Spindle staircase

Abstract

Conventionally a spindle staircase is mounted in the building in the course of construction so that fine, for example, hard-wood steps may be damaged or be at least soiled with building material on account of rough treatment. Cleaning of the steps requires much labour and time. If during the building operations steps are damaged, they have to be replaced by new ones, resulting in high costs. These problems are avoided by first fastening provisional step units formed each by a working step and a step support secured thereto in a detachable manner to the spindle and by replacing these provisional step units afterwards by new ones.

Description

The invention relates to a method of mounting a spindle staircase in a building, said staircase comprising a spindle and a plurality of steps, each of which is secured to the spindle by means of a step support.

In the prior art method the spindle staircase is mounted in the building in the course of construction so that fine, for example, hard-wood steps may be damaged or be at least soiled with building material on account of rough treatment. Cleaning of the steps requires much labour and time. If during the building operations steps are damaged, they have to be replaced by new ones. From the aesthetical point of view it cannot be allowed to insert screws into the steps from the top side. For this reason screws are inserted into the steps from below in order to fasten them to the step supports, which is a troublesome operation: it is not possible to use strong screws which require a heavy pressure for screwing into and out of the wood.

The invention provides a method of the kind set forth, which dissolves the aforesaid problems by first fastening provisional step units formed each by a working step and a step support secured thereto in a detachable manner to the spindle and by replacing these provisional step units afterwards by new ones. Because the step is screwed to the associated step support when the step support is not yet fastened to the spindle, screwing may be carried out in an upside down position of the step unit so that rugged screws can then be readily inserted by heavy pressure into a hard-wood step.

The invention provides furthermore a set of provisional step units each consisting of a working step and a step support secured thereto, characterised by securing means for securing said step unit detachably and provisionally to a spindle of a spindle staircase. This set can be repeatedly employed for mounting spindle stairs of the same type.

In addition the invention provides a spindle staircase at least comprising a spindle built up from spindle sections and a plurality of steps, each of which is fastened by means of a step support in a detachable manner to a section of the spindle, said staircase being particularly suitable in carrying out the method according to the invention, because the step support comprises a step holder secured to a spindle section and manufactured like said spindle section by casting of spray-casting. Casting or spray-casting enables accurate manufacture of spindle section and step holder accurately registering with each other. The spindle section and the step holder may be manufactured as a single casting, in which case the step support is preferably formed by a profiled bar secured to the step and adapted to be detachably fastened to the step holder.

The spindle sections and/or the step holders are, for example, made of aluminum or nodular cast iron, but preferably of malleable cast iron (temper iron). The detachable connection between the step holder and the spindle section is particularly simple and rigid, when one of the two connecting elements has at least one pin and the other connecting element has at least one recess matching said pin.

Preferably one connecting element has two conical pins whereas the other connecting element has two matching conical recesses, whilst the step holder is connected with the spindle section not only by means of said pin-recess connection but also by a safety screw.

The staircase comprising at least a spindle built up from spindle sections, a plurality of steps and a plurality of profiled bars each secured to a step and each engaging in a detachable manner a gutter-shaped step support of a spindle sections is improved according to a further development of the invention in that each profiled bar extends as fas as into the spindle. In this case the gutter-shaped step support may be shorter so that material is saved, whilst casting of such a spindle section is facilitated. Moreover, this spindle staircase has a more beautiful appearance, whilst adequate rigidity is maintained.

In order to further simplify the shape of the spindle sections each profiled bar is in abutment with the lower rim of the superjacent spindle section.

The exchange of steps can be very readily carried out, if at least one transverse strip welded to each profiled bar is fastened by means of at least one bolt to the guttershaped step support of a spindle section.

A rattle-free, simply mounted spindle staircase is obtained when each profiled bar bears in at least two internal ridges of the gutter-shaped step support made to measure after casting.

The aforesaid and further features of the invention will be explained more fully in the following description of an embodiment of the spindle staircase in accordance with the invention with reference to a drawing.

In the drawing:

FIG. 1 is a perspective view of a preferred embodiment of spindle stairs in accordance with the invention,

FIG. 2 is an enlarged elevation partly broken away of the lower end of the spindle stairs shown in FIG. 1,

FIG. 3 is a sectional view taken on the line III--III in FIG. 2,

FIG. 4 is a sectional view taken on the line IV--IV in FIG. 2,

FIG. 5 is an enlarged perspective view of the dismounted parts of a step of the spindle stairs shown in FIG. 1,

FIG. 6 is an enlarged, perspective view of a detail of the spindle of the spindle stairs shown in FIG. 1 with mounting tools,

FIGS. 7 and 8 show tools for orientating the cast spindle sections and step holders,

FIGS. 9 and 10 show each a detail like that of FIG. 2 for two variants of the spindle stairs in accordance with the invention,

FIG. 11 is a plan view, partly broken away, of the detail of FIG. 10,

FIG. 12 is a vertical sectional view of part of a spindle and the two steps of a further developed spindle staircase embodying the invention,

FIG. 13 is an enlarged perspective view of the dismounted parts associated with a step of the spindle staircase shown in FIG. 12,

FIG. 14 is an enlarged sectional view taken on the line XIV--XIV in FIG. 12,

FIG. 15 is an enlarged sectional view taken on the line XV--XV in FIG. 12,

FIG. 16 is a plan view of a casting for a spindle section still to be finished of the spindle staircase of FIG. 12,

FIG. 17 is a sectional view taken on the line XVII--XVII in FIG. 16, and

FIG. 18 is a sectional view taken on the line XVIII--XVIII in FIG. 16.

The spindle staircase 1 of FIG. 1 comprises a spindle 2 built up from alternately piled spindle sections 3 and 4 and a plurality of steps 5, each detachably fastened by means of a step holder 6 to a connecting element 7 rigidly secured to the former and to a connecting element 8 rigidly secured to the spindle section 3. Each step holder 6 and each spindle section 3 together with an integral connecting element 7 and 8 respectively are manufactured by casting or spray-casting.

Each spindle section 3 comprises a casting having a cylindrical sheath 9 having annularly recessed rims 11, which engage the adjacent rims 12 of the spindle sections 4 formed in the shape of spacer sleeves.

Each spindle section 3 formed by a single casting comprises furthermore a transverse wall 13, a console 14 with two conical pins 15 at right angles thereto, the diameter of which decreases towards the free top end. The console 14 and the two pins 15 form together the connecting element 8 integral with the spindle section 3. The other connecting element 7 integral with the cast step holder 6 has two conical recesses 16 matching the pins 15. The connecting elements 7 and 8 are interconnected not only by said pins 15 and recesses 16 but also by means of a safety screw 17, which is countersunk in the console 14 and engages a tapped hole 19 of the connecting element 7.

The direction of the step 5 with respect to the spindle section 3 is completely determined by the accurate match of the pins 15 and the recesses 16. On the outer side the connecting elements 7 and 8 fit one into the other as is shown in the drawing -- be it with a slight amount of clearance 20 -- so that a smooth appearance of the transition from the spindle section 3 to the step holder 6 is obtained. The step holder 6 has a channel-section profile tapering towards its free end and having stiffening ridges 21 forming a elongated, three-sided gutter 25 for accommodating a profiled bar 22. During the casting operation the step holder 6 is provided with ears 23 having holes 24 and with a tongue-like cam 26 having a downwardly extending extension 27. The extension 27 is engaged in an opening 28 of the profiled bar 22 formed by a square-section tubing.

The end 29 of the step 5 remote from the spindle 2 is held via the profiled bar 22 on the step holder 6 and is secured to the profiled bar 22 by means of a bridge piece 30 made by casting, having holes 31 for passing the bridge piece 30 and screws 32 of the step 5 and having a bearing 33 matching the profiled bar 22 and engaging the latter.

In the spindle staircase 1 shown in FIGS. 1 to 9 and in FIGS. 11 and 12 the profiled bar 22 and a step holder 6 constitutes together a step support. Such a step support together with a step 5 constitutes a step unit 37.

A step unit 37 is assembled as follows. A fine step 5, for example, a hardwood board or a slab of natural stone, metal or other material is screwed by its end 29 to the bridge piece 30. A profiled bar 22 is put into the gutter 25 of the step holder 6, the opening 28 engaging the extension 27 of the cam 26. The profiled bar 22 is arranged around the bearing 33 and the step 5 is secured to the step holder 6 by means of screws 34 and 35 passed through holes 24 and extending through holes 36 registering with the recesses 16.

The spindle 2 is assembled as follows. A castiron foot plate 38 is put in a horizontal position and secured by bolts 39 to the floor 40. The foot plate has a collar 41, around which grips a spindle section 42 formed by a short tubing and a central tapped sleeve 43 receiving a bolt 44, the head 45 of which engages the transverse edge 13 of the spindle section 3, which is previously put down on the spindle section 42 and is orientated by its connecting element 8 in the required direction. Then a long spindle section 4 is arranged on the spindle section 3 and a spindle section 3 is put down on the former. The alignment of every further spindle section 3 is performed by means of tools 46 (FIG. 6) formed by a horizontal foot 47 having two conical recesses 48 fitting to two pins 15 and a vertical bar 49 fastened to the foot and fitting in a hole 18 and being displaced through an angle a with respect to the centre b between the recesses 48. The angle a is equal to the required tread angle of the steps 5 of the spindle staircase 1. The foot 47 is fitted by its recesses 48 to the pins 15 of the spindle section 3 previously fastened and the next-following spindle section 3 is slipped by the hole 18 onto the bar 48. After tightening a bolt 50 in the head 45 of a lower bolt 44 the spindle section 3 is rigdly secured to the subjacent portion of the spindle 2 with the required accurate angular displacement a. In this way the spindle is built up stepwise and preferably crowned with a spindle section 51 in the form of a pole, which serves as a support for banisters (not shown). The upper spindle section 52 is secured to a ceiling 56 by means of a supporting plate 53 and bolts 54 and 55.

In the method according to the invention first provisional step units 37 having ordinary steps, for example, of deal are secured to the spindle 2 for use during the building operations by slipping the step holders 6 thereof onto the pins 15 and by screwing in the safety screw 17. After the completion of the building and, as the case may be, after the installation of furniture said provisional step units 37 having the function of working steps are replaced by new step units 37, the steps 5 of which are made of fine hard-wood.

The spindle sections 3 and 52, the step holders 6 and the bridge pieces 30 are preferably made of malleable cast iron (tempered iron). They are cast in a conventional manner in sand moulds and annealed by a tempering annealing process and subsequently aligned.

FIGS. 7 and 8 show each a stationary die table 58, to which a lower die 59, 60 is secured for receiving a step holder 6 and a spindle section 4 respectively and an aligning die 61, 62 pushed downwards for aligning the step holder 6 and the spindle section 4 respectively.

With spindle stairs 1 for various storeys the same spindle sections 4 are employed and the lengths of the spindle sections 3 for different spindle stairs 1 are adapted to the relevant heights of the storeys.

The spindle 2 can be readily mounted in the factory together with the foot plate 38 and be transported as a whole to the building site, the space occupied in transport being small. The step units 37 can be suspended in situ to the erected spindle 2.

In the variant shown in FIG. 9 one connecting element 8 having two pins 15 is cast integrally with the step holder 6, whereas the other connecting element 7 having recesses 16 matching the pins 15 is cast integrally with the spindle section 3. A safety screw 17 extends through a hole of the connecting element 7 and is screwed into the connecting element 8.

In the variant shown in FIGS. 10 and 11 the step holder 6 and the spindle section 3 form part of one casting 63 so that they can be accurately aligned relatively to one another by means of dies as described above. The detachable step unit 65 illustrated in FIGS. 10 and 11 comprises a step 5 and a profiled bar 22 forming a step support and secured to said step by means of the above-mentioned bridge piece 30. The profiled bar 22 is furthermore fastened to the step 5 by means of wood-screws 64. The step unit 65 can be readily secured to the step holder 6 by slipping the profiled bar 22 into the gutter 25 of the step holder beneath the cam 26 and by inserting finally a single screw or pin 66 through holes of the profiled bar 22 and of the step holder 6.

The bridge piece 30 has an ear 67 projecting from the step 5 and having fastened to it a baluster 68 of a handrail (not shown) by means of a screw member 69 fastened in the baluster 68 and of a cap nut 70.

FIG. 12 shows that a channel-section connecting element 8 may have two flanges 71 on each spindle section 3, said flanges being connected with the flanges 72 of the channel-section connecting element 7 of the step holder 6 by means of a tapped sleeve 75 to be passed through the flanges 71 and 72 and of a shoulder screw 79 to be screwed into the tapped sleeve 75. The connecting element 7 of the step holder 6 bears on a stop rim 73 as well as below on a stop rim 80 of the spindle section 3. A hard-wood step 5 is preferably fastened to the step holder 6 and the bridge piece 30 respectively with the interposition of a rubber layer 81 and rubber rings 76 to reduce the transfer of body sound as is shown in FIG. 12 whilst rubber washers 79 are arranged around the screws 64 and 32.

Within the scope of the invention various modifications of the embodiments described and shown are possible. For example, each spindle section 3 may have two diametrically opposite connecting elements 8 so that a twin staircase is obtained by fastening steps of two helical runs to one and the same spindle.

The pins 15 of the connecting elements 8 and the matching recesses of the connecting elements 7 may have a pyramidal shape rather than a conical form, for example, they may have the shape of a truncated cone of rectangular or dovetail-shaped section.

Whilst for mounting the spindle 2 in the building it is preferred for the spindle to have a series of inter-screwed bolts 44, it is possible in prefabrication to use a bolt covering the whole length of the spindle, the spindle sections 3 being then arranged in the prescribed positions by means of a jig covering the length of the spindle 2.

The spindle staircase 1 shown in FIGS. 12-16 comprises a spindle 2 built up from alternately stacked spindle sections 3 and 4 and a plurality of steps 5. Each step 5, which may be made of wood, is fastened by bolt screws 32 and has two transverse strips 82 and 83 welded to a profiled bar 22 having a squaresection hollow profile. The step 5 has recesses 84 and 85 on the bottom side for receiving the transverse strips 82 and 83. The step 5 together with the profiled bar 22 constitutes an exchangeable step unit 65, which is detachably fastened in a gutter-shaped step support 16, which is united with the spindle section 3 in a single casting 63. The casting has at the free end and at the centre of the step support 6 internal ridges 86 and 87, which are accurately planed or milled to measure subsequent to casting along the broken lines 88 for a rattle-free accomodation of a profiled bar 22.

The profiled bar 22 extends as far as into the spindle 2 and butts against the lower rim 89 of the superjacent spindle section 4.

The profiled bar 22 guided in the step support 6 is secured to the step support 6 by means of hollow screws 90 extending across external ears 91 of the step support 6 into tapped holes 92 of the transverse strip 83.

Claims

What we claim is:

1. A spindle staircase comprising:

a. a spindle having a plurality of spindle sections;

b. a step holder attached to at least some of said spindle sections, said step holder having an elongated, three-sided gutter and tongue-like cam;

c. a detachable step support having a bar and integral bridge piece, said bar being received in said step holder gutter and fitting with said cam;

d. means for locking said bar in said gutter; and

e. a step connected to said step support by screws hidden from view at the top side of the step;

whereby said step support with connected step is easily removable by releasing the means for locking, and said step may be conveniently replaced by mounting a new step to said step support at a convenient work area.

2. A spindle staircase as claimed in claim 1 in which said step holder and attached spindle are an integral casting.

3. A spindle staircase as claimed in claim 1 in which said step holder is detachably connected to said spindle sections by recesses on said step holder and matching pins on said spindle section, said recesses and pins being locked together by screws.

4. A spindle staircase comprising:

a. a spindle having a plurality of spindle sections, at least some of which have a first channel section connection element as an integral part thereof;

b. a step holder having a gutter and a second channel section connection element, said first and second channel section elements mating and being locked together by a single locking screw to form a detachable connection between said step holder and said spindle sections with first channel section elements;

c. a step support having a bar and a transverse metal strip at one end thereof said bar being received in said step holder gutter; and

d. a step connected to both said metal strip of the step support and said step holder by screws hidden from view at the top side of said step;

whereby said step holder with attached step and step support is easily detachable by removing said locking screw, and said step may be easily replaced by mounting a new step to said step support and step holder at a convenient work area.

5. A spindle staircase comprising:

a. a spindle having a plurality of spindle sections;

b. a step holder attached to at least some of said spindle sections, said step holder having an elongated, three-sided gutter;

c. a detachable step support having a bar and integral bridge piece, said bar being received in said step holder gutter;

d. means for locking said bar in said gutter; and

e. a step connected to said step support by screws hidden from view at the top side of the step;

whereby said step support with connected step is easily removable by releasing the means for locking, and said step may be conveniently replaced by mounting a new step to said step support at a convenient work area.