Using Derwent Classification to improve your subject searching - STN Example

Search Tips - July 2000

This is a search for patents on antilock braking systems (ABS) for cars and other vehicles which illustrates how Derwent Classes can be used to overcome the problem of ambiguous search terms. We begin with a keyword search, which yields more than fifteen thousand records. This is an unexpectedly high number, so the next step is to display a few records free-of-charge using the SCAN format. This will enable us to check what is being retrieved.

Begin searching in Derwent World Patent Index (Derwent WPI) (WPINDEX/WPIDS/WPIX)

=> file wpindex

In this word search, "w" means that the search terms are adjacent to each other in the specific order.

=> s abs or (antilock? or anti lock?)(w)brak?
 
13579
2135
136172
283633
2662

116868
2987
15778
ABS
ANTILOCK?
ANTI
LOCK?
ANTI LOCK?
(ANTI(W)LOCK?)
BRAK?
(ANTILOCK? OR ANTI LOCK?)(W)BRAK?
ABS OR (ANTILOCK? OR ANTI LOCK?)(W)BRAK?
=> d scan

 

L1   15778  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
      
TI   Tire arrangement for cars fitted with anti-lock-
     brake-system in which rear tires have tread pattern
     rigidity which is greater than that of front tires.


HOW MANY MORE ANSWERS DO YOU WISH TO SCAN? (1):4
 
L1   15778  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
      
TI   Anti-lock braking system for a motor vehicle
     sets period for which pressure rise signal is output
     based on change in wheel rotation state at time of 
     peak wheel speed detection.
 
L1   15778  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
      
TI   Catalyst for polymerization of conjugated diene 
     compounds.
 
L1   15778  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
      
TI   Unsaturated polyether, used as polymer and cement
     additive, and as prepolymer.


HOW MANY MORE ANSWERS DO YOU WISH TO SCAN? (1):0

Large numbers of irrelevant records are being retrieved. The problem is the search term "ABS", which must be included in the strategy. However, ABS can also be an abbreviation for acrylonitrile-butadiene-styrene polymer and an abbreviation for antibodies.

Our search could be refined by incorporating further keywords such as cars or vehicles, but this would probably be too restrictive. The best way to overcome the problem is to confine the search to Derwent Class Q18 - Vehicle Brake Control Systems.

=> s l1 and q18/dc

L2
31370
3187
Q18/DC
L1 AND Q18/DC

Display a few of the records in an inexpensive format:
[for more details on display formats see Useful formats for Derent WPI]

=> d ti tri 2-5

L2   ANSWER 2 OF 3187  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
TI   Antilock brake system for motor vehicle, judges
     failure frequency which is lower for vehicle without parking 
     brake compared to vehicle with parking brake.
AN   2000-394270 [34]   WPINDEX
DNN  N2000-296136
TT   TT: ANTILOCK BRAKE SYSTEM MOTOR VEHICLE JUDGEMENT FAIL
         FREQUENCY LOWER VEHICLE PARK BRAKE COMPARE VEHICLE PARK BRAKE.
DC   Q18 X22
IC   ICM  B60T008-88
MC   EPI: X22-C02C3
PNC  1
CYC  1
 
L2   ANSWER 3 OF 3187  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
TI   Vehicle braking system for controlling speed of electrohydraulic 
     braking comprises accumulator and replenished by pumping 
     additional working fluid.
AN   2000-389151 [34]   WPINDEX
DNN  N2000-291402
TT   TT: VEHICLE BRAKE SYSTEM CONTROL SPEED ELECTROHYDRAULIC BRAKE 
         COMPRISE ACCUMULATOR REPLENISH PUMP ADD WORK FLUID.
DC   Q18 X22
IC   ICM  B60T008-40
ICA  B60T013-14
ICI  B60T101:00, B60T103:00
MC   EPI: X22-C02C
PNC  2
CYC  25
 
L2   ANSWER 4 OF 3187  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
TI   Integrated ABS, traction control, vehicle stability control,
     braking system with a separate boost valve has boost valve 
     actuated by a single solenoid.
AN   2000-386331 [33]   WPINDEX
DNN  N2000-289154
TT   TT: INTEGRATE TRACTION CONTROL VEHICLE STABILISED CONTROL BRAKE 
         SYSTEM SEPARATE BOOST VALVE BOOST VALVE ACTUATE SINGLE 
         SOLENOID.
DC   Q18 X22
IC   ICM  B60T008-34
MC   EPI: X22-C02C; X22-C02C1; X22-C02C3
PNC  1
CYC  1
 
L2   ANSWER 5 OF 3187  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
TI   Auxiliary brake mechanism for ABS in vehicle, uses treading
     force information to judge shearing stress on brake pedal arm so 
     that based on applied braking force, auxiliary braking force is 
     generated.
AN   2000-381465 [33]   WPINDEX
DNN  N2000-286846
TT   TT: AUXILIARY BRAKE MECHANISM VEHICLE TREAD FORCE INFORMATION 
         JUDGEMENT SHEAR STRESS BRAKE PEDAL ARM SO BASED APPLY BRAKE 
         FORCE AUXILIARY BRAKE FORCE GENERATE.
DC   Q18
IC   ICM  B60T013-74
PNC  1
CYC  1

This is a good result - but can we do better? We can use STN's ANALYSE command to find out which Derwent Classifications appear most frequently in this set of records. All you need to do is to type in ANALYSE, and STN will come back with a number of prompts. If you wish to confirm STN's recommendations, just type in ".", i.e. (full stop/period), otherwise type in your own option.

=> analyse
ENTER ANSWER SET OR ANALYZE L# OR (L2):. 
ENTER ANSWER NUMBER OR RANGE (1-):. 
ENTER DISPLAY CODE (TI) OR ?:dc 
ANALYZE IS APPROXIMATELY 25% COMPLETE 
ANALYZE IS APPROXIMATELY 30% COMPLETE
ANALYZE IS APPROXIMATELY 52% COMPLETE
ANALYZE IS APPROXIMATELY 59% COMPLETE
ANALYZE IS APPROXIMATELY 79% COMPLETE
ANALYZE IS APPROXIMATELY 85% COMPLETE
L3 ANALYZE L2 1- DC : 93 TERMS

Display the result of our analysis:

=> d
L3          ANALYZE L2 1- DC :      93 TERMS

TERM #   # OCC  # DOC  % DOC DC
------ ------- ------ ------ ---------------
     1    3187   3187 100.00 Q18
     2    2497   2497  78.35 X22
     3     388    388  12.17 S02
     4     366    366  11.48 Q13
     5     145    145   4.55 T01
     6     117    117   3.67 Q66
     7     113    113   3.55 Q57
     8      90     90   2.82 Q17
     9      90     90   2.82 T06
    10      77     77   2.42 V06

From the result of our analysis we can see that X22 (Automotive Electrics) comes in second place. We can therefore bring X22 into our search as well. As can be seen in answer set "L4", we have considerably improved our search result by using both Derwent Classes.

=> s l1 and (q18 or x22)/dc 
         31370 Q18/DC 
        187292 X22/DC 
L4        4132 L1 AND (Q18 OR X22)/DC 
=> d ti tri 13-15 
L4   ANSWER 13 OF 4132  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
TI   Solenoid-controlled valve, e.g. for antilock braking
     system, has two valves with opening/closing modes varied in number 
     of steps according to displacement of movable part.
AN   2000-367144 [32]   WPINDEX
CR   2000-334058 [29]
DNN  N2000-274709
TT   TT: SOLENOID CONTROL VALVE ANTILOCK BRAKE SYSTEM TWO
         VALVE OPEN CLOSE MODE VARY NUMBER STEP ACCORD DISPLACEMENT 
         MOVE PART.
DC   Q18 Q57 Q66 X22
IC   ICM  F16K031-06
     ICS  B60T008-36; B60T013-68; F15B013-044
MC   EPI: X22-C02C3
PNC  1
CYC  1
 
L4   ANSWER 14 OF 4132  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
TI   Anti-lock braking system brake operation
     monitoring apparatus and method based on calculating wheel speed
     differentials and electronic control unit.
AN   2000-364823 [31]   WPINDEX
DNN  N2000-273046
TT   TT: ANTI LOCK BRAKE SYSTEM BRAKE OPERATE
         MONITOR APPARATUS METHOD BASED CALCULATE WHEEL SPEED 
         DIFFERENTIAL ELECTRONIC CONTROL UNIT.
DC   Q18 X22
IC   ICM  B60T008-88
MC   EPI: X22-C02C3; X22-X06A
PNC  1
CYC  23
 
L4   ANSWER 15 OF 4132  WPINDEX  COPYRIGHT 2002 Derwent INFORMATION LTD  
TI   Mechanical anti-lock braking system for
     bicycle wheel comprises gyrating bodies and inclined actinic slip 
     rings with brake pad mechanically connected to upper inclined 
     actinic slip ring.
AN   2000-364529 [31]   WPINDEX
DNN  N2000-272786
TT   TT: MECHANICAL ANTI LOCK BRAKE SYSTEM
         BICYCLE WHEEL COMPRISE GYRATORY BODY INCLINE ACTINIC SLIP RING 
         BRAKE PAD MECHANICAL CONNECT UPPER INCLINE ACTINIC SLIP RING.
DC   Q18 Q23
IC   ICM  B62L001-00
     ICS  B60T008-32; B60T008-54; B60T008-74
PNC  1
CYC  83

Analysing Derwent Classifications is also a useful way of identifying a company's key activities. We will be looking at this in further detail in a Search Tip later this year.

For further assistance please contact your local Derwent Help Desk.