Grave-constructions for above ground, multiple burials
The invention relates to a grave-construction in several versions, designed for the interment of the ashes or corpses of the deceased - mainly collectively in sets - in a space- saving manner, even aboveground, with limited constructed installation.
There are a number of know forms of urn interment, e.g. in various cemetery facilities, columbariums, niches in urn walls, constructed urn chambers, purchased family grave sites. It is also legal to take the ashes of the deceased home, but there is no adequate practice of constructing structures for urn interment at home, on private land.
One of the greatest disadvantages of interring urns in cemeteries, shrine buildings according to the current practice, as mentioned above, is that no sets of family or clan grave sites can develop, as the burial of family members passing away at different times next to or above one another is only possible in the case of grave sites purchased in advance and maintained, by partially or completely upsetting the existing resting place. Another great disadvantage of this traditional interment, burial practice is the shortness of resting times, as well as the very complex and complicated task of exhumation and the re-utilization of the land.
The currently applied methods for urn burial waste space, they do not solve the problem of family members being separated from one another, and the eternal rest for the deceased is meant to be provided by interring urns in urn niches (leased for 10-15 years) of "solid pillar-torsos" or stereotyped cage-systems reflecting the taste of craftsmen, built mostly in a material-wasting manner, sealed with provisionally fixed stone slabs of often doubtful durability, decorated with engraved inscriptions.
Sarcophaguses and constructed coffins encasing the mortal remains of the deceased used to be interred or placed typically in burial vaults, crypts dug into the ground, the aisles, niches of crypts under churches, casemates, etc. underground or constructed holes covered with soil. Sarcophaguses used to be interred in the ground of cemeteries, under the floor of churches, cloisters mostly in the form of traditional burials. These methods of
burial have similar problems, such as e.g. the shortness of resting times, exhumation, the difficulty of developing sets of family, clan grave sites.
The main purpose of the invention concerning urn-containers and collective sets of urn-containers, as well as a new type of sarcophagus shells, is to solve the problem of the separation of family members passing away at different times, to achieve area-structure economy through collective family, clan grave sites for interring ashes in greater numbers, to multiply the resting times, to allow the development of grave sites outside cemeteries, at home, to simplify the re-utilization of grave sites, as well as to significantly modernize the work involved in burials, interments and relocations. With the urn-containers as per the aim of the development, the urns separated from one another according to the current practice and the structures housing them are united in an integral structure.
The grave-constructions as per the invention are based on the idea that urns holding the ashes of the deceased or corpses are placed into individual closed-system single- or multi-layer shell covers of proper strength and durability, attached in any number to a stable supporting structure with a foundation. The attachment points of the shell covers to the supporting structure are properly protected, but at the same time they are designed to be simply releasable through professional, local, small-scale interventions.
The shell covers as per the invention can be single- or multi-layer ones. The multilayer shell covers can consist of any number of lining layers, structural elements and outer layers.
One possible form of the urn-container shell covers as per the invention is that the urn holding the ashes is placed in a pre-fabricated shell cover attached to a stand, the outer surface of which is then covered with a net, an insert plaiting, and the surface of the pillar, the supporting arm and the shell cover are covered with a monolithically applied and setting material in one or more layers, with the desired surface finish. This solution allows, in addition to the interment of the ashes, the inclusion of a genetic cartridge, or other mark, reminder in the constructed shell cover, or sealed under the shell cover, but also in such a manner that it is accessible, removable from the outside.
The other possible form of the urn-containers as per the invention is that the shell cover is prepared from pre-fabricated elements. The final urn-container is prepared from the elements on the site by assembling the parts, gluing or welding them together, and by applying a releasable joint, or a joint non-releasable without destruction. This solution also
allows the inclusion of a genetic cartridge, or other mark, reminder, either in a manner that it is non-accessible without the destruction of the pre-fabricated shell cover, or in such a manner that it is accessible, removable from the outside.
In either form of the urn-containers, the urn holding the ashes of the deceased is encased by a single- or multi-layer constructed shell cover, which is connected to a supporting structure of any form and material, e.g. a pillar, stand or other structure, holding the urn-container in a stable position in space permanently. By attaching several urn- container shell covers to a supporting structure collectively, as a set, an urn-tree can be formed, in order to develop a family, clan or community grave site.
The shell covers as per the invention, as sarcophagus shells, are also suitable for the interment of corpses. The new type of sarcophagus shells as per the invention can be of a hermetically sealed, or a directionally open (mummifying) form, based on the idea that the corpses of the deceased are placed into individual closed/open single- or multi-layer, monolithically prepared or pre-fabricated shell covers of proper strength and durability, attached, fixed in a stable manner to a supporting structure with a foundation, located on the surface of the ground/aboveground, inside a building/outside, individually and/or together with urn-container shell covers, or other sarcophagus shells. The attachment points of the sarcophagus shells to the supporting structure are properly protected, the joints can be releasable, or non-releasable without destruction (in both cases the intactness of the coherent cover of the sarcophagus shell and the whole grave-construction can be favourably ensured).
The hermetically sealed sarcophagus shells are in full compliance with the environmental requirements, as the single- or multi-layer shell covers encasing the corpses are completely waterproof, provide hermetic sealing and prevent the penetration of microorganisms. The sarcophagus shell can be made of e.g. metal, plastic, glass, porcelain, etc. highly-resistant materials, and an airtight shell cover can be prepared by welding, gluing, etc. hermetic sealing. The shell cover can have a final surface finish (e.g. it can be made of surface machined, decorated cast metal, metal plate, and sealed favourably by welding/soldering), or additional outer layers can be constructed on the outer surface of the assembled lining layers from monolithically applied, setting material combinations, or additional pre-fabricated elements can be added to meet any aesthetic, durability, insulation, etc. requirement or expectation.
One possible form of the hermetically sealed sarcophagus shells as per the invention is that the dead body is placed in a shell cover made of assembled and sealed elements, the outer surface of which is then hermetically sealed on the site with one or more layers of a monolithically applied and setting material meeting the aesthetic requirements. Suspension/attachment (stabilization in space) is ensured by a supporting arm/supporting arms attached to one of the elements of the sarcophagus shell (favourably in a releasable manner), but in such a manner that they are isolated, separated from the inside containing the corpse.
The other possible form of the hermetically sealed sarcophagus shells as per the invention is that the corpse is placed in a shell prepared from pre-fabricated (favourably two halves; a lower and an upper) single- or multi-layer shell elements delivered to the site in a pre-fabricated state, and the only on-site work is their hermetic sealing and the attachment (fixing to the supporting structure) of one of the elements. The supporting arm/supporting arms attached favourably in a releasable manner to one of the elements of the sarcophagus shells, prepared from pre-fabricated elements with final layers and machined surfaces, are not in contact with the inside containing the dead body. In the case of the sarcophagus shells as well, a genetic cartridge, or other mark/reminder can be included under the cover (favourably in the lower part more protected from the climatic conditions) (non-accessible without destruction), but also in such a manner that it is accessible, removable from the outside by professional intervention, while it is protected against unauthorized action.
In both possible versions, the fact that the primary requirement of placing the corpse in a closed shell cover spatially, physically and biologically completely isolated from the external environment surrounding it is met, ensures a great degree of freedom with respect to the suspensions, the attachments to the main pillar, the foundations, the installation elements (shrine object holders, tablets, inscriptions, lifting eyes, etc. supplements), the surface covers of the grave-constructions, the protection of the joining elements, etc. construction details.
The invention concerning the directionally opened (mummifying) sarcophagus shells is based mainly on health, environmental, technical/technological and also reverential efforts to close the dead body in the shell suitable for drying in a manner not burdening the environment. The openness is only apparent, as the space in which the dead body is placed is connected to the inside of the foundation structure, storing disinfectant, moisture
absorbent, deodorant and, among others, biological-chemical neutralizing materials, which is after all a completely closed system and emits cleaned/filtered air into the open (air, soil, or a central cleaner).
The general structure, attachments, construction and outward appearance of the directionally open (mummifying) sarcophagus shells are similar to those of the hermetically sealed sarcophagus shells. The differences are manifest in the inclusion of devices-parts allowing the constant periodical discharge of the air - the expanding air via a planned or designed route through the opening and closing of weighted valves and spring rods operated by the temperature fluctuations - surrounding the corpse, as well as the periodical intake of outside air (air intake due to the vacuum generated by cooling in the corpse space). The sarcophagus shells can be also monolithically prepared or pre-fabricated, and the grave-construction itself receiving the directionally open sarcophagus/sarcophaguses can be a closed or an open system as well. The openness of the sarcophagus shell and the grave-construction to which it is attached shall be interpreted on the basis of the place of origin of the inlet fresh air (directly from the open, or recycled filtered/dried air from a tank in the foundation structure), and the method of the discharge, emission of the filtered/disinfected air. As a function of these solution versions, in practice there are two types of the directionally open (mummifying) sarcophagus shells:
The ventilation of the directionally open sarcophagus shells can be solved by internal circulation as well. In the case of internal circulation the sarcophagus takes in dry air from a tank after filtering and moisture absorption. With this solution the grave- construction shall be regarded as practically hermetically sealed from the environmental- health point of view, with the difference that the corpse is mummified.
As a grave-construction, the new type of sarcophagus shells, alone or together with urn-containers and/or several sarcophagus shells in sets, is equipped with single- or multilayer, closed and/or directionally open shell covers containing the corpses of the deceased individually, a supporting arm/supporting arms with releasable joints, or joints non- releasable without destruction, a pillar - favourably suitable for storing water and in given cases including pipe liners as well - with one or more releasable suspension joints, or joints non-releasable without destruction, a foundation structure and markings, information carriers relating to the deceased, as well as other shrine accessories.
The supporting structure of the grave-construction as per the invention can be constructed in such a way that the main pillar is suitable for e.g. storing water. This is
important because the dripping-leaking or soaking irrigation of the live plant cover of the grave-construction or the plants placed in the flower pot holders can be solved with the water stored here. The water stored in the main pillar, with refilling every 1 to 2 months, allows continuous water supply to the plants, an increase in the surfaces covered with plants, and the shortening of maintenance/care times.
In this case the pillar itself is favourably a multiple pipe structure (pipe/pipes in pipe), with the following functions: a.) a large diameter casing pipe, support and tank suitable for storing water; b.) hidden/vertical pipes, as the continuation of the supporting arms, leading the air with body moisture to a metal/plastic tank in the foundation structure, and c.) pipes returning the dry/filtered air from the tank filled with filtering/cleaning, moisture absorbent materials to the sarcophagus shell, or discharging it into the open, or leading it into a central cleaner.
The invention is presented in detail on the basis of the following figures: Figure 1 shows partial cross section A-A of one form of the grave-construction, with a monolithic shell cover as per the invention, together with the schematic representation of the foundation and attachment joints.
Figure 2a shows partial cross section B-B of one of the possible forms of the pre-fabricated urn-container shell covers as per the invention in an assembled state, and with the main units in a separated state.
Figure 2b shows a cross-section sketch of one of the possible forms of the grave- construction, a mixed family, clan, community urn-tree, indicating the planes of cross- sections A-A and B-B.
Figure 3 shows one of the possible forms of the grave-construction, including a sarcophagus shell sealed with layers constructed on the site, and additional shell covers (urn-containers and sarcophagus shells).
Figure 4 shows the schematic drawing of a grave-construction suitable for irrigation, including a directionally open (mummifying) sarcophagus shell.
It can be seen in Figure 1 showing one of the possible forms as an example, that the urn (11) is placed in a shell cover (1) that can be assembled, prepared from a lining layer (2), favourably from earthenware/plastic elements, a structural element (3), e.g. a net/basket, advisably from steel, plastic plaiting, and monolithic outer covers, an outer layer
(4) (among others from concrete, artificial stone, synthetic resin), a surface finish (5) (mainly from plastic plaster and synthetic resin combinations) and a coating (6), e.g. painting, on the site for the purpose of holding, interring the ashes.
An information carrier (7), e.g. a genetic cartridge and other mark/reminder containing important information on the deceased can also be placed in the shell cover (1) constructed on the site, which can be sealed in completely in the course of the construction, or remain accessible, removable from the outside without the destruction of the urn cover.
The shell cover can be attached to the pillar (12) (favourably a steel pipe, a closed hollow section steel support) for example with a pipe joint (9), or with pin stabilization by means of a supporting arm (10) (favourably a steel pipe, a section steel) with a pipe clamp (9) connection (among others a stand clamp). The pillar (12) can be attached with a releasable flanged pipe joint (14) to the base stub (13) fixed in the foundation structure (mainly a concrete or stone block). It is advisable to cover, as the continuation of the outer layer (4) of the urn-container shell covers, the supporting arms (10), together with their attaching elements (9), and the pillar (12), including its releasable and/or non-releasable (e.g. welded) joints (14) to the base stub (13), with a coherent, thick, setting, highly resistant (favourably plastic plaster, synthetic resin) covering layer in order to increase the protection and to meet the aesthetic expectations.
Inscriptions (8) and/or the information carrier tablets (16), as well as other shrine objects can be placed on the coated (6) shell cover (1) and the pillar (12).
Figure 2a shows one of the possible forms of the urn (11) shell cover (1) assembled from pre-fabricated elements, where the shell cover has a single layer (e.g. of metal) and the complete final cover is constructed from two half shell cover elements, in the given case shown in the example by welding together the assembled rims, one of the elements is attached to the supporting arm (10) with a welded joint (9). In stead of a pipe clamp (9), the supporting arm (10) can be welded to the pillar (12), the attachment of which to the base stub (13) can be solved by welding as well, in stead of the releasable flanged pipe joint (14). The metal shell cover (1) and its supporting structure shown in the example can be left in a natural metal state, but an outer layer (4), a surface finish (5) and a coating (6) can be applied to their surfaces in part or in whole, and inscriptions (8) and/or information carrier tables (16) or other shrine objects can be placed on the surfaces, sections of the grave- constructions of pre-fabricated shell covers. In the course of the construction a genetic cartridge (7), as well as marks/reminders containing information on the deceased can be
placed in the shell cover (1) in a completely sealed manner, or in such a manner that they are removable from the outside without the destruction of the urn cover.
Figure 2b shows the cross-section sketch of one of the possible forms of the grave- construction, a mixed family, clan, community urn-tree, where partial cross-section A-A shows the interpretation of the drawing details of the monolithic, while partial cross-section B-B that of the pre-fabricated shell cover (1). Shell covers (1) of different construction and any form, containing urns (11) holding the ashes of the deceased, can be attached by various methods and in numerous structures to a pillar (12), favourably suitable for storing water, stabilized with a foundation structure (15). In the case of solutions with releasable joints, it is advisable to apply securing/protecting covers to the individual parts, which can be removed locally, if necessary, this construction allows the relocation, removal, attachment of shell covers (1) by releasing, detaching the elements (9) and (10), while by detaching the joining element (14), the whole constructed family, clan or community grave- construction can be removed. The individual urn-containers can be pieces of fine/applied arts as well, and shrine objects, inscriptions (8) and/or information carrier tablets (16) can be placed on the whole urn-tree.
Figure 3 shows one of the possible forms of the grave-construction, including a sarcophagus shell (1) sealed with layers constructed on the site, and additional shell covers (urn-containers and sarcophagus shells). The corpse (28) lies on a filtering mattress (29), hermetically sealed inside the sarcophagus shell (1) consisting of two half lining elements. The already perfectly sealed shell can be stored, transported and attached to the pillar of a grave-construction at the final resting place with the supporting arm (10), by means of a pipe clamp (9), a flanged pipe joint (14), a flare/pin joint (17). The pillar (12) acting as the main support is connected to the foundation structure (15) by means of a pillar joint (14). The sarcophagus shell (1) consisting of (2) raw lining/insert elements attached/fixed in space is covered with a steel/plastic net/cage as a structural element (3), to which an additional outer layer (4), a textured surface finish (5), and painting (6) can be applied on the site. The outer layer (4) and the additional coatings (5) and (6) can coherently cover the supporting arms consisting of elements (9) and (10), and the pillar (12), ensuring the protection of their surfaces, joints, and the uniform appearance of the surface of the grave- construction. A genetic cartridge (7) and a mark/reminder containing information on the deceased can be placed into the outer layer, or within the outer layer.
The hermetically sealed and pre-fabricated sarcophagus shells differ from the monolithic solution shown in Figure 3 mainly in that the lining elements (2), the structural element (3), the outer layer .(4), and in given cases the surface finish (5) and the coat of paint (6) form a coherent, built-together sandwich shell structure. The pre-fabricated shell elements (favourably again two half elements), consisting of sandwich layers, can be assembled in a traditional manner with e.g. quick-action clamps, self-locking clips, releasable bolts and non-releasable glues, welding. The sealed sarcophagus shells (1) can be attached to a pillar (12) with a supporting arm (10), by means of a pipe clamp (9), a pin joint, a flanged joint or a flare joint (17). The foundation, foundation structure connection of a grave-construction consisting of pre-fabricated sarcophagus shells (1) can be of any construction.
Figure 4 shows a form of the directionally open sarcophagus shells, with external ventilation. The corpse (28) lies on a filtering mattress (29) in a lining insert shell structure (2) consisting of two half elements. The lining layer (2) is connected with a flare joint (17) at its lower part to a supporting arm (10), which can have a flange connection (14) as well, and this supporting pipe is attached to a pillar (12) with a pipe clamp (9) with a through pipe hole. The pillar (12) is attached with a flanged pillar joint (14) to a thick underground pipe (26), the perforated lower part of which extends into a tank (27) filled with filtering/cleaning material (19). There is a service opening (18) on the top of the foundation structure (15). The assembled and sealed lining layers (2) of the sarcophagus shell (1) are surrounded by - in the case of the monolithic version - a steel/plastic net-cage structural element (3), an outer layer (4), a surface finish (5) (a textured coating), and a coat of paint (6). In the shown example the sarcophagus shell (1) takes in fresh/dry air via an air intake pipe (25) (e.g. through a weighted or a ball valve) due to the vacuum generated by the cooling (during the night) of the inside. The filtered/disinfected air is led from the upper part of the sealed tank (27) via a moisture discharge pipe liner (21) along the pillar (12), favourably filled with water, to a pillar cap (20), which has a built-in weighted air valve (22), as well as a lifting eye (24) -just as the top of the sarcophagus shell - and information carrier tablets (16) (inscriptions, picture frames, cartridge marks, alphanumeric combinations indicating information on the inclusion of a genetic/informatics cartridge), flower pot holders (23) or shrine accessories, family-clan tablets (16) are placed on the main pillar, the supporting arm, and the sarcophagus shell. A genetic/informatics cartridge
(7) can be inserted in the lower cover of the sarcophagus shell (1) in a removable or sealed manner.
The supporting arms (10) of the grave-construction shown in Figure 4 are pipe-like structures and their openings lead into the inside of the shell (1), and they are also open towards the hollow of the pillar (12), which is also open towards the foundation structure (15). The supporting arms (10) are connected to the bottom of the sarcophagus shells (1) and slope down in the direction of the pillar (12). A tank (27) is built-in in the foundation structure (15), accessible via a service opening (18) located on the top of the foundation structure (15). The tank (27) is filled with filtering and/or cleaning material.
Not only the pillar (12), but the supporting arms (10) can also be suitable for storing water, if required, allowing the controlled supply of water (favourably by dripping irrigation) tq live plants planted around/under the whole urn-tree.
One practical version of the numerous possible forms of water storing supports is that the supporting arms (10) of a sarcophagus shell (1), suitable for discharging moisture, are attached to the pillar (12) in such a manner that the pipe ends of the supporting arms (10) attached to the pillar (12) are plugged, but the openings of the supporting arms (10) are connected with flexible connections to moisture discharge stubs (21) formed in advance on the pillars (12) (for several connections to the moisture discharge pipe/pipes in the water storing support, leading to the outer surface of the pillar and temporarily plugged).
On the lower part of the pillar (12) suitable for storing water a pipe connection equipped with a cock needs to be constructed, allowing the filling-up of irrigation water, while on the upper part of the pillar (12) it is advisable to construct a overflow pipe outlet. If the expectation is a pressurized solution for storing irrigation water, the overflow pipe of the closed-system pipe-tank shall be equipped with a valve cock as well. A pressurized dripping-leaking system can be achieved by closing the overflow cock and pumping air into the tank filled with water.
For discharging the water to be used for dripping irrigation, pipe-eyes with adjustable openings need to be built in the pillar, leading to the outer surface.
The surface of the grave-constructions detailed above can be covered with a coherent outer layer (prepared practicably from cement, plastic, gypsum, etc. materials) for the purpose of achieving a uniform surface finish, covering the connections points, sections, joints, attaching elements, etc., as well as protecting the sepulchre.
The most important advantages of all versions of the sarcophagus shells as per the invention are related to health, the protection of the environment and the undesirable deviations of the constructed shrine environment (in general the current cemetery culture).
The trend of sepulchral architecture as per the invention carries outstanding advantages concerning the possibilities of moderating the irregularities of the current cemetery culture (tasteless forms made by craftsmen lacking style, wasting material, money, resources, misinterpreted status symbols, aimless, illogical, even unethical interpersonal on-top constructions, etc. undesirable deviations from the idealism of reverence). Its definite advantages are space saving burials, extended resting times, liquidation/relocation without exhumation, low material consumption, relatively cheap production, low need for maintenance, and partially monolithic preparation.
The significant advantages of the shell covers as per the invention are evident in a number of potential fields of application, namely their need for burial area is minimal, up to 8 to 10 urn-container shell covers can be placed on a grave site, when the resting time expires they can be replaced, relocated, frequent grave site purchases are eliminated, become less frequent, the construction of the shell covers requires little material, the grave- constructions are free from any unnecessary, wasting application and machining of materials. Urn interments (burials) can be held simply, quickly in the case of the construction of both monolithic urn-containers (where the urn is placed in its final place by sealing the lining layers (2)), and urn-containers prepared from pre-fabricated elements (assembled simply, quickly with quick-action clamps).
The outstanding advantages of the shell covers as per the invention are that they are made of strong materials, designed for long resting times, the grave-constructions, also as pieces of fine art, applied art, can be constructed in family, clan and community sizes, and can be placed outside cemeteries - even on private lands, at home in privately owned buildings. They need no or minimal maintenance. The urn-containers and the urn-tree grave-constructions made of them are stable constructions, due to their simplicity they are fashion-proof, they have a normalizing influence on the tastelessness often manifest in the cemetery culture. Through their implementation, in general, the complicated time and cost consuming burial procedures are simplified, and the constructions, technologies of sepulchral architecture are significantly developed, modernized.
A special advantage is that the elements of the shell cover are simple, easy to produce, their production is not resource, machine or energy consuming. The shell covers
can be assembled for the purpose of preparing a resting place with craftsmen's skills, within a short time, with low construction costs, on a small area, the finished creations can be modified simply, without exhumation, developed upon the interment (burial) of others dying at a later date, terminated in a problem-free manner, if necessary, with simple interventions of dismantling nature, with minimal surface, structural disruption. The construction, maintenance of these advantageous objects of sepulchral architecture, by allowing the performance of the activities on the surface of the ground, aboveground, is independent of the weather.
The most important advantages of the application of the sarcophagus shells as per the invention are that their interment does not require buildings, individuality is replaced by standardization in a number of forms, production in large series, their need for burial area is minimal and in the case of collective burials - referring to the development of sets of family, clan grave sites - the current average capacity of grave sites can be multiplied. The 2 m2/person, or the 7 to 8 m2 for a grave site with a path, plants, covered area as per the norm, can be reduced by an order of magnitude.
An important part of the grave-construction with directionally open (mummifying) sarcophagus shells is the foundation structure, the environmental, health function of which, in addition to its supporting structure function, is also indispensable. Accordingly, liquid and/or solid state filtering, disinfecting, moisture absorbing, air refreshing, etc. materials ensuring chemical-biological cleaning are placed in a tank insulated with lining layers. The foundation structure has a service opening, allowing the refilling of the filtering materials, their periodical inspection and replacement when saturated. The discharge of cleaned air into the open is solved favourably in a pipe-end head protected against driving rain, located on the top of the main pillar, where a weighted air valve can be built-in. The moisture discharge pipes of the main pillar and the pipe-like supporting arms, and the filtered air discharge pipe can be equipped with probe openings (openings allowing measurements) for the purpose of performing health, environmental recordings, inspections.
List of references
(1) shell cover
(2) lining layer
(3) structural element
(4) outer layer
(5) surface finish
(6) coating
(7) information carrier
(8) inscription
(9) releasable or permanent attaching joint
(10) supporting arm
01) urn
(12) pillar
(13) base stub
(14) joining element
(15) foundation structure
(16) information carrier tablet
(17) flare joint
(18) service opening
(19) filtering and/or cleaning material
(20) pillar cap
(21) moisture discharge pipe liner
(22) air valve
(23) flower pot holder or other shrine accessory
(24) lifting eye
(25) air intake
(26) underground pipe
(27) tank
(28) corpse
(29) filtering mattress