CN202214743U - Backhoe loader - Google Patents
Backhoe loader Download PDFInfo
- Publication number
- CN202214743U CN202214743U CN2011202797176U CN201120279717U CN202214743U CN 202214743 U CN202214743 U CN 202214743U CN 2011202797176 U CN2011202797176 U CN 2011202797176U CN 201120279717 U CN201120279717 U CN 201120279717U CN 202214743 U CN202214743 U CN 202214743U
- Authority
- CN
- China
- Prior art keywords
- body frame
- hydraulic cylinder
- bearing pin
- excavating gear
- loader
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn - After Issue
Links
Images
Abstract
The utility model provides a backhoe loader, which comprises a body frame (1), an excavating gear (2), a shovel plate part (3), a running gear (4), an operating system (5), a scraper conveyor (7) and an explosion insulation motor (8), wherein the excavating gear (2) comprises a first excavating gear (21) and a second excavating gear (22), which are parallelly arranged on the left and right above the front of the body frame (1). The integral width of the backhoe loader can be reduced, the digging efficiency of the excavating gear is improved, the weight of the whole machine is reduced, the labor intensity of workers is reduced, and the roadway construction mechanization degree is improved.
Description
Technical field
The utility model relates to a kind of colliery and loads transloading equipment with excavating, and more specifically, relates to a kind of loader-digger.
Background technology
Loader-digger is that the unique backhoe type of a kind of employing that is applicable to blast mining face operating mechanism takes off and gets rock; And carry rock through the scratch board conveyor structure of self, the tunnel trackless construction that is discharged into a kind of continuous loading transportation of mine car or other Transport Machinery (belt conveyer, scratch board conveyor) from the afterbody equipment of slagging tap.By excavating gear, the shovel plate, scratch board conveyor, body, running gear, several parts such as operating system are formed.
The integral width of loader-digger is all bigger at present, is not suitable for being used with other plant equipment of colliery; Excavating gear excavates takes off that to get efficient low; Adopt ordinary carbon steel to do structural member, complete machine weight is big, is not suitable for the transportation of in the tunnel, disintegrating.These problems cause tunnelling machineryization degree low, and tunnelling speed is slow, and labor strength is big.
Therefore, the utility model technical problem to be solved just is, reduces integral width, the raising excavating gear of loader-digger and takes off the efficient of getting ore, the weight that reduces complete machine, alleviates working strength of workers, and tunnelling machineryization degree is provided.
The utility model content
For the integral width that solves loader-digger in the above-mentioned prior art is big, excavating gear take off technical problem such as get that efficient is low, the weight of complete machine big, the transportation that is not suitable for disintegrating, working strength of workers are big or one of at least; The utility model provides a kind of loader-digger, can effectively overcome the problems referred to above of prior art.
In view of this; The utility model provides a kind of loader-digger; Comprise body frame 1, excavating gear 2, shovel board 3, running gear 4, operating system 5, scratch board conveyor 7 and explosion separation motor 8, said excavating gear 2 comprises first excavating gear 21 and second excavating gear 22, is arranged in parallel at the left and right sides of said body frame 1 front upper place; Said operating system 5 is arranged on the rear portion of said body frame 1 the above excavating gear 2; Said shovel board 3 is arranged on the front lower place of said body frame 1, and said running gear 4 is installed in the both sides of said body frame 1, and said scratch board conveyor 7 is installed on the said body frame 1; The front end of said scratch board conveyor 7 is connected with the rear end of said shovel board 3, said body frame 1 is stretched out in the rear end, and said explosion separation motor 8 is arranged on the body frame 1.
In technique scheme, preferably, said operating system 5 comprises first operating system 51 and second operating system 52, respectively said first excavating gear 21 of independent operation and second excavating gear 22.
Preferably; Said first excavating gear 21 is hinged through first bearing pin 9 and the said body frame 1 of vertical direction; Be provided with hydraulic cylinder between said first excavating gear 21 and the said body frame 1, said first excavating gear 21 can rotate in 0～90 ° of scope in the left side around said first bearing pin 9 under the effect of said hydraulic cylinder;
Said second excavating gear 22 is hinged through second bearing pin 10 and the said body frame 1 of vertical direction; Be provided with hydraulic cylinder between said second excavating gear 22 and the said body frame 1, said second excavating gear 22 can rotate in 0～90 ° of scope on the right side around said second bearing pin 10 under the effect of said hydraulic cylinder.
Preferably; Said shovel board 3 comprises scraper bowl 31, shovel postlaminar part 32, the 3rd bearing pin 33, the 4th bearing pin 34; Said scraper bowl 31 is connected with said shovel postlaminar part 32 through the 3rd bearing pin 33, is provided with first hydraulic cylinder 311 in the both sides of said scraper bowl 31, and an end and the said scraper bowl 31 of said first hydraulic cylinder 311 are hinged; The other end is fixed on said the 3rd bearing pin 33, and said scraper bowl 31 can be around 33 rotations of said the 3rd bearing pin under the effect of said first hydraulic cylinder 311;
Said shovel postlaminar part 32 is fixed on the preceding bottom of said body frame 1 through horizontally disposed the 4th bearing pin 34; The both sides of said shovel postlaminar part 32 are provided with said the 4th hydraulic cylinder 321; One end of said the 4th hydraulic cylinder 321 is arranged on said the 3rd bearing pin 33; The other end is arranged on said the 4th bearing pin 34, and said scraper bowl rear portion 32 can be around 34 rotations of said the 4th bearing pin under the effect of said the 4th hydraulic cylinder 321.
Preferably; The rear portion of said scratch board conveyor 7 is hinged on the said body frame 1 through the 5th bearing pin 71 of vertical direction; The both sides, rear portion of said scratch board conveyor 7 also are provided with said the 5th hydraulic cylinder 72; One end of said the 5th hydraulic cylinder 72 is hinged on the said scratch board conveyor 7, and the other end and said body frame 1 are hinged, and the below of said scratch board conveyor 7 also is provided with the 6th hydraulic cylinder 73; One end of said the 6th hydraulic cylinder 73 is hinged on the said body frame 1; The other end is hinged on the said scratch board conveyor 7, and said scratch board conveyor 7 can rotate up and down under the effect of said the 6th hydraulic pressure 73 around said the 5th bearing pin 71 left-right rotation under the effect of said the 5th hydraulic cylinder 72.
Preferably, said explosion separation motor 8 is arranged on the rear end of said body frame 1, and outer setting has protective cover 81.
Preferably, said running gear 4 comprises track frame, hydraulic motor, reductor, crawler belt and caterpillar chain, and said hydraulic motor, reductor, crawler belt and caterpillar chain are installed on the said track frame, and said hydraulic motor drives said caterpillar chain through said reductor.
Preferably, said body frame 1, excavating gear 2, scraper bowl 31, scratch board conveyor 7 all adopt 30 chromium manganese silicon to process.
Through the loader-digger that the utility model provides, can reduce loader-digger integral width, improve the weight that taking off of excavating gear got efficient, reduced complete machine, alleviate working strength of workers, tunnelling machineryization degree is provided.
Description of drawings
Fig. 1 shows the overall structure sketch map according to the loader-digger of the utility model embodiment;
Fig. 2 shows the schematic top plan view of structure shown in Figure 1;
Fig. 3 shows the excavating gear work track sketch map according to the utility model embodiment;
Fig. 4 shows the operating position sketch map according to the excavating gear of the utility model embodiment, scratch board conveyor.
The specific embodiment
Below in conjunction with the specific embodiment of description of drawings according to the utility model.
Fig. 1, Fig. 2 show the overall structure sketch map according to the described loader-digger of the utility model.Wherein, Fig. 1 shows the overall structure sketch map according to the loader-digger of the utility model embodiment; Fig. 2 shows the schematic top plan view of structure shown in Figure 1.
Like Fig. 1, shown in Figure 2; The utility model provides a kind of loader-digger; Comprise body frame 1, excavating gear 2, shovel board 3, running gear 4, operating system 5, scratch board conveyor 7 and explosion separation motor 8, said excavating gear 2 comprises first excavating gear 21 and second excavating gear 22, is arranged in parallel at the left and right sides of the front upper place of said body frame 1; Said operating system 5 is arranged on the rear portion of the said excavating gear 2 on the said body frame 1; Said shovel board 3 is arranged on the front lower place of said body frame 1, and said running gear 4 is installed in the both sides of said body frame 1, and said scratch board conveyor 7 is installed on the said body frame 1; The front end of said scratch board conveyor 7 is connected with the rear end of said shovel board 3, said body frame 1 is stretched out in the rear end, and said explosion separation motor 8 is arranged on the body frame 1.
Like this, two excavating gears are installed on a loader-digger, the excavation that can improve loader-digger is taken off and is got efficient.
Said operating system 5 comprises first operating system 51 and second operating system 52, respectively said first excavating gear 21 of independent operation and second excavating gear 22.Operating system is positioned at the rear end of excavating gear, respectively by two workman's operations.Two operating systems work alone separately, do not disturb mutually.
Said explosion separation motor 8 is arranged on the positive rear end of said body frame 1, and for said running gear 4, operating system 5 provide power, outer setting has protective cover 81.Existing explosion separation motor places the left side or the right side of body frame; Increased the complete machine width of loader-digger; Be not easy to and other tunnels equipment cooperates practically, explosion separation motor 8 is arranged on the rear end of body frame 1, can effectively reduce the complete machine width; Improve the flexibility of loader-digger, improved tunnelling machineryization degree simultaneously.
Said body frame 1, excavating gear 2, scraper bowl 31, scratch board conveyor 7 all adopt high-tensile structural steel 30 chromium manganese silicon to process.Adopt high-tensile structural steel, can effectively reduce the weight of complete machine, be convenient to the disintegration transportation of equipment, reduce labor strength, improve the mechanization degree of tunnelling in the down-hole.
Said running gear 4 comprises track frame, hydraulic motor, reductor, crawler belt and caterpillar chain, and said hydraulic motor, reductor, crawler belt and caterpillar chain are installed on the said track frame, and said hydraulic motor drives said caterpillar chain through said reductor.
Running gear 4 adopts track structure, adapts to many rubbles under the ore deposit, heavy road face more, improves the trafficability characteristic of loader-digger, the destruction of reducing the body weight road pavement simultaneously.
Fig. 3, Fig. 4 show the working state schematic representation according to the loader-digger of the utility model embodiment.Track sketch map when wherein, Fig. 3 shows according to the work of the excavating gear of the utility model embodiment; Fig. 4 shows the operating position sketch map according to the excavating gear of the utility model embodiment, scratch board conveyor.
As shown in Figure 3; Said shovel board 3 comprises scraper bowl 31, shovel postlaminar part 32, the 3rd bearing pin 33, the 4th bearing pin 34; Said scraper bowl 31 is hinged through the 3rd bearing pin 33 and said shovel postlaminar part 32, is provided with first hydraulic cylinder 311 in the both sides of said scraper bowl 31, and an end of said first hydraulic cylinder 311 is fixed on the said scraper bowl 31; The other end is hinged on the 3rd bearing pin 33 on the said scraper bowl rear portion 32, and said scraper bowl 31 rotates around said the 3rd bearing pin 33 under the effect of said first hydraulic cylinder 311.
Said shovel postlaminar part 32 is hinged on the preceding bottom of said body frame 1 through horizontally disposed the 4th bearing pin 34; The both sides of said shovel postlaminar part 32 are provided with said the 4th hydraulic cylinder 321; One end of said the 4th hydraulic cylinder 321 is hinged on said the 3rd bearing pin 33; The other end is hinged on said the 4th bearing pin 34, and said scraper bowl rear portion 32 rotates around said the 4th bearing pin 34 under the effect of said the 4th hydraulic cylinder 321.Like this; Scraper bowl 31 is outwards folding under the effect of hydraulic jack 311; Promptly realize the move left and right of scraper bowl 31; Said shovel postlaminar part 32 and scraper bowl 31 can be realized moving up and down of shovel postlaminar part 32 around 34 rotations of said the 4th bearing pin under the effect of said the 4th hydraulic cylinder 321, realize suitable " loaded " position.
As shown in Figure 3, tracing point b be said scraper bowl 31 under the effect of the 4th hydraulic cylinder 321, regulate the tracing point that the working depth of scraper bowl 31 stays, this can realize producing the work and the running efficiency that move up and down, improve shovel board 3 of board 3.Swinging of said shovel board 3, shown in tracing point f and tracing point g among Fig. 4, the position view that tracing point f swings for shovel board 3 to the left, the position view that tracing point g swings for shovel board 3 to the right.
As shown in Figure 4; Said first excavating gear 21 is connected with said body frame 1 through first bearing pin 9 of vertical direction; Be provided with hydraulic cylinder between said first excavating gear 21 and the said body frame 1; Said first excavating gear 21 shown in tracing point d among Fig. 4, is the position view that first excavating gear 21 turns clockwise around first bearing pin 9 to the left in 0～90 ° of scope of said first bearing pin 9 in said left side, turning clockwise under the effect of said hydraulic cylinder.
Said second excavating gear 22 is hinged through second bearing pin 10 and the said body frame 1 of vertical direction; Be provided with hydraulic cylinder between said second excavating gear 22 and the said body frame 1; Said second excavating gear 22 can revolve in 0～90 ° of scope of said second bearing pin 10 on the right side under the effect of said hydraulic cylinder counterclockwise; Shown in tracing point e among Fig. 4, be the position view that second excavating gear 22 is rotated counterclockwise around said second bearing pin 10.
And for example shown in Figure 3, trajectory a is an excavating gear 2 when work, in said shovel board 3, takes off the circuit of getting mineral, and said excavating gear 2 curves inwardly to take off under the effect of hydraulic cylinder and gets mineral.Realize action to be prior art also, repeat no more.
Like this, the hydraulic cylinder two ends are articulated in respectively on body frame 1 and two excavating gears 2, and two excavating gears can be realized left and right sides gyration by Driven by Hydraulic Cylinder, realize that the scope of getting is taken off in the excavation of big width.
The rear portion of said scratch board conveyor 7 is hinged on the said body frame 1 through the 5th bearing pin 71 of vertical direction; The both sides, rear portion of said scratch board conveyor 7 also are provided with said the 5th hydraulic cylinder 72; One end of said the 5th hydraulic cylinder 72 is hinged on the said scratch board conveyor 7; The other end and said body frame 1 are hinged; The below of said scratch board conveyor 7 also is provided with the 6th hydraulic cylinder 73, and an end of said the 6th hydraulic cylinder 73 is hinged on the said body frame 1, and the other end is hinged on the said scratch board conveyor 7.Said scratch board conveyor 7 rotates around said the 5th bearing pin 71 under the effect of said the 5th hydraulic cylinder 72; Realize the move left and right of scratch board conveyor 7 afterbodys; Shown in tracing point h among Fig. 4 and tracing point i; Tracing point h is the position view that scratch board conveyor 7 is swung to the right, and tracing point i is the position view that swing left the rear end of scratch board conveyor 7; Said scratch board conveyor 7 can rotate up and down around its back shaft under the effect of said the 6th hydraulic cylinder 73; The afterbody of realizing said scratch board conveyor 7 moves up and down; Shown in tracing point c among Fig. 3, tracing point c is the track position sketch map that scratch board conveyor 7 rotates around its back shaft.Swinging of scratch board conveyor 7 can make said excavation charging appliance be positioned at the both sides of tramroad, to realize once loading many mine cars, improves efficiency of loading and loading scope.
The utility model adopts two excavating gear bilateral operations, has increased an excavating gear more and has improved the efficient of loading; Explosion separation motor is positioned at the complete machine rear portion, has reduced the complete machine width, and has protected motor; The whole machine using high-tensile structural steel is done the weight that critical component has lowered complete machine greatly, is convenient to the disintegration transportation in underworkings; Scratch board conveyor can swing and load many mine cars in the situation that does not increase car load length next time, has reduced the assisted loading time, has increased efficiency of loading.
Through the loader-digger that the utility model provides, can also reduce loader-digger integral width, improve the weight that taking off of excavating gear got efficient, reduced complete machine, alleviate working strength of workers, tunnelling machineryization degree is provided.
The preferred embodiment that the above is merely the utility model is not limited to the utility model, and for a person skilled in the art, the utility model can have various changes and variation.All within the spirit and principle of the utility model, any modification of being done, be equal to replacement, improvement etc., all should be included within the protection domain of the utility model.
Claims (8)
1. loader-digger; Comprise body frame (1), excavating gear (2), shovel board (3), running gear (4), operating system (5), scratch board conveyor (7) and explosion separation motor (8); It is characterized in that; Said excavating gear (2) comprises first excavating gear (21) and second excavating gear (22); Be arranged in parallel at the left and right sides of said body frame (1) front upper place, said operating system (5) is arranged on the rear portion of the above excavating gear of said body frame (1) (2), and said shovel board (3) is arranged on the front lower place of said body frame (1); Said running gear (4) is installed in the both sides of said body frame (1); Said scratch board conveyor (7) is installed on the said body frame (1), and the front end of said scratch board conveyor (7) is connected with the rear end of said shovel board (3), said body frame (1) is stretched out in the rear end, and said explosion separation motor (8) is arranged on the body frame (1).
2. loader-digger according to claim 1 is characterized in that, said operating system (5) comprises first operating system (51) and second operating system (52), respectively said first excavating gear of independent operation (21) and second excavating gear (22).
3. loader-digger according to claim 2; It is characterized in that; Said first excavating gear (21) is hinged with said body frame (1) through first bearing pin (9) of vertical direction; Be provided with hydraulic cylinder between said first excavating gear (21) and the said body frame (1), said first excavating gear (21) can rotate in 0～90 ° of scope in the left side around said first bearing pin (9) under the effect of said hydraulic cylinder;
Said second excavating gear (22) is hinged with said body frame (1) through second bearing pin (10) of vertical direction; Be provided with hydraulic cylinder between said second excavating gear (22) and the said body frame (1), said second excavating gear (22) can rotate in 0～90 ° of scope on the right side around said second bearing pin (10) under the effect of said hydraulic cylinder.
4. loader-digger according to claim 3; It is characterized in that; Said shovel board (3) comprises scraper bowl (31), shovel postlaminar part (32), the 3rd bearing pin (33), the 4th bearing pin (34); Said scraper bowl (31) is connected with said shovel postlaminar part (32) through the 3rd bearing pin (33), is provided with first hydraulic cylinder (311) in the both sides of said scraper bowl (31), and an end of said first hydraulic cylinder (311) and said scraper bowl (31) are hinged; The other end is fixed on said the 3rd bearing pin (33), and said scraper bowl (31) can rotate around said the 3rd bearing pin (33) under the effect of said first hydraulic cylinder (311);
Said shovel postlaminar part (32) is fixed on the preceding bottom of said body frame (1) through horizontally disposed the 4th bearing pin (34); The both sides of said shovel postlaminar part (32) are provided with said the 4th hydraulic cylinder (321); One end of said the 4th hydraulic cylinder (321) is arranged on said the 3rd bearing pin (33); The other end is arranged on said the 4th bearing pin (34), and said scraper bowl rear portion (32) can rotate around said the 4th bearing pin (34) under the effect of said the 4th hydraulic cylinder (321).
5. according to the arbitrary described loader-digger of claim 1 to 4; It is characterized in that; Said scratch board conveyor (7) is hinged on the said body frame (1) through the 5th bearing pin (71) of vertical direction, and the both sides, rear portion of said scratch board conveyor (7) also are provided with said the 5th hydraulic cylinder (72), and an end of said the 5th hydraulic cylinder (72) is hinged on the said scratch board conveyor (7); The other end and said body frame (1) are hinged; The below of said scratch board conveyor (7) also is provided with the 6th hydraulic cylinder (73), and an end of said the 6th hydraulic cylinder (73) is hinged on the said body frame (1), and the other end is hinged on the said scratch board conveyor (7); Said scratch board conveyor (7) can rotate up and down under the effect of said the 6th hydraulic cylinder (73) around said the 5th bearing pin (71) left-right rotation under the effect of said the 5th hydraulic cylinder (72).
6. loader-digger according to claim 5 is characterized in that, said explosion separation motor (8) is arranged on the rear end of said body frame (1), and outer setting has protective cover (81).
7. loader-digger according to claim 6; It is characterized in that; Said running gear (4) comprises track frame, hydraulic motor, reductor, crawler belt and caterpillar chain; Said hydraulic motor, reductor, crawler belt and caterpillar chain are installed on the said track frame, and said hydraulic motor drives said caterpillar chain through said reductor.
8. loader-digger according to claim 7 is characterized in that, all employings 30 chromium manganese silicon of said body frame (1), excavating gear (2), scraper bowl (31), scratch board conveyor (7) are processed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202797176U CN202214743U (en) | 2011-08-03 | 2011-08-03 | Backhoe loader |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202797176U CN202214743U (en) | 2011-08-03 | 2011-08-03 | Backhoe loader |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202214743U true CN202214743U (en) | 2012-05-09 |
Family
ID=46014003
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011202797176U Withdrawn - After Issue CN202214743U (en) | 2011-08-03 | 2011-08-03 | Backhoe loader |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202214743U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102383449A (en) * | 2011-08-03 | 2012-03-21 | 石家庄中煤装备制造股份有限公司 | Digging loader |
| CN104727817A (en) * | 2015-01-19 | 2015-06-24 | 中国矿业大学 | Tunneling and loading all-in-one machine |
-
2011
- 2011-08-03 CN CN2011202797176U patent/CN202214743U/en not_active Withdrawn - After Issue
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102383449A (en) * | 2011-08-03 | 2012-03-21 | 石家庄中煤装备制造股份有限公司 | Digging loader |
| CN102383449B (en) * | 2011-08-03 | 2014-09-10 | 石家庄中煤装备制造股份有限公司 | Digging loader |
| CN104727817A (en) * | 2015-01-19 | 2015-06-24 | 中国矿业大学 | Tunneling and loading all-in-one machine |
| CN104727817B (en) * | 2015-01-19 | 2017-02-22 | 中国矿业大学 | Tunneling and loading all-in-one machine |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103835720B (en) | Hard Rock Breaking System | |
| CN102587914A (en) | Strip-type Wongawilli mining method of coal buried under building | |
| CN205503122U (en) | Chisel dress anchor all -in -one | |
| CN103883329A (en) | Excavation construction method for mine hard rock roadway | |
| CN101881162A (en) | Drill loader | |
| CN112412450A (en) | Drilling, loading and anchoring integrated machine | |
| CN102561433A (en) | Drilling, crushing, digging and loading integrated machine for all-hydraulic tunneling | |
| CN102383449B (en) | Digging loader | |
| CN214784273U (en) | Drilling, crushing, excavating and loading integrated machine | |
| CN103075153A (en) | Open-air drilling coal cutter | |
| CN202214743U (en) | Backhoe loader | |
| CN103867203B (en) | Mine working chain saw type hard rock mole | |
| CN211648172U (en) | Ten-arm tunneling and tracing machine | |
| CN209780954U (en) | Coal face end triangular space filling device | |
| CN202108509U (en) | Rock loading machine in mining area | |
| CN204849883U (en) | Three -dimensional excavation system | |
| CN204609879U (en) | A kind of pick anchor all-in-one | |
| CN203668994U (en) | Ditcher | |
| CN207420567U (en) | A kind of mining underground breaker | |
| CN103741742B (en) | Ditcher | |
| CN203805992U (en) | Novel mining crawler-type loader-digger | |
| CN201021499Y (en) | Dynamic arm hole digger | |
| CN102808431B (en) | Double-arm excavator | |
| CN205895231U (en) | Be used for mine mining and automatic conveying equipment | |
| CN201896617U (en) | Coal charging machinery used on blasting driving face of coal mine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20120509 Effective date of abandoning: 20140910 |
|
| RGAV | Abandon patent right to avoid regrant |