Title of Invention

A MASONRY BUILDING UNIT

Abstract

A masonry building unit, hollow trapezoidal in configuration, comprising upper (1) and lower (2) rectangular parallel surfaces, front and rear rectangular parallel surfaces and one solid side surface (3) hollow from the other side surface with wall thickness of 10 to 30 mm depending on the size of the masonry building unit wherein the lower surface (2) has a matching projection within its width along its longitudinal axis, the upper surface (1) has matching projection within its width along its longitudinal axis in conformity with the said depression, the solid side surface having interlocking / interfitting projection or depression within its width along its vertical axis and the other side surface with opening (4) having interlocking / interfitting projection or depression within the thickness of four walls of the masonry building unit. FIG 5

Full Text

FIELD OF INVENTION The present invention relates to a masonry building unit, hallow trapezoidal in configuration. More specifically, the subject invention relates to a novel and unique building masonry units having interlocking or interfitting projections and depressions which are self aligned and self adjustable. The masonry units are solid or hollow. It can be of any dimensions. The length may vary from 150 mm to 600 mm, width may vary from 75 mm to 300 mm and depth may vary from 75 mm to 300 mm. The masonry units are made out of any materials such as clay in plastic stage which require to be burnt or a homogeneous mixture of about 5-15 % cement, 40-65 % flyash and 25-50 % sand or homogeneous mixture of 5-15 % cement, 40-65 % flyash and 25-50 % clay or homogeneous mixture of 5-15 % cement, 40-60 % sand and 40-60 % clay or homogeneous mixture of sand and lime in suitable proportion. It is mixed with required quantity of water to make moist mix. Also, it can be of any strength up to approximately 30 Mpa. The subject invention also relates to masonry system that deals with the process of masonry construction. The masonry walls are made by placing masonry units one after another and one above other without any mortar between them. Then the bonding of masonry units are achieved by pouring / pumping mortar from the top or from the sides as desired. The mortar is made by mixing cement with water in a suitable proportion such that it flows freely. It is also mixed with non-shrinkable material to avoid shrinkage of mortar. Cement based polymer / epoxy can be also mixed with mortar to achieve better bond between masonry units. The subject invention also relates to masonry system at L, T and + joints. The masonry units are modified to achieve these joints. The subject invention also relates to reinforced masonry. It is achieved by making two symmetric holes in masonry units at its mid-width and at equidistance from its center. The holes in the upper and lower masonry units are aligned. The reinforcement bars inserted in it and grouted with the grouting of the brick / block masonry. The subject invention also relates to machine for making masonry units. It has a free standing steel fabricated frame. It has a hopper which receives the material from the mixer through the conveyor. Receiver mould forms the middle part of the machine. It is attached to the hydraulic jack for positioning of the receiver mould. Upper part of the die is attached to the hydraulic jack for positioning of the receiver mould. It is attached to the hydraulic ram that can create a pressing force to each sector of four die. Lower part of the mould acts as an ejector. The present invention shall facilitate semi automatic masonry construction resulting in uniform and better quality of work, reduced manpower requirement, reduced time of construction and hence reduced cost of construction. Also the construction shall lead to self-alignment and self-adjustment of masonry units. The thickness of mortar for bonding masonry units is also reduced. The strength of such masonry is about 60-70 percent of the strength of masonry unit where as the strength of conventional masonry is only 30 to 40 percent of the strength of masonry unit. BACKGROUND OF THE INVENTION Very few citations are available in the literature on limited mechanization in masonry construction. The existing masonry constructions is non-uniform. Mortar mixed at the job site are used beyond its useful mix life. The thickness of mortar in vertical and horizontal joints varies considerably which results in large variation in quality of work. This leads to variation in strength of masonry. Also the masonry units are not aligned properly that require large thickness of plasters. Prior art Masonry somewhat relevant to the present invention known to the inventors relate to a new type of self-adjusting masonry block developed in West Germany for increasing the efficiency of masonry construction. The masonry units have a small groove running in the middle of top and bottom faces of the block parallel to the bed joint. Small plastic discs are inserted into the groove for adjusting the blocks in the next course. Thus fast work ensuring well-aligned wall with plane surfaces is achieved. Another innovative masonry unit somewhat relevant to present invention was developed in New York, USA for insulated building for energy conservation. The concrete masonry block comprises of two masonry shells with inner faces that interlock with a styrofoam layer inserted between them for thermal insulation. Automation in masonry construction is mostly restricted to the prefabrication industry. U.S. Patent No. 4,262,463 describes pressed blocks for interlocked assembly. The block comprises at least one male assembly means projecting from the first face. The female assembly means is arranged on the second face of the block and has a substantially rectangular cross section. U.S. Patent No. 4,896,472 describes a construction system based on the combined use of full, half and knock out blocks designed to lock together. U.S. Patent No. 6,240,658 describes tongue and groove arrangement In this arrangement, an interlocking and insulating pattern assembly is used in creating a wall structure for receiving a poured concrete. U.S. Patent No. 6,244,009 describes a masonry wall system wherein a plurality of courses of masonry blocks consist of interlocking dovetail along with vertical and horizontal melting surfaces. Indian Patent application no. 676/DEL/2002 by the third inventor describes semi automatic masonry construction wherein interlocking / interfitting of solid masonry unit are self aligned and self adjusting. Being solid masonry unit, the consumption of material is more and does not remain cost effective. Dry stacked masonry, interlocking mortar less masonry and surface bonded masonry have been developed and used in various countries. Consolidated review of masonry unit units and their geometry are summarized as follows. No literature is available on automated masonry construction where bonding can be achieved automatically. Masonry units are bonded by providing mortar in each layer or left unbounded. Therefore there is need for invention such that the construction is automated for uniform and better quality of masonry construction, reduced manpower requirement, reduced time of construction and hence reduced cost of construction. Consolidated review of masonry units (Table Removed) OBJECTIVE OF THE INVENTION. The main objective of the present invention is to provide three types of novel and unique masonry building units having interlocking / interfitting projections and depressions which are self aligned and self adjustable. The masonry units are solid or hollow. It may be of any dimensions. The brick / block units are made out of any materials such as clay in plastic stage which require to be burnt or a homogeneous mixture of cement, flyash and sand or homogeneous mixture of cement, flyash and clay or homogeneous mixture of cement, sand and clay. It is mixed with required quantity of water to make moist mixture. It can be made of strength up to approximately 30 MPa. The type-I masonry unit is hollow trapezoidal unit comprising lower and upper rectangular parallel interlocking / interfitting surfaces, front and back rectangular parallel plane surfaces and one solid side surface. It is hollow from the other side surface. The thickness of the walls may be 10 to 30mm depending on the size of the masonry unit. The said lower and upper surfaces has interlocking / interfitting depression and projection respectively within its width along its longitudinal axis. The solid side surface has interlocking / interfitting projection or depression within its width along its vertical axis. The other side surface with opening has interlocking / interfitting projection or depression within the thickness of four walls of the masonry unit. The width of projections and depressions on lower / upper and solid side surfaces will be 0.4 to 0.9 times the width of masonry unit. The depth of such projections and depressions will be 3 mm to 9 mm and 6mm to 12 mm respectively so that a gap of 3 mm to 9 mm is created all around the masonry unit within the width of projection and depression. However, the depth of projection and depression within the four walls on the side surfaces with opening are equal so that no gap is created. The type - 2 masonry unit is similar to masonry unit of type - 1 except that it is not hollow but solid and the middle half of the lower and upper surfaces are projected downward and upward respectively. The downward and upward projection of the middle half of lower and upper surfaces may be 10 mm to 30 mm depending on the size of the masonry unit. The other details of the masonry unit are similar to that of masonry unit of type-1 except that the other side surface is also solid and has similar interlocking / interfitting surfaces. The other objective of the present invention is to transform the masonry unit of type-2 to solid trapezoidal unit if the middle half of the lower and upper surfaces are not projected downward and upward respectively. In that case, the lower and upper surfaces shall be plane parallel surfaces with interlocking / interfitting depression and projection similar to that of lower and upper surfaces of masonry unit of type-1. Type - 3 masonry unit is similar to solid masonry unit of type - 2 except that it is hollow with opening on one of its side surface. The remaining upper and lower surfaces,front and real surfaces and one solid side surface is similar to that of solid masonry unit of type - 2. The other side surface with opening is similar to masonry unit of type-1. The thickness of walls over lower and upper projected surfaces of the masonry unit may be 10 mm to 30 mm depending on the size of the masonry unit. The masonry unit of type-3 can be transformed to masonry unit of type-1 if the middle half of the lower and upper surfaces are not projected downward and upward respectively. In that case, the lower and upper surfaces shall be plan parallel surfaces similar to that of masonry unit of type-1. Also the other objective of present invention is to provide novel and innovative masonry units which can be obtained by inward depression of the middle half of the side surface with interlocking / interfitting depression and outward projection of the middle half of side surface with interlocking / intefitting projection of the masonry units as described above. The middle half of the side surface with opening having interlocking and interfitting depression and projection can be also depressed inward and projected outward respectively. The inward depression and outward projection of the middle half of side surfaces may be 5 mm to 25 mm depending on the size of masonry units. The other details of the masonry units are similar to the masonry units claimed above. The other objective of the present invention is to provide masonry system dealing with the process of masonry construction. The construction of masonry walls are done by placing one masonry unit along with other masonry unit side by side. Then the masonry units are placed one after another without any mortar between them. The projection of one masonry unit interlock with the depression of other masonry unit leaving a gap inside. The vertical and horizontal gaps form a continuous gape all around the masonry units within its width. Then the bonding of masonry units are achieved by pouring / pumping mortar from the top or from the sides as appropriate. The mortar is made by mixing cement with water in a suitable proportion such that it flow freely. It is also mixed with non-shrinkable material to avoid shrinkage of mortal. Cement based polymer / epoxy can be also mixed with mortar to achieve better bond between masonry units. The other objective of the present invention is masonry system at L, T and + joints. The masonry units are modified to achieve these joints. The other objective of the present invention is to provide reinforced masonry. It is achieved by making two symmetric holes in brick / block units at its mid-width and at equidistance from its center. The holes of upper and lower masonry units are aligned and reinforcement bars inserted in it. It is grouted with the grouting of the brick / block masonry. The subject invention also relates to machine for making masonry units. It has a free standing steel fabricated frame. It has a hopper which receives the material from the mixer through the conveyor. Receiver mould forms the middle part of the machine. It is attached to the hydraulic jack for positioning of the receiver mould. Upper part of the die is attached to the hydraulic jack for positioning of the receiver mould. It is attached to the hydraulic ram that can create a pressing force to each sector of four die. Lower part of the mould acts as an ejector. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described with reference to the accompanying drawings where Fig. 1 shows some of the masonry systems already known in the art where Fig. 1(a) shows the masonry block known as Haener Block. Fig. 1(b) shows a system known as Mecano System. Fig. 1(c) shows Sparlock System. Fig. 1(d) shows WHD System. Fig. 1(e) shows Tasta System and Fig. 1(f) shows Link Block System. Figures 2 to 5 shows various embodiments of masonry building unit of type-1. Figure 2 shows interlocking / interfitting projection in the middle width of top surface (1), interlocking / interfitting depression in the middle width of bottom surface (2), interlocking / interfitting projection / depression in the middle width of solid side surface (3) and interlocking / interfitting projection / depression in the middle of four walls of side surface with opening (4) of masonry unit of type-1. Figure 3 shows interlocking / interfitting depression in the middle width of bottom surfaces (2), interlocking / interfitting projection / depression in the middle width of solid side surfaces (3) and plane front / rear surfaces (5) of masonry unit of type-1. Figure 4 shows interlocking / interfitting depression in the middle width of bottom surface (2), interlocking / interfitting projection / depression in the middle of four walls of side surface with opening (4) and plane front / rear surfaces (5) of masonry unit of type-1. Figure 5 shows interlocking / interfitting projection in the middle of four walls of side surface with opening (4) and a thin support in the center of opening (6) of masonry unit of type-1. Figures 6 shows various embodiments of masonry unit of type-2 such as upward projection of middle half of bottom surface with interlocking / interfitting depression in its middle width (7), interlocking / interfitting depression in the middle width of solid side surface (3) and plane front / rear surface (8). Figures 7 shows various embodiments of masonry unit of type-3 such as upward projection of middle half of top surface with interlocking / interfitting projection in its middle width (9), interlocking / interfitting projection in the middle of four walls of side surface with opening (4) and plane front / rear surface (8). Figures 8 and 9 show various embodiments of masonry system with masonry units of types 1 and 2, 3 respectively. Figures 10 to 12 shows various embodiments of L,T and cross joints in masonry system. Figure 13 shows various embodiments of machine for making brick / block units. STATEMENT OF THE INVENTION According to the present invention, a masonry building unit, hollow trapezoidal in configuration, comprises upper and lower rectangular parallel surfaces, front and rear rectangular parallel surfaces and one solid side surface hollow from the other side surface with wall thickness of 10 to 30 mm depending on the size of the masonry building unit, wherein the lower surface has a matching projection within its width along its longitudinal axis, the upper surface has matching projection within its width along its longitudinal axis in conformity with the said depression, the solid side surface having interlocking / interfitting projection or depression within its width along its vertical axis and the other side surface with opening having interlocking / interfitting projection or depression within the thickness of four walls of the masonry building unit. The present invention relates to a masonry building unit, hollow trapezoidal in configuration. More specifically, the subject invention relates to a novel and unique masonry building units having interlocking / interfitting projections and depressions, which are self aligned and self adjustable. The masonry building units are solid or hollow. It is of any dimensions. Length may vary from 150 mm to 600 mm, width may vary from 75 mm to 300 mm and depth may vary from 75 mm to 300 mm. The masonry units are made out of any materials such as clay in plastic stage which require to be burnt or a homogeneous mixture of about 5-15 % cement, 3070 % flyash and 20-60 % sand or homogeneous mixture of 5-15 % cement, 40-60 % flyash and 40-60 % clay or homogeneous mixture of 5-15 % cement, 40-60 % sand sand and 40-60 % clay. It is mixed with required quantity of water to make moist mixture. Also, it can be made of any strength up to approximately 30 Mpa. Strength of such masonry has been observed to be about 60-80 percent of the strength of masonry unit where as the strength of masonry made as per the existing method is only 30 to 40 percent of the strength of masonry unit. The three types of masonry units are described below: Type - I: It is hollow trapezoidal masonry unit as shown in Figs 1 to 4. It comprises upper and lower rectangular parallel surfaces, front and back rectangular plane parallel surfaces and one solid side surface. It is hollow from the other side surface. The thickness of the walls may be 10 mm to 30 mm depending on the size of the masonry unit. The said lower surface has a depression within its width along its longitudinal axis, the upper surface has matching projection within its width along its longitudinal axis in conformity with the said depression. The solid side surface has interlocking / interfitting projection or depression within its width along its vertical axis. The other side surface with opening has interlocking / interfitting projection or depression within the thickness of four walls of the masonry unit. One of the masonry unit shall have interlocking / interfitting projection on solid side surface and interlocking / interfitting depression within its four walls on the other surface with opening. The other masonry unit shall have interlocking / interfitting depression on solid side surface and interlocking or interfitting projection within its four walls on the other surface with opening. The inclined surfaces of projections and depressions are at an angle of about 30 to 60 with the lower / upper surface. It will have same inclination for interfitting / interlocking. The projection on solid side surface of one masonry unit and depression on solid side surface of other masonry unit are matching and in conformity with each other to get interfitted and interlocked. Similarly the depression in four walls of one masonry unit and projection on four walls of other masonry unit are matching and in conformity with each other to get interfitted and interlocked. The width of projections and depressions on lower / upper and solid side surfaces will be 0.4 to 0.9 times the width of masonry unit. The depth of such projections and depressions will be 3 mm to 8 mm and 6 mm to 12 mm respectively so that a gape of 3 mm to 9 mm is created all around the masonry unit within the width of projection and depression. However, the depth of depression and projection within the four walls are equal so that no gape is created. Also a thin wall in the center of opening may be provided as shown in Fig.4. This shall enhance the stability / strength of the masonry unit. Thus the important feature of the masonry unit is that the height of the said projection is less than the depth of the depression such that a gap is formed in the masonry system when interlocked / interfitted with the adjacent masonry unit. Such gap formed around each masonry unit are interconnected and become continuous in the masonry system. Thus the mortar poured from one location in the masonry system spread all over within the masonry system providing bond to all masonry units. Type - 2: It is solid masonry unit as shown in Fig5. It is similar to masonry unit of type -1 except that it is not hollow but solid and the middle half of the lower and upper surfaces are projected downward and upward respectively. The downward and upward projection of the middle half of lower and upper surfaces may be 10 mm to 30 mm depending on the size of the masonry unit. The other details of the masonry unit are similar to that of masonry unit of type - 1 such as upper and lower rectangular parallel surfaces, front and back rectangular parallel surfaces and one of the solid side surface except that the other side surface is also solid and has similar interfitting / interlocking surface. The masonry unit of type-2 can be transformed to solid trapezoidal unit if the middle half of the lower and upper surfaces are not projected downward and upward respectively. In that case, the lower and upper surfaces shall be plan parallel surfaces with interlocking / interfitting depression and projection similar to that of lower and upper surfaces of masonry unit of type-1. The resulting masonry unit shall be similar to masonry unit of type-1 except that it is not hollow but solid and both the side surfaces shall have interlocking / interfitting depression and projection. The depression and projection on side surfaces shall be similar to that of masonry unit of type-2. Type - 3: It is similar to solid masonry unit of type - 2 except that it is hollow with opening on one of its side surface as shown in Fig 6. The remaining upper and lower surfaces, front and rear surfaces and one of the side surfaces are similar to that of solid masonry unit of type - 2. The other side surface with opening is similar to that of masonry unit of type-1 as shown in Figs 3 and 4. This masonry unit of type-3 can be transformed to masonry unit of type-1 if the middle half of the lower and upper surfaces are not projected downward and upward respectively. In that case, the lower and upper surfaces shall be parallel surfaces similar to that of masonry unit of type-1. Also novel and innovative masonry units can be obtained by inward depression of the middle half of the side surface with interlocking / interfitting depression and outward projection of the middle half of side surface with interlocking / intefitting projection of the masonry units as claimed above. The middle half of the side surface with opening having interlocking and interfitting depression and projection can be also depressed inward and projected outward respectively. The inward depression and outward projection of the middle half of side surfaces may be 5 mm to 25 mm depending on the size of masonry units. The other details of the masonry units are similar to the masonry units claimed above. The subject invention also relates to masonry system that deals with the process of masonry construction. The masonry walls are made by placing one masonry unit along with other masonry unit side by side. In case of solid masonry units, the projection on side surface of one masonry unit will interlock with the depression on side surface of other masonry unit leaving a vertical gape. In case of hollow masonry units, the interlocking of solid side surfaces will be similar to that of the solid masonry units but the side surface with opening of one hollow masonry unit will interlock with the side surface with opening of other hollow masonry unit without leaving any gape. Then the masonry units are placed one after another without any mortar between them as shown in Figs 8 and 9. The projection of one masonry unit interlock with the depression of other masonry unit leaving a horizontal gap inside. The vertical and horizontal gaps form a continuous gape all around the masonry unit within its width. Then the bonding of masonry units are achieved by pouring / pumping mortar from the top or from the sides as appropriate. The mortar is made by mixing cement with water in a suitable proportion such that it flow freely. It is also mixed with non-shrinkable material to avoid shrinkage of mortal. Cement based polymer / epoxy can be also mixed with mortar to achieve better bond between masonry units. Due to pouring / pumping of mortar from the top or sides as appropriate, it shall spread all over the masonry and provide bond to all masonry units. The subject invention also relates to masonry system at L, T and + joints as shown in Figs 10 to 12. The masonry units are modified to achieve these joints. The subject invention also relates to reinforced brick / block masonry. It is achieved by making two symmetric holes in brick / block units at its mid-width and at equidistance from its center. The center to center distance between two holes will be twice the distance between the edge of brick unit and the near by hole. The holes in lower and upper masonry units of masonry wall are aligned. The diameter of holes shall be larger than the diameter of reinforcement bars inserted in it. It is grouted with the grouting of the brick / block masonry. The subject invention also relates to machine for making brick / block units as shown in Fig. 13. It is fast manufacturing machine to produce approximately 5000 bricks or 2500 blocks in a shift of 8 hours. It has a free standing steel fabricated frame capable of withstanding fatigue load of about 750 kN. It has a hopper which receives the material from the mixer through the conveyor. High frequency vibrator is fixed to the hopper for creating easy flow of the material to the receiver mould. Receiver mould forms the middle part of the machine and is placed in between the upper and lower part of the mould. Volume of the receiver is designed to accommodate desired quantity of material for brick / block. There are small partitions powered by independent stirring blades for even distribution of the material to the moulds. A cleaner brush is attached to the upper side of the receiver for cleaning lower part of the mould. Receiver mould is attached to the hydraulic jack for positioning of the receiver mould. Upper part of the die is attached to the hydraulic jack for positioning of the receiver mould. It is attached to the hydraulic ram that can create a pressing force of about 600 kN. Since there are four moulds, 150 kN force act on each sector of the die. Two stiff guides are provided, one on each side of the hydraulic ram, for guiding the upper half of the die. Movement of all the rams is controlled by PLC. Lower part of the mould acts as an ejector. Ejector is also connected to the guided hydraulic ram. As the machine is operated through PLC, it is almost semi automatic, fast and accurate. Thus the subject invention relates to semi automatic masonry construction. It is made easier by distribution of the mortar by pouring / pumping it in void space between the masonry units so that the quality of construction is better and uniform, man power requirement and time of construction is reduced resulting in reduced cost of construction. Also the strength of masonry is very large as compared to conventional masonry. ADVANTAGES Following are advantages of the present invention: 1. The present invention shall facilitate semi automatic masonry construction. 2. The construction shall lead to self-alignment and self-adjustment of The masonry units due to its interlocking and interfitting. 3. It provides uniform and better quality of work due to self alignment of masonry units and its uniform bonding by pumping / pouring of mortar from top or from sides as appropriate. 4. It provides reduced man power requirements and reduced time of construction. 5. The hollow masonry units results in reduced dead weight of masonry wall. Thus the earthquake has reduced effect. 6. The inward depression of lower surface and outward projection of upper surface of masonry units shall provide enhanced interlocking / interfitting of masonry units resulting in its improved behaviour under gravity and earthquake loads. It shall also increase its strength. 7. The thickness of mortar for bonding masonry units is small under automated masonry construction. Therefore the strength of the proposed masonry are large as compared to strength of the conventional masonry. The strength of such masonry has been observed to be about 60-80 percent of the strength of masonry unit where as the strength of masonry made as per existing method is only 30 to 40 percent of the strength of masonry unit. 8. It has reduced cost of construction. We claim: 1. A masonry building unit, hollow trapezoidal in configuration, comprising upper (1) and lower (2) rectangular parallel surfaces, front and rear rectangular parallel surfaces and one solid side surface (3) hollow from the other side surface with wall thickness of 10 to 30 mm depending on the size of the masonry building unit, wherein the lower surface (2) has a matching projection within its width along its longitudinal axis, the upper surface (1) has matching projection within its width along its longitudinal axis in conformity with the said depression, the solid side surface having interlocking / interfitting projection or depression within its width along its vertical axis and the other side surface with opening (4) having interlocking / interfitting projection or depression within the thickness of four walls of the masonry building unit. 2. A masonry building unit as claimed in claim 1, wherein said building unit is made out of material such as clay in plastic stage which require to be burnt or a homogeneous mixture of about 5-15% cement, 30-70% fly ash and 20-60% sand or homogeneous mixture of 5-15% cement, 30-70% fly ash and 20-60% clay or homogeneous mixture of 5-15% cement, 40-60% sand and 40-60% clay or homogeneous mixture of sand, fly ash and lime or homogeneous mixture of sand and lime or homogeneous mixture of fly ash and lime in suitable proportion, mixed with required quantity of water to make moist mixture. 3. A masonry building unit as claimed in claim 1, wherein the lower surface of the said masonry building unit has a depression within its width along its longitudinal axis in conformity with the said depression, the solid side surface has interlocking / interfitting projection or depression within its width along its vertical axis and the other side surface with opening has interlocking / interfitting projection or depression within the thickness of four walls of the masonry building unit such that the masonry building unit have interlocking / interfitting projection on solid side surface and interlocking / interfitting depression within its four walls on the other surface with opening, the other masonry building unit provided with a interlocking / interfitting depression on solid side surface and interlocking / interfitting projection within its four walls on the other surface with opening. 4. A masonry building unit as claimed in any of the preceding claims, wherein the inclined surfaces of projections and depressions at any angle varies from about 30 to 60 with the horizontal surface. 5. A masonry building unit as claimed in the preceding claims, wherein the width of projections and depressions on lower, upper and solid side surface are 0.4 to 0.9 times the width of masonry building unit, the depth of projections and depressions is 3 mm to 8 mm and 6 mm to 12 mm respectively so that a gap of 3 mm to 9 mm is created all around the solid surface of masonry building unit within the width of projection and depression, such that the depth of depression and projection within the four walls are equal avoiding the gap between the masonry building units. 6. A masonry building unit as claimed in the preceding claims, wherein the height of the said projection is less than the depth of the depression creating a gap in the masonry system when interlocked / interfitted with the adjoining masonry building unit and the gap formed around solid surface of masonry building units are interconnected and continuous in the masonry system so that the mortar poured from one location in the masonry system spread all over within the masonry system providing bond to all masonry building units. 7. A masonry building unit as claimed in the preceding claims, wherein a thin support is provided in the center of opening of masonry building unit to enhance the stability / strength of the masonry building unit. 8. A masonry building unit as claimed in the preceding claims, wherein the middle half of the lower and upper surfaces of the masonry building unit are projected downward and upward respectively with downward and upward projection of the middle half of the lower and upper surfaces varying from 10 mm to 30 mm depending on the size of the masonry building unit. 9. A masonry building unit as claimed in claim , where in the middle half of the lower and upper surfaces are not projected downward and upward respectively resulting in plane parallel lower and upper surfaces with interlocking / interfitting projection and depression. 10.A masonry building unit as claimed in claim 9, wherein the building unit is hollow with opening on one of its side surfaces, the remaining upper and lower surfaces, front and rear surfaces are solid side surface similar to that of solid masonry building unit, the other side surface with opening has interlocking / interfitting projection or depression within the thickness of four walls of the adjacent masonry building unit. 11. A masonry building unit as claimed in claim 10, wherein the middle half of the side surface with opening having interlocking and interfitting depression and projection is also depressed inwardly and projected outwardly respectively such that the interlocking / interfitting inward depression and outward projection of the middle half of side surfaces is 5 mm to 25 mm depending on the size of masonry building units. 12.A masonry building unit, hollow trapezoidal in configuration substantially as hereinbefore described with reference to the accompanying drawings.

Documents:

1373-DEL-2006-Abstract-(09-02-2009).pdf

1373-del-2006-abstract.pdf

1373-DEL-2006-Claims-(09-02-2009).pdf

1373-DEL-2006-Claims-(22-10-2008).pdf

1373-del-2006-claims.pdf

1373-del-2006-correspondencce-others.pdf

1373-del-2006-correspondence-others 1.pdf

1373-DEL-2006-Correspondence-Others-(09-02-2009).pdf

1373-DEL-2006-Correspondence-Others-(22-10-2008).pdf

1373-DEL-2006-Description (Complete)-(09-02-2009).pdf

1373-DEL-2006-Description (Complete)-(22-10-2008).pdf

1373-del-2006-description (complete).pdf

1373-DEL-2006-Drawings-(09-02-2009).pdf

1373-del-2006-drawings.pdf

1373-DEL-2006-Form-1-(09-02-2009).pdf

1373-del-2006-form-1.pdf

1373-del-2006-form-18.pdf

1373-DEL-2006-Form-2-(09-02-2009).pdf

1373-del-2006-form-2.pdf

1373-del-2006-form-26.pdf

1373-del-2006-form-3.pdf

1373-DEL-2006-Form-5-(09-02-2009).pdf

1373-del-2006-form-5.pdf

1373-del-2006-form-9.pdf