US 2235646 A
Description (OCR text may contain errors)
March 18, i941. M, D. SCHFFER MASONRY Filed Dec. 23, 1938 Patented Mar. 18, 1941 PATENT OFFICE MASONRY DimantSchffer, Vienna, Germany l Application December 23, 1938, Serial No. 247,417
4 f In Austria December 23, 1937 2 Claims.
This invention relates to masonry in which the horizontal courses of bricks are interconnected by bodies inserted into vertical apertures. In the known constructions of such masonry the apertures in the bricks are enlarged at both ends so that shoulder-like bearing surfaces are formed on which substantially cylindrical dowels rest. This form of construction is not practical, because the formation of the enlarged portion in the aper-l ture is complicated and expensive. The invention relates to masonry which overcomes this objection. According to the invention bricks are used whose apertures pass right through them vertically in uniform cross-section, every two courses of bricks being connected by inserted dowels tapering at both ends on at least onefth of their length, which dowels hold on the walls of the apertures solely by friction. The bricks used can therefore be made cheaply on the string press in the usual manner. The bricks are preferably made with several elongated apertures extending vertically through the bricks obliquely to the edges thereof so that, when the bricks are built up, the apertures cross and the dowels can be inserted at the points of intersection, suitable points for inserting the dowels being present even when the courses of bricks are inaccurately placed the one on the other. Moreover, if bricks are used according to the invention having two longitudinal rows of elongated apertures one row of which slopes towards one side and the other row towards the other side of the brick at right angles to the first row it is only necessary to always lay the next following course upside down f to ensure that all apertures of the bricks, laid in longitudinal direction cross, and when at least three dowels are distributed on the two longitudinal rows the brick is anchored against shifting and turning. Solid, slightly bllged bodies are preferably used as dowels.
An embodiment of the invention is illustrated by way of example in the accompanying drawing, in which:
Fig. 1 shows in top plan view a section of masonry,
Fig. 2 is a section on line II-II of Fig. 1.
The individual bricks 2| each have eight apertures 22 extending right through them and uniformly distributed in two rows M and N extending parallel to the longitudinal edges of the brick. The apertures 22' are of elongated` cross-sectional shape with semi-circular ends. In the row M they are inclined towards the left at an angle of 45 to the longitudinal edge of the brick and in the row N they are inclined towards the right at the same angle. If the next following course is laid with the bricks turned through 180 about their longitudinal axis, all the apertures will cross. Dowels 25 of solid material such as concrete, ferro concrete, baked clay or wood are used for connecting the courses of bricks. These dowels are substantially cylindrical but tapered slightly at their ends 26 so that they have a slight bilge. Their diameter corresponds approximately to the smallest width of the apertures 22.
When building up each course is preferably strewn with a bedding or levelling layer of sand 21 whereupon the next course is laid with inverted bricks. These two courses are then connected the one with the other by inserting the dowels 25 from above. Owing to the conical end 26 of the dowel and the fact that the apertures cross, it is not diicult to insert the dowels even if the courses are not laid accurately. Moreover, owing to the elongated shape of the apertures there is ample room for the fingers in the aperture in the uppermost brick. After the dowel has been loosely inserted, it is driven into the bricks with a striking instrument until it is half in the top brick and half in the bottom brick, an intermediate member 28 being preferably inserted between the instrument and dowel, to determine the correct position of the dowel by an abutment 29 contacting with the surface of the brick. The dowel is held in position by friction in the two bricks.
Every brick is preferably connected by at least three dowels with the brick of the course directly under it. When two dowels have been inserted in apertures of the same longitudinal row the brick can still be shifted in the oblique direction, when two dowels are inserted in apertures in different rows the brick may be turned about one of the dowels as pivot: if, however, a brick is connected with the lower course by three dowels distributed on the two longitudinal rows of apertures, it is locked against shifting or turning'.
The intermediate layer used when laying the courses of bricks, serve for levelling the unevennesses in the superposed bricks and the thus ensuring uniform transmission of pressure.
According to the invention the procedure is preferably as follows:
Sand of as uniform grain as possible and used in its natural moist state is mixed with ordinary cement in a very poor proportion without addition of water and this mixture is applied in the desired joint thickness, the hygroscopic properties of the bricks and of the sand cause additional moisture to be absorbed from the air and the resultant swelling of the cement causes hardening of thev bedding layer to a kind of plate. The bedding layer also absorbs the undesirable moisture present in or penetrating into the bricks until the setting process is terminated. The setting does not affect the binding between brick and intermediate plateA Thus a rm bedding adopting itself perfectly to the unevennesses of the bricks is produced by which the possibility of pulling down is not impaired and the character of dry masonry is ensured.
In the case of masonry in which appreciable expansion stresses occur, it is also preferable to place in the bedding layer 21 some kind of material 3|] with a high tensile strength such as reed, bamboo, cardboard, perforated sheet metal, wires or the like.
1. Masonry comprising Vertical courses of bricks having apertures of elongated cross-section and extending at an incline to the edges right through the brick and crossing the one the other in two superposed bricks, and separate solid dowels having each a smooth straight middle portion and tapering at both ends along at least one-fth of the length and inserted in vertical position into the registering apertures of two superposed courses of bricks and held in position solely by friction on the walls of the apertures.
2. Masonry as specied in claim 1, in which the apertures of one row are inclined towards one side and those of the other row towards the other side of the edges of the bricks each brick being locked against shifting and turning by at last three dowels distributed on the two longitudinal rows of apertures.
MAX DIMANT SCHFFER..