal rotation of the excavating tool.
These embodiments have the advantage of being easily retrofit onto excavating machines without modification of the hydraulic system. An additional advantage is the lower cost of materials and installation. Optionally, an uncontrolled hydraulic or pneumatic cylinder may be used to prevent free fall of the breaker upon release of the latch-lock. An advantage of this embodiment is increased safety.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
Refer now to the drawings wherein depicted elements are, for the sake of clarity, not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
A single hydraulic cylinder assembly 110 is pivotally attached at one end to second pivot 104 on bracket 140. Hydraulic cylinder assembly 110 is pivotally attached at its other end to third pivot 106 on breaker assembly 100. In the most preferred embodiment, the distance between first pivot 102 and second pivot 104 is less than the distance between first pivot 102 and the third pivot 106. A latch 190 is located on boom stick 200. When breaker assembly 100 is in the retracted position, latch 190 engages strike 132 (best seen in
As shown in
In
A pair of opposing lower lock plates 122 and a pair of upper lock plates 124 are provided for securing breaker 180 between body sections 112 and 114. Aligned holes 118 are also located on lower lock plates 122 and upper lock plates 124. Lock plates 122 and 124 are secured between breaker 180 and body sections 112 and 114 by nut and bolt assemblies 126 passing through aligned holes 118. In the preferred embodiment, the nuts of nut and bolt assemblies 126 are of the acorn type.
A stop bar 128 is provided for bolted attachment between body sections 112 and 114 at aligned holes 118. A pivot bar 130 is provided for bolted attachment between body sections 112 and 114 at aligned holes 118. Third pivot 106 is comprised of pivot bar 130. A strike 132 is provided for bolted attachment between body sections 112 and 114 at aligned holes 118.
Second pivot 104 comprises a pivot bar 146 located between bracket sides 144. In the preferred embodiment, a pair of hub sockets 148 is coaxially located in bracket sides 144. A series of bolt holes 150 are located generally symmetrically in each of bracket sides 144. In a more preferred embodiment including hub sockets 148, bolt holes 150 are located generally symmetrically around hub sockets 148 in bracket sides 144.
In a preferred embodiment best seen in
In the preferred embodiment, a plurality of bolt holes 168 extend through outer plate 162 and cylindrical bearing 164 in generally symmetric relationship. In a more preferred embodiment including hub 166, bolt holes 168 are located in a ring around hub 166. In a more preferred embodiment, bolt holes 168 include countersunk portions 170 for receiving the heads of bolts.
In a more preferred embodiment, trunnion 160 further comprises a lubrication system 172. A lubrication connection 174, such as a grease nipple, is attached to trunnion 160, preferably within a bore 176. A fluid channel 178 connects lubrication connection 174 to the surface of cylindrical bearing 164. Optionally, fluid channel 178 may intersect the surface of bearing 164 in more than one location.
Experience in field operation of an excavating tool in accordance with the disclosure of U.S. Pat. No. 6,751,896 has disclosed the opportunity for improvements in the invention of that patent, which are particular to an excavating machine having a deployable hammer pivotally attached to a boom stick. Specifically, the deployment system may suffer premature destruction of breaker assembly 100.
Referring to
The disclosed configuration allows an excavating machine 10 to have multiple uses, and therefore reduce the cost of operation. The deployment and retraction of breaker assembly 100 is accomplished by the relationships between breaker assembly 100, boom stick 200, and hydraulic cylinder 110, as associated with the configuration first pivot 102, second pivot 104, and third pivot 106. In the most preferred embodiment, the distance between first pivot 102 and the second pivot 104 is less than the distance between first pivot 102 and third pivot 106.
As illustrated in
In the preferred embodiment, first pivot 102 is comprised of a pair of coaxial trunnions 160 located on bracket 140. Trunnions 160 are fully illustrated in
Second pivot 104 comprises pivot bar 146, which extends between sides 144. Pivot bar 146 provides pivotal coupling between hydraulic cylinder 110 and bracket 140.
Third pivot 106 comprises a pivot bar 130 coupled between body sections 112 and 114. Pivot bar 130 provides pivotal coupling between hydraulic cylinder 110 and breaker assembly 100.
As seen in
As seen in
In a more preferred embodiment, trunnion 160 further comprises lubrication system 172. Lubrication system 172 comprises lubrication connection 174 at, such as a grease cert for adding grease, attached to fluid channel 178 within trunnion 160. Preferably, lubrication connection 174 is located within bore 176 to provide protection during excavating activities, thus adding durability to the tool system. Fluid channel 178 connects lubrication connection 174 to the surface of cylindrical bearing 164. Optionally, fluid channel 178 may intersect the surface of bearing 164 in more than one location.
Lubrication system 172 thus provides the advantage of a protected and accessible means of maintaining lubrication at first pivot 102, which receives the heaviest load and impacts of the system. The large bearing area provided by cylindrical bearing 164, when lubricated, has the advantage of distributing the significant impact forces of operation over a larger area. Similarly, the use of hubs 166 and multiple threaded fasteners (not illustrated) through bolt holes 150 to secure trunnions 160 to bracket 140 distributes the impact forces of operation over the collectively larger cross-sectional area of the multiple fasteners and hubs 166.
As best seen in
As illustrated in
Nut and bolt assemblies 126 connect through aligned holes 118 to secure lower lock plates 122 and upper lock plates 124 around breaker 180 and between body sections 112 and 114. Additionally, nut and bolt assemblies 126 connect through aligned holes 118 to secure pivot bar 130, stop bar 152, and strike 132 between body sections 112 and 114 at aligned holes 118. Stop bar 152 is located immediately adjacent to breaker end 184 of breaker 180.
Strike 132 provides a means of engagement with latch 190 when it is desired to retain breaker assembly 100 in the retracted, or stowed, position. The retracted, or stowed, position is illustrated in
In a preferred embodiment of the present invention illustrated in
Another advantage of the present invention is that the bucket can be operated without fully stowing the breaker. Likewise, the breaker may be operated without the necessity to fully extend the bucket. This increases the efficiency of the excavation process by providing immediate access to each of the tools, without delay. Another advantage of this capability is that it further increases the efficiency of the excavation process by rendering the bucket available to frequently scrape away the freshly generated cuttings so the breaker tool is always exposed to fresh refusal material, avoiding operation against previously generated cuttings. Another advantage of this capability is that by avoiding operation against previously generated cuttings, the breaker tool will last longer.
Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
This application is a continuation-in-part of co-pending U.S. application Ser. No. 10/871,898, filed Jun. 18, 2004, which is a continuation-in-part of co-pending U.S. application Ser. No. 10/150,057, filed May 17, 2002, now U.S. Pat. No. 6,751,896, which is a continuation-in-part of co-pending U.S. application Ser. No. 09/624,099, filed Jul. 24, 2000, now U.S. Pat. No. 6,430,849. This is also a continuation of U.S. application Ser. No. 11/362,670, filed Feb. 27, 2006. All applications from which priority is claimed are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11362670 | Feb 2006 | US |
| Child | 11504994 | Aug 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10871898 | Jun 2004 | US |
| Child | 11504994 | Aug 2006 | US |
| Parent | 10150057 | May 2002 | US |
| Child | 10871898 | Jun 2004 | US |
| Parent | 09624099 | Jul 2000 | US |
| Child | 10150057 | May 2002 | US |
