CHRISTMAS TREE STAND

Abstract

 The invention relates to a Christmas tree stand comprising a holding part (2) which can be attached to a lower end part of the trunk of a Christmas tree, and a standing part (3), where there is a ball joint between the holding part (2) and the standing part (3), and where an outer spherical shell part with an inner spherical shell surface is coupled to the holding part (2), and an inner spherical shell part with an outer spherical shell surface is coupled to the standing part (3), where the outer spherical shell part has a cut encompassing a through slot from an outer surface and through the inner spherical shell surface. Furthermore, there is a tightening ring (11) belonging to the holding part (2) and extending around the outer spherical shell part, and in the tightening ring (11) are lock screws (13) inserted in radially extending threaded bores, which by tightening are adapted to put the outer spherical shell part under pressure in an inward direction towards the inner spherical shell part while reducing the size of the slot to lock the outer spherical shell part against the inner spherical shell part.

Description

[0001] The invention relates to a Christmas tree stand comprising a holding part which can be attached to a lower end part of the trunk of a Christmas tree, and a standing part, where a ball joint between the holding part and the standing part can be fixed in a certain angular position between the holding part and the standing part, where an outer spherical shell part with an inner spherical shell surface is coupled to the holding part, and an inner spherical shell part with an outer spherical shell surface is coupled to the standing part, where the outer spherical shell part has a cut encompassing a through slot from an outer surface and through the inner spherical shell surface.

[0002] A Christmas tree stand is known from the German utility model DE 29617240 U1. According to this, the holding part and the outer spherical shell part are formed as one element, whereby the tensions the element is exposed to during mounting on the inner spherical shell part of the holding part will become unnecessarily large. It is the object of the invention to provide a Christmas tree stand wherein the outer spherical shell part can be deformed easily without it being subjected to too large tensions.

[0003] The object of the invention is met by means of a Christmas tree stand of the type mentioned in the preamble of claim 1, which is characterized in a holding part which has a tightening ring that extends around the outer spherical shell part, and in the tightening ring are lock screws inserted in radially extending threaded bores, which by tightening are adapted to put the outer spherical shell part under pressure in an inward direction towards the inner spherical shell part while reducing the size of the slot to lock the outer spherical shell part against the inner spherical shell part.

[0004] Hereby the locking screws are pushed in an inward direction against the outer spherical shell part which gives way for the pressure due to the through slot, whereby the outer spherical shell part is pushed inwardly and is brought in close contact with the inner spherical shell part. By further tightening of the locking screws a fixed grip is obtained between the inner and the outer spherical shell part, as the tightening ring absorbs the resultant forces of tension herein. Furthermore, it should be stated, that the slot of the outer spherical shell part, which is mounted inside the tightening ring, by this design will become hidden, so that it is kept from accumulation of grime and is not visible.

[0005] As stated in claim 2, the holding part comprises a tube with a first and a second end having an inner and outer circumference and a thickness, and where the outer spherical shell part is inserted in and axially fixed in the first end of the tube, which first end of the tube hereby forms the tightening ring that extends around the outer spherical shell part, and where several radially extending through upper threaded bores with inserted locking screws which are adapted to engage with a lower trunk part of a Christmas tree are provided at the second end of the tube. When the outer spherical shell part is only fixed axially in the tube, is it possible that the spherical shell part can be moved inwards, without the tube itself being moved, and having the tightening ring formed as a lower part of the tube which at the same time holds the Christmas tree results in a very simple design.

[0006] As noted in claim 3 it is preferred, that the outer spherical shell part is fixed axially in the tube by means of locking rings which are inserted in circumferentially extending grooves. Hereby is an axial fixation achieved, which can be realized with easily accessible means, and it will also be easy to remove the spherical shell part from the tube.

[0007] According to claim 4, the standing part comprises a base with a lower surface having one or more support points in the same plane of which at least three support points are spaced equally on a circle, where the support points are in connection with a central area at the centre of the circle via connecting parts, where at the central area there is a supporting part, and where the inner spherical shell part is mounted on the supporting part, so that the inner spherical shell surface of the holding part encloses the inner spherical shell part and is moved angularly and fixed thereto in such a way that a lower rim of the cylindrical tube of the holding part does not collide with the floor or the connecting parts between the supporting points and the central area. Such a standing part can for instance be formed by a circular disc of metal. In this case, the supporting points would in reality be an endless number of supporting points, and the connection between supporting points and the central area is simply continuous disc material. But there is a large number of possible designs for such a standing part. The supporting part is necessary if there is a need of a significant angular motion between the holding part and the standing part, and thus it is the height of the supporting part above the floor or the connecting part between support points and the floor that is involved in deciding, how much the holding part can be moved angularly before there is a collision between the parts.

[0008] As noted in claim 5 it is preferred that that inner spherical shell part as well as the outer spherical shell part extend in both directions away from an equatorial plane and are limited by boundary planes that extend parallel to the equatorial plan, where the outer spherical shell part in the tube is mounted with its equatorial plan extending perpendicular to the centre axis of the tube, and where the equatorial plane of inner spherical shell part extends parallel to the plane of the circle of the support points of the standing part. The boundary of the outer spherical shell part helps to ensure that it is not necessary to deform it too much to mount it over the inner spherical shell part. However, the spherical shell parts must have a certain length to ensure a stable mutual grip, also when their equatorial planes or centre planes are positioned with an angular distance.

[0009] Even though only spherical shell parts have been mentioned, it should, as claimed in claim 6, be noted, that the geometry of the surfaces deviate slightly from an ideal spherical shell. The purpose of this deviation is to ensure that when the inner spherical shell surface of the outer spherical shell part is tightened around the outer spherical shell surface of the inner spherical shell part, a contact will arise along surfaces that only represent a small part of the total possible contact surface, which ensures that the surface pressure can be multiplied. In this way a strong grip between the surfaces of the two spherical shell parts is obtained, so that a large torque can be transferred from the holding part to the standing part.

[0010] It is preferred that there are at least two threaded bores with associated tightening screws in the tightening ring, where the outer spherical shell part is mounted in the tube in such a way, that the first tightening screw puts the spherical shell part under pressure in an area diametrically opposite the slot, and that the other tightening screw puts the spherical shell part under pressure at an angle that is shifted 45 degrees in the peripheral direction from the first tightening screw. Hereby is ensured that the obtained pressure on the spherical shell part is distributed evenly across the inner spherical shell parts external spherical shell surface so as to avoid excessive pressure marks in the surface thereof.

[0011] It is furthermore preferred that the outer spherical shell part comprises a blind bore in an external outer surface facing the tube for accommodation of the tightening screw diametrically opposite the slot. Hereby is ensured that the tightening screw can keep the outer spherical shell part from rotating inside the tube.

[0012] The invention will be further explained in the following with reference to the drawings, in which:

Fig. 1 shows a graphical representation of the Christmas tree stand in a side view,

Fig. 2 shows a graphical representation in 3D of the Christmas tree stand,

Fig. 3 shows an exploded side view of the Christmas tree stand,

Fig. 4 shows a part of the tightening ring 11 in partly cross-sectional view,

Fig. 5 shows a 3D representation of the ball joint, and

Fig. 6 is an enlarged part of a cross-sectional view through the ball joint and the tightening ring 11.

[0013] Fig. 1 and Fig. 2 shows a Christmas tree stand 1 which has a holding part 2 adapted to enable the lowermost part of the trunk of a Christmas tree to be fixed thereto. There is also shown a standing part 3 where a ball joint between the holding part 2 and the standing part 3 is adapted to be locked in a fixed angular position between the holding part and the standing part. A Christmas tree with a trunk which is not totally straight will thereby be able to stand in a position, so that at least the top of the tree has an approximately vertical centre axis.

[0014] An outer spherical shell part 5 is mounted in the holding part 2, which has an internal spherical shell surface 6, and an inner spherical shell part 7 with an inner spherical shell surface 8 is in connection with the standing part. The two spherical shell parts 5, 7 are mounted one around the other which enables them to be rotated and turned in relation to one another in any direction. The outer spherical shell part 5 has a cut and an associated through slot 9 extending from the outer surface 10 through the inner spherical shell surface. The slot 9 makes it possible to deform the outer spherical shell part, so that there is enough room for the inner spherical shell part to be inserted here, and so that the outer spherical shell part can be tightened around the inner spherical shell part.

[0015] In connection with the holding part 2 is a tightening ring 11 which extends around the outer spherical shell part, and lock screws 13 are mounted in the tightening ring 11 in radially extending threaded holes 12. When the locking screws 13 are tightened, the outer spherical shell part 5 is tightened inwards towards the outer spherical shell surface 8 of the inner spherical shell part 7, while reducing the width of the slot 9. In this way, the outer spherical shell part 5 is locked against the inner spherical shell part 7. As shown in Fig. 3, the locking screws 13 are set screws.

[0016] The holding part 2 encompasses a tube 14 which in a first end 15 is in the form of a tightening ring 11 and has an internally mounted outer spherical shell part 5. The locking screws 17 are mounted in the second end 16 of the tube, which are adapted to be mounted in radially extending threaded bores 30, and when they are screwed in they will squeeze the trunk (not shown) of the Christmas tree, which is guided into the tube beforehand. The tube has a uniform inner and outer circumference and one thickness. It can be seen in the enlarged partial view of the cross sectional view in Fig. 6 that the outer spherical shell part 5 is inserted in and axially fixed to the first end 15 of the tube.

[0017] As can be seen in Fig. 4 and Fig 6, the outer spherical shell part 5 is fixed axially in the tube by means of locking rings 19 which are mounted in peripheral grooves 18.

[0018] The standing part can be seen in Figs. 1, 2 and 3, and it has a base 20 with a lower surface 21. As can be seen in the figure, the lower surface is plane and has one or more supporting points in the same plan, whereby at least three supporting points will be spaced equally along a circle. The plane lower surface 21 of the chosen embodiment is appropriate in the chosen material, but if the base was to be moulded in plastic, a base with legs extending from a common centre would be more appropriate. In a not shown embodiment where the base comprises separate legs, is it from a stability point of view necessary with at least 3 legs, and to achieve the best stability the supporting points of the legs on the surface must be spaced equally on a circle. In this case the legs meet at a central area in the centre of the circle where the legs are connected and the supporting part is situated.

[0019] In the embodiment shown in the figure, the supporting points are connected, via connecting parts 25, to a central area 24 at the centre of the circle 23 where a supporting part 26 is located. The supporting part 26 is mounted directly on the base 20 with a screw 30 which also extends through a central bore in the inner spherical shell part 7. Thereby, the screw 30 fixes the inner spherical shell part 7 to the supporting part 26. The inner spherical shell part 7 is thereby mounted on the supporting part 26, so that the inner spherical shell surface 6 encloses the inner spherical shell part 7. The outer spherical shell part 5 can now be moved angularly in relation to and be fixed to the inner spherical shell part 7, thereby avoiding that the lower rim 27 of the tube 14 of the supporting part collides with the floor or the connecting parts 25 between the supporting points and the central area. It is possible, by carefully choosing the length of the supporting part 26, to decide how big an angular motion is needed.

[0020] The inner and outer spherical shell parts extend in both directions away from an equatorial plane (not shown) and are limited by boundary planes (not shown) which extend in parallel to the equatorial plane, so that they both form parts of a sphere that is symmetrical around a great circle which then will be situated in the equatorial plane. The boundary planes can be plane, stepped, convex or concave or can deviate from a simple plane surface in any other way. In Fig. 6 the upper boundary plane is shown as being stepped.

[0021] The outer spherical shell part 5 in the tube 14 is mounted with its equatorial plan extending perpendicular to the centre axis, and the equatorial plane of the inner spherical shell part 7 extends in parallel with the circle plane of the support points of the standing part 3.

[0022] As can be seen in Fig. 6, the outer spherical shell surface 8 of the inner spherical shell part 7 and/or the inner spherical shell surface 6 of the outer spherical shell part 5 are machined, so that one or the other or they both differ from a mathematical spherical shell shape. In fig. 6 is shown how the distance between to two spherical shell surfaces 6, 8 is largest at the equatorial plane, here shown to be 0.3 mm, and is reduced towards the boundary planes and reaches its minimum of 0.15 mm, when the two spherical shell parts are mounted with common centre axes. This means that when the outer spherical shell part 5 is tightened towards the spherical shell surface 8 of the inner spherical shell part 7, it will be the areas with the minimal distance between the spherical shell surfaces that will come into contact. As the tightening force is increased, the force of contact can become extremely high, and thereby the outer spherical shell part will actually make an indentation in the inner spherical shell part, which enables the ball joint to transfer quite large forces of torque from the holding part to the standing part.

[0023] Fig. 1 shows two tightening screws 13 each inserted in its own threaded bore in the tightening ring 11, and as can be seen in Fig. 5, there is a blind bore 28 in the outer spherical shell part 5 opposite one of the threaded bores, so that at least one of the tightening screws 13 puts the spherical shell part under pressure via the blind bore 28. As also shown in Fig. 5, the blind bore is situated right above the slot 9, whereby the outer spherical shell part is mounted in the tube in such a way that this tightening screw puts the spherical shell part 5 under pressure in an area situated diametrically opposite the slot 9. The second tightening screw puts the spherical shell part under pressure in an angle that is shifted 45 degrees in the peripheral direction form the first tightening screw 13, as can be seen in Fig. 1.

[0024] As can be seen in Fig. 5, there is also an adjustment mark 32 which can help to ensure that a preassembled ball joint comprising the inner spherical shell part 7 and the outer spherical shell part 5 can be inserted correctly in the end part 15 of the tube 14, so that the blind bore 28 will be situated opposite one of the threaded bores 12.

Reference signs:

[0025] 

1 Christmas tree stand

2 Holding part

3 Standing part

4 Ball joint

5 Outer spherical shell part

6 Inner spherical shell surface

7 Inner spherical shell part

8 Outer spherical shell surface

9 Through slot

10 External surface

11 Tightening ring

12 Radially extending threaded bores

13 Lock screws

14 Tube

15 First end of the tube

16 Second end of the tube

17 Locking screws

18 Peripheral groove

19 Locking rings

20 Base

21 Lower side

22 Support points

23 Circle

24 Central area

25 Connecting parts

26 Supporting part

27 Lower circumference

28 Blind bore

29 (not used)

30 Screw

31 Upper threaded bore

32 Adjustment mark

Claims

1. Christmas tree stand (1) comprising a holding part (2) which can be attached to a lower end part of the trunk of a Christmas tree, and a standing part (3), where a ball joint (4) between the holding part (2) and the standing part (3) can be fixed in a certain angular position between the holding part (2) and the standing part (3), where an outer spherical shell part (5) with an inner spherical shell surface (6) is coupled to the holding part (2), and an inner spherical shell part (7) with an outer spherical shell surface (8) is coupled to the standing part (3), where the outer spherical shell part (5) has a cut encompassing a through slot (9) from an outer surface (10) and through the inner spherical shell surface (6), characterized in a holding part (2) which has a tightening ring (11) that extends around the outer spherical shell part (5), and in the tightening ring (11) are lock screws (13) inserted in radially extending threaded bores (12), which by tightening are adapted to put the outer spherical shell part (5) under pressure in an inward direction towards the inner spherical shell part (7) while reducing the size of the slot (9) to lock the outer spherical shell part (5) against the inner spherical shell part (7).

2. Christmas tree stand (1) according to claim 1, characterized in, that the holding part (2) comprises a tube (14) with a first end (15) and a second end (16) having an inner and outer circumference and a thickness, and where the outer spherical shell part (5) is inserted in and axially fixed in the first end (15) of the tube (14), which first end (15) hereby forms the tightening ring (11) that extends around the outer spherical shell part, and where several radially extending through upper threaded bores (31) with inserted locking screws (17) which are adapted to engage with a lower trunk part of a Christmas tree are provided at the second end (16) of the tube.

3. Christmas tree stand according to claim 2, characterized in, that the outer spherical shell part (5) is fixed axially in the tube (14) by means of locking rings (19) which are inserted in circumferentially extending grooves (18).

4. Christmas tree stand according to any of claims 1 - 3, characterized in, that the standing part (3) comprises a base (20) with a lower surface (21) having one or more support points in the same plane, of which at least three support points are spaced equally on a circle (23), where the support points are in connection with a central area (24) at the centre of the circle (23) via connecting parts (25), where at the central area (24) there is a supporting part (26), and where the inner spherical shell part (7) is mounted on the supporting part (26), so that the inner spherical shell surface (6) of the holding part (2) encloses the inner spherical shell part (7) and is moved angularly and fixed thereto in such a way that a lower rim of the tube (14) of the holding part (2) does not collide with the floor or the connecting parts (25) between the supporting points and the central area (24).

5. Christmas tree stand according to any of claims 1 - 4, characterized in, that the inner spherical shell part (7) as well as the outer spherical shell part (5) extend in both directions away form an equatorial plane and are limited by boundary planes that extend parallel to the equatorial plan, where the outer spherical shell part (5) in the tube (14) is mounted with its equatorial plan extending perpendicular to the centre axis of the tube (14), and where the equatorial plane of the inner spherical shell part (7) extends parallel to the plane of the circle (23) of the support points (22) of the standing part (2).

6. Christmas tree stand according to claim 4, characterized in, that the outer spherical shell surface (8) of the inner spherical shell part (7) and/or the inner spherical shell surface (6) of the outer spherical shell part (5) deviate from the mathematical spherical shell form in such a way that the distance between the spherical shell surfaces is largest at the equatorial plane and is reduced towards the boundary planes, when the two spherical shell parts are mounted with coinciding centre axes.

7. Christmas tree stand according to claim 6, characterized in, that there are at least two threaded bores (12) with associated tightening screws in the tightening ring (11), where the outer spherical shell part (5) is mounted in the tube (14) in such a way, that the first tightening screw puts the spherical shell part (5) under pressure in an area diametrically opposite the slot (9), and that the other tightening screw puts the spherical shell part (5) under pressure at an angle that is shifted 45 degrees in the peripheral direction from the first tightening screw.

8. Christmas tree stand according to claim 7, characterized in, that the outer spherical shell part (5) comprises a blind bore (29) in an external outer surface (10) facing the tube for accommodation of the tightening screw diametrically opposite the slot (9).

Drawing