JPS6110610Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an extension tube for a vacuum cleaner.

Generally, vacuum cleaners use a telescopic extension tube for convenience in storage and use, and a tightening ring is used to hold and fix the inner tube and maintain airtightness. It is something.
In this case, the tightening ring must be made of a relatively hard material due to its structure, making it difficult to improve airtightness. Therefore, it is conceivable to provide seal packing made of a relatively soft material to improve airtightness, as shown in FIG. That is, in FIG. 1, reference numeral 1 denotes an outer tube having an enlarged distal end portion 2 having a plurality of grooves (not shown) split along the axial direction and having an enlarged diameter. A male threaded portion 3 is formed on the outer peripheral surface, and a locking lip 4 is formed at the tip. 5 has a large diameter portion 6 at the tip and an outer tube 1
This is an inner tube that is slidably fitted into the inner tube 5, and a tightening split ring 7 in which a plurality of split grooves (not shown) are formed along the axial direction is slidably attached to the outer peripheral surface of the inner tube 5. It is fitted. Further, a tightening threaded pipe 9 is provided around the widened end portion 2 and has a female threaded portion 8 that engages with the male threaded portion 3 . The tightening screw pipe 9 and the tightening split ring 7 are formed with a tapered portion 10 and an inner tapered portion 11 that face each other. A fitting recess 12 is formed on the other end side of the inner tapered portion 11 of the tightening split ring 7.
A substantially U-shaped seal packing 14 is provided with an engagement convex portion 13 that engages with the seal member 2 .
Note that 15 is a protrusion formed on the tightening split ring 7 to prevent it from coming off.

However, when the tightening threaded pipe 9 is tightened, the tightening split ring 7 receives the tightening force in the radial direction only in the vicinity of section A, where the tapered part 10 and the inner taper part 11 are located, and the tightening split ring 7 receives the entire tightening force. The inner tube 5 is not tightened evenly around the circumference, and is only partially tightened in the axial direction, so the inner tube 5 is not securely fixed and is prone to slipping. In addition, the tightening screw pipe 9
If the tightening force is somewhat weak when tightening, there is a possibility that the tightening split ring 7 will tilt internally and leakage may occur from the inner diameter of the seal packing 14, as shown in Fig. 2. .

This idea was devised in view of these points, and the purpose is to obtain an extension tube for a vacuum cleaner that has strong tightening force, holds and secures the inner tube well, and has good airtightness and ease of handling. It is.

An embodiment of this invention will be explained based on FIGS. 3 to 6. First, as shown in Figure 3, 16
is an outer tube having a highly elastic distal end enlarged portion 17 with a large diameter and a plurality of split grooves (not shown) split in the axial direction, and a male threaded portion 18 is formed on the outer circumferential surface of the distal enlarged portion 17. Further, an expanding taper portion 20 is formed at the open end of the inner diameter portion 19 . 21 has a large-diameter portion 22 at the tip of the outer tube 1.
6, and a tightening split ring 23 having a plurality of split grooves (not shown) is slidably fitted on the outer peripheral surface of this inner pipe 21. . Further, for the distal end enlarged portion 17, a female threaded portion 24 that engages with the male threaded portion 18 is formed at one end of the inner diameter portion, and an inner tapered portion 25 is formed at the other end of the inner diameter portion of the tightening threaded pipe. 26 are provided. Here, the male threaded portion 18 and the female threaded portion 24 may be configured to slide in the axial direction simply by the engagement of the inclined protrusion and the inclined box. Further, the tightening split ring 23 is formed with tapered portions 27 and 28 that are opposed to the expanding tapered portion 20 and the inner tapered portion 25, respectively. Further, a holding portion 29 is formed by the inner diameter portion 19 and the outer peripheral surface of the inner tube 21, and a seal packing 30 that is loosely fitted and held in the holding portion 29 is provided. Here, this seal packing 30 is fitted to one end of the tightening split ring 23 on the tapered portion 27 side, and this tightening split ring 23 is formed with a mouth end 31 for fitting. There is. moreover,
A rib portion 32 is formed on the side opposite to the fitting portion of the seal packing 30 and protrudes outward from the outer circumferential surface of the large diameter portion 22 of the inner tube 21. In addition, 33
is a protrusion formed on the tightening split ring 23 to prevent it from coming off. Further, 34 is a groove formed in the tightening screw pipe 26.

In such a configuration, first, the material of the seal packing 30 will be considered. The essential functions of this type of extension tube are that it has good airtightness, that the inner tube 21 is securely held and fixed when the tightening screw tube 26 is tightened, and that the tightening screw tube 2
6 is loosened, the inner tube 21 and the outer tube 16 slide smoothly, and the inner tube 21 and the outer tube 16 can withstand frequent sliding movements. From this point of view, if a soft material such as rubber is used as the seal packing 30, the airtightness is good, but the frictional resistance on the surface is large and the inner tube 21 and the outer tube 1 are
6, and is undesirable from the standpoint of wear and aging. Therefore, a material that has a certain degree of softness but does not have a large surface resistance, such as a resin such as soft polyethylene or soft polypropylene, is used. There is.

Therefore, the operation will be described in the case where the seal packing 30 is made of such a material but does not have the rib portion 32. In this case, as shown in FIG. 4, when the tightening threaded pipe 26 is tightened, the diameter of the tightening split ring 23 is reduced in the radial direction at two places, the expansion taper part 20 and the inner taper part 25, so that the inner pipe 21 is tightened. Can be held and fixed well. At the same time, the tapered portion 27 relative to the expanded tapered portion 20
and a mouth end portion 31 into which the seal packing 30 is fitted.
Since they are relatively close to each other, even with a relatively weak tightening force, the inner diameter of the seal packing 30 can be pressed against the outer peripheral surface of the inner tube 21 to effectively maintain airtightness.

However, the problem here is that as this type of extension tube for household vacuum cleaners is produced in large quantities, there is a non-negligible variation in the dimensions of the individual parts. That is, if the dimension D is large as shown in FIG. Due to the gaps, leaks occur and airtightness is compromised. Further, as shown in FIG. 6, when this dimension D is small, when the tightening screw pipe 26 is tightened, the seal packing 30
is firmly pressed against the wall 35 and the airtightness is good, but the expansion taper part 20 and the taper part 27 do not come into contact with each other and the radial tightening force on the tightening split ring 23 becomes weak. Although the cases shown in FIGS. 5 and 6 are extreme examples, the inner tube 2
1, retention and fixity and airtightness appear to be contradictory issues, and variations due to mass production are undesirable.

However, since the seal packing 30 is formed with a rib portion 32 as shown in FIG.
We can solve this problem. That is, the tightening screw pipe 2
6, it is possible to increase the length in the axial direction in which the rib portion 32 is elastically pressed against the wall 35 of the holding portion 29, thereby ensuring good airtightness and eliminating variations in the dimensions of individual parts. Even if there is a problem, it will be buffered at this portion, and the inner tube 21 can be held and fixed well.

The shape of the rib portion 32 formed on the seal packing 30 may be any shape as long as it can come into contact with the wall 35 on the outside of the outer peripheral surface of the large diameter portion 22 of the inner tube 21, as shown in FIG. 7a. The outer periphery of the rib portion 32 may be chamfered or rounded to improve airtightness with the wall 35, or as shown in FIG.
The airtightness may be improved by making the tip end thinner and making it more flexible.
In addition, as shown in figure c, the seal packing 30
A tongue-shaped rib portion 32 may be provided on the outer circumferential side, thereby eliminating loss of force in the axial direction.
Furthermore, as shown in FIG. 4D, a rib portion 32 may be used that acts in the suction direction.

This device is configured as described above, so that when the tightening screw tube is loosened, the inner tube and the outer tube have good sliding properties, and when the tightening screw tube is tightened, the tightening action is strong and the inner tube is This has the advantage of being able to hold and fix well, at the same time ensuring airtightness, and being able to deal with dimensional variations.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view showing a conventional example, Fig. 2 is a partially cutaway side view showing one state of the conventional example, and Fig. 3 is a partially cutaway side view showing an embodiment of the invention. Figure 4 is a partially cutaway side view showing the basic tightening state, Figures 5 and 6 are partially cutaway side views for explanation, and Figures 7a, b, c, and d are seal parts. It is a longitudinal side view which shows the modification of a king. 16...Outer tube, 17...Tip expansion part, 18...
Male thread part, 19... Inner diameter part, 20... Expanding taper part, 21... Inner tube, 22... Large diameter part, 23...
Tightening split ring, 24... Female threaded part, 25... Inner taper part, 26... Tightening threaded pipe, 27-28...
Tapered part, 29... Holding tube, 30... Seal packing, 31... Mouth end, 32... Rib part.

Claims (1)

[Scope of utility model registration request] A holding part for seal packing has a plurality of grooves split in the axial direction, has a large diameter, has a male screw part formed on the outer peripheral surface of the expanded tip part, and has a stepped wall on the inner peripheral part. an outer tube in which an expanding tapered portion is formed at the open end of the inner circumferential portion and expands toward the tip; and a large diameter portion at the tip that is slidably fitted into the outer tube. an inner tube; a split ring that is slidably fitted onto the outer circumferential surface of a portion of the inner tube other than the large diameter portion and has a plurality of split grooves split in the axial direction; and one end side of the inner diameter portion. a tightening threaded tube having a female threaded portion that engages with the male threaded portion, is slidable relative to the outer tube, and has an internally tapered portion formed at the other end of the inner diameter portion of the tightening threaded tube; a mouth end where the expansion taper part of the outer tube and the inner taper part of the tightening screw tube are formed with opposing taper parts, respectively, and the seal packing is fitted to the end of the tightening split ring; the seal packing is formed of a relatively soft soft material, and a rib is located on the wall side of the holding portion and protrudes in the axial direction at least outwardly from the outer circumferential surface of the large diameter portion of the inner tube. An extension tube for a vacuum cleaner, characterized in that a part is integrally formed.