GB1593918A

GB1593918A - Reversible driving units

Info

Publication number: GB1593918A
Application number: GB2358178A
Authority: GB
Original assignee: Tromp T A; VALKERING J
Current assignee: Tromp T A; VALKERING J
Priority date: 1978-04-14
Filing date: 1978-05-26
Publication date: 1981-07-22
Also published as: FR2422877A1; NL7803991A; DE2914573A1

Description

(54) REVERSIBLE DRIVING UNITS (71) We, JAN VALKERING, of 15 Oosterzijweg, Limmen, and THEODOR US ALBERTUS TROMP, of 30 Kon.

Emmastraat, Castricum, The Netherlands, both having Dutch Nationality, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to reversible driving units, in which a reciprocatory movement is converted into a rotary movement.

The object of the invention is to provide a driving unit of the kind set forth in which the reversal of the rotary movement can take place very rapidly without the need for stopping the basic reciprocatory movement.

The driving unit according to the invention is distinguished by at least one set of three wheels, two of which are permanently in peripheral driving engagement with one another, whilst the third is arbitrarily in driving engagement with either of said two wheels, the two wheels being each fixed to a respective coaxial pawl wheel, said pawl wheels cooperating in relatively opposite senses with pawls arranged on a common, oscillatorily driven carrier.

In this way the reciprocatory movement is converted through the pawl wheel system and the two wheels in constant engagement with one another into a rotary movement of the third wheel, which is in engagement either with one or with the other wheel of said pair. The reversal of the rotary movement can, therefore, take place rapidly by moving the third wheel from one wheel to the other of the pair without the need for halting the reciprocatory movement.

In a preferred embodiment the rotary axes of the wheels are parallel to one another, and there is a first housing holding the third wheel, and a second housing adapted to pivot with respect to the first housing about an axis parallel to the rotary axis, said second housing holding the two wheels, the pawl wheels, the pawls and the carrier. The reversal of the movement can thus be performed by turning the second housing into one position or the other.

In order to ensure a slip-free transmission the wheels are preferably gear wheels.

The carrier of the pawls may be caused to reciprocate in any suitable manner. This may be performed mechanically or electrically, but preferably the carrier is formed by a cylinder adapted to slide in the second housing at right angles to the rotary axes, and to receive a pressure medium from the outside.

This liquid may be supplied by a plunger pump, in which in order to avoid any subatmospheric pressure in the system, there is a housing and at least one cylinder with a plunger arranged therein as well as a member moving said plunger, such that only pressure contact can be established between the plunger and said member.

In order to maintain a constant excess pressure in said system, the plunger pump is preferably provided with a buffer space which communicates through a non-return valve with each cylinder in the plunger pump.

If in the hydraulic system, comprising the aforesaid driving unit and plunger pump, flexible conduits are employed, it is preferred to couple the conduits through nipples with the pump and the driving unit, each nipple comprising an inwardly tapped sleeve. It is only necessary to screw into it the non-machined end of the flexible conduit in order to establish a leakage-free connection between the conduit and the nipple.

Since, owing to the pawl mechanism in the driving unit, the third wheel is freely rotatable in a sense opposite the driving direction, the driving unit preferably is associated with a brake mechanism comprising a brake drum fastened to the first housing and arranged coaxially with the third wheel, and brake bodies eccentrically and pivotally fastened to a brake carrier coupled with the third wheel.

The above-described driving unit and hydraulic system respectively are particularly suitable for use with a sun blind principally comprising a roller arranged on a facade, and a cloth to be wound thereon, the third wheel being coupled with a shaft of the roller.

A system automatically responding to sunlight or temperature is obtained by tilting the pivotable second housing by means of a temperature or sunlight detector.

In a particularly simple form the temperature detector is constituted by a liquid vessel with a displacer body, which is coupled with the pivotable second housing.

Owing to the volume variation of the liquid in the vessel, the displacer body is displaced, which displacement is transferred to the pivotable housing.

The accompanying drawings illustrate one driving unit embodying the invention, and also a pump, a brake mechanism, and a sun blind. In these drawings: Figure I is a side elevation, with a front panel partly broken away, of the driving unit; Figure 2 is a sectional view taken on the line II-II in Figure 1; Figure 3 is a longitudinal sectional view of the hydraulic plunger pump, suitable for use with the driving unit; Figure 4 is a sectional view taken on the line IV-IV in Figure 3; Figure 5 is a sectional view of the brake mechanism, suitable for use in the hydraulic driving unit of Figure 1; Figure 6 is a sectional view taken on the line VI-VI in Figure 5; and Figure 7 is a perspective view of the sun blind.

The driving unit shown in Figures 1 and 2 includes a first housing 1 fastened to any suitable support with the aid of any suitable fastening means. The unit furthermore comprises a second housing 2 adapted to pivot with respect to the first housing. The two housings accommodate a set of gear wheels 3, 4 and 5, the rotary axes of which are parallel to one another. The gear wheels 3 and 4 are permanently in engagement with one another, whereas the gear wheel 5 can mesh either with the gear wheel 3 or with the gear wheel 4, as will be explained more fully hereinafter.

Each of the permanently intermeshing gear wheels is fixed to a pawl wheel 6 and 7 respectively, associated with a pawl 8 and 9 respectively. The pawls 8 and 9 are carried by a cylinder 10, which is arranged in the second housing 2 so as to be slidable at right angles to the rotary axes of the wheels 3, 4 and 5. The pawls 8 and 9 are capable of turning, around a pin 11, in the plane going through the pawl wheels 6 and 7, and are urged by a spring 12 into the recesses of the pawl wheels. Lugs 13 ensure a correct position of the pawls relative to the pawl wheels.

Inside the cylinder 10 there is a central wall 14 formed by a cylindrical part, circumferential grooves of which receive two sealing rings 15 to define two pressure chambers in the cylinder 10. The central wall 14 is fixed in the cylinder 10 by means of a pin 16.

The open end portions of the cylinder 10 each contain a loose plunger 17, whose end located in the cylinder is sealed by means of a sealing ring located in a circumferential groove.

On the side of the cylinder 10 opposite the pawls, a pipe connection 18 permits of connecting two connecting nipples 19 for flexible supply conduits 20. The nipples are inserted into the bores 21 of the pipe connection 18, said bores 21 opening out near the end faces of the central wall 14.

The driving unit described above operates as follows. By supplying a pressure medium through the conduits 20 alternately on either side of the central wall 14 in the cylinder 10, the cylinder 10 is caused to move to the left and to the right respectively as viewed in Figure 1. In the position shown in Figure 1, fluid is supplied into the right-hand pressure chamber of the cylinder 10 so that the right-hand plunger 17 will push on the inner wall of the housing 2. The cylinder 10 is thus urged to the left so that the fluid contained in the left-hand pressure chamber is expelled through the left-hand conduit 20. During this movement of the cylinder 10, the left-hand pawl 8 will carry the pawl wheel 6 in clockwise direction, said pawl wheel 6 driving the gear wheel 3 in the same direction so that the gear wheel 4 meshing with the gear wheel 3 will rotate in anticlockwise direction and hence the gear wheel 5 will rotate in clockwise direction.

Thus the gear wheel 5 will rotate in clockwise direction. Thus the gear wheel 5 can turn with it a spindle 22 of square crosssection (see Figure 2), in the desired direction of rotation. The spindle 22 may be fastened or coupled to or with any element to be driven.

It should be noted that during this movement the right-hand pawl 9 will rise out of the recesses of the pawl wheel 7 and ride over the teeth of the pawl wheel 7.

During the return movement of the cylinder 10, that is to say, the right in Figure 1, to which end the pressure medium has to be supplied to the left-hand pressure chamber of the cylinder, the pawl 9 will carry the pawl wheel 7 in anti-clockwise direction so that the gear wheel 5 will be turned in clockwise direction, i.e. the same direction of this gear wheel 5 as during the preceding stroke of the cylinder 10. In this movement the pawl mechanism 8, 6 does not drive.

If it is desired to reverse the direction of rotation of the gear wheel 5, it is only necessary to turn the housing 2 with respect to the housing 1 about the pivotal axis 23, which is parallel to the rotary axes of the wheels 3, 4 and 5, so that the gear wheel 4 is disengaged from the gear wheel 5, whereas the gear wheel 3 will mesh with gear wheel 5.

Without stopping the pulsatory inlet and outlet of the fluid in the conduits 20, and hence without halting the reciprocatory movement of the cylinder 10, the reversal of the sense of rotation of the wheel 5 is directly performed, since the gear wheel 3 will constantly rotate in clockwise direction and, when engaging the wheel 5, it will cause the latter to move in anti-clockwise direction.

Figures 3 and 4 show a plunger pump by which the pressure medium, in this case a liquid, can be supplied to the driving unit shown in Figures 1 and 2. The pump comprises a housing 30 accommodating two cylinders 31. Each cylinder 31 contains a plunger 32 having an elastic sealing member 33 on the pressure side.

Each plunger has a longitudinal bore, in which a thrust rod 34 is freely movable, the free end of said rod being engaged by a driving member 35. The member 35 is fastened to a spindle 36 having a hexagonal cross-section. The spindle is passed through the sidewall of the housing 30 (Figure 4), one end of the spindle being prolonged for mounting a lever 37 thereon.

The housing 30 has three connection openings 38 in a pipe connection 39. The right-hand opening as seen in Figure 3 communicates with the upper pressure space 31 of the cylinder, the central opening communicates with the lower pressure space of the cylinder as indicated by broken lines in the Figure, whereas the left-hand opening communicates with a buffer space 40 located opposite the cylinders 31. The two openings 38 leading to the cylinders receive connecting nipples 19 of flexible conduits 20, which lead to the driving unit shown in Figures 1 and 2. The left-hand opening 38 of the housing 30 is closed by a blind nipple 41 and it should be noted that this connecting opening 38 has furthermore a non-return valve 42.

The buffer space 40 has a buffer body 44 loaded by a spring 43 and having a sealing ring 45 held in a circumferential groove.

Each cylinder 31 communicates with the buffer space through a channel passing through the inner wall of the housing 30, in which channel 46 a non-return valve 47 is operative.

The plunger pump described above operates as follows.

By moving the lever 37 to and fro, for example manually, the driving member 35 will perform a rocking movement and thus alternately exert pressure on the upper and lower thrust rod 34 respectively of the plungers 32 of Figure 3. It should be noted that only a pressure contact can be effective so that the body 35 cannot draw the plunger 32 to the right as seen in Figure 3. Starting from the position shown in Figure 3, a left-hand movement of the lower plunger 32 will result in a pressure being produced in the fluid, which is subsequently urged through the central connecting opening 38 through the left-hand conduit 20 towards the driving unit of Figure 1. On the other hand the fluid in the driving unit will be urged out of the cylinder 10 sliding therein and will be conducted back to the upper cylinder 31 of the plunger pump so that the upper plunger body 32 is moved to the right in Figure 3. Subsequently the driving member 35 can be turned in anti-clockwise direction, as a result of which the fluid will flow in the reverse sense through the conduits 20 and the cylinder 10 will perform a return movement in the driving unit.

In this normal operational state the nonreturn valves 37 remain closed since their sealing rings are urged against the valve seats in the partition of the cylinder 30.

The buffer space 40 serves as a reservoir for spare fluid to meet any leakage.

Moreover, the buffer space serves for maintaining a desired operational pressure, which can be adjusted in dependence upon the spring 43, since, after removal of the screw cover, pressurized fluid can be introduced into the connection nipple 41 so that the non-return valve 42 is lifted from its seat and the fluid flows into the buffer space 40.

The body 44 is thus urged to the left against the action of the spring 43, so that the fluid is exposed to a given pressure. If this pressure is higher than the pressure in the cylinders 31, fluid will flow through the valves 47 to the right in Figure 3 until the pressure in the cylinders 31 is equal to the pressure in the buffer space 40. When the plungers 32 are again moved, the valves 47 will close so that the normal operational state can be resumed.

Figures 5 and 6 illustrate a brake mechanism, which is particularly suitable for use with the driving unit of Figures 1 and 2.

From the description of the driving unit it will be obvious that the gear wheel 5 can rotate freely in the direction opposite the sense of driving owing to the pawl mechan ism 6, 8 and 7, 9 respectively. In certain uses it may be desirable, with said free rotation, to brake the spindle 22, when it attains a given speed.

This is achieved by means of a brake mechanism shown in Figures 5 and 6, which comprises a drum 50, which can be fastened by means of the screw bolts 24 of the stationary housing 1 of the driving unit, as shown in Figure 6. The spindle 22 of the gear wheel 5 is passed through the drum 50 and passes through a recess of a carrier 51.

The width of the recess 52 thereof is substantially equal to the width of the spindle 22, so that upon a turn of the spindle 22 the carrier 51 is carried along, as a result of which the carrier 51 performs an angular rotation with respect to the drum 50.

The carrier 51 supports two brake shoes 53, each of which is pivoted by a pin 54 to the carrier. Since the pin is located eccentrically to the centre of rotation, the brake shoe 53 is swung outwardly during rotation, the frictional material 55 being thus urged against the inner side of the drum 50, a braking effect being thus produced and hence a reduction of the speed of revolution.

Figure 7 illustrates a hydraulic system including the component parts described above. The hydraulic system is employed with a sun blind 60 comprising a roller 61, on which a sun screening cloth 62 can be wound. To the free lower edge of the sun blind 62 is fastened a lower batten 63, which can be swung out by means of extension arms 64. The roller 61 and the extension arms 64 are secured to a facade, the window and the cavity wall of which are schematically indicated in Figure 7.

To one end of the shaft of the roller 61 is fastened the driving unit of Figure 1, which is provided on the outer side with the drum 50 of Figure 5. On the inner side of the facade is arranged a plunger pump 30 as shown in Figures 3 and 4, the lever 37 being shown in the form of a hand crank. Conduits 20 pass from the plunger pump through the cavity wall to the outside and are coupled with the pivotable part of the driving unit of Figure 1.

In order to turn the lower part of the driving unit it is provided at one end with a connecting ear 65, with which is coupled a Bowden cable 66, which can be operated on the inner side of the wall by the user by means of a pull ring 67. Below the driving unit 1 a bracket 68 is secured to the facade for supporting the sheath of the Bowden cable 66 on the lower side, whilst a compression spring 69 is arranged between the pivotable part of the driving unit 1 and the bracket 68.

The system is arranged so that the spring 69 invariably moves the driving unit into the position in which the cloth can be wound up by reciprocating the crank 37.

When the cloth is wound up, the user can reverse the direction of rotation of the unit by pulling the Bowden cable and moving the crank 37 so that the cloth is released. As soon as the travel of the batten 63 is sufficiently large, the device becomes free to move owing to gravity and to the release of the ring 67 of the Bowden cable so that the cloth is freely wound off. The brake 50 will control this movement.

Figure 7 shows furthermore a hydraulic temperature detector which takes over the function of the Bowden cable so that the cloth automatically lowers when a given temperature is attained as a result of incident sunlight.

The temperature detector comprises a screened fluid vessel 70 and an unscreened fluid vessel 71, which are coupled with one another by means of a beam 72. The beam is connected with the piston of a cylinder 73, which communicates through a duct with a second cylinder 74. The piston of the latter is coupled with the pivotable part of the driving unit 1. As soon as the fluid in the vessels 70 and 71 expands as a result of an increase in temperature, the displacement of the piston in the cylinder 73 will cause a displacement of the piston in the cylinder 74 and the pivotal part of the driving unit will be changed over. It will be obvious that the beam 72 with the double fluid vessels 70, 71 excludes the influence of the ambient temperature.

WHAT WE CLAIM IS: 1. A reversible driving unit in which a reciprocatory movement is converted into a rotary movement comprising at least one set of three wheels, two of which are permanently in peripheral driving engagement with one another, whilst the third is arbitrarily in driving engagement with either of said two wheels, the two wheels being each fixed to a respective coaxial pawl wheel, said pawl wheels cooperating in relatively opposite senses with pawls arranged on a common oscillatorily driven carrier.

2. A unit as claimed in claim 1, in which said wheels are gear wheels.

3. A unit as claimed in claim 1 or claim 2, in which the rotary axes of the wheels are parallel to one another, including a first housing holding the third wheel, and a second housing adapted to pivot with respect to the first housing about an axis parallel to the rotary axes, said second housing holding the two wheels, the pawl wheels, the pawls and the carrier.

4. A unit as claimed in claim 3, in which the carrier is formed by a cylinder adapted to slide in the second housing at right angles to the rotary axes, and to receive a pressure medium from the outside.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ism 6, 8 and 7, 9 respectively. In certain uses it may be desirable, with said free rotation, to brake the spindle 22, when it attains a given speed. This is achieved by means of a brake mechanism shown in Figures 5 and 6, which comprises a drum 50, which can be fastened by means of the screw bolts 24 of the stationary housing 1 of the driving unit, as shown in Figure 6. The spindle 22 of the gear wheel 5 is passed through the drum 50 and passes through a recess of a carrier 51. The width of the recess 52 thereof is substantially equal to the width of the spindle 22, so that upon a turn of the spindle 22 the carrier 51 is carried along, as a result of which the carrier 51 performs an angular rotation with respect to the drum 50. The carrier 51 supports two brake shoes 53, each of which is pivoted by a pin 54 to the carrier. Since the pin is located eccentrically to the centre of rotation, the brake shoe 53 is swung outwardly during rotation, the frictional material 55 being thus urged against the inner side of the drum 50, a braking effect being thus produced and hence a reduction of the speed of revolution. Figure 7 illustrates a hydraulic system including the component parts described above. The hydraulic system is employed with a sun blind 60 comprising a roller 61, on which a sun screening cloth 62 can be wound. To the free lower edge of the sun blind 62 is fastened a lower batten 63, which can be swung out by means of extension arms 64. The roller 61 and the extension arms 64 are secured to a facade, the window and the cavity wall of which are schematically indicated in Figure 7. To one end of the shaft of the roller 61 is fastened the driving unit of Figure 1, which is provided on the outer side with the drum 50 of Figure 5. On the inner side of the facade is arranged a plunger pump 30 as shown in Figures 3 and 4, the lever 37 being shown in the form of a hand crank. Conduits 20 pass from the plunger pump through the cavity wall to the outside and are coupled with the pivotable part of the driving unit of Figure 1. In order to turn the lower part of the driving unit it is provided at one end with a connecting ear 65, with which is coupled a Bowden cable 66, which can be operated on the inner side of the wall by the user by means of a pull ring 67. Below the driving unit 1 a bracket 68 is secured to the facade for supporting the sheath of the Bowden cable 66 on the lower side, whilst a compression spring 69 is arranged between the pivotable part of the driving unit 1 and the bracket 68. The system is arranged so that the spring 69 invariably moves the driving unit into the position in which the cloth can be wound up by reciprocating the crank 37. When the cloth is wound up, the user can reverse the direction of rotation of the unit by pulling the Bowden cable and moving the crank 37 so that the cloth is released. As soon as the travel of the batten 63 is sufficiently large, the device becomes free to move owing to gravity and to the release of the ring 67 of the Bowden cable so that the cloth is freely wound off. The brake 50 will control this movement. Figure 7 shows furthermore a hydraulic temperature detector which takes over the function of the Bowden cable so that the cloth automatically lowers when a given temperature is attained as a result of incident sunlight. The temperature detector comprises a screened fluid vessel 70 and an unscreened fluid vessel 71, which are coupled with one another by means of a beam 72. The beam is connected with the piston of a cylinder 73, which communicates through a duct with a second cylinder 74. The piston of the latter is coupled with the pivotable part of the driving unit 1. As soon as the fluid in the vessels 70 and 71 expands as a result of an increase in temperature, the displacement of the piston in the cylinder 73 will cause a displacement of the piston in the cylinder 74 and the pivotal part of the driving unit will be changed over. It will be obvious that the beam 72 with the double fluid vessels 70, 71 excludes the influence of the ambient temperature. WHAT WE CLAIM IS:

1. A reversible driving unit in which a reciprocatory movement is converted into a rotary movement comprising at least one set of three wheels, two of which are permanently in peripheral driving engagement with one another, whilst the third is arbitrarily in driving engagement with either of said two wheels, the two wheels being each fixed to a respective coaxial pawl wheel, said pawl wheels cooperating in relatively opposite senses with pawls arranged on a common oscillatorily driven carrier.

2. A unit as claimed in claim 1, in which said wheels are gear wheels.

5. A unit as claimed in claim 4, in which

the cylinder is a double-acting cylinder.

6. A unit as claimed in claims 4 or 5, in which the cylinder comprises a central wall, whilst each open end contains a plunger thrusting against the inner wall of the second housing.

7. A driving unit as claimed in any of claims 3 to 6, and a brake mechanism comprising a brake drum fastened to the first housing and arranged coaxially with the third wheel, and brake bodies eccentrically and pivotally fastened to a brake carrier coupled with the third wheel.

8. A sun blind principally comprising a roller, a cloth to be wound thereon, and a driving unit as claimed in any of claims 1 to 7, in which the third wheel is coupled with a shaft of the roller.

9. A sun blind as claimed in claim 8, in which the driving unit is as claimed in any of claims 3 to 6, and the pivotable second housing of the driving unit is controlled by means of a temperature or sunlight detector.

10. A sun blind as claimed in claim 9, in which the temperature detector is formed by a liquid vessel with a displacer body, which is coupled with the pivotable second housing of the driving unit.

11. A sun blind as claimed in claim 10, in which the temperature detector comprises a second liquid vessel, which communicates through a beam with the first liquid vessel.

12. A sun blind as claimed in claim 11, in which the beam of the temperature detector is connected through a hydraulic system with the pivotable second housing of the driving unit.

13. A hydraulic system comprising a driving unit as claimed in any one of claims 1 to 6, and a plunger pump comprising a housing and at least one cylinder with a plunger arranged therein as well as a member moving said plunger, such that only pressure contact can be established between the plunger and said member.

14. A system as claimed in claim 13, in which there is a buffer space, which communicates through a non-return valve with each cylinder in the plunger pump.

15. A unit as claimed in claim 1, substantially as described hereinbefore with reference to Figures 1 and 2 of the accompanying drawings.

16. A system as claimed in claim 13, substantially as described with reference to Figures 1 to 4 of the accompanying drawings.

17. A sun blind as claimed in claim 8, substantially as described with reference to Figures 1 to 7 of the accompanying drawings.