JPH0379641B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape measure case, and more particularly, it is an object of the present invention to propose an improvement to the tape measure case that reduces the spring friction noise that occurs during handling.

Generally, this type of tape measure has a rotatably supported drum for winding the scale tape in an internal cavity formed between two half-case shells, and the inner end of a barrel spring built into this drum. , which is usually adapted to be engaged with a slit in a core shaft projecting across the internal cavity from one of the half shells of the case.

The barrel spring is tightened when the scale tape is pulled out, and loosened when it is retracted. Therefore, when the scale tape is fully retracted, the barrel spring assumes its most relaxed position. The inner end of the barrel spring tends to shift laterally in the slit of the core shaft.

When tightening occurs at a position where the inner end of the barrel spring is shifted laterally, it often comes into contact with the side wall of the drum in a so-called bamboo-wound state, which causes the spring to tighten when the scale tape is pulled out or retracted. This was a cause of friction noise, and when the case half shell is made of die-cast metal such as zinc or aluminum, the case half shell is affected by the thrust brought to the drum by the bamboo shoot winding of the barrel spring. Further frictional resistance is added between the shell and the shell.

Therefore, in order to effectively and easily reduce such spring friction noise, this invention effectively suppresses the erroneous movement, that is, the sideways displacement movement that may occur within the slit at the locking inner end of the barrel spring. This new measure prevents the occurrence of "bamboo curling" and ensures that the barrel spring is always wound in an aligned manner while the tape measure is in use.

This invention consists of a pair of case half-shells, in which a drum for winding up a scale tape is rotatably supported within the internal cavity formed by these case half-shells, and an inner cavity is provided between the case half-shells. In the slit provided in the core shaft extending into the cavity,
In the tape measure case of the type that locks the inner end of the barrel spring installed in the drum, both of the case half shells prevent the locking end of the spring from running out from both sides in the width direction within the slit of the core shaft. The solution to the above problem is to provide a stop.

The steady rest can advantageously be implemented by means of a set screw with a restraining leg end that projects from the outside of the housing half into the slot of the core shaft, and which is preferably provided when the housing half is made of plastic. In addition to reducing noise and weight, it can also be used as a set screw for a decorative cover such as a metal cover, which is useful for improving the solid appearance of the case. These embodiments are particularly advantageous. be.

Now, Fig. 1 illustrates the cross section of a tape measure case. In the figure, 1 and 1' are a pair of case half shells, 2 is an internal cavity formed between them, and 3 is an internal cavity of this internal cavity 2. A drum for winding the scale tape rotatably housed inside, and 4 and 4' are drum 3.
A boss or 5 protrudes from the inner surface of the case half shell 1, 1' to support the rotation of the case half shell 1, 1'.
It is a core axis that extends between the two.

In the illustrated example, the core shaft 5 is provided as an integral projecting member on one case half shell 1, and is fitted into a receiving hole 6 provided in a boss 4' of the other case half shell 1'. The core shaft 5 may be provided with the receiving hole 6 shown for the case half shell 1', for example, with a non-circular inner contour, or provided on at least one of the case half shells 1, 1' (the other may be provided with a simple fit). ) When implementing such an integrated means for preventing rotation, it can be provided separately from the case half shells 1, 1'.

The drum 3 forms a spring chamber 8 between it and the lid 7, and, according to custom, incorporates a so-called spiral barrel spring 9, the outer end of which is drawn in through a partial opening provided in the body wall of the drum 3. While engaging the inner end of the tape (not shown), the inner end of the barrel spring 9 is usually
It is annealed over a length of 10 mm, and during this time it is made into a slightly narrow width, and this is used as the locking end to insert into the slit 10 cut into the core shaft 5, and then wrapped and locked as shown in Figure 2. It is customary to do so.
An example of the shape of both ends of the barrel spring 9 is shown in FIGS. 3a and 3b.

In the conventional tape measure case, the inner end of the barrel spring 9 that is locked as described above is not restrained within the slit 10 in the axial direction of the core shaft 5, that is, in the width direction of the locked end. When the winding is loose, it tends to shift sideways, and this is the traditional practice, for example,
As shown in Figure 3 of Publication No. 96965, even if one side of the inside of the barrel spring 9 is brought into contact with the bottom of the slit 10, the displacement movement to the other side cannot be restrained, so the scale tape It has become clear that in the process of tightening the winding with the drawer, thrust is applied to the drum 3 in a so-called bamboo winding, which causes the spring friction noise.

Therefore, in the present invention, a steadying means is provided to restrain the locking end of the barrel spring 9 from both sides in the width direction within the slit 10 to prevent the above-mentioned thrust from occurring.

That is, as shown in FIG. 1, this restraining means includes a set screw 12 having a restraining leg end 11 projecting into a slit 10 through a core shaft 5 integral with one case half shell 1, and a set screw 12 having a restraining leg end 11 projecting into a slit 10 through a core shaft 5 formed integrally with the case half shell 1; The half-shell 1' may have a rod-like projection 13 protruding from the center of its inner surface, and although not shown, both case half-shells 1, 1' may have the set screw 12 or the rod on both sides. It may also have a shaped protrusion 13.

In particular, when the set screw 12 is used as a restraining means, a decorative cover 14 as shown in FIG. The countersunk head can also be used as a set screw to be restrained by the head, and the countersunk head may be hidden by a name plate 16 affixed to the decorative cover 14. In addition, in Fig. 1, the decorative cover 1 applied to the right case half shell 1'
Regarding 4', an example was shown in which it was fixed to case half shell 1' with rivets 17, but case half shell 1
The same deterrence as described above may be applied.

The decorative covers 14, 14' are the case half shells 1,
1', the peripheral edges of the case half shells 1, 1' are preferably provided with receiving grooves 18, 18', and at the bottom of the grooves, the substance of the case half shell, which can preferably be made of a plastic molded body, is formed. It is also possible to use a metal cover with jagged irregularities that fit inside the cover.

Based on the above-described structure, the inner end of the barrel spring 9 ensures aligned winding of the barrel spring 9 within the slit 10 of the core shaft 5 under restraint without causing any axial deviation. , there is no way to apply thrust to the drum 3, and therefore the scale tape cannot be pulled out.
This eliminates the problem of spring friction noise during loading.

Thus, according to the present invention, the tape measure case can be used to draw out and retract the scale tape without producing a spring scraping noise caused by irregular winding of the barrel spring, and by using the frictional force derived from the spring scraping sound. To enable convenient use of a tape measure without excessive force for drawing out the tape or inconvenience in feeding the tape.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the tape measure case, FIG. 2 is a sectional view of the main part, and FIGS. 3a and 3b are plan views of the end of the barrel spring. 1, 1'...Case half shell, 2...Inner cavity, 3
...Drum, 5...Core shaft, 8...Spring chamber, 9...
Barrel spring, 10... slit, 11, 13... steady rest, 12... set screw, 14, 14'... decorative cover.

Claims (1)

[Scope of Claims] 1. Consisting of a pair of case half shells, a drum for winding up a scale tape is rotatably supported in an internal cavity formed by these case half shells, and a drum for winding a scale tape is rotatably supported. In a tape measure case of the type in which the inner end of a barrel spring installed in the drum is locked to a slit provided in a core shaft extending into the internal cavity, both of the case half shells are connected to the inner end of the barrel spring installed in the drum. A tape measure case characterized by having a steady rest that restrains the locking end of a spring from both sides in its width direction. 2. The tape measure case according to claim 1, wherein the steady rest is a set screw having a restraining leg end that projects into the slit of the core shaft from the outer surface of the case half shell. 3. The tape measure case according to claim 2, wherein the push screw also serves as a decorative cover set screw provided on the outer surface of the case half shell.