GB2161688A - Ventilating a pig fattening house - Google Patents

Abstract

A pig fattening house having a monopitch roof 16 has a ventilation flap (20) in one end wall (12) and a temperature sensor (32) inside. A motor is provided to open and close the flap by pivoting the flap about a horizontal axis. The motor is connected to the temperature sensor so that the flap is opened and closed automatically to maintain a constant, preset temperature inside the house. <IMAGE>

Description

SPECIFICATION Ventilating a pig fattening house This invention relates to a pig fattening and growing house with automatically controlled natural ventilation. The primary aim of the ventilation is to control the temperature in the house.

Pig fattening houses are known which have a monopitch roof, i.e. the roof slopes from a high front wall to a low rear wall. It has been found that the characteristic temperature distribution in such houses results in the pigs congregating at the back, which is a good thing because it allows the front of the house to be easily cleaned out.

Such houses have a door in the lower part of the front wall and a ventilation flap in the upper part of the front wall. The ventilation flap is hinged to the structure of the house, and the stockman keeping the pigs observes the pigs in the house and then uses his judgment and experience to decide whether or not they are at the correct temperature.

The temperature at which the pigs should be kept changes as the pigs grow. If the temperature needs to be changed, the stockman either opens or closes the flap to the extent he deems necessary. There is usually a chain hanging close to the flap, and the flap can be adjusted by hooking it in to one or other of the links of the chain.

According to the present invention there is provided a pig fattening house having a monopitch roof, a door in its higher end wall, at least one ventilation flap above the door, the or each ventilation flap being pivoted for rotation about a horizonatal axis, a motor for driving the flap orflaps in rotation, a temperature sensor in the house and control means responsive to the temperature sensor for controlling operation of the motor.

The horizontal pivot axis of the ventilation flap preferably passes through the centre of gravity of the flap. Where there is more than one flap, the flaps may be arranged in the manner of louvres.

In one embodiment, the flap may be constructed so that its centre of gravity is near its top edge.

The flaps may be mounted in a frame, and the frame may be pivoted to the house structure so that the whole frame can be raised to provide access to the house. A catch may be provided to hold the frame in its raised position.

The frame may be made of aluminium sections so that it is light in weight. The flaps may be made of transparent board material, preferably with insulating properties.

The motor may drive a ram which acts on the flap through a linkage, or a winch which pulls on a cable or the like to turn the flap.

The motor is preferably electrically driven.

The invention extends to a bank of a plurality of fattening houses as set forth above, arranged side by side, with one motor between two adjacent houses driving the ventilation flaps on both houses.

If there are more than two adjacent houses, the flaps on the houses outlying the houses which are adjacent to the motor may be connected to the flaps on the houses adjacent the motor, and the motor may drive all the connected flaps.

The invention may be applied to an existing house by attaching to the existing flap a vertically extending arm which carries a counterweight, so as to effectively move the centre of gravity of the flap up towards its top edge.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure lisa side view of a pig fattening house in accordance with the invention; Figure 2 is a front view of a bank of houses in accordance with the invention; Figure 3 is a front view of a frame; Figure 4 is an end view of the frame of Figure 3; Figure 5 is a front view of a flap; Figure 6 is an end view of the flap of Figure 5; Figure 7 is a side view of a ram motor, on a larger scale; Figure 8 is a detail front view of the front wall of the houses of Figure 2 with some components omitted; Figure 9 is another detail front view of the front wall, also with some components omitted; Figures 10 and 11 are views of an alternative flap; Figure 12 is a schematic view of another alternative construction;; Figure 13 is a front view of yet another alternative construction; and Figures 14 and 15 are side views of two further alternative constructions.

The house shown in Figure 1 is a monopitch building which is often known as a "Trobridge-type" pig fattening house. It has a low rear wall 10, a high front wall 12 and side walls 14. A sloping roof 16 is above the walls.

In the front wall 12, there is a door 18 and a ventilation flap 20. The door will normally be hinged at one of its vertical sides. The flap 20 is arranged so that it can be lifted up as indicated by an arrow 22 and engaged in a latch 24. Thus, with the door opened and the flap 20 raised, the whole of the front wall 12 is open so that there is sufficient headroom for a person to enter to clean out the house or gain access to the animals inside.

It is a well-established characteristic of the "Trobridge-type" house that the pigs congregate at the back, under the lowest part of the roof.

The flap 20 is supported a little out of the vertical by wedge pieces 26 at the sides of the flap, to keep the weather out.

Houses of the type described are usually arranged in banks, as shown in Figure 2.

The positions of the ventilation flaps 20 of all the houses are adjusted automatically by a motordriven ram 28. The manner in which this ram 28 moves the flaps will be described later. However the ram itself is controlled by an electric control unit 30 which is fed with signals from a temperature monitoring sensor 32 mounted in each cabin. A single control unit 30 can be connected to the sensors in a number of cabins and can operate the rams operating a number of flaps. The control unit includes the facility of being able to set any desired temperature within a suitable range, and the flaps are then moved to maintain the temperature which has been set.

Each flap 20 has a frame 34 and a flap panel 36.

The frame 34 is hinged to the structure of the house by hinges 38 at its top edge. Brackets 40 on the vertical edges of the frame receive pivot pins 42 at the edges of the flap panel 36. Thus, when the panel is fitted in its frame, the panel can turn about its central horizontal axis. The panel can be lifted out of the frame simply by lifting the pins 42 out of the angled slots in the brackets 40.

There are two different modes of movement; to obtain ventilation, the flap panel 36 is moved relative to the frame 34 by the ram 28, and the frame stays stationary. To allow access to the interior of the house, the frame is lifted on its hinges 38, taking with it the panel 36 and the ram 28.

The panel 36 comprises a sheet 44 of transparent, insulating sheet, such as the sheet sold underthe Trade Name Thermoclear by Thermoclear (UK) Ltd.

This sheet is held in a surround 46 to which the pivot pins 42 are attached. The frame 34 and the surround 46 are both made of aluminium sections, for lightness and freedom from corrosion.

The ram 28 is shown in more detail in Figure 7.

The ram housing 48 houses an electric motor which acts on a rod 50 by means of a worm drive, so that the rod can be extended of retracted. A suitable motor can be driven from a 24v power source and has a consumption of only 0.2A, with a rating of 20 Newtons. As an alternative to the ram shown, a direct-coupled damper motor as made by Belimo Automation could be used, although it would need to be differently positioned from the motor housing 48. As another alternative, a motor driven winch could be used, and this will be explained later with reference to Figure 13.

The housing 48 is pivotably mounted on a bracket 52 which itself is fixed to a strut 54 connecting the frames 34 of two adjacent flaps. An additional strut 56 (Figure 8) connects the frames 34 at the top. A handle 58 is attached below the strut 54. The top of the rod 50 is connected to a transverse rod 60, the location of which is shown in Figure 9. Note that the entire ram unit has been omitted from Figures 8 and 9, for clarity in those Figures.

Figure 9 shows how the transverse rod 60 is mounted between brackets 62 fixed to the backs of two adjacent panels 36. At the flap edges where the ram 28 is located, the wedge pieces 26 are omitted, so that there is a wedge-shaped gap between the frame 34 and the structure of the house, and the rod 60 passes through this gap onto the brackets 62. The brackets 62 are positioned offset from the pivot axes 42 of the panels 36 in the frame 34 so that, when the rod 50 of the ram 28 is extended or retracted, the panel is turned.

It may be convenient for the ram to move in steps, to provide a number (for example sixteen) discrete different opening positions. If the temperature in the house is sampled every two minutes, and the flap opened a step if the actual temperature is above the desired temperature, then in an extreme case the flap would move from fully closed to fully open in about half an hour. The ram should be set so that the panels 36 never reach a fully vertical position, because in such a position they might admit the weather into the house.

Because the flap panels 36 are pivoted at their centre, the ram 28 does not support their weight, and the power needed to open and close the flap panel will be very small. It is therefore possible to link up the flaps of a number of adjacent houses so that all the flaps are operated by the same ram. Such an arrangement is shown in Figure 2.

Figure 2 shows two centre houses with flaps 20a on either side of the ram 28. The ram only moves the flap panels 36, and not the flap frames 34. Although the ram acts n both the flaps 20a through the rod 60, it is advisable to provide a second interconnection between the panels of these flaps to make sure that the panels move in unison. This interconnection is provided by a bar 64. Outside flaps 20b are connected in by bolts 66 which can be shot to connect the panels on flaps 20a and 20b, or can be drawn back to disconnect the panels. For ventilation control, the panels will normally all be connected. When the flaps are to be raised for access to the houses, four panels at a time will be too much for a man to iift. The bolts 66 will be drawn back, and the two centre flaps can be raised together by lifting with the handle 58.Note that the latches 24 for the two centre flaps 20a are interconnected by a bar 68 so that both latches can be released together when the flaps are to be lowered.

The outside flaps 20b are raised independently.

The remaining figures show various alternative constructions and will only be described insofar as these constructions differ from what has already been shown.

Figures 10 and 11 show a flap panel 70 which is asymmetric and has its centre of gravity near its top edge. This panel can have sufficient inherent stiffness to dispense with a frame. The advantage of this construction is that the panel can be raised sufficiently far on its pivot axis 72 (to the position shown in dotted lines in Figure 12) to allow access, without needing a separate mechanism for raising the whole flap with a frame.

The panel 70 can be made of glass fibre reinforced materials with a main structural spine 74 coincident with the pivot axis 72.

Figure 12 shows an embodiment substantially the same as seen in Figures 1 to 9, but where the position of the ram 28 is inverted. The brackets 62 are now below the pivot axis 42.

In Figure 13, the motor drives a winch to move a cable 80 which passes along the top of a bank of houses. A pulley 82 is mounted above each flap and a rope or cable or chain link 84 is provided over this pulley to a fixing point 86 on the panel 88. The other end of the link 84 is attached to the cable 80 and when the cable is moved, the flap is pulled. The weight of chain links 90 shown in Figure 15 may be sufficient to cause the panel to be closed by gravity.

In Figure 14, the single panel 34 is replaced by a set of louvre panels 100 which can be actuated in a manner known for louvres using any one of the actuating mechanisms already described.

In Figure 15, the position of the centre of gravity of the flap panel 110 is raised by bolting to the panel an arm 112 with a counterweight 114 at the top. The counterweight can be moved until the right position is found, where the panel balances about its upper, hinged edge. The panel can then be pivoted about a pivot axis which is coincident with the top edge of the panel. This embodiment is particularly suitable for converting existing ventilation flaps to work in accordance with this invention. Such existing flaps are usually plain sheets of plywood hinged at their top edges.

Further alternative constructions are possible within the scope of the invention. For example, the panels 36 need not be mounted in a frame; the hinge brackets 40 could be screwed directly to the inner faces of the house side walls 14.

Claims (15)

1. A pig fattening house having a monopitch roof, a door in its higher end wall, at least one ventilation flap above the door, the or each ventilation flap being pivoted for rotation about a horizontal axis, a motor for driving the flap or flaps in rotation, a temperature sensor in the house and control means reponsive to the temperature sensor for controlling operation of the motor.

2. A house as claimed in Claim 1, wherein the horizontal pivot axis of the ventilation flap passes through the centre of gravity of the flap.

3. A house as claimed in Claim 1 or Claim 2 having more than one flap with the flaps being arranged in the manner of louvres.

4. A house as claimed in any preceding claim, wherein the flap is constructed so that its centre of gravity is near its top edge.

5. A house as claimed in any preceding claim, wherein the flaps are mounted in a frame, and the frame is pivoted to the house structure so that the whole frame can be raised to provide access to the house.

6. A house as claimed in Claim 5, wherein a catch is provided to hold the frame in its raised position.

7. A house as claimed in Claim 5 or Claim 6, wherein the frame is made of aluminium sections so that it is light in weight.

8. A house as claimed in any preceding claim, wherein the flaps are made of transparent board material, preferably with insulating properties.

9. A house as claimed in any preceding claim, wherein the motor drives a ram which acts on the flap through a linkage.

10. A house as claimed in any one of claims 1 to 8, wherein the motor drives a winch which pulls on a cable or the like to turn the flap.

11. A house as claimed in any preceding claim, wherein the motor is electrically driven.

12. A bank of pig fattening houses as claimed in any preceding claim and arranged side by side, with one motor between two adjacent houses driving the ventilation flaps on both houses.

13. A bank of houses as claimed in Claim 12, in which there are more than two adjacent houses, the flaps on the houses outlying the houses which are adjacent to the motor being connected to the flaps in the houses adjacent the motor, so that the motor drives all the connected flaps.

14. Apparatus for modifying a pig fattening house having a monopitch roof, a door in its higher end wall, and a ventilation flap above the door, the ventilation flap being pivoted for rotation about a horizontal axis near to its top edge, the operation comprising a motor for driving the flap in rotation, a temperature sensor to be placed in the house, control means responsive to the temperature sensor for controlling operation of the motor and an arm which carries a counterweight, and which can be attached to the flap so as to effectively move the centre of gravity of the flap up towards its axis of rotation.

15. A pig fattening house substantially as herein described with reference any one embodiment shown in the accompanying drawings.