Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS1601519 A
Publication typeGrant
Publication dateSep 28, 1926
Filing dateJul 16, 1925
Priority dateJul 16, 1925
Publication numberUS 1601519 A, US 1601519A, US-A-1601519, US1601519 A, US1601519A
InventorsYoung Christian
Original AssigneeYoung Christian
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Door construction
US 1601519 A
Images(8)
Previous page
Next page
Description  (OCR text may contain errors)

Sept. 28 1926.

C. YOUNG DOOR CONSTRUCTION 1925 8 Sheets-Sheet 2 INVEN TOR.

flfimmzianyzny a \g@ AT 0 N Y.

Filed July 16 Sept. 28 1926.

boon coris'raucnou Filed July 16, 192s C. YOUNG 8 Sheets-Sheet 5 N VEN TOR.

Sept. 28,1926. 1,601,519

' C. YOUNG DOOR CONSTRUC'II 0N Filed July 1a. 1925 a Sheets-Sheet 4 1 n/ INVENTOR. 1/4 1'. Q5 4 flrzs'lmn @92 2; I

1 BY 4-41 1-62 M 4 1 ATTORNEY.

1,601,519 c. YOUNG DOOR CONSTRUCTION Filed July 16. 1925 s sheets-sh t 5 Sept. 28, 1926.

Sept. 28 1926. 1,601,519

, C. YOUNG DOOR CONSTRUCTION Filedduly 16, 1925 8 'Shee1s-Sheet e I N VEN TOR.

Sept. 28 1926. 1,601,519

7 c. YOUNG DOOR CONSTRUCTION Filed July 16, 1925 a Sheets-Sheet 7 I N VEN TOR.

ATTORNEY.

Se t. 28, 1926.

c. YOUNG DOOR CONSTRUCTION Filed July is,

8 Sheets-Shea 8 a w W lh y w nn l knn. n 5 I 1 7/ w n hwfluuwufivn Hul t INVENTOR i X 25W M, ATTORNEY.

Patented Sept. 28, 1926 res st-9 CHRISTIAN YOUNG, OF DETROIT, MICHIGAN.

DOOR CONSTRUCTION.

Application fi led July 16, 1925. Serial No. 44,084.

This invention relates to a door construction, and-more particularly to a door which is commonly known as a fire-proof door. This term iire=proof is only a relative one, as such doors, .lrnown as fire-proof doors, merely serve as fire retarders; .that is, they retard the fire from breaking through the door for a considerable length of time, though if thesedoors are exposed to an in- .tenseheat for a long period of time they will finally break down.

It is the object of this invention to so construct a door as to prolong the usefulness of-the door when the same is exposed to an intensive heat. This result is preferably obtained by building a double door structure .whichis permitted to have relative movement between the parts, therebyallowing the outer part of the dooradiacentthe hot or intense heat to'eXpand and warp without affecting the inner door construction. This nner door structure, of course. will in .time give wayybutdue to the fact thatitis V protected first by the outer door, and secondly, bythe nsulation which may be interposed between the two door structures, its life is very much prolonged. This inner door structure will probably notbe heated-t such an extent as to causethe same to warp or distort until the outer door structure is broken down.

A. further object is the pro-vision of an air passageway through the door structurewhi ch permits the circulation of the airthrough the interior of the door, thus serving to-cool the innerdoor structure and prolong the'life of the door. 7

An advantage of this construction is-that the door, comprising inner and outer door structures, is very easily assembled as the different parts are arranged to fitwith each other in such a way as to permit a bolt to tie the same all together.

In the drawings:

Fig. 1 is an elevation of a door-provided with solid metal panels.

Fig. 2 is an elevation of the-door in which the upper half is provided .-with a glass panel.

Fig. 3 is a section on the line 3.3 of Fig. 1.

Fig. 4 is an elevation of the doorstructure with the panels removed.

Figs. -5 and 6 are sectional views taken on the lines 5-5 and. 66 of'Fig. 2.

-Fig. 7 is apartial elevation of -the door,

construction which shows the inner door frame where a glass panel is incorporated in the upper portion of the door.

Figs. 8 and 9 are sectional views taken on the lines 88 and 99 of Fig.2, respectively.

Fig. lOis a perspective view of thegusset member included in the inner door structure, showing the vent openings whiclnpermit air-to enterinto the interior of thedoor posts.

Fig. 11 is a sectional view through aframe member of the outer door post.

Fig. 12 is a sectionalview of a locking strip.

Fig. 13 is a section through the frame member of one of the inner door posts shoring the reinforcements.

Fig. 14 is a sectional View showing the reinforcements incorporated .between. the in ner and outer door structures for supporting hardware secured to the door at this point.

Fig. 15 is a sectional viewtaken onthe line 1515 of Fig. 2.

Fig. 16 is a section view on the line 1616 of Fig.2.

Fig. 17 is a perspective view ofa portion of the frame of the inner door post.

Fig. 18 is a view in elevation of the inner door structure of alarge size door.

Fig. 19 is a view in elevation of a completed large size door.

Fig. 20 is a section taken. on the line 20 20 of Fig. 19.

Fig. 21 is a section taken on the line 2l 21 of Fig. 19. p This door is built preferably out of relatively thin gauge sheetmetal an d-is built as a double door with independent inner and outer door structures.

The inner door frame is preferably con- .structed of a plurality of hollow rectangular frame members (1 provided with reinforcements 2O andwhich I term the inner door post. These frame members are folded and bent so as to providethe flanges b which are spaced as shown in Figs. 13 and 3. These hollow frame members extend vertically and serve as vertical door posts for the inner door structure. Fitted over this inner. door post of the inner door structure is another rectangular hollow member 0 which is provided with the inwardly turned back flanges d; I preferablyterm this the outer door post. Asbestos or .other insulating material, e, is fitted between the walls of these two llO ' flanges 9 arranged frame members and serves to provide a bet ter insulation between the two door posts than could be had by merely an air space. Preferably he asbestos is cemented to the outside of frame members a (see Fig. 13).

In order to secure these t v0 frame members together and to lock the sam. in spaced relation with each other, it provide a. thenneled locking strip 7 (see Figs. 3, i and 152) which is provided with the turned over to interlock with the turned over flanges (Z carried by the outer frame member or outer door post 0. shown in Fig. 4 these channeled loch strips are made in sections and of various lengths. Some of these locking strips as shown in Fig. 10, are provided with an er:- tended web portion h, while the nth provided with short web portions These locking strips are attached to the outer door post as above described, the different sections being fitted together as shown-in Fig. 4:. which provides deep webs at the top and bottom and the middle point serving as gussets and with small or shallow webs in between. The inner door post is preferably assembled to the outer door post the locking strips have been secured thereto by simply sliding the inner post in lengthwise into the outer post.

Fig. t shows an inner door which is built specially for a no glass panels. When a glass panel is incorporated in the upper part of the door these deep web portions h are omitted at the top of the door and the deep web at the middle point of the door is cut square on one end, as the glass is square and must lit in the panel and not be obstructed by a gusset member, (see Fig. 7

In a door structure, as shown in Fig. 4, 1 construct two of these door posts which are identical in form, but one is a right-hand post and the other is a leftdiand. post. To connect these door posts I proviee the cross beams j, preferably in pairs at the top and bottom and the middle point. These cross beams are folded as clearl shown in F- 9, into grooves and ridges for materiall strengthening the same, and are bolted to the posts by means of the bolts which pass through these cross beams and the web portions of the channeled locking strips 72. Also as shown in Fig. 16 it will be seen how some of the bolts 70 pass through the flanges 79 carried by the inner frame member as well as through the web of the locking strips. The diagonal braces 1% may be utilized for further reinforcing the door structure. It will be noticed that where the channeled locking strips are ohamfered,

off as at n (Figs. i and 10) there is provided an air opening 0 which permits air to enter into the inte tor of tie door posts. It will be noticed that these air openings oowill now be described.

door having cur at the corners of the door structure, and this permits a complete circulation of air through the posts. Also these openings permit the diagonal braces to enter into the interior of the door posts to be secured to the posts by the bolts 7c-a.

The inner door structure is now complete and the outer door structure is assembled to this inner door structure in a way that The outer frame member 0 is in reality a part of the outer door structure, although it is first assembled to the frame members a, while the innor door structure is being built. The top and bottom of tl ese door posts are constructed as shown in Fig. 16, where the out- Side walls of the outer frame member are bent over at the top and bottom, the meeting edges being lock-seamed together as at p.

The next step in the assembly of the door is the securing of the metal rail 1 to this inner door structure (see Fig.2). In the detailed sectional views, Figs. 5, 8 and 9, I show a door which is provided with a glass panel 25 in the upper half. This necessitates a slightly different construction than if all metal panels are used. Refer to Fig. 15. Fitted over the top cross beam 'j is a rail structure made up of the two rail sections 7" joined together on the inside by the channel-ed locking strip 14, which is constructed somewhat similar to the locking strips f, but as shown in Fig. 5, it will be seen thatthe web o is offset from the center line and also carries the relatively heavy reinforcing strip 20 which is bolted or riveted to the strip. The locking strip a is also provided. with the turned back flanges which interlock with the turned back flanges carried by the rail sections r, as shown at a; 5). These rail sections 7" are connected to gether first by the locking strip a forming a U-shaped panel structure and then slipped over the top cross beam j, the upper free edges of said rail sections r being turned over and-interlocked together as at g This will securely lock this rail structure'to the inner door structure and hold the same in spaced relation therewith as the hollow rail 1* fits closely over the lower portions o@ of the cross beams 7', which are spaced apart.

In Fig. 5 I show a reinforcement strip 1 which extends along the top of the door and is supported by the turned on portions of the cross beam j. It will be noticed that this reinforcement strip is practically wide as the door is thick. and of course it will properly space the rail sections 1* with respect to the cross beam of the inner door.

The rail sections 3 (see Fig. 9) are se cured over the cross beam j at the middle point of the door in son'iewhat' similar manner, the difference being that the free edges of said rail sections are not lockseamed together as at the top of the door,

loo

til

'VVhen these are bolted together by means but are folded-in along one edge, here shown along the bottom edge, to provide the flanges 4 lying in the plane of the door, but set in from the face of the door. The panels 4* are slipped in between these flanges 4t and the portion 11-64 of the cross beam j. The moulding lock strip 5 is assembled therewith on both sides of the door and the bolts 8 are passed through these locking strips 5, flanges 4, panels 4 of the rail sections and the cross beam j, and when these bolts are tightened down all these members are secured together. I provide two panels 4 which are spaced apart, each lying adjacent to one of the cross beams j, the spaced cross beams thereby spacing the panels. Preferably I put in the space between the panel 4*, asbestos or other suitable insulation t and preferably provide an air space 4 between the two panels. These moulding lock strips 5 serve merely to provide means by which the moulding 6 may be secured to the door. These mouldings serve only as decorative parts of the door, and with the construction shown here, these mouldings are very easily assembled to the door.

here a glass panel is used, I provide a different means for securing the moulding about the glass panel. This is clearly shown in igs. 8, 5 and 9, and show a combination window channel and moulding. The same is made in two partsone part positioned on one side of the window and the other part positioned on the opposite side of the window. One of these n1ould ing strips designated 7 is adapted to be secured to the door by driving the flange 8 carried by the moulding strip in between the turned-in flange of the panel section 3 and the reinforcing strip to. IVhen this moulding strip is driven home it will be noticed that the inner end of this flange 8 is bent over as at 9, which of course, securely locks the moulding in place. The other moulding 7 on the opposite side of the window is secured in a very similar manner and the inside edge of said moulding strip is turned back against the glass and then under the edge of the glass as at 10 where it will engage under the flange 10 carried by the first mentioned'strip. The glass is fitted in the channel formed by these moulding strips, but the glass may be readily removed if it becomes broken by prying out and removing these moulding strips. Fig. 8 shows a slightly different construc tion, in which the same principle is em loyed with only minor structural changes.

In Fig. 6 I show a section through a part of the glassportion of the door which shows how the glass maybe divided into smaller panels. This shows a moulding and channel member formed of two parts 11 and '12.

of the bolt 18 they provide a channel for or other hardware thereto.

1s my purpose to make the inner-door -structure of greatstrengt-h and tosimply provide an outer door structure which may be secured thereto in spaced relation for protecting the inner door structure and prcventing lire from reaching the same until it flrst'breaks down the outer door structure.

However, if this outer door structure were secured to the inner door structure rigidly it would becomewarped and distorted when the outer door structure warps and distorts when exposed to the heat. As I carry the hinges on the inner door structure it is quite essential that this inner door should not warp or distort or be prevented from doing so for as long a time as is possible, as the longer the inner door structure stands up the longer the door will block the travel of the flames.

Fig. let shows how the metal plate 21 may be placed in between the two shell structures where "it is desired to secure a lock or other hardware to the door. This prevents the bending or springing of the thin metal panelof .the door when fastening the lock Fig. shows a hinge 22 secured to the inner door structure,

the said inner door structure being rein- .forced by a plate 23 and the outer shell provided with an opening 24 which permits this hinge to pass through.

To obtain a relative movement between the outer and inner door structures I so secure the same together as above describedas to provide a slight clearance at the joints. For example, F ig. 3 shows how the channeled locking strip 7' and the outer shell 0 of the door posts are connected together by a lock seam joint. There is sufiicient clearance in this lock seam joint so as to allow room for the outer shell to expand without ullin on the inner door structure. In

fact,.the actual door is so designed as to provide suflicient clearance to allow for a movement of approximately of an inch of the outer, door with respect tothe inner door. Theclearance in the lock seamjoint on both sides of the door permits this relative movement, and all this clearance-is taken up before any strain is placed on the inner door. In addition there is clearance between the bolt holes and bolts which secure'the outer panels in place, thus permitting relative movementat thispoint. As the metal inthe outer shell expands, the bolt holes enlarge warping or the outer and provide more clearance which permits more expansion or relative movement between the parts.

It will thus be seen that as the temperature on one side of the door rises the metal of the outer door structure expands due to this heat, and sufiicient clearance has been provided for in the construction of the door and in the joints between the inner and outer door structures so as to permit the outer door structure to become extremely hot heifore any real pull stress is tra -sn itted to the inner door structure. it is believed that such a door eonstr .ction in which there are provided two door structures, an inner door structure entirely enclosed by an out-er door structure, the said outer door structure permitted to have relative movement with respect to the inner coor structure, an aid in prolonging the life of the door. This is due primarily to the fact that the inner door structure is protected and insulated from the heat and also is so connected to the outer door structure that any warping oi the outer door structure is not transmitted immediately to the inner door structure. Such door structure which is due to the expansion is considerable be fore it begins to aiiect the inner door structure. The door is supported by hinges ried the inner door structure so the distorting of the outer door structure will not weaken the door support until the distortion begins to affect or warp the inner door structure. 7

if desired. 1 may enlarge on this plan and construct a door h aving a larger width than the one shown in Fig. l. Figs. 18 to 21 show such door and I here construct a door provided with end pos and intermediate vertical posts, connected together by the cross beams ;)'a and braces m-a. Obviously, I could here more than one intermediate post, depending upon the width of the door required. l. prei'er to construct the intermediate posts similar to the cross beams j/1. The panels would be secured in place the same way as before.

The essential feature governing the large door is that the great width should be properly braced so that the door rill not how or bend. To obtain this end, I provide as many reinroi no: beai'ns ja as is necessary and that portion. the door between the two end posts is assembled in the same manner as described in assembling the two posts in the narrow door. It is quite obvious that such a principle as outlined above which provides a double door structure, consisting of an inner and outer door structure, and which structures have relative movement with respect to each other, could readily be incorporated in a wide door as well as in a narrow door. I

To summarize, 1 provide a door serving as a fire retardant comprising inner and outer door structures, which are secured together in spaced relation with respect to each other. The door structures are properly insulated from each other and are secured together with sufficient clearance so as to permit relative in vement to allow the outer door structure to warp or distort within certain limits without warping or distorting the inner door structure.

Another feature or this corstruction is that i may use copper, b onze other metals in my ou door sir 'zture. metals or other alloys hich migiit used are not required to car any ot the strain of the door support since the l rer door structure is built to carry the load, As a result I am permitted to have wide the kind of metal used in structure.

Preferably I use the fillers 100 to fill up the space il of the veb in the locking strips, see Fig. These fillers comprise a strip of wood sheathing 102. When such a filler is exposed to tire the wood simply chars and does not blaze.

The rails use post. Fig. cle. r y shows this. This shows the rail sect on r turned in as at 80, and which is torn inwardly and is bent over as at 81 in behind the lockseam joint which secures the outer panel 0 of the door post to the locking strip. this way all the the outer door secured to the ad scent outer in outer panels, rail sections and outer post panels are secured to each other.

in 19 to :21 inclusive 1 show details of the assembly of the panels in the large size door. lteiter to Fig. which'is a horizontal section through one of the intermedi ate door posts This intermediate door post similar in cross section to the cross beams j and is designated j b. The intermediate door panels are bent inwardly and then flanged outwardly in the plane of the door, each forming su stantially a Ll-shaped panel structure. The outer flange of these post panels 85 are secured to the panels 88 and to the posts 3 -4) by means of the bolts 84. Moulding strips us are secured to too door str insure the same w strips in the narrow 1 shows the cons ruction tle inter-section between the innediote door post and cross beam 7'a.. The outer rail sections which enclose the cross beam ]'C6 are sir ilar in cross section to the post panel 85, and are designated 90. Each rail section 90 preferably extends from one side of the door to the other. between the two side door posts and is provided with a slot- 91 at tie center having a width approximating the width of the itermediate door post The post panels 85 which enclose this intermediate door post are bent in 93 and provided. with {I asthemoulding .i door. Fig. 21

range in selecting l ll enclosed by the metal the turned out lip 94 which when the post panel 85 forced in, is arranged to spring in the slot 91 and thus secure the post panel 85 in place. The fillers 95 are used to space the two metal forms which whensecured together, form the intermediate door post. Asbestos sheets 96ers also assembled between the inner and outer door structures, as in the narrow door for the purpose ofinsulating the two structures.-

VVhat I claim is:

1. A door for the purpose specified, comprising two independent self-supporting spaced door structures, one of which is located within the other.

2. A door for the purpose specified, comprising inner and outer door structures secured together by joints which permit the structures to have a limited relative move ment bodily in all directions with respect to each other. 7

3. A door for the purpose specified, com prising a metal inner door structure, and a separate metal outer door structure complete in itself enveloping said inner door structure and which is secured thereto.

4. A door for the purpose specified, comprising an inner meta-l door structure, and an outer door structure enveloping said inner door structure and secured thereto, to permit a limited relative movement bodily in all directions between said door structures.

5. A door for the purpose specified, comprising two separate self-contained sheet metal structures secured together one within the other.

6. A door for the purpose specified, comprising twoseparate self-contained sheet metal door structures secured together in' spaced relation one within the other.

7. A door for the purpose specified, comprising an inner rein-forced sheet metal door structure, and an outer sheet metal door structure, said door structures secured together in spaced relation, one within the other but arranged to have a limited relative movement with respect to each other.

8. A door for the purpose specified, comprising two independent self-contained'and self-supporting metal door structures secured together in spaced relation one within the other, and insulation material located between said door structures.

9. A door for the purpose specified, comprising two independent sheet metal door structures secured together one within the other and permitted to'have a limited relative movement with respect to each other, the inner door structure arranged to carry the door hinges for supporting the door, thereby permitting the outer door structure to warp or expand relative to the inner door structure.

10. A door for the purpose specified, comwhich comprises anjoining said door and an outer door structure which tion with said door prising two independent sheet metal door structures secured together one within the other and permitted to have a limited relative movement with respect to each other, the inner door structure provided with reinfo'cements at the point of attachment of hardware fixtures.

11. A'door for the purpose specified, which comprises an inner door structure which includes a door post provided with spaced flanges along the inside edge, and an outer door structure which includes a door post open along the inside edge to permit the spacing flanges. carried by the inner door post to project therethrough, a locking strip provided with a hollow web arranged to fit over said spacing flanges and secured to the free edgesof said outer door post to close the opening inthe door post of the outer door structure, and a panel secured to the web portion of said locking strip.

12. A door for the purpose specified, inner door structure having an inner door post, an outer door structure which includes an outer door post which encloses the inner door post, a panel, and locking means for securing the outer door post and panel together and to the inner door post but permitting relative movementtherebetween.

13. A which comprises an inner door structure, and an outer door structure which includes a door post and panel, and means-for loosely post and panel together but which permits relative movement therebetween.

14. A door for the purpose specified, which comprises" an inner door structure, includes a door post and panel, and a locking strip having a relative loose lock seam connec post and secured to said panel for the purpose of tyingthe panet and door post together but permitting relative movement therebetweenx 15. A door for the purpose specified, comprising. an inner door structurewhieh includes inner door posts and cross beams connecting the posts and both formed of sheet metal and an outer door structure which includes sheet metal door posts and panels joined together and to said inner door structure. and enclosing the same and which are permitted to move bodily relative to said inner door structure and to each other.

16. A door for the purpose specified, comprising an inner door structure which includes an inner door post provided with inwardly projecting spacing flanges and reinforcing cross beams, and an outer door structure which includes a panel and an outer door post arranged to be fitted over the inner door post and locking strips secured to said outer door post and provided with a door for the purpose specified,

lll]

intorcing web fitting over said spacing flanges, said locking strips formed in sections, some 0 said sections having relative deeper web portions, the said cross beams secured to said deeper web portions and to the spacing flanges of said inner door post.

17. A loor for the purpose specified having a glass panel, which includes inner and outer door posts, a locking strip "for securing the inner and outer doors posts together and which permits relative movement therebetween, said locking strip provided with a restrip extending longitudinally thereof, and combined moulding and window channel member secured to said door posts.

18. A door for the purpose specified, comprising an inner door structure which includes door posts and cross beams secured thereto, and an outer door structure, which includes sheet metal rails secured together along one edge and arranged to enclose said cross beams, the panels folded along their free'edges over the cross beam and secured together.

19. A door for the purpose specified, comprising an inner door structure which includes door posts and cross beams secured thereto, and an outer door structure which includes sheet metal rails, a locking strip for tying apair of said rails together in spaced relation along one edge to form a rail structure substantially U-shaped in cross section and arranged to be fitted over one of said cross beams, and the free edges or" said U-shaped rail structure folded on over the cross beam and secured together to enclose the cross beam of said inner door structure, and means for securing said U- shaped rail to a next adjacent panel.

20. A door for the purpose specified, comprising an inner door structure which includes door posts and cross beams secured thereto, and an outer door structure composed of sheet metal panel strips, locking strips each tying the panel strips together in pairs and in spaced relation along one edge to form rail structures shaped in cross section and which are arranged to be fitted over the cross beams and folded in over the cross beams, the free edges of said U-shaped rail structures secured together to enclose said cross beams, said locking strips provided with projecting webs, and panels secured to said webs.

21. A door for the purpose specified comprising an inner door structure having inner door posts, and an outer door structure consisting of a plurality of panels and outer door posts secured together and to the inner door structure, said outer door posts enclosing said inner door posts while the panels span the gap between the door posts and are spaced apart to provide an air space, said door posts provided with air openings which connect the interior of the said inner door posts with the air space between the vanels which permits the circulation or" air through the interior of the door.

22. A fire door comprising an inner door structure and an outer door structure, means for locking the door structures together, this locking means consisting or joint forming members which permit relative movement between the inner and outer door 23. A fire door comprising an inner and an outer door structure secured together in spaced relation, the inner door having an air space formed therein, and means permitting circulation of air from the interior of the inner door to the space between thetwo door structures.

24. A fire door comprising an inner door structure and an outer door structure.means for securing these doors together in spaced relation the said inner door structure being formed to provide an air chamber therein, a part of the said securing means being open to connectthe space between the doors and the air space within the inner door to permit circulation of air.

In'testimony whereof I have afiixed my signature.

substantially U CHRISTIAN YOUNG.

structure.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3599703 *Mar 17, 1969Aug 17, 1971Mennuto Anthony RInsulated storm door assembly
US4897975 *Oct 23, 1987Feb 6, 1990Odl, IncorporatedIntegral door light with glazing stop
US4920718 *May 1, 1989May 1, 1990Odl, IncorporatedIntegral door light and related door construction
US5438808 *Feb 9, 1994Aug 8, 1995Costello; JamesWood-surfaced door
US6622449Jan 29, 2002Sep 23, 2003Mdf, Inc.Door panel and method of forming same
Classifications
U.S. Classification49/501, 52/302.3, 52/784.13
International ClassificationE06B5/10, E06B5/16
Cooperative ClassificationE06B5/16, E06B5/162
European ClassificationE06B5/16B, E06B5/16