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7. PRECAUTIONS IN SALES PROMOTION
In the interest of promoting the safest and most efficient use of the Model DH 20PB Hammer Drill by all of our
customers, it is very important that at the time of sales the salesperson carefully ensures that the buyer seriously
recognizes the importance of the contents of the Handling Instructions, and fully understands the meaning of the
precautions listed on the Caution Plate attached to each tool.
7-1. Handling Instructions
Although every effort is made in each step of design, manufacture and inspection to provide protection against
safety hazards, the dangers inherent in the use of any electric power tool cannot be completely eliminated.
Accordingly, general precautions and suggestions for the use of electric power tools, and specific precautions and
suggestions for the use of the Hammer Drill are listed in the Handling Instructions to enhance the safe, efficient
use of the tool by the customer. Salespersons must be thoroughly familiar with the contents of the Handling
Instructions to be able to offer appropriate guidance to the customer during sales promotion.
8. REFERENCE MATERIAL
8-1. Lubrication
It is not necessary to replenish the grease lubricant unless the tool is disassembled or there is grease leakage
due to a defective seal. Special grease is used in the striking section. Should the striking section (within the gear
cover) be disassembled, carefully remove the old grease from all parts and, on reassembly, insert 70 g (0.15 lbs.)
of new grease into the gear cover. Be careful not to exceed the designed amount of grease. Excessive grease
will reduce striking efficiency.
8-2. Tool Structure
While the structure is essentially the same as the Model DH 24PB, the descriptions below are included to
enhance your understanding of the tool and its mechanisms.
Transmission of rotation
Unlike conventional hammer drills, the armature shaft in the Model DH 20PB is in parallel with the tool shaft---
the same structure that is employed in most impact drills. This structure was adopted in order to make the
Model DH 20PB more compact for easier handling and operability. Thus, the appearance of the Model
DH 20PB is similar to that of an impact drill. The rotation of the armature is transmitted to the second shaft via
the first gear, and causes it to rotate. The second pinion provided on the second shaft engages the second
gear mounted on the outer circumference of the cylinder. The cylinder is coupled to the second gear by
means of a slip mechanism, and they rotate together. The end of the cylinder also functions as the drill bit
retainer. The cylinder is key-connected to the inserted drill bit by means of two key rails, and transmits rotation
to the drill bit. A steel ball is used to prevent the bit from falling.
