GB2180865A - Base for posts - Google Patents

Abstract

The base comprises a base member (1), e.g. of concrete, which at its lower portion (4) has obliquely upwardly extending surfaces of a vertical extent corresponding to approximately half the height of the base member, and has an overall height which is considerably less than the distance from the bottom surface (6) of the base to the fixing means (3) for the post (i.e.than the depth by which the base is lowered into the ground before fixing the post) the base member being connected with a number of rod means (2) consisting of pairs of rods (10) which at their upper ends are rigidly connected to the fixing means (3) and at their lower ends are embedded in the base member (1) in spaced apart relationship. <IMAGE>

Description

SPECIFICATION Base for posts or the like The present invention relates to a base for posts or the like comprising a base member of concrete or like material andfixing meansforthe postwhich are provided at the base member.

As bases for posts, especially lamp posts, use is curently made of precast concrete bodies provided with a recess in which the lower end portion ofthe post is inserted and fixed, optionally rigidly, to the upper concrete partofthe base by the intermediary of a foot-plate on the post. Prior art bases ofthistype which normally are cylindrical and have a widened lower part, have a weight in the order of700-1 kg for post lengths of about 10 m. The weight and shape of conventional bases make the costs oftransportation substantial,which of course adds to the total installation costs. Despite their considerable weight and large volume, conventional post bases are not capable ofwithstanding major loads.

The object of the present invention is to provide a base of substantially reduced weightwhich is easier to transportthan conventional bases, but yet ensures an at leastequally good anchorage asthe known bases.

According to the invention, this object is achieved inthatthe base memberwhich ata lower portion thereof has obliquely upwardly extending surfaces of a vertical extent corresponding to approximately half the height ofthe base member, has an overall heightwhich is considerably less tha n the distance from the bottom surface ofthe base to said fixing means, i.e. than the depth by which the base is lowered into the ground before fixing the post, and in thatthe base member is connected with a numberof rod means comprising pairsofrodswhichattheir upper ends are rigidly connected to the fixing means forthe postand attheirlowerendsareembedded in the base member in spaced apart relationship.

The invention will be described in more detail hererin below with reference to the accompanying draw ing, in which; Figure lisa side view of a complete base according to the invention; Figure 2 shows the same base as seen from above and in a section taken along the line A-A in Figure 1; Figure3 on a larger scale, shows a broken-apart corner portion ofthe base as seen from above; Figure a larger scale, shows one of the rod means being part of the finished base as seen from the side; and Figure5showsthe same rod meansfrom above.

The base according to the invention consists of a base member 1 and rod means 2 having fixing means 3forthepost(notshown).

In the illustrated embodiment, the base 1 is of square cross-section and has a lower portion 4with oblique surfaces, and an upper portion 5 with vertical surfaces. The bottom surface 6 and the top surface 7 are planar. At the top surface 7 there are provided a number of downwardly extending holes 8, suitably four, which have been formed during casting ofthe base member by means of mandrels and are so posts tioned in relation to a reinforcement 9, provided at least at the upper end of the base member, that the reinforcement will externally enclose the holes 8. the base members can be supplied in this state from the concrete plant and maythen, due to their shape, be suitably loaded so as to occupy a minimum of space, for instance with every other base memberturned upside down, and be transported to a suitable place in the vicinity of the site of use, for purposes of completion.

The holes 8 have been given such a tolerance that rod means provided with fixing means for posts of varying base dimensions can be passed into the holes. Similarly, the same base member of concrete can be used for posts of highly varying size. The dimension and length of the fixing means and the rod means determine the strength and stability of the finished base.

In the illustrated embodiment, each of the four rod means 2 ofthe base comprises two rods 10 which at thetop are welded to a sleeve 11 forming the actual fixing means. The two rods 10 which are bent to promote their capacity of taking up torsional stresses, torques, are intended with their straight lower end portions 12 to be inserted in a respective one oftwo adjacent holes 8 in the base member 1 in the manner shown in Figure 1.

When the rods 10 of all the rod means have been inserted in their respective holes, these are filled with concrete which upon hardening will solidly anchor the rod means in the base member.

Thus,thefinished base hasfourfixing means, i.e.

sleeves 11, each of which is anchored by means of two rods 10 in two holes 8.

The base is placed in a hole prepared in the ground, and the hole is filled to aboutthe level ofthe sleeves 11.

The post to be used together with the base is provided with bolts 13 the numberofwhich corresponds to the number of sleeves and which are suitably fixed in a bottom plate on the post and can be inserted in the sleeve 11 and tightened. Suitably, the bolts are provided with a nut 14 with a washer 15 which is disposed at some distance from the free end ofthe bolt and which will rest on thetopface ofthesleeve 11, while a locking nut 1 6with a washer 17 is provided on the bolts below the sleeve. Thus, it will be possible readily to adjustthe vertical position of the post by means ofthe upper and lower nuts.The sleeves 11, independent of each other before the post is mounted, will be fixed in relation to each other by the bottom plate or the lower end ofthe post.

The lower portion of the post, together with the rods 10 anchored in the corner holes 8 ofthe base member 1, will form a rigid basket-like unit having very high strength with regard to load stresses.

By using a base having a lower base memberwith obliquely upwardly extending surfaces, very high resistance is obtained to upsetting and extraction of the base if the post, especially in the case of "soft" posts, is hit buy a vehicle because the oblique surfaces then act as extended passive sliding surfaces. The absence of a continuous circumferential or outer surface at the upper portion of the base facilitates cable pul ling. As opposed to the case of conventional bases, it is thus not necessary to provide the base member with through ducts for cables, thus overcoming the problems of making the base proof against water and frost.

It may seen surprising that the base, despite the absence of a continuous circumferential or outer sur- face atthetop, yet affords good stability. However, the thing is that beyond each separate rod as seen in the direciton of action on the rod,there is created, figuratively speaking, a counteracting wedge-like soil body the area of which increases with the dis- tance. This meansthatthe base, which e.g. when hit by a vehicle or likewise acted on, apartfrom the normal forces would be so affected asto turn about an axis extending transversely of the direction of impact at a certain distance belowthe upper end atthe base, will prevent such torsional movement thanks to the rods - cooperating with the surface layers - and the base member - cooperating with the surrounding soil.

Afurther advantage ofthe base according to the invention is that, after being run into by a vehicle, it can be readily repaired by straightening any rods that may have been deformed by the impact on the post.

It goes without saying that several modifications of the invention are conveivable. Thus, instead of sleeves joining the rods 10 of the rod means 2, it is possible to weld the two rods to a threaded bar or bolt projecting above the rods. The post may then be provided with an annular foot-plate with holes. It is of course possibieto embedthefixing meansintheir entirety, i.e. the rod means with sleeves orthreaded bars, in connection with the casting of the concrete base member, instead of embedding them ata later stage in the preformed holes 8.

Also in this case, it is possible by using double nuts to permit adjusting the vertical position ofthe post.

In the preferred embodiment, the rods 10 are bent, but they may also be straight, especially in the case of minor posts.

Although the square cross-section is the most convenient in most cases, other cross-sectional shapes may be used. Also, it is possible to provide the base member with fewer or more holes than stated above and adjustthe number of rod means to the number of holes.

Hence,the invention should not be considered restricted to the embodiment described above and shown in the drawing but may be modified in several different ways within the spirit and scope of the accompanying claims.

Claims (8)

1. A base for posts or the like comprising a base member of concrete or like material and fixing means forthe post which are disposed at said base member, ch a ra cte rized inthatthe base member(1)which at a lower portion (4) thereof has obliquely upwardly extending surfaces of a vertical extent corresponding to approximatelyhalfthe heightofthe base member, has an overall height which is considerably less than the distance from the bottom surface (6) of the base to said fixing means, i.e. than the depth by which the base is lowered into the ground before fixing the post, and inthatthe base member (1 ) isconnecteed with a number of rod means (2) comprising pairs of rods (10) which at their upper ends are rigidly connected to the fixing means (3) for the post and at their lower ends are embedded in the base member (1) in spaced apart relationship.

2. Base asclaimed in claim 1,characterized inthattheconcrete base member (1 ) is provided during casting with holes (8) the number of which agrees with the number of rod means (2) and in which the lower ends (12) of rods (10) included in the rod means are inserted and secured, the pair of rods (10) of each rod means (2) being inserted and secured in respective adjacent holes (8), such that each hole receives one rod from each of two rod means.

3. Baseasclaimedinclaim 1 or2,characteriz e din that each of said fixing means (3) connected to the two rods of each rod means comprises a sleeve for receiving a fixing bolt provided on the post.

4. Baseasclaimedinclaim 1 or2,characteriz e d in that each of said fixing means connected to the two rods of each rod means comprises a threaded boltorthe like to be inserted in bores of flange provided on the post, and connected to said fiange by means of nuts.

5. Base as claimed in any one of claims 1-4, char acte rized in thatthat rods (10) ofthe rod means (2) are so bentthat a lower portion (12) thereof is parallel to a hole (8) in the base member, while an upper portion thereof obliquely connects to the fixing means (3).

6. Base as claimed in any one ofthe preceding claims, c h a r a ct e r i z e d inthatthe heightofthe base member (1 ) is approximately halfthe overall height of the base as counted from the bottom poriton thereof to the fixing means (3).

7. A base for posts or the like, the base being sub stantially as hereinbefore described with reference to the accompanying drawings.

8. A post or the like when provided with a base as claimed in any preceding claim.