IKONEN ALPO (FI)
| FR814229A | 1937-06-18 | |||
| EP0258508A1 | 1988-03-09 | |||
| US4771771A | 1988-09-20 |
| 1. | A respirator filter spool (1) for a filter bridge type of a respirator requiring the use of a platelike filter (3) , characterized in that a filter spool (1) is attached at least to one side of the respirator, the said filter spool including fastening devices (4, 5) for the purpose of fastening onto the respirator and several filters (3) , the said filters lending themselves for drawing over the respi rator body (7) . |
| 2. | A respirator filter spool as claimed in claim 1, charac¬ terized in that a used filter (3) has to be detached from the other filters (3) after use. |
| 3. | A respirator filter spool as claimed in claim 1, charac¬ terized in that the consecutive filters (3) are provided with a perforated zone (12) to make it easier to detach the filters (3) . |
| 4. | A respirator filter spool as claimed in claim 1, charac¬ terized in that a gap (2) has been executed along the periphery of the filter spool (1) parallel to its axis enabling the filters (3) to be drawn out through it. |
| 5. | A respirator spool as claimed in any of the preceding claims, characterized in that the filter spool (1) is essentially cylindrical in form. |
| 6. | A respirator filter spool as claimed in claim 1, charac¬ terized in that used filters are wound, without detaching them from unused filters, onto a filter spool (10) reserved for the purpose. |
| 7. | A respirator filter spool as claimed in claim 1, charac¬ terized in that both of the filter spools (1, 10) contain fresh filters and these are detached after use. |
The object of this invention is a new type of filter spool to for mounting onto respirators of the filter bridge type.
In filter bridge type of respirators as described in FI application 900375, for instance, the filter material used is platelike. The filter is placed on top of the body section which covers the face of the user in an arclike manner. A perforated plate is placed over the filter so that the filter becomes fastened against the body of the respirator. Being of the disposable type, filters are discarded after use or once they become dirty, and a clean filter is taken out of a filter cloth package.
Filter packages are often stored in places not necessarily in the proximity of where they are used. This being so, the user has to fetch the new filter from the place of storage or continue using a partially blocked filter for excessive periods of time in which case particles may pass through the filter or the filter may restrict the adequate passage of air through it. Should the user keep extra filter cloths on hand in his pocket, these often become unfit for use through becoming moist or crumpled even when well packed. This being so, filters should be replaced where they are stored. Additionally, mounting the filter onto the body section without crumpling the filter and holding it there until the perforated plate is put in place may prove diffi¬ cult.
The device in accordance with the invention represents a decisive improvement on the shortcomings described in the above. In order to implement this improvement, the filter spool in accordance with this invention is characterized in that the respirator in question has attached to it, at least to one side of it, a filter spool including fastening devices for attaching to the respirator and several filters that can be drawn over the body of the respirator.
The foremost advantages of the invention are that it signi¬ ficantly eases the replacement of filters and that the user of a respirator is provided with a stock of new filters. These factors mean ease of use and of replacing filters and 5 they also speed up the user's work in dusty environments. Furthermore, the invention enhances the health of the person using such a respirator, because of the ease of replacing dirty filters.
0 In the following, the invention is described in detail with references being made to the appended drawing.
Figure 1 is a schematic sectional view of the spool at¬ tached to one side of a respirator. 5
Figure 2 depicts another form of implementation of the invention.
Figure 3 shows the perforation executed between consecutive 0 filters.
The filter spool (or replacement filter cartridge) 1 shown in figure 1 is attached to the respirator's T-piece 4 by means of the fastening devices 5. The gap 2, parallel to
25 the axis of the spool 1 and equal in width to the filters, has been executed on the periphery of the spool 1 enabling the filters 3 to be drawn from the spool through the gap 2. The gap 2 is executed to be close to the fastening point of the respirator on the side of the filter surface. The
30 perforated plate 6 to be mounted on top of the body section 7 and the filter 3 for the purpose of holding the filter 3 in place is attached to the body section 7 by means of a two-stage hinge 8 X and 8 2 (8 in figure 2) . Hinge 8 X is used to open and shut the perforated plate 6 and the other hinge
35 8 2 is used to bring the perforated plate 6 into a position in which the filter 3 can be drawn out (the position shown in figure 1) while in the other position the filter 3 becomes firmly arrested between the perforated plate 6 and the body section 7 (this position is not shown) when the
perforated plate 6 is pressed against the body section 7. The hinge pins have been joined to one another by means of the perforated plate so that the distance between the pins remains unchanged as the positions change.
In the situation depicted in figure 1, there are five filters in the spool 1. The number of filters can, of course, be increased or reduced as desired. Additionally, figure 1 shows the fastening strap 9.
Figure 2 shows another form of implementation of the inven¬ tion. It shows two spools 1, 10; spool 1 is for clean filters and spool 10 for filters that have become dirty. This enables the used package to be thrown away at the one time and individual filters need not be detached. This may be referred to by the name of cassette technique. When this is done, it is practicable to provide the spools with axles onto which the ends of the filter can be attached. Yet another alternative is one in which both spools contain a spool of clean filter and in which case the spools are not attached to one another but can instead be used in turn in order to maintain balance.
In order to have the user know how far to pull a fresh piece of filter, the line between consecutive filters has been marked. In addition, this line is perforated to make it easier to tear off the required filter. Figure 3 shows this perforation. The edges of the filter material have been heat treated to prevent fraying. The same applies to the zone between consecutive filters over a distance of 2-3 mm. The perforation 12 has been executed along the middle of this zone.
The filters can be inserted into the spool by rolling the filters into a tight bundle and by then inserting this bundle into the spool from one end of it.
In the case of two spools, the fastening of the filter can be eased by having the perforated plate divided into two
along the middle of the perforated plate. This is where there is a joint, e.g. a snap-on joint, for joining the two halves. In addition, the perforated plate is joined to the filter from the ends adjacent to the spools (e.g. by means of the aforementioned two-stage hinges) . Instead of the hinges, it is, of course, possible to use other prior art means of fastening the perforated plate to the respirator.
In the above, we have described the invention with referen- ce being made to only two of its advantageous implementati¬ on examples. All variations within the framework of the inventive idea are, naturally, possible.