US1952175A

US1952175A - Fire wall

Info

Publication number: US1952175A
Application number: US396184A
Authority: US
Inventors: Liptak Michael
Original assignee: Individual
Current assignee: Individual
Priority date: 1929-09-30
Filing date: 1929-09-30
Publication date: 1934-03-27
Anticipated expiration: 1951-03-27

Description

March 27, 1934. M. LIPTAK 1,952,175

' I FIRE WALL Filed Sept. 30, 1929 3 Sheets-Sheet 1 2 MICHAEL L/PTAK ATTORNEYS March 27, 1934- M. UPTAK I 1,952,175

FIRE WALL Filed Sept.- 30, I929 3 sheets sheet 2 fm/enfofi M I MICHAEL L/P774K flEM M/ZII ATTORNEYS Maw, 27, 1934.

M. LIPTAK FIRE WALL Filed Sept. so, 1929 3 Sheets-Sheet 3 Jul/670502" M/c/ma L/PmK m MM ATTORNEYS Patented Mar. 27, 1934 UNITED STATES PATENT OFFICE 27 Claims.

This invention relates generally to improvements in fire walls and particularly to improvements in walls of this class having a permanent wall, and a replaceable wall attached thereto in such manner that the bricks of the replaceable wall may be removed without disturbing the elements of the permanent wall. The invention further relates to an air-cooled or hollow wall construction comprising permanent and replaceable portions in which the replaceable portion is spaced from the permanent portion either to provide separate ducts extending horizontally through the wall, or to provide ducts which intercommunicate vertically.

Objects of the invention are to provide permanent and replaceable portions which are connected together in a manner to prevent great but permit small horizontal motions of the replaceablewall; to provide connecting means for carrying out the above purpose which may be dropped into place during construction of the wall; to so position the connections that they are air cooled or, so that they will have the minimum exposure toheat; to provide a hollow wall construction in which the permanent wall above the replaceable portion is extended the full transverse width of both walls; to provide reinforcement for this superposed permanent wall portion which will substantially relieve all strain on the replaceable portion due to its overhanging relation to said replaceable portion; to include in the overhanging portion header elements which lie at an angle to the header elements of both walls; to provide an arrangement of the elements of the replaceable wall such as to permit of compensatory longitudi nal expansion; and to provide improved hollow wall constructions respectively of the horizontal and vertical circulatory types.

Features of the invention include all details of construction, combinations and subcombinations of the parts, along with the broader features.

Objects. advantages and features of the invention will appear in the description of the drawings forming a part of this application, and in said drawings:

Figure 1 is a perspective view, with some of the bricks removed tomore. clearly illustrate a type of hollow wall construction in which separate horizontal ducts arev provided;

Figure 2 is a vertical cross section substantially on line 2-2 of Figure 1;

Figure 3 is a plan taken substantially on line 3-3 ofFigure 2;

Figure 4 is a perspective view illustrating a type. of hollow wall: construction in which vertical each filled with cement or mortar indicated at.

2, which cement is of course soft when the blocks, now to be described are laid upon the irons. A course composed of blocks 3 is laid upon each channel iron, and each block has a projection 4 extending longitudinally of the iron which is embedded in the cement to form a key to prevent horizontal motion of the block or motion transversely of the wall. These elements may be functionally considered as headers or tie members. Each block is provided with an inner vertically thick portion generally indicated at 5, and an outer vertically thinner portion indicated at 6, whereby a shoulder '7 is provided facing outwardly.

In all but the top course the blocks 3 rest upon the channels but in the top course the thinner portions 6 abuttingly engage beneath the channel. Certain of the blocks are provided with corner recesses 8' opening on the top and on the vertical inner ends of the bricks. Of course, every block may be so recessed, as shown in Figure 1. The bottom of this recess is additionally vertically recessed to provide a shoulder lying inwardly from the vertical and top faces of the block. The vertical height of each recess 8 is such as to permit introduction or removal of the connectors (later to be described) in a horizontal direction after the wall is completed. In Figure 1 each block is provided with

recesses

8 and 9,'because in this formof the inventionthe wall is divided into a series of separate horizontal passages, all blocks being extended across the space between the walls to form partition members.

The header elements 3' project inwardly a substantial distance beyond the channel irons, as shown in Figure 1, and facing bricks 10 are laid as stretchers upon the top of the header elements 3. The lower innermost courses engage the shoulders '7.- Upon these bricks, in this instance, is laid a course of blocks 6 and upon this course are laid stretcher courses substantially similar to those first described except that the outside bricks are laid up to the under surface of the channel iron 1 and the upper inner course lies laterally thereof and engages the inner vertical surface of the channel iron. Courses of filler bricks 19 just described may be common brick. Facing bricks 11, preferably of refractory material, face the bricks 10 at the inner side of the permanent wall and the inner faces of these bricks lie flush with the vertical faces of the header or anchor blocks 6. By this construction the stretcher bricks l1 cap the openings 8 to form recesses, open only at the inner surface of the permanent wall.

The replaceable wall is formed of refractory brick and is in this instance spaced from the permanent wall. Bricks 12 are laid as stretchers and upon these stretchers at levels corresponding to the level of the courses of elements 3, header courses are laid, and are composed of bricks 13 which have their inner ends flush with the inner surface of the replaceable wall and which project into and in this instance across, the space between the permanent and replaceable walls to abut the inner faces of the headers 3. Each of these header elements 13 is provided with an open top recess 14 which, in this instance, lies immediately adjacent the inner surface of the replaceable wall. Connectors including body portions 15 and abutment portions 16 are arranged as best shown in Figure 2 with the abutting portions engaged respectively within the

sockets

8 and 14 in a manner to prevent large but permit small horizontal motions of the elements 13 toward and. away from the permanent wall due to changes in temperature. abutments 16 are of such vertical height that when their bottoms are engaged with the bottoms of the recesses, the under surface of the body portion 15 will be spaced above the tops of the substantially coplanar surfaces of the bottom of the recesses 8 and top of the header element 13. In this way cooling circulation for the metal connecting element is assured. Suitable refractory stretcher elements are laid between the courses of elements 13.

Another feature of the invention is best illustrated in Figures 1 and 3 and consists in the arrangements of the stretcher courses of the replaceable wall in a manner to permit longitudinal expansion without fracture. To this end, certain pairs of blocks 13 are specially formed (as by vertically corner-notching from upper and lower faces of respective blocks) to overlap as at 18 in such manner that the blocks may slide upon one another in a direction lengthwise of the wall. Certain of the blocks of the stretcher courses are also formed in pairs to overlap as at 17, see Figure 3, as by horizontally corner-notching laterally) to permit compensatory longitudinal motion of these stretcher courses and yet maintain a horizontal seal which substantially prevents the entrance of heat through the replaceable wall into the space between the wall. As shown, the elements of the expansion construction of one course are staggered in relation to the next and this is also true for the expansion construction of header elements 13, see Figure 1.

Another feature of the invention is the arrangement of the upper portion of the permanent wall with respect to the two walls. As well known, the permanent wall is extended a substantial distance above that portion of the fire wall which is provided with replaceable refractory elements, and it is desirable to have the upper portion of the wall extend the entire width of both walls. The

The I object here is therefore to extend this wall but to have the weight of this wall supported entirely by the permanent wall and not by the replaceable portion and so that the replaceable portion, can be replaced without dismantling the permanent wall. To this end, metal header plates (or a single elongated plate) 20 are provided, each having a vertical rib 21 extending longitudinally of the plate and therefore transversely of the wall. A course of these plates is provided and each plate has a downwardly extending projection 22 which engages the mortar or cement 2 of the channel iron 1. The plates in this instance rest directly upon the thicker portion 5 of the elements 3 and project across the space between the walls and in this instance abut the inner surface of the replaceable wall. Laid upon this course of metal plates are other bricks generally indicated at 25, some as headers and others 26 as stretchers. Three courses in this instance are used, the top surface of the bottom course lying at av level slightly above the upper surface of the ribs 21. Upon the top course of the bricks just described are laid specially formed blocks indicated at 30 forming sockets or recesses 31 diagonal with respect to the transverse dimension of the wall. Into these recesses are inserted header elements 32 which extend beyond the blocks 30 and into the replaceable Wall, the terminal portions 33 having faces which are parallel with the transverse dimension of the wall. It will be noted that the lower surfaces of the elements 32 are spaced above the upper surface 34 of the top stretcher course of the replaceable wall. Between the elements 32 are inserted short filler elements 35 which rest upon the upper surface of the top course of the replaceable wall. The upper surface of the elements 35 are at a level below the under surfaces of the elements 32. The elements 35 are substantially the same shape as elements 32, (have angularly related inner and outer portions) and the faces 33 of

elements

32 and 35 cooperate to normally prevent withdrawal of the elements 35, which form anchoring keys, to substantially prevent movement in a direction transversely of the wall. In this instance, ordinary bricks 38 are laid as stretchers against the outer surface of the blocks 30, and the bricks 38, blocks 30, and

elements

32 and 35 are topped by other brick ele ments respectively shown at 39l0 and 41. All details of arrangement are features of this invention and are claimed along with the broader features.

In Figure 5 a modification has been shown in which provision is made for vertical circulation of air and also for introduction or removal of air at the top of the wall. In this case, only certain of the elements 50, (which correspond to the elements 13 of the first form) extend across the space between the walls, see Figures 4 and 5, thus providing vertical intercommunication. In this instance, the plates 51, (functionally corresponding to plates 20) together form a hollow transversely extending conduit. Each plate in this instance is composed of a bottom portion 52 and atop portion 53 spaced therefrom, the portions being connected by a centrally arranged flange 54. which extends longitudinally of the plate or transversely of the wall. On the top of each top plate or portion is provided a rfb 55 which in this instance extends longitudinally of the wall to form a key for cement 56, laid between the elements 57, 58, which top the plates. On the bottom of the plate 52 is provided a key rib 56 which also extends longitudinally and corresponds functionally to the rib 22 of the plate 20. The conduit-forming elements extend in this instance .beyond the wall at. the outer side asshown in Figure 5 to permitconnection of the air circulating. manifold of an airpumping.apparatusand the inner. end of the lower plate member 50 extends only tothe vertical inner'surface of the permanentwall while the upper plates 53 extend across the space between the walls and are abutted by the inner faces of the bricks of the replaceable wall. See Figure 5.

Eachflange 54 is provided with anopening 59 which establishes intercommunication lengthwise of the wall, partly to increase the cooling effect, and also to reduce weight.

It will be understood that header-like bridge elements may be formed of refractory material such as heavy fire brick tile or other preferred material, and the invention is considered broader than the material used, but the use of metal elements, in this environment, is also believed broadly new, and is claimed An important feature of the invention is the construction of the block 3 with its vertically thick and thinner portions respectively indicated 5-6. By inspection of Figure 2, it will be seen that no mortar is used for laying the bricks 11 but that mortar is used for laying the bricks 10. The depth of the shoulder is substantially equal to the thickness of the mortar between the three courses of bricks l0, and therefore in layingup the wall the upper surfaces of the topmost bricks of the courses 11 and can easily be made coplanar which facilitates the building of the wall. Common bricklO can be used for the outermost portion of the wall, and lad in mortar while the fire brick courses 10 can be laid without mortar as is required in this type ofconstruction. This materially reduces production costs.

It is to be understood that the shoulders 9 or their equivalents may be formed, either by the means of irons embedded in the wall, or in either wall, or by the use of special bricks as shown in the drawings, or by the formation of longitudinally extending grooves by the laying of common brick. The gist of the invention is the use of a connector for preventing transverse separation of certain elements of the two walls, with the groove or abutments formed so that the elements can be dropped into place while the wall isbeing built. Also an important feature is the provision of means whereby if it is necessary to replace a portion of the replaceable wall, and to remove the elements or their equivalents which have been injured, these elements can be disconnected from the permanent wall without in any way dismantling any portion of said wall. In this way, any elements 1.5 which may be burned or weakened by heat, can be replaced without any dismantling whatever of the permanent wall.

It is further to be notedthat it is not necessary that the walls be spaced but that the connecting means can be used for connecting any replaceable wall portion whether it be spaced or not spaced from the permanent wall, the gist of the invention being the simple connecting means, as well as such a means which can be dropped into place while the wall is being constructed.

One of the advantages of this invention is the provision of the bricks 11 as fire brick facing which act in an emergency to alone protect the permanent wall from heat, in case of the burning out of the replaceable wall so that the heating plant; of, which the wall forms a part may be operated over an extended period if necessary, without serious injury to theexpensive permanent wall portion.

It will be noted by inspection of the drawings that the inner ends of the elements 3.do nonproject beyondthe inner face of the permanent wall. It istruethat they do so project beyond the common brick portion of the permanent wall, and that they support the fire brick facingll; but this facing 11 may be of common brick. Therefore, the sockets are formed in portions of these bricks. which lie within the permanent wall. This isof particular advantage becauseordinarily these bricks project beyond the permanent wall and certain bricks of the replaceable wallrest upon them. In other words, heretofore the elements 3 or. their equivalents have projected as shelves to partly or entirely support the replaceable wall. This has resulted in fracture of the bricks often due to shearing action, so that the bricks 3 had to be dug out of the permanent wall or said wall had to be dismantled to replace them. It is to be further noted that although the bricks 13 of the replaceable wall project inwardly when it is desired to form an air-cooled wall, this is not always the case, because the sockets of these bricks can be within the confines of the replaceable wall and not projecting therebeyond as shown. It is obvious that this .invention can be applied to the building of fire walls other than the air-cooled form shown in the drawings. It is again to be noted that in this construction, there are no tie bricks or header or socket-providing bricks which project from one wall into the other and, therefore, there can be no shearing effect to break the projecting portions of the bricks.

Insofar as I am aware, before this invention, it was not possible to build any considerable portion of either wall before the other, and then to properly connect the two walls together. By the practice of this invention, because of the releasable relations of the socket-providing shoulders, and the abutments of the connectors, after either wall is built, the connectors can be inserted and then the other wall built to the proper level, and the abutment-providing sockets of that other wall made to register with the corresponding sockets of the wall first built.

In ordinary practice, it is necessary to lay, for example, five courses of the replaceable wall and then lay a corresponding number of courses of the permanent wall. For any given number of courses laid, in these two walls, the final courses must be in substantially coplanar relation, so that the header elements may properly extend from one wall into the other. This means that the workman must lay a few courses of one wall and then a few of the other.

Another advantage is that the replaceable wall, which requires fire clay cement, can be built up using this particular kind of cement, and then the permanent wall can be built up using common mortar, so that it is not necessary for the workman to frequently alternate with fire clay cement, and common mortar. As a matter of fact, either wall can be separately substantially entirely completed before the other because of the fact that the connector elements can be inserted in one Wall after building, and the other wall can then be built up, and the courses brought to the proper level to connect these inserted connectors. with the sockets of the second wall, which-ever wall it may be. Generally, however, the replaceable, or fire, wall is built first.

This invention, therefore, provides a method for building fire walls, as well as a specific construction. Insofar as I am aware, it has never been possible to properly substantially complete one of the walls beforethe other, and then to properly connect the wall last to be built to the other wall.

I claimas my invention:

1. A permanent wall and a replaceable wall, means connecting the walls to prevent separation, a course of metal bridge plates laid upon the top of the permanent wall and extending across the space between the walls, and a wall forming a continuation of said permanent wall built upon and supported by said plates and extending substantially the full width of both walls, and including courses of bricks laid to form diagonally disposed sockets, bricks in said sockets also diagonally disposed and topping the upper course of said replaceable wall and. filler bricks between said last mentioned blocks and also topping the upper course of said replaceable wall.

2. A permanent wall and a replaceable Wall, means connecting the walls to prevent separation, a course of metal bridge plates laid upon the top of the permanent wall and extending across the space between the walls, and a wall forming a continuation of said permanent wall built upon and supported by said plates and extending substantially the full width of both walls, and including courses of bricks laid to form diagonally disposed sockets, bricks in said sockets also diagonally disposed and topping the upper course of said replaceable Wall and filler bricks between said last mentioned blocks and also topping the upper course of said replaceable wall, the side faces of the terminal portions of said diagonally disposed bricks being substantially perpendicular to the outer faces of both walls.

3. A permanent wall and a replaceable wall, spaced therefrom to provide vertical circulation, means connecting the walls to prevent separation, a hollow metal bridge plate laid upon the top of the permanent wall and communicating with the space between the walls, and a wall forming a continuation of said permanent wall built upon and supported by said plate.

4. A permanent wall and a replaceable wall, spaced therefrom to provide vertical circulation, means connecting the walls to prevent separation, a hollow metal bridge plate laid upon the top of the permanent wall and communicating withthe space between the walls, and a wall forming a continuation of said permanent wall built upon and supported by said plates and extending substantially the full width of both walls, and including bricks laid at angles to both walls.

5. A permanent wall, a replaceable wall, means connecting the walls to prevent separation, a course of metal bridge plates laid and supported only upon the top of the permanent wall, and another permanent wall built upon the top and supported by said plates and extending substantially the full width of both walls.

6. A permanent wall including bricks certain of which have open top sockets therein providing shoulders of less height than the sockets, a replaceable wall spaced from the permanent wall including bricks which extend into the space between the walls, said extended bricks having open top sockets therein providing shoulders, and metal connectors including body and abutment portions, the abutment portions being engaged with the shoulders in a manner to prevent separation of the bricks in a horizontal direction, and

the height of the sockets of the permanent wall above the shoulders being sufficient to permit disengagement of the corresponding abutment of the connector by a vertical motion.

7. A permanent wall including bricks having shouldered sockets therein, a replaceable wall spaced from the permanent wall including bricks which extend into the space between the walls in a manner to divide the wall into horizontal passages vertically, superposed, said bricks having shouldered sockets therein, metal connectors including body and abutment portions, the abutment portions being detachably engaged with the shoulders in a manner to prevent separation of the bricks in a horizontal direction but to allow the abutments to be detached by a vertical motion in the socket, and said connectors being spaced from the bricks in a manner to permit air circulation thereabout substantially throughout their entire surface.

8. A permanent wall including bricks having shouldered sockets therein, a replaceable Wall spaced from the permanent wall including bricks which extend into the space between the Walls, said bricks having shouldered sockets therein, metal connectors including body and abutment portions, the abutment portions being engaged with the shoulders in a manner to prevent separation of the bricks in a horizontal direction, said connectors being spaced from the bricks in a manner to permit air circulation thereabout substantially throughout their entire surfaces, and said sockets being arranged so that said connectors can be dropped into position, other blocks overlying the sockets oi the replaceable Wall and capping them, and said shoulders, sockets, and abutments of the permanent wall being of the proper vertical heights to permit the connectors to be raised to disengage the corresponding abutment.

9. A permanent wall including bricks having shouldered sockets therein, a replaceable wall spaced from the permanent wall including bricks which extend into the space between the walls, said bricks having shouldered sockets therein, metal connectors including body and abutment portions, the abutment portions being engaged with the shoulders in a manner to prevent separation of the bricks in a horizontal direction, other blocks overlying the sockets of the replaceable wall and capping them, said sockets shoulders, and abutrnents of the permanent wall being of the proper vertical height to permit vertical motions of the connectors and removal thereafter by a motion in a horizontal direction, the sockets of the bricks extending downwardly from the top surface of the bricks.

10. A permanent wall and a replaceable wall, means connecting the walls to prevent separation, a metal bridge plate laid upon the top of the permanent wall and extending across the space between the walls, and a wall forming a continuation of said permanent wall built upon and partly supported by said plate and extending substantially the full width of both Walls.

11. A wall including longitudinally extending channel irons having their concave faces upward- 1y, cement held in said headers, header elements topping the irons and laid transversely thereof, said header elements having projections integral therewith and extending thereacross and longitu-w dinally of the irons which extend into the cement in a manner to anchor the header elements against movement transversely of the irons, and

" coplanar.

bricks filling thespace betweenthe channel irons certain off the .bricksjof each wall having'shoul "derejd sockets therein, metalconnectors engaged inj'the sockets by dropping thereinto during'tlie formation of tl ie wall 'and'having abutment por tions engaged with the shoulders in am'anner' tofprevent separation of the bricks in a horizontal direction.

213. In a fire wall including a course of header elements each having surface portionsat different levels, courses of bricks laid with mortarand topping the 'portionrat the lowest level, and an equal number oi 'courses of bricks topping the portion at the highest level, and laid without mor tar, thedistance difference between the surface levelsbeingsuch thatthe top surfaces of all uppermost bricks after laying are substantially 14. A device of the class described comprising a permanent wall and a replaceable wall spaced from the permanent wall, both walls being built 'of bricks and said walls having shoulders the shoulder of one wall lying outside of the normal line of the wall, metal connectors each having portions respectively engaged with corresponding shoulders of the walls in a manner to prevent separation of certain bricks in a direction transversely of the wall, the shoulders of the permanent Wall and the corresponding connector portions being arranged to permit detachment of the connectors from the shoulders by motions in a vertical plane, Without dismantling any portion of the permanent wall, and then in a direction transversely of the wall.

15. A device of the class described comprising a permanent wall and a replaceable wall spaced from the permanent wall, both walls being built of bricks and each wall having shoulders, the shoulders or" one wall being outside the normal line of the wall, metal connectors each having portions respectively engaged with correspondi ing shoulders of the walls in a manner to prevent separation of certain bricks in a direction transversely of the wall, the shoulders of the permanent wall and the corresponding connector portion being arranged to permit detachment of the connectors from the shoulders by motions in a vertical plane transversely of the wall without a part may be operated over an extended period dismantling any portion of the permanent wall. 16. A device of the class described comprising a permanent wall, and a replaceable wall, and

P means securing the walls together, the permanent wall having a fire brick facing adapted to act, in an emergency, to alone protect the permanent wall from injury by heat in case of burning out of said replaceable wall, or portions thereof, whereby a heating plant of which the wall forms cident to expansion by heat in a direction transversely of the wall.

18. A permanent wall, and a replaceable wall spaced therefrom, means connecting the walls to prevent separation, a course of bridge elements laid on top of the permanent wall and extending re s h Space b tw he w ls bet 1 1.912. 519? A hanging the repiaeeamewafl, andapenfianjen wall built upon the top andsupportedby said bridgeeleme'nts and extending substantially t full width of "130th?Walls andthere are the replaceable wall.

19. A permanent wall 'ncluding eleme nt s which project beyond its" face, bricks "gtne between and supported bythe 'pro ec ments to forma replaceable facing, a' re' wall, and; means connecting" themeplaceab to the projectingelements 't o preven f separation of thew alls."

20. A'permanent wallincluding elements which project beyond its face, saig em nts havinsfi sockets therein providing shoulders, bricksfill the 'spacebetween and supported byth pro selem isto fmare c a a in r of saidbricks forming"the tops of'th"sockets, the shoulders being at a level below the tops of the sockets thus formed, a replaceable wall including certain elements having shouldered sockets, and connectors each having abutment portions engaging shoulders of corresponding walls to prevent transverse separation of the walls, the depth of the sockets in the elements of the permanent wall being sufficiently greater than the depth of the abutment portions of the connectors to permit the connectors to be raised and be disengaged and withdrawn from the wall without dismantling it.

21. A device of the class described including tWo walls, both walls having elements therein arranged to form horizontal openings having shoulders arranged substantially perpendicularly to the transverse dimension of the-walls, the shoulders formed by the elements of one of the walls being arranged at a level below the tops of the openings, and connectors each having abutment portions engaging the shoulders of corresponding walls in a manner to prevent separation of the walls in transverse direction, the depth of the openings in the elements of one of the walls being sufiiciently greater than the depth of the abutment portions of the connectors to permit the connectors to be raised sufficiently to disengage the abutments and permit free withdrawal.

22-. A permanent wall including bricks providing shouldered sockets, and a replaceable'wall unsupported by the permanent wall and having bricks some of which are complemental to said first mentioned bricks, and also providing shouldered sockets, and means engaging the sockets of complemental socket-providing bricks to prevent separation in direction transversely of the wall.

23. A permanent wall, a replaceable wall, means connecting the walls to prevent separation, bridging means supported only by the permanent wall, and another permanent wall built upon and supported only by said bridging meanaand extending substantially the full width-of bothwalls.

24. A permanent wall, a replaceable wall, means connecting the walls to prevent separation, bridging means supported only by the permanent Q11 wall, and not overlapping the replaceable wall,: and another permanent wall built upon and supported only by said bridging means and extending substantially the full width of both walls.

25. A permanent wall, a replaceable wall, means connecting the walls to prevent separation, metal bridging means supported only by the permanent wall, and another permanent wall built upon and supported only by said bridging means 15Q and extending substantially the full width of both walls.

26. A permanent wall providing sockets having ashoulders, a replaceable wall having shoulders corresponding to the sockets of the permanent walkmetal links having abutments cooperating with the shoulders of the walls to prevent separation of the walls in a transverse direction, and

a the links being loose in the sockets to permit their ing shoulders, a replaceable wall having shoulders corresponding to the sockets of the permanent wall, metal links having abutments cooperating with the shoulders of the walls to prevent separation of the walls in a transverse direction, and

the links being loose in the sockets to permit their free motions to compensate for corresponding expansion motions in the replaceable wall, the

vertical heights of the shoulders of the sockets of the permanent wall and the heights of the corresponding abutments being such that the links can be raised and Withdrawn in a horizontal direction without dismantling or changing any portion of the permanent wall, and the sockets being so formed that the links can be dropped into them during formation of the wall.

MICHAEL LIPTAK.