Machine foot and method for supporting machines
The invention relates a machine foot for supporting items such as devices and machines with a movable, preferably, metallic spindle with external thread, fastened to a base of a preferably polymer material.
The invention furthermore relates to a method for supporting items and machines.
From patent document number EP 1 113 212 A1 a machine foot is known, where a movable spindle with an external thread is seated in a base. The seating of the spindle in the base is made by a ball or spherical part in the seating end of the spindle, which is fastened in the base by the use of an undercutting in the base part.
By use of the ball shape in the bottom of the spindle it is achieved that the spindle can be moved freely in all directions within a certain angle, which is required when the machine foot is going to be used for e.g. levelling of a machine.
The force, which will affect the machine foot, when it is used for its purpose, is transmitted from the spindle to the underlying base part via the ball part in the bottom of the spindle.
It has been found, however, that there are some drawbacks connected to this prior art, which primarily occurs when the ball shaped end of the spindle is used for transmission of the force from the spindle to the base part, as a result of the machine support.
It is therefore a problem that a force, which is transmitted from the ball shape to the base part, will result in that the undercut seating in the base
part will be exposed to a pressure, which will inevitably create a gap between the seating part and the ball part of the spindle. When there in this way arises a gap or crevice, the gap will potentially accumulate impurities and bacteria, which will be both very hard and costly to clean.
This is obviously a big problem in many situations, where there is made stringent demands to the hygiene including e.g. hospitals and slaughterhouses.
Another problem, which originates from the force transmission from the ball part at the end of the spindle to the base part, occours as a result of that there is obviously an upper limit of how great a force there can be transmitted per unit area between the ball surface and the base part. The size of this maximum allowable force per unit area will obviously depend of the selected material for the two force transmitting components.
But no matter what material is chosen it will be obvious that the greater the force, which is going to be transmitted, the greater the ball surface must be.
Because the ball part is the most expensive single component in a machine foot, it is therefore expensive to transmit high forces via the ball shape, in that a big ball part must be used, which is relatively resource demanding to manufacture.
The problem is in addition aggravated because the use of a ball part with a diameter, which is greater than the superjacent spindle's thread diameter either requires a big waste of material and an expensive manufacturing process by recessing the spindle part or demands that the spindle and the ball part are assembled from two separate manufactured parts, which is again resource demanding and thereby expensive.
Finally it is also a drawback that a big ball will usually result in a heavy product in terms of weight, given that the ball will often be manufactured in a metallic material so that the ball can be exposed to great forces. This again results in an expensive transport, which lowers the product's competitiveness, in case a lighter product can be used.
It is therefore a purpose of the invention to improve the known method and machine foot/feet for supporting machines.
The object of the invention is achieved by a machine foot of the type stated in the introductory portion of claim 1 , which is characterized in that the spindle in the base ends with a ball segment, where the ball's diameter is smaller than the spindle's thread diameter.
In this way it thereby becomes possible to quickly, effectively and cheaply with minimal waste of material to produce the spindle part to a machine foot. Simultaneously the weight of the product is reduced to a minimum, which again enhances the product's competitive position in that the transport costs are reduced to a minimum
As stated in claim 2 it is likewise a distinctive feature of the invention that the spindle between the thread and the ball segment is installed with a sleeve or a ring for transmitting the force from the machine base from the spindle to the base.
By providing the spindle with a ring or a sleeve for the force transmission from the spindle to the subjacent base it is achieved that the greater power there is being transmitted from spindle to base, the more the sleeve or ring squeezes around the base, whereby the open gap between the parts become smaller, the more power there is going to be transmitted.
Hereby it is ensured that the product becomes still more resistant to impurities and bacteria, the greater the pressure, which shall be transmitted. The product will therefore be especially suited for application in environments, which sets high demands to hygiene.
In claim 3 it is stated that it is furthermore a distinctive feature of the invention that the surface of the ring or the sleeve in direction towards the base is shaped like a ball segment.
The ball shape itself will here secure optimum force transmission with a minimal use of materials.
Additional appropriate embodiments of the machine foot are stated in claims 4 to 6.
As mentioned the invention also relates to a method for support of devices and machines.
This method is characterized in that there is used one or more of the in claim 1 to 6 described components for the support.
Hereby it becomes possible to optimize the machine support so that there are used components for the purpose, which are both environmental and production technical resource friendly and furthermore hygienic to use.
The invention will now be explained more fully with reference to the drawing, in which:
Fig. 1 shows a sectional view of an assembled machine foot.
Fig. 2 A shows a sectional view of the base part of a machine foot.
Fig. 2B shows the base part of a machine foot seen from above.
Fig. 3 shows an assembled machine foot where the spindle is turned in relation to the base part.
In fig. 1 is shown a sectional view of a machine foot produced in accordance with the invention. The machine foot consists of a spindle 1 with an external thread, which can be screwed into the machine or device, which needs support. On the thread part of the spindle there is usually in the bottom such as grinded shapes for wrench connection, in order to fasten the spindle's thread part in the machine.
The spindle 1 is provided with a sleeve 3, which can also be a separate ring, which is mounted as shown in fig. 1. The sleeve 3 encloses the base part 4 and is used for transmitting the force from the machine, which is supported from the spindle 1 to the base part 4.
The spindle 1 ends in the bottom of a ball part 2, which is fastened to the base 4 by the use of an undercutting in the base part, so that the ball part must be pressed into the undercutting in order to become fastened to this.
The ball part 2 in this way secures by mounting in the undercut base part 4 that the spindle 1 and the base 4 is held together during transport and assembly. Furthermore the ball shape 2 ensures that the spindle 1 can move freely in relation to the base part 4, within the limits, which lies in the gap cut/passage between the base part 4 and the spindle 3, which is often nedeed for adjustment of the machine support.
It is obviously a demand for the product that the sleeve 3 covers the free cutting/carving between the spindle 1 and the base 4 no matter which angle the spindle 1 assumes in relation to the base 4.
The base is in the bottom and up the sides provided with a dirt- and bacteria inhibitive material 8, which enhances the hygiene attributes of the product. The machine foot is provided with the same dirt-- and bacteria inhibitive and blocking material in the gap/transition between the base 4 and a mounted cover 5.
Beneath the cover 5 there is placed nuts 7 for fastening of the machine foot's base for thread pieces screwed into the floor on which the machine foot is going to be placed.
As it will be obvious by looking at fig. 1 , the use of the disc 3 to force transmission from the spindle 1 to the base 4 will result in that the gap between the disc 3 and the base 4 will be pressed together, whereby the sealing against impurities and bacteria will be increased proportionally with the force, which is going to be transmitted.
Hereby it is achieved that the product is highly suited for application in environments with high demands to hygiene, including e.g. hospitals and slaughterhouses.
Concurrently it is achieved that the ball part 2 can be made relatively small because it is not going to transmit the force from the machine support. Hereby the working process, the material consumption and the final product weight can be reduced to a minimum.
The force transmission from the spindle 1 to the base 4 occours as mentioned via the sleeve or disc 3. The disc and/or sleeve can obviously be manufactured from the same basis material as the spindle 1 itself, but can also be mounted on this as an isolated stand-alone disc.
Especially if the force transmitting part is mounted on a stand-alone disc this is a particularly price favourable as well as in terms of weight light single component, which with advantage can have a larger diameter than the spindle's thread diameter, whereby very high powers cheaply, effectively and hygienically can be transmitted from the spindle 1 to the base 4.
As it will appear from fig. 1 , the surface of the force transmitting disc or sleeve 3 is in the direction of the base part 4 shaped as part of a sphere/ball, which ensures an optimum force transmission per unit area and also ensures that the spindle easily can be turned in relation to the base, simultaneously with that the sealing between the components stays optimized.
The base part 4 is in the top, which touches the force transmitting disc 3, obviously shaped with a sphere segment form, which is complementary to the surface of the disc 3, which it is contact with.
The machine foot is provided with a cover 5, which eases cleaning. In the surfaces between the cover 5 and the base 4, the product is provided with a dirt- and bacteria inhibitive sealing material 8 and 6, which in a preferred embodiment can be a sealing polymer, including a sealing rubber.
In certain applications the product will be sufficiently tight towards penetrating dirt or bacteria without an applied sealing polymer, in case the edge zone with contact with the cover and the base is shaped appropriately within suiting mechanical tolerances.
Fig. 2A shows the base part 4 in a sectional view, where the undercutting 11 is used for fastening the ends of the spindle, and where the opening surface's 10 angle in relation to the vertical center axis composes the limit
for the spindle's movement in relation to the base part 4.
The base is furthermore provided with ribs for supporting the cover, which is shown in fig. 1.
Fig. 2B shows the base part 4 seen from above, where the ribs 9 clearly appear, and where the sealing material 8 and 6 between the base and the cover lid is clarified.
Fig. 3 shows a machine foot where the spindle 1 is turned in relation to the base part 4 in an angle shown by 12, but where there is still optimum sealing between the force transmitting disc/sleeve 3 and the base part 4, so that the hygiene properties are secured no matter the size of the angle 12.
By using the present invention it is possible to manufacture a machine foot for a given application with optimum hygienic characteristics, which are not only dependant of the load but increases with the load rate. In addition the manufacturing process' complexity as well as the material consumption and thereby the total production cost as well as the product's weight is reduced to a minimum.