EP0353360A1

EP0353360A1 - Combined floor pedestal and floor outlet

Info

Publication number: EP0353360A1
Application number: EP88307224A
Authority: EP
Inventors: Chien-Teh Huang
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-08-04
Filing date: 1988-08-04
Publication date: 1990-02-07
Anticipated expiration: 2008-08-04
Also published as: DE3885276D1; ATE96492T1; DE3885276T2; EP0353360B1

Abstract

A combined floor pedestal and floor outlets which include a base drum 1 and a support drum 2 interconnected by an adjustment sleeve member 4 which is sleeved around and threadedly connected to the base drum and a support drum. The support drum 2 has a top annular bearing face 23 with grooves 25 and projections 27 to support and engage with floor rails and receives a plug body 3 which has sockets 33, 34 35 mounted thereon to be used for electrical connection on the floor. The support drum 2 is also provided with socket means 51 connected to the sockets of the plug. The assembly is convenient for making height adjustments as well as electrical connection.

Description

This invention relates to a raised false floor set up in computer and control rooms, and particularly to a combined floor pedestal and floor out assembly for supporting floor rails which in turn hold floor panels.
Pedestal assemblies for supporting a raised false floor exist various forms in the prior art. U.S. Patent No. 4,438,610 discloses a pedestal assembly which includes a height-adjustable, telescopic shaft of two sections with an enlarged base and a top bearing plate with a clamping means to support and clamp floor panels. Such a pedestal assembly is found to be disadvantageous since the telescopic shaft, which is slim and threaded, and the bearing top plate are susceptible to damage when subjected to heavy loads, especially when the base floor below is uneven. Furthermore, it is inconvenient to adjust the height of the pedestals after the panels are installed thereon.
U.S. Patent Number 572836 to Sorsoleil and U.S. Patent Number No. 651,511 disclose height-adjustable telescopic pipe constructions to be placed under ground surface for supplying water and gas. These constructions can be adjusted in height to be flush with the ground surface, and are designed to be used as connectors rather than as supports which must usually be adjusted in height after supported elements are mounted thereon.
U.S. Patent No. 3,398,933 discloses a pedestal assembly, as shown in Figure 1, in which a nut is employed to adjust the height of a threaded rod which is inserted slideably in a lower tubular support with a bottom flange. The threaded rod is also provided with a top bearing plate. Such a construction is also weak.
Floor outlets for a raised floor are also known in the arts. U.S. Patent Numbers 1,767,323, 2,996,566 and 3,794,956 disclose floor outlet devices by means of which an apparatus, such as a computor, telephone, telegrpaph instrument, light, etc., may be readily connected with electric conductors disposed under a floor. Such floor outlets generally include a hollow cylindrical support body, and a plug body inserted in the support body in a telescopic manner and having an electric outlet means mounted thereon.
An object of the invention is to provide a combined floor pedestal and floor outlet which has a strong pedestal and a strong bearing face for supporting floor rail and by which additional requirements for installing floor outlets can be eliminated.
Another object of the invention is to provide a combined floor pedestal and floor outlet assembly which is convenient for height adjustment even after floor rails are mounted on the assembly, and which has a height adjustment member capable of changing the height of the pedestal upon slight turning of the adjustment member.
The invention provides a combined floor pedestal and floor outlet which includes upper and lower threaded cylindrical members of enlarged cross-section interconnected by a threaded adjustment sleeve member which is sleeved around the upper and lower cylindrical members. The upper cylindrical member is provided with at its top annular portion radial grooves spaced apart from each other and opening at the periphery and the top face for receiving floor rails and upstanding projections to engage with floor rails. The screw threads on the adjustment sleeve member are arranged such that they can cause the screw threads of the upper and lower cylindrical members to advance simultaneously into the sleeve member. By slight turning of the adjustment sleeve member, the upper and lower cylindrical member can move inwardly or outwardly simultaneously relative to the adjustment sleeve member, changing appreciably the totel height of the pedestal. On the upper cylindrical member is mounted a plug body in a telescopic manner. The plug body includes first electric socket means which are connected with second electric socket means disposed in the upper cylindrical member, thereby enabling the wires below the floor to be connected easily to the electric elements on the floor. The pedestal assembly is particularly so arranged that the height adjustment of assembly can be effected independently of the parts incorporating floor outlet means so that the adjustment therefor does not change the position of the floor outlet means or affect the arrangement of the wiring system below the false floor.
The present exemplary preferred embodiment will be described in detail with reference to the accompanying drawings, in which:

Figure 1 shows a known pedestal assembly;
Figure 2 is an exploded view of a combined floor support and floor outlet assembly according to the invention;
Figure 3 is a fragmentary sectional view of the support member showing how electric sockets thereof are interconnected; and
Figures 4, 5 and 6 show how tests are conducted to investicate the performance of the present invention.

Referring to Figures 2 and 3, there is shown a pedestal assembly according to the present invention which includes a base drum member 1, an adjustment sleeve member 4, a support drum member 2 and a cylindrical plug body 3. The base member 1 has a radially extending bottom flange 11 having four upwardly arched portions 13 each defining a passage 131. Nut 134 and screw 133 are attached to each arched portion 13 to be used for grounding. At the upper portion of the base member is an external right-hand screw thread 121.
The adjustment sleeve member 4 has a cylindrical wall with an upper left-hand internal screw thread 42 and a lower right-hand internal screw thread 43. The lower right-hand internal screw thread 43 is engaged with the external screw thread 121 of the base member.
Above the adjustment sleeve member 4 is the support member 2 which has a lower external left-hand screw thread 21 engaging with the internal left-hand screw thread 42 of the adjustment sleeve member 4. In the peripheral wall of the support member 2 are provided openings 22 at intervals to be used for attachment of electric socket members 51. The socket members 51 are fitted in the openings 22 respectively by means of screws. At the upper portion of the support member 2 is an annular top bearing face 23 and an internal screw thread 24. The top bearing face 23 is provided with four pairs of radial grooves 25 spaced apart from each other, extending radially and opening at the periphery and at the top annular face of the support member 2 for receiving four rails 70. Between each pair of radial grooves 25 is a recessed face 26 on which is disposed an upstanding projection 27 for engaging with holes 71 of the floor rails 70.
The cylindrical plug 3 is fitted in the hole 20 of the drum support, and provided with an external screw thread 31 to engage with the internal screw thread 24. At the top of the plug 3 are disposed electric sockets 34 and 35 which are connected electrically in a conventional manner with electric sockets 51 of the support 2 by means of conductors 52 as shown in Figure 3. A hole 38 is provided on the plug body, through which a grounding wire (not shown) can extend from above the floor to the bottom flange 11 of the base drum 1.
On the plug body 3 is a circular cover plate 32 having a bottom attachment protrusion 321 used to penetrate into a hole 33 of the plug body 3 so as to cover the electric sockets 34 and 35 when no electric connection is desired. A pull ring 322 is attached to the cover plate 32 for ease of uncovering the plug body 3.
It can be appreciated that the assembly according to the invention has an advantage in that the height of the assembly can be adjusted after the floor rails 70 are mounted on the support 2. The adjustment can be effected by turning the adjustment sleeve member 4.
The adjustment sleeve member 4 can make both screw threads 21 and 121 move into or move outward simultaneously when it is turned so that the height of the assembly can be changed appreciably with a slight turn of the adjustment sleeve.
In order to prove that the bearing power of the assembly of the present invention is stronger than that of the conventional assembly shown in Figure 1, the applicant of the invention conducted a series of tests in connection the above two assemblies.

The material used for making the two assemblies is aluminum ( Al-6061, T6) which has a young's modulus of 6.83 x 10⁶N per sq.cm, an ultimate strength of 3.1 x 10⁴N per sq.cm, and a yield strength of 2.75 x 10⁴ N per sq.cm. The yield strength which is lower than the ultimate strength is used for determining the failure of the assemblies. The dimensions and the moments of inertia (I) of the two assemblies are as follows:

	Assembly 1 conventional	Assembly	2 present invention
Outside diameter (cm):	2.87	8.14
Inside diameter (cm):	2.57	7.84
Cross sectional area (cm²):	1.282	3.765
Moment of inertia (cm⁴):	1.185	30.046

Tests were made, using four floor tiles placed side by side adjacent to each other and assemblies 1 or 2 supporting the floor tiles at their corners. A central one of assemblies 1 or 2 is a common support which supported the corners of all four floor tiles. A load of 1500 kgf per sq.in was applied on one of the floor tiles at two locations, one location being at one side of the floor tile (Figure 4) and the other at the center of the floor tile (Figures 5). The load acting on the central assembly for the case of Figure 4 and 5 were determined by computer analysis. The results of the determination showed that the load acting on the central assembly was 28,756 N for the case of Figure 4 and 14,700N for the case of Figure 5.
While applying the load, a maximum stress occured at the lower portion of each assembly 1 or 2. The maximum allowable height of the central assembly 1 or 2, and the maximum allowable inclination of the floor on which the central assembly 1 or 2 rested, were determined by varying the height and the inclination and estimating the maximum stress (σ_max) produced in the central assembly 1 or 2, using the expression:
σ_max = -P cosϑ/A + (P sinϑ . 1. r)/I
where P is the load acting on the central assembly 1 or 2, ϑ is the inclination angle of the floor, 1 is the height of the central assembly 1 or 2, A is the cross section of the central assembly 1 or 2, r is the outer radius of the central assembly 1 or 2, and I is the moment of inertia of the central assembly 1 or 2.

Figure 6 illustrates schematically the central assembly 1 or 2 which is placed on an inclined floor. Tables 1 and 2 show the results of the determination. The assembly 1 or 2 is considered as being in failure when the σ max is greater than σ y where σy is the yield strength of the material as described hereinbefore.

TABLE 1

The Results of the Tests on Assembly 1
Load	Height (cm)	Angle ϑ	σ_max (N/cm)	Performance
A	30	0	-22431
A	30	2	14041
A	30	3	32274	fail
A	40	0	-22431
A	40	2	26195
A	40	3	50499	fail
A	50	0	-22431
A	50	1	7959
A	50	2	38347	fail
B	30	0	-11466
B	30	4	25814
B	30	5	35121	fail
B	40	0	-11466
B	40	3	25815
B	40	4	38231	fail
B	50	0	-11466
B	50	2	19603
B	50	3	35131	fail
where load A = 28756 N (load acting on the central assembly in the case of Figure 4), and
load B = 14700 N (load acting on the central assembly in the case of Figure 5)

Table 2

The Results of the Tests on Assembly 2
Load	Height (cm)	Angle ϑ	σ_max (N/cm)	Remark
A	30	0	-7637
A	30	17	268761
A	30	18	28847	fail
A	40	0	-7637
A	40	12	24923
A	40	13	27607	fail
A	50	0	-7637
A	50	10	26298
A	50	11	29665	Fail
B	30	0	-3904
B	30	31	27401
B	30	32	28344	fail
B	40	0	-3904
B	40	22	26217
B	40	23	27527	fail
B	50	0	-3904
B	50	18	27053
B	50	19	28722	fail

From the above described tests, it can be appreciated that the maximum allowable inclination "ϑ" in the case of the central assembly 1 is 2 deg under the acting load A and 4 deg under the acting load B, and the maximum allowable inclination "ϑ" in the case of the assembly 2 is 17 deg under the load A and 31 deg under the load B. Also, It can be seen that the bearing power of the assembly 1 is lower than that of the assembly 2, and that the maximum allowable inclination " ϑ " decreases as the height "1" increases.

Claims

1. A combined floor pedestal and floor outlet for supporting floor rails and floor panels of a raised false floor comprising:
a drum base member 1 having a cylindrical wall with an external screw thread 121 on said cylindrical wall, and a bottom end flange 11 extending radially at the bottom of said cylindrical wall;
a sleeve member 4 having a cylindrical wall with a first internal screw thread 43 at a lower portion of said cylindrical wall of said sleeve member and a second internal screw thread 42 at an upper portion of said cylindrical wall of said sleeve member, said sleeve member 4 being sleeved around the upper portion of said drum base member 1, said second internal thread 42 engaging with said external thread 121 of said drum base member;
a support member 2 having a cylindrical wall substantially similar in cross-section to said drum base member, said support member being inserted in said sleeve member, said cylindrical wall of said support member 2 having a top annular portion which has a means for engaging with the floor rails of the false floor, an external thread 21 at a lower portion of said cylindrical wall of said support member 2, engaging with said second internal thread 42 of said sleeve member 4, an internal thread 24 at an upper portion of said cylindrical wall of said support member, said first and second internal threads 43 and 43 of said sleeve member being arranged such that they cause said external threads of said drum base member 1 and support member 2 to advance in opposite directions when said sleeve member 4 is turned; and a plug body 3 inserted in said support member 2 and including a cylindrical wall having an external thread 31 engaging with said internal thread 24 of said support member 2, and a top end having an electric socket means 33, 34 or 35 mounted thereon.

2. A pedestal assembly as claimed in Claim 1, wherein said support member 2 further includes a second electric socket means 51 disposed in said cylindrical wall of said support member 2 below said grooves, said second electric socket means 51 being connected electrically to said first electric socket means 33, 34 or 35.

3. A pedestal assembly as claimed in Claim 1, wherein said engaging means of said support member includes radial grooves 25 for receiving floor rails, opening at the periphery and the top face 23 of said top annular portion, and upstanding engaging projections 27.

4. A pedestal assembly as claimed in Claim 1, further comprising a top cover 32 mounted detachably on said plug body 3.

5. A pedestal assembly as claimed in Claim 1, wherein said bottom end flange 11 of said drum base member has upwardly arched portions 13 for receiving grounding wires and screw means 133, 134 for connecting the wire to said arched portions.