GB1585957A

GB1585957A - Weight placing and removing attachment to piston-type dead-weight test apparatus

Info

Publication number: GB1585957A
Application number: GB2522278A
Authority: GB
Original assignee: VNII METROLOGI SLUZBY
Current assignee: VNII METROLOGI SLUZBY
Priority date: 1977-06-14
Filing date: 1978-05-31
Publication date: 1981-03-11
Also published as: PL112652B1; ATA426278A; SU636948A1; PL207520A1; DE2825891C2; AT370883B; FR2394791A1; DE2825891A1; FR2394791B1

Description

(54) WEIGHT PLACING AND REMOVING ATTACHMENT TO PISTON-TYPE DEAD-WEIGHT TEST APPARATUS (71) We, VSESOJUZNY NAUCHNO-IS SLEDOVATELSKY INSTITUT METROLOGICHE SKOI SLUZHBY, of Ezdakov pereulok, 1, Moscow, Union of Soviet Socialist Republics, a Corporation organised and existing under the laws of the Union of Soviet Socialist Republics, 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 particu la'riy described, in and by the following statement: The present invention relates to control and measuring installations and more particularly, to the weight placing and removing attachments to a piston-type deadweight test apparatus.

The present invention can be used to advantage in automatic pressure setters with a programming unit.

The essence of the invention resides,in that in a weight-placing.and removing t- tachment to a piston-type deadweight test apparatus comprising rigidly-interconnected piston and weight pan and having a set of weights in the form of coaxial cylinders placed on the weight. pan-and a programming unit interacting with the set of weights as they are placed on, and removed from, the weight pan and comprising a vertically-movable support, a weight holder and electromagnets connected with the latter wherein, according to the invention, the weight holder of the programming unit comprises three brackets arranged on a vertically-movable support at 120 from one another, each bracket having a vertical row of horizontal holes, as many as there are the weights, and provided with two guides, three spring-loaded cam racks with the number of cams corresponding to that of the weights, each rack being installed in the guides of the corresponding bracket with a provision for vertical movement relative to the bracket, and detents entering partly into the horizontal holes of the brackets, kinematically linked with the cams of the spring-loaded cam rack and interacting with the electromagnets and the circular flanges on the ends -of the weight cylinders that are farthest from the weight pan, the outside diameters of the flanges of all the weights being - identical while the cylindrical weights proper differ from one another in height.

The present invention provides for direct power supply to the electromagnets which promotes reliability.

Moreover, the present invention. permits the use of a great variety of weights with respect to their size and, consequently, weight, which increases the load - capacity of the mechanism.

Now the invention will be described in detail by way of example with- reference to the accompanying drawings in which: Fig. 1 is a front sectionalized view of the weight placing and removing attachment to a piston-type deadweight test apparatus according to the invention; Fig. 2 is a section taken along line II-II in Fig. 1; Fig. 3 illustrates the weight placing and removing attachment to a piston-type deadweight test apparatus in a position when the set of weights is placed on the weight pan of the test apparatus and the springloaded cam rack has reached the -fixed stop, according to the invention, a sect tionalized front view; Fig. 4 is -a front sectionalized view of the weight placing and removing attachment to a piston-type deadweight test apparatus at the moment when the weight holder occupies the downmost position and all the detents are withdrawn from the weights, according to the invention; Fig. 5 is a front sectionalized view of the weight placing and removing attachment to a piston-type deadweight test apparatus in a position when one of the weights is placed on the weight pan, according to the invention.

The weight-placing and removing at tachment to a piston-type deadweight test apparatus 1 (Fig. 1) comprises a programming unit 2 and a set 3 of weights 4. The test apparatus 1 has rigidly interconnected piston S and weight pan 6 on which the set 3 of the weights 4 is placed. The weights 4 have the form of coaxially arranged cylinders of different height, the end of each cylinder located farther from the weight pan 6 being provided with a circular flange 7. The outside diameters of the circular flanges 7 of all the weights 4 are identical.

The programming unit 2 comprises a vertically-movable support 8 rigidly interconnected with a weight holder 9. The weight holder 9 consists of three brackets 10 (Figs. 1, 2), three spring-loaded cam racks 11, electromagnets 12 and detents 13. The brackets 10 are arranged on the support 8 at an angle of 1200 from one another.

Each bracket 10 is provided with two guides 14 (Fig. 1, 2) and a vertical row of horizontal holes, their number correspond- ing to that of the weights 4; said holes partly receive the detents 13. Each detent 13 has a collar 15 against which a spring 16 bears. One end of the detent 13 has a slot accommodating a roller 7. Each spring-loaded cam rack 11 (Fig. 1) is installed in the guides 14 of. the corresponding bracket 10 with a provision for moving vertically relative to said bracket 10. Each rack 11 has cams 18, their number being equal to that of the weights 4. Each cam 18 is located opposite the corresponding roller 17 (Fig. 2).

Secured in the lower end of the rack Ii (as shown in the drawing) is a spring 19.

Under the racks 11 there is a fixed stop 20. The number of electromagnets - 12 on each bracket 10 is equal to that of the weights 4. The rod 21 (Fig. 2) of each electromagnet 12 is arranged opposite the collar 15 of the detent 13.

The movable support 8 (Fig. 1) is secured on the cylinder 22 of the hydraulic cylinder 23 whose piston 24 is made in the form of a circular collar on the stationary pillar 25. Fixed rigidly on the pillar 25 are the stop 20 and the piston-type deadweight test apparatus 1. The pillar 25 has three passages 26, 27 and 28. The passages 26 and 28 communicate with the chambers 29 and 30, respectively, of the cylinder 23.

The passage 27 is in communication with the test apparatus 1.

The attachment functions as follows.

Pressure is delivered into the hydraulic cylinder 23 (Fig. 1) through the passage 28 while the passage 26 is connected to the return line. The cylinder 22 of the hydraulic cylinder 23 goes down together with the vertically-movable support 8 and the weight holder 9. During this process first all the weights 4 are placed on the weight pan 6 (Fig. 3) and there appear clearances between the circular flanges 7 of the weights 4 and the detents 13. As the cylinder 22 (Fig. 4) goes further down to the downmost position together with the weight holder 9, the spring-loaded cam racks 11 come to bear' against the fixed stop 20 compressing the spring 19 and the cams 18 pull all the detents 13 to the ex- treme left position (as shown in the drawing). In this, position of the cylinder 22 the programming unit (not shown in the draw .ing) gives a command to energize the corresponding electromagnets 12 so that their rods 21 (Figs. 4, 2) extend out before .,the collars 15 of the detents 13. Then pressure is delivered into the passage 26 (Fig.

4), the passage 28 is connected to the return line and the cylinder 22 starts rising together with the weight holder 9. Under the force of the spring 19 the cam racks 11 move down relative to the brackets 10 and release the detents 13 while some of the detents which are not held by the rods 21 of the electromagnets 12 are returned by the springs 16 to the extreme right position (as shown in the drawings). The ends of the detents 13 facing the weights 4 come under the circular flanges 7 of the corresponding weights 4. As the cylinder 22 with the weight holder 9 move farther up, the weights 4 whose circular flanges 7 rest on the ends of the detents 13 are removed from the weight pan 6 while the weights 4 whose electromagnets 12 have been energized remain lying on the weight pan 6.

The present invention permits the use of less powerful electromagnets and thus cuts down the cost of the programming unit utilized in the apparatus.

Besides, the present invention simplifies the design of the attachment which like- wise reduces its cost.

Claims

WHAT WE CLAIM IS: -

1. A weight placing and removing at tachment to a piston-type deadweight test apparatus comprising rigidly interconnected piston and a weight pan, having a set of weights in the form of coaxially arranged cylinders installed on a weight pan, and a programming unit interacting with the set of weights during their placing on, and removal from, the weight pan and having rigidly interconnected vertically-movabIe support and a weight holder with electro magnets, said holder consisting of three brackets arranged on the vertically-mov- able support at an angle of 1200 to one another, each bracket being provided with a vertical row of horizontal holes, whose number .is equal to that of the weights anb with two.guides fixed - thereto, three spring-.loaded -cam racks, the number of their cams corresponding to the number of the weights and each rack being installed in the guides of the corresponding bracket with a provision for moving vertically relative to the bracket, and detents located partly in the horizontal holes of the brackets, kinematically linked with the cams of the spring-loaded cam racks and interacting with the electromagnets and with the circular flanges made on the ends of the cylindrical weights located farther from the weight pan, the outside diameters of the circular flanges of all the weights being identical though the weights proper differ from one another in height.

2. A weight placing and removing attachment to a piston-type deadweight test apparatus realized substantially as disclosed in the description with reference to the accompanying drawings.