CA1193498A - Synchronous vibratory impact hammer - Google Patents
Synchronous vibratory impact hammerInfo
- Publication number
- CA1193498A CA1193498A CA000422509A CA422509A CA1193498A CA 1193498 A CA1193498 A CA 1193498A CA 000422509 A CA000422509 A CA 000422509A CA 422509 A CA422509 A CA 422509A CA 1193498 A CA1193498 A CA 1193498A
- Authority
- CA
- Canada
- Prior art keywords
- hammer
- hammer body
- assemblage
- body assemblage
- vibratory
- 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.)
- Expired
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/96—Dredgers; Soil-shifting machines mechanically-driven with arrangements for alternate or simultaneous use of different digging elements
- E02F3/966—Dredgers; Soil-shifting machines mechanically-driven with arrangements for alternate or simultaneous use of different digging elements of hammer-type tools
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D11/00—Portable percussive tools with electromotor or other motor drive
- B25D11/06—Means for driving the impulse member
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D11/00—Portable percussive tools with electromotor or other motor drive
- B25D11/06—Means for driving the impulse member
- B25D11/066—Means for driving the impulse member using centrifugal or rotary impact elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D17/00—Details of, or accessories for, portable power-driven percussive tools
- B25D17/24—Damping the reaction force
Abstract
ABSTRACT OF THE DISCLOSURE
A vibratory impact hammer is disclosed having no mechanical restraints which can absorb energy. The hammer includes a hammer body assemblage suspended by rubber mounts for reciprocal axial movement in a support frame, the rubber mounts providing guiding and damping action of the assemblage in either direction of axial movement without extraneous friction forces acting thereupon, and a pair of synchronously driven eccentric weights which are arranged to provide vibratory move-ment of the assemblage.
A vibratory impact hammer is disclosed having no mechanical restraints which can absorb energy. The hammer includes a hammer body assemblage suspended by rubber mounts for reciprocal axial movement in a support frame, the rubber mounts providing guiding and damping action of the assemblage in either direction of axial movement without extraneous friction forces acting thereupon, and a pair of synchronously driven eccentric weights which are arranged to provide vibratory move-ment of the assemblage.
Description
3~
This invention relatec; to a synchrono~s vibra-tory hammer employing a driving and a driven eccentric weight arranged to produce vibratory action which may be used for impacting a tool upon a work surface.
The art of vibratory hammers, of the type with which this invention is concerned, is well developed and many different designs have been proposed and employed with varying degrees of success. Patent 3r866,693, dated February 18, 1975 to Bernard A. Century, iO is representative of one such vibratory hammer.
The subject invention has certain elements in common with the device of the Century patent, however, it dif~ers in at least one important respect, namely, it has no mechanical restraints which can absorb energy, such as would be caused by the guides 186 and 188 of Centuryls patent. The mechanical restraints in the Century patent are used to control non-linear motion of the hammer element being driven by a single eccentric.
The device o~ the subject invention eliminates the need for such mechanical restraints because of the act that two eccentrics are used.
The device of the subject invention requires less maintenance than vibratory hammers having non-linear impacting vihrations, which not only shake the hammer supporting mechanism, but are subject to greater wear and breakage.
A primary ohject of the invention is to provide a vibratory hammer with improved operating efficiency, and which minimize.s maintenance costs.
The presenl: invention provides a vibratory im-pact hammer including a support frame, a hammer body assemblage suspendecl within the support frame by resilient means arl-anged to provide guiding and damping action in either direction of axial movement o~ the ha~mer body zssemblage, said hamm~r body having a given '''',~''`' stro~e t the xesilient means being the sole means engaglng the hammer body assemblage so that extraneous frictional forces are avoided, vibration dri~e means arranged to de-velop a forcing frequency to vibrate the hammer body as-semblage in an axial direction, said forcing frequency setto lead the vibrated ~requency of the hamrner body assem-blage by 135, and a tool reciprocably mounted in the sup-port frame and positioned to receive impact blows of the hammer body assemblage when reciprocated by the vibratory drive means.
These and further objects and features of the invention will become more apparent from an understanding of the following disclosure.
In drawings which illustrate embodiments of the invention, Fig. 1 is a side elevation view of a vibratory hammer embodying the principles of the in~ention;
Fig. 2 is an enlarged section view as seen from line 2-2 in Fig. l;
Figs. 3, 4 and 5 are cross section views as seen from lines 3-3, 4-4 and 5-5 respectively in Fig. 2;
Fig. 6 is an exterior view of a hammer body com-ponent used in the device of Fig. l;
Fig. 7 is an end view of the eccentric weights mounted on a shaft.
Referring now to Figs. 1 to 5, numeral 1 identi-fies a vibratory hammer having a support frame consisting of a pair of side plates 3, which are maintained in par-allel position by means of tubular space bars 5, welded to the plates~ as well as a tool holder element 7, similarly welded thexeto. A hammer body assemblage 9, as shown in Fig. 6, is suspended between the side plates 3 by resilient means consisting of four rubber mounts 11 affixed to thc side plates and the hammex body assemblage by means of bolts 13 and 15~ As will be apparent, the mounts serve as - 2a -the sole guiding and damping mea~ns for the assemblage when the latter is vibrated duri.ng t~l operation.
"~, ~3~
The hammer body assemblage 9 includes an eccentric weight chamber 17, shown in Fig. 7~ enclosing a pair of eccentric weights 19 and-21, mounted upon shafts 23 supported in roller bearings 25 positioned in end caps 27 r the latter being secured by bolt means 29 to side members 31 of -the eccentric weight chamber 15 by bolts 32~ Projecting from the top surface of the eccentric weight chamber 17 and affixed theretol is an upper axm member 33 adapted to be affixed to the rubber mounts 11 by the bo]ts 15.
Projecting from the bottom surface of the eccen-tric weight chamber 7 and aEfixed khereto, is a lower arm member 35 adapted to be affixed to the rubber mounts 11 by the bolts 15. Brace members 37 are secured to the sides of the lower arm member 35 and the hammer body assem~lage 9, to stabilize the arm member. An hydraulic motor 39, affixed to the end of shaft 23, is provided to rotate the eccentric weight 19. A pair of gears 41, mounted upon the shaft 23, ~s arranged to transmit rotary motion from the shaft which supports eccentric weight 19, to the sha~t which supports eccen-tric weight 21, so that both weights are rotated at the same speed but in opposite directions. Hose means 43 5uppiy pressurized hydraulic fluid to the motor 39 when desired, from a power source, not shown.
At the lower extremity of the arm member 35 is a striker plake 45 affixed thereto by means of pin 47.
The striker plate is arranged to impact upon a conical tool 49 mounted in the tool holder element 7 as best seen in Fig~ 2~ Retaining means, including a key 51 projecting into a slot 53 formed in the tool 49, allow reciprocal movement of the tool~ The tool slides in bushi.ngs 55 supported in a bushin~ housing 5?, the latter positionally maintained against axial movement hy a tool stop plate 59,affixed to the end of the tool ~3~
holder by means of cap screws 61~
Support means for the vibratory hammer 1, are provided by a pivotally attached linkage assemblage 63, which may be operatively positioned by power machinery, e.g. tractor, not shown.
The desi.gn parameters of a vibratory hammer built in acco.rdance with the invention disclosed herein, obviously will vary in accordance with the work impact output desired.
It is to be recognized -that when a forcing frequency vibrates a mass at its natural frequency, the mass of the forcing frequency generator leads the vibrated mass by 90. When the forcing frequency is much higher than the natural frequency, the forcing frequency mass could lead the vibrated mass by 180.
Accordingly, if the leading phase is 135, the vertical componen-t of centrifugal force of the vibrated mass, coupled with the stored energy of the rubber mounts, will produce maximum impacting on the tool 49.
The optimum phase angle of 135 l~) is deter-mined by the following equation:
This invention relatec; to a synchrono~s vibra-tory hammer employing a driving and a driven eccentric weight arranged to produce vibratory action which may be used for impacting a tool upon a work surface.
The art of vibratory hammers, of the type with which this invention is concerned, is well developed and many different designs have been proposed and employed with varying degrees of success. Patent 3r866,693, dated February 18, 1975 to Bernard A. Century, iO is representative of one such vibratory hammer.
The subject invention has certain elements in common with the device of the Century patent, however, it dif~ers in at least one important respect, namely, it has no mechanical restraints which can absorb energy, such as would be caused by the guides 186 and 188 of Centuryls patent. The mechanical restraints in the Century patent are used to control non-linear motion of the hammer element being driven by a single eccentric.
The device o~ the subject invention eliminates the need for such mechanical restraints because of the act that two eccentrics are used.
The device of the subject invention requires less maintenance than vibratory hammers having non-linear impacting vihrations, which not only shake the hammer supporting mechanism, but are subject to greater wear and breakage.
A primary ohject of the invention is to provide a vibratory hammer with improved operating efficiency, and which minimize.s maintenance costs.
The presenl: invention provides a vibratory im-pact hammer including a support frame, a hammer body assemblage suspendecl within the support frame by resilient means arl-anged to provide guiding and damping action in either direction of axial movement o~ the ha~mer body zssemblage, said hamm~r body having a given '''',~''`' stro~e t the xesilient means being the sole means engaglng the hammer body assemblage so that extraneous frictional forces are avoided, vibration dri~e means arranged to de-velop a forcing frequency to vibrate the hammer body as-semblage in an axial direction, said forcing frequency setto lead the vibrated ~requency of the hamrner body assem-blage by 135, and a tool reciprocably mounted in the sup-port frame and positioned to receive impact blows of the hammer body assemblage when reciprocated by the vibratory drive means.
These and further objects and features of the invention will become more apparent from an understanding of the following disclosure.
In drawings which illustrate embodiments of the invention, Fig. 1 is a side elevation view of a vibratory hammer embodying the principles of the in~ention;
Fig. 2 is an enlarged section view as seen from line 2-2 in Fig. l;
Figs. 3, 4 and 5 are cross section views as seen from lines 3-3, 4-4 and 5-5 respectively in Fig. 2;
Fig. 6 is an exterior view of a hammer body com-ponent used in the device of Fig. l;
Fig. 7 is an end view of the eccentric weights mounted on a shaft.
Referring now to Figs. 1 to 5, numeral 1 identi-fies a vibratory hammer having a support frame consisting of a pair of side plates 3, which are maintained in par-allel position by means of tubular space bars 5, welded to the plates~ as well as a tool holder element 7, similarly welded thexeto. A hammer body assemblage 9, as shown in Fig. 6, is suspended between the side plates 3 by resilient means consisting of four rubber mounts 11 affixed to thc side plates and the hammex body assemblage by means of bolts 13 and 15~ As will be apparent, the mounts serve as - 2a -the sole guiding and damping mea~ns for the assemblage when the latter is vibrated duri.ng t~l operation.
"~, ~3~
The hammer body assemblage 9 includes an eccentric weight chamber 17, shown in Fig. 7~ enclosing a pair of eccentric weights 19 and-21, mounted upon shafts 23 supported in roller bearings 25 positioned in end caps 27 r the latter being secured by bolt means 29 to side members 31 of -the eccentric weight chamber 15 by bolts 32~ Projecting from the top surface of the eccentric weight chamber 17 and affixed theretol is an upper axm member 33 adapted to be affixed to the rubber mounts 11 by the bo]ts 15.
Projecting from the bottom surface of the eccen-tric weight chamber 7 and aEfixed khereto, is a lower arm member 35 adapted to be affixed to the rubber mounts 11 by the bolts 15. Brace members 37 are secured to the sides of the lower arm member 35 and the hammer body assem~lage 9, to stabilize the arm member. An hydraulic motor 39, affixed to the end of shaft 23, is provided to rotate the eccentric weight 19. A pair of gears 41, mounted upon the shaft 23, ~s arranged to transmit rotary motion from the shaft which supports eccentric weight 19, to the sha~t which supports eccen-tric weight 21, so that both weights are rotated at the same speed but in opposite directions. Hose means 43 5uppiy pressurized hydraulic fluid to the motor 39 when desired, from a power source, not shown.
At the lower extremity of the arm member 35 is a striker plake 45 affixed thereto by means of pin 47.
The striker plate is arranged to impact upon a conical tool 49 mounted in the tool holder element 7 as best seen in Fig~ 2~ Retaining means, including a key 51 projecting into a slot 53 formed in the tool 49, allow reciprocal movement of the tool~ The tool slides in bushi.ngs 55 supported in a bushin~ housing 5?, the latter positionally maintained against axial movement hy a tool stop plate 59,affixed to the end of the tool ~3~
holder by means of cap screws 61~
Support means for the vibratory hammer 1, are provided by a pivotally attached linkage assemblage 63, which may be operatively positioned by power machinery, e.g. tractor, not shown.
The desi.gn parameters of a vibratory hammer built in acco.rdance with the invention disclosed herein, obviously will vary in accordance with the work impact output desired.
It is to be recognized -that when a forcing frequency vibrates a mass at its natural frequency, the mass of the forcing frequency generator leads the vibrated mass by 90. When the forcing frequency is much higher than the natural frequency, the forcing frequency mass could lead the vibrated mass by 180.
Accordingly, if the leading phase is 135, the vertical componen-t of centrifugal force of the vibrated mass, coupled with the stored energy of the rubber mounts, will produce maximum impacting on the tool 49.
The optimum phase angle of 135 l~) is deter-mined by the following equation:
2 ~
tan ~ = fn 1 f2 fn where ~ - phase anqle ~ = damping factor f = forcing frequency CPM,RAD/SEC
fn = natural frequency ~3~
It can be demonstrated by plottiny frequency ratio vs. ~ wi.th varying damping factors, that any-thing less than a critically damped system gives phase angles of a~proximately 180 at any frequency ratio greater than 1, hence, critical damping of the system is essential for optimum operative results. Critical damping by definition means no over oscillation when a mass is deflected from its static position and re-turned to the same static position. Critical damping is achieved by a preload, in the present vibratory hammer, by use of the rubber mounts ll.
It is essential, for optimum operation, that the stroke of the hammer be equal to the -in the air displacement (S ), which is provided by the following equation:
S = 2 wr W
Where w - unbalanced weight r = radius where unbalanced weight is located from the center of rotation W = total weight vibrated By application of these formula, a vibratory hammer in accorclance with the invention will have the followirlg numeral values, if a work impact output of 200 ft.-lbs. at 1200 rpm is to be achieved:
Stroke 0.4144 inches Weiyht of hammer body assemblage (9) 485.52 lbs.
w = 60.69 lbs.
r = 1.6576 inches wr2 - 100.59 in lbs.
wr - 166.76 in2 lbs.
K - 3gO0 #/in.
,. ., ~
While an embodimenk of the invention has been illustrated and described in detail to enable any person skilled in the art, to which it pertains, to make and use the same, it is expressly understood that the invention is not limited thereto~ Various changes in form, design, or arrangement may be made in its parts without departing from the spirit and scope of the invention; it is my intention, therefore, to claim the invention/ not only as shown and described, but also in all such forms and modifications thereof as might be reasonably construed to be within the spirit of the invent.ion and the scope of the appended claims.
tan ~ = fn 1 f2 fn where ~ - phase anqle ~ = damping factor f = forcing frequency CPM,RAD/SEC
fn = natural frequency ~3~
It can be demonstrated by plottiny frequency ratio vs. ~ wi.th varying damping factors, that any-thing less than a critically damped system gives phase angles of a~proximately 180 at any frequency ratio greater than 1, hence, critical damping of the system is essential for optimum operative results. Critical damping by definition means no over oscillation when a mass is deflected from its static position and re-turned to the same static position. Critical damping is achieved by a preload, in the present vibratory hammer, by use of the rubber mounts ll.
It is essential, for optimum operation, that the stroke of the hammer be equal to the -in the air displacement (S ), which is provided by the following equation:
S = 2 wr W
Where w - unbalanced weight r = radius where unbalanced weight is located from the center of rotation W = total weight vibrated By application of these formula, a vibratory hammer in accorclance with the invention will have the followirlg numeral values, if a work impact output of 200 ft.-lbs. at 1200 rpm is to be achieved:
Stroke 0.4144 inches Weiyht of hammer body assemblage (9) 485.52 lbs.
w = 60.69 lbs.
r = 1.6576 inches wr2 - 100.59 in lbs.
wr - 166.76 in2 lbs.
K - 3gO0 #/in.
,. ., ~
While an embodimenk of the invention has been illustrated and described in detail to enable any person skilled in the art, to which it pertains, to make and use the same, it is expressly understood that the invention is not limited thereto~ Various changes in form, design, or arrangement may be made in its parts without departing from the spirit and scope of the invention; it is my intention, therefore, to claim the invention/ not only as shown and described, but also in all such forms and modifications thereof as might be reasonably construed to be within the spirit of the invent.ion and the scope of the appended claims.
Claims (9)
1. A vibratory impact hammer including a support frame, a hammer body assemblage suspended within the support frame by resilient means arranged to provide guiding and damping action in either direction of axial movement of the hammer body assemblage, said hammer body having a given stroke said resilient means being the sole means engaging the hammer body assemblage so that extra-neous frictional forces are avoided, vibration drive means arranged to develop a forcing frequency to vibrate the hammer body assemblage in an axial direction said forcing frequency set to lead the vibrated frequency of the hammer body assemblage by 135°, and a tool reciprocably mounted in the support frame and positioned to receive impact blows of the hammer body assemblage when recipro-cated by the vibration drive means.
2. A vibratory impact hammer according to claim 1, wherein said resilient means are rubber mounts.
3. A vibratory impact hammer according to claim 2, wherein said rubber mounts are arranged in pairs, one above the hammer body assemblage, the other below the hammer body assemblage.
4. A vibratory impact hammer according to claim 1, wherein said vibration drive means includes a driving eccentric weight and a driven eccentric weight, and a motor means arranged to rotate the weights in syn-chronism.
5. A vibratory impact hammer according to claim 4, wherein said eccentric weights are inter-connected by a gear means.
6. A vibratory impact hammer according to claim 1, wherein a tool holder is provided for the tool, which tool holder includes means for removal of the tool from the hammer.
7. A vibratory impact hammer according to claim 1, wherein the stroke of the hammer body assemblage, is equal to the in the air displacement of the hammer body assemblage.
8. A vibratory impact hammer according to claim 7, wherein the stroke of the hammer body assem-blage is equal to , wherein w = unbalanced weight, v = radius where unbalance is located from the center of rotation, and W = total weight vibrated.
9. A vibratory impact hammer according to claim 8, wherein a hammer with a work impact output of 200 ft.-lbs at 1200 rpm, would have a stroke of 0.4144 inches, and design parameters as follows:
W = 485.52 lbs.
w = 60.69 lbs.
r = 1.6576 inches wr = 100.59 in lbs.
wr2 = 166.76 in2 lbs.
K = 3400 #/in.
spring rate
W = 485.52 lbs.
w = 60.69 lbs.
r = 1.6576 inches wr = 100.59 in lbs.
wr2 = 166.76 in2 lbs.
K = 3400 #/in.
spring rate
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US35362882A | 1982-03-01 | 1982-03-01 | |
| US353,628 | 1982-03-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1193498A true CA1193498A (en) | 1985-09-17 |
Family
ID=23389915
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000422509A Expired CA1193498A (en) | 1982-03-01 | 1983-02-28 | Synchronous vibratory impact hammer |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0089140B1 (en) |
| JP (1) | JPS58155180A (en) |
| AT (1) | ATE28817T1 (en) |
| AU (1) | AU550165B2 (en) |
| CA (1) | CA1193498A (en) |
| DE (1) | DE3372941D1 (en) |
| ES (1) | ES8402746A1 (en) |
| IN (1) | IN160366B (en) |
| MX (1) | MX154871A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0763944B2 (en) * | 1987-02-21 | 1995-07-12 | 株式会社山田重機 | Breaker |
| JP5559879B2 (en) * | 2009-07-16 | 2014-07-23 | ハビエル・アラカマ・マルティネス・デ・ラヒダルガ | Hydraulic hammer ripper for excavator |
| FI123475B (en) | 2011-09-15 | 2013-05-31 | Sandvik Mining & Constr Oy | Impact hammer tool, impact hammer and its use |
| JP6210840B2 (en) * | 2013-10-28 | 2017-10-11 | 博 小野寺 | Working attachments and implements |
| WO2016090516A1 (en) * | 2014-12-08 | 2016-06-16 | 杨一男 | Breaker |
| CN104878794A (en) * | 2015-05-11 | 2015-09-02 | 创银机械技术(上海)有限公司 | Vibratory hammer |
| ES2644886B1 (en) * | 2016-05-31 | 2018-09-13 | Talleres Betoño, S.A. | LINEAR DRIVE RIPPER |
| CN113512912B (en) * | 2021-04-30 | 2023-03-31 | 淄博洁翔机电科技开发有限公司 | Tamping device |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE463901A (en) * | ||||
| US1386329A (en) * | 1921-01-10 | 1921-08-02 | Det Tekniske Forsphigsaktiesel | Mechanism for converting rotary into reciprocatory motion |
| US1657387A (en) * | 1925-06-17 | 1928-01-24 | Goldschmidt Rudolf | Mechanical hammer |
| FR1392399A (en) * | 1964-05-09 | 1965-03-12 | Improvements in percussion hammers and similar machines | |
| US3467207A (en) * | 1966-10-10 | 1969-09-16 | Harley G Pyles | Universal drilling machine |
| GB1248202A (en) * | 1967-07-12 | 1971-09-29 | Herbert Clement Tampin | Improvements in or relating to portable motors for driving reciprocating tools |
| FR2209311A5 (en) * | 1972-12-05 | 1974-06-28 | Maco Meudon Sa | |
| US3866693A (en) * | 1973-06-11 | 1975-02-18 | Allied Steel Tractor Prod Inc | Vibratory impact hammer |
| US4257648A (en) * | 1979-04-09 | 1981-03-24 | Bodine Albert G | Non-resonant cyclic drive system employing rectification of the cyclic output |
-
1983
- 1983-02-09 AU AU11254/83A patent/AU550165B2/en not_active Ceased
- 1983-02-17 IN IN197/CAL/83A patent/IN160366B/en unknown
- 1983-02-28 ES ES520156A patent/ES8402746A1/en not_active Expired
- 1983-02-28 CA CA000422509A patent/CA1193498A/en not_active Expired
- 1983-02-28 MX MX196416A patent/MX154871A/en unknown
- 1983-02-28 JP JP58031085A patent/JPS58155180A/en active Granted
- 1983-03-01 EP EP83301078A patent/EP0089140B1/en not_active Expired
- 1983-03-01 AT AT83301078T patent/ATE28817T1/en not_active IP Right Cessation
- 1983-03-01 DE DE8383301078T patent/DE3372941D1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| ES520156A0 (en) | 1984-02-16 |
| MX154871A (en) | 1987-12-23 |
| ATE28817T1 (en) | 1987-08-15 |
| EP0089140A3 (en) | 1984-02-22 |
| IN160366B (en) | 1987-07-11 |
| ES8402746A1 (en) | 1984-02-16 |
| JPS58155180A (en) | 1983-09-14 |
| EP0089140B1 (en) | 1987-08-12 |
| AU1125483A (en) | 1983-09-08 |
| EP0089140A2 (en) | 1983-09-21 |
| JPH028875B2 (en) | 1990-02-27 |
| DE3372941D1 (en) | 1987-09-17 |
| AU550165B2 (en) | 1986-03-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry |