Sophisticated structure for a tape measure

A sophisticated structure for a tape measure is disclosed having a measuring tape, a main body, and a brake apparatus, the brake apparatus including a plurality of acute teeth, a brake lever and two positioning pins. A user may pull out the tape with an estimated shortest measuring length which assures him of being free from the fear that the tape might wind up abruptly causing injury to the user. The tape measure also can be used to successively measure different lengths by increasing the tape length from the shortest to the longest. When winding up the tape, the user may further pull out a short section of the tape by hand, then tilt the main body in an axial direction to a certain angle and release the tape to perform the withdrawal operation.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a sophisticated structure for a tape 
measure, and more particularly, to a tape measure whose withdrawal may be 
performed easily without forcibly operating a brake key as in a 
conventional tape measure. 
2. Description of the Prior Art 
The tape measure is frequently used in a construction site for professional 
measurement, estimation and examination. It is also necessary for domestic 
application such as house repairing or furniture making done by the owner 
in an amateur do-it-yourself way. The common disadvantageous shortcomings 
of conventional tape measures are that they are either too large in size 
or too hard to handle. Consequently it is although a minor, yet important 
matter to develop a tape measure with a structure which can be securely, 
easily and conveniently handled. The practical disadvantageous 
shortcomings of known tape measures are: 
1. The pulled out measuring tape will automatically retract with a strong 
bouncing action if it is not properly controlled, which in the worst case, 
results in injury to the user himself or to a third person nearby. 
2. The failure rate is high in spite of their simple construction. This is 
caused by frequent on-off operation of the control key to hold or release 
the measuring tape. Consequently the lifetime of the conventional tape 
measures is not as long as expected by users. 
3. It is hard to operate when several measurements are required. As the 
shortcoming described in item 1, it is difficult to halt the tape measure 
at the desired length for measurement resulting in repeated extending or 
rewinding of the measuring tape. 
4. A bulky structure with an inconvenient operational mechanism makes the 
conventional tape measures not only unable to be handled by skilled 
technicians, but also dangerous for amateurs to handle them in 
do-it-yourself work for fear of hurting users due to careless handling. 
Accordingly, there is an urgent need for developing a new structure for a 
tape measure which is simply constructed, and securely and conveniently 
useable. 
SUMMARY OF THE INVENTION 
It is a first object of the present invention to provide a sophisticated 
structure for a tape measure which looks clean and neat in its appearance 
with a simple operative structure. 
To achieve this object, the present invention provides a sophisticated but 
simple structure for a tape measure in which a control key, as is usually 
equipped in a conventional tape measure, provides better usability. The 
tape measure with the structure according to the present invention can be 
used for several measurements in one time conveniently, by pulling out the 
shortest estimated length among those several lengths to be measured, and 
increasing its length to the longest one to be measured. The particular 
structure provided by the invention is that when winding the measuring 
tape, the user may further pull out a short section of the measuring tape 
by hand, then immediately afterwards tilt the main body in its axial 
direction to a certain angle thereby releasing the measuring tape to 
perform the withdrawal operation. 
It is a second object of the present invention to provide the structure for 
a measuring tape which is securely useable with low failure rate and good 
durability. 
To achieve this object, the present invention provides a sophisticated 
structure for a tape measure which is securely protected from sudden 
automatic winding back of the measuring tape after being extended that may 
cause unexpected injury to the user or a nearby third person is prevented, 
and it is secure enough for a child to handle. A control key provided for 
the conventional tape measure is generally apt to slip and is hard to fix 
the measuring tape. Moreover, it cannot bear frequent use, and it will get 
stuck when the tape measure has been left unused for a long time. The 
structure of the present invention is free from such troublesome 
mechanisms.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 to 3, showing the assembly and exploded drawings of 
the tape measure according to the present invention which comprises: a 
measuring tape 2; a tape reel 21 for winding the measuring tape 2 around 
it, with a depressed groove 22 provided around thereunder. There are a 
plurality of acute teeth 32 disposed along the inner wall of the 
circumference of the depressed groove 22 forming in into a toothed wheel. 
Further, a spring (not shown) is provided in the tape reel 21 for winding 
up the measuring tape 2; a main body 1 including an upper cover 10 and a 
base frame 11 with a pivot axis 12 standing at the center of the base 
frame 11 for fixing and connecting the tape reel 21 and the upper cover 
10; and a brake apparatus in direct control of the rotation of the tape 
reel 21. 
Referring to FIGS. 3 and 4 showing the exploded drawings of the tape 
measure and the operation of its brake apparatus according to the present 
invention respectively. The brake apparatus includes a brake lever 3 and 
two positioning pins 31 all installed inside the base frame. The brake 
lever 3 is located between two positioning pins 31. 
As the measuring tape 2 is pulled out, the tape reel 21 rotates in the 
counter clockwise-direction in the direction of the arrow in FIG. 4, 
causing the brake lever 3 to bounce upward by slipping along the sloped 
surface of one of the acute teeth 32 allowing the measuring tape 2 to be 
pulled out. As the control is released, the tape reel 21 on way of 
returning to its initial position by rotating in the clockwise direction 
(as viewed in FIG. 4) by the spring restoring force, is halted by the 
brake lever 3 moving against the sloped direction of the acute tooth 32 
and stops at the lower positioning pin 31 to cease the winding of the 
measuring tape 2. 
If the measuring tape 2 is to be wound up, the user may further pull out an 
additional short length of the tape 2 and hold it, then tilt the main body 
1 with a certain angle in its axial direction and release the tape 2, at 
this moment, being freed from the restraint of the acute tooth 32, the 
brake lever 3 stays at the upper positioning pins 31 so that the measuring 
tape may be wound back entirely into the main body 1. 
Accordingly, the sophisticated structure for a tape measure according to 
the present invention can provide a tape measure having a simple structure 
without the need of a control key, but with a better usability, security, 
durability and low failure rate. 
Many changes and modifications in the above described embodiment of the 
invention can, be carried out without departing from the scope thereof. 
Accordingly, to promote the progress in science and the useful arts, the 
invention is disclosed and is intended to be limited only by the scope of 
the appended claims.