Title of Invention


Abstract "Special Pre-tensioning Mechanism is commonly used to give some tension to the test specimen before testing. This invention makes the pre-tension automatically by pnuematic cylinders and its arrange- ments. It avoids the vast variation between test results."Pneumatic clamping arrangements at Jaws" is commonly used in clamping, any test spcimen in tensile testing instruments. The specimen breakage due to overtighting at clamps known as Jaw breakage and it can be avoided.Clamping is much faster, when compared to manual clampings.
Full Text Summary of the Invention:
Tensile testing Instruments were commonly used to test the tensile properties of all materials.The present
invention relates to a" Special Pre-tensioning mechanism and clamping arrangement for Jaws" in the
tensile testing instruments.
The above invention provides a easy way for Pre-tensioning arragement by using pneumatic cylinders.
This invention is useful to test the materials like single yam, Multiple yarn; clothes; fine wire"s
flexible rod.etc.
Background Art:
1. Pre-tensioning Mechanism
Existing tensile testing instruments are having following two type of pre-tensioning arrangements.
a. Manual tensioning arrangement:
In this type, pre-tension applied by standard weights in the form of clip to hold the testing specimen. Disadvantages.Time consuming and inaccurate.
b. Moving jaw pre-tensioning arrangement:
In this type moving jaw itself used to apply the pre-tension on the test specimen.After applying pre-tension by moving jaw.the top jaw will clamp.
Disadvantages:Testing length of specimen may be varied depending upon the enlongation.of the test specimen.This lead to error in test values.
2. In Clamping Jaws
Some models are using pneumatic cylinders with some mechnical components to clamp jaws.few models are having mechanical clampings alone.These methods are time consuming and inaccurate.
Object of the Invention:
The principle objective of the present invention is to overcome the above mentioned difficulties and disadvantages.In our invention clamping and pre-tensioning is automatic,highly accurate ,easy and more precise.
Brief Description of the Drawings:
The Invention will be explained in more details below with aid of an exemplary embodiment illustrated in drawings, wherein
Fig 1 shows the isometric view of one type of Pre-tension mechanism assembly.
Fig 2 shows isometric view of one type of Pre-tension mechanism assembly with Top jaw
and its moving mechanism. Fig 3 shows the Sectional elevation of Pre-tension assembly. Fig 4 shows the isometric view of Bottom jaw with load cell. Fig 5 shows the isometric view of one type of Tensile Testing Instrument with yam loaded before testing.

An embodiment of this is described herein after with reference to accompanying drawing {Fig. 1,2,3,4 and 5) showing new invention arrangement in the special Pre-tensioning Mechanism and clamping arrangements for jaws.
"Pre-tension mechanism" (Ref.fig. 1) in this invention the pneumatic cylinder (2) is fitted inside the Pre-tension body (1). The Pre-tension pad (12) is mounted on piston rod (11) of pneumatic cylinder (2). The pneumatic cylinder (2), Pre-tension body (1) and Pre-tension pad (12) is arranged in such a way to clamp the test specimen (21) while operating pneumatic cylinder (2) by compressed air. The other end of Pre-tension body (1) is fitted with a hook (7) to mount Pre-tension weight (10).
A ring (9) is inserted on the Pre-tension body (1) and this is located in such a way to balance both side of Pre-tension body(1). The ring (9) is fitted with two balancing shafts (4) & (5) to balance the whole arrangement on two bearings (6) at both sides. The bearings (6) fitted with a bracket (8).One side of the balancing shaft (5) is a hollow one, it is connecting the pneumatic hose to pneumatic cylinder (2),
Both side of the Pre-tension body (1) dosed.So while passing compressed air through the balancing shaft (4) it will reach easily to pneumatic cylinder (2) and it will operate. The spiral pneumatic hose (22) is fitted on the balancing hollow shaft (4) in such a way that it does not affect the balanced condition of the arrangement ref fig 3.
At the back of the Pre-tension body (1) a small pneumatic cylinder (3) is provided on the top plate(15). While operating this pneumatic cylinder (3) the piston rod (27) will push the back side of Pre-tension body (1) upward and simultaneously the other end of the Pre-tension body (1) goes downward,
While operating the pneumatic cylinder (2) it will clamp the test specimen (21) in between Pre - tension pad (12) and Pre-tension body (1). After clamping, piston (11) of pneumatic cylinder (2) will operate to release the Pre-tension body (1).Due to Pre-tension weight (10), the unbalanced Pre-tension body (1) will put the test specimen (21) upward, at the same time this specimen(21) will also be clamped at the bottom jaw (28). Due to this arrangement the Pre-tension will act, directly on the test specimen(21). Ref fig 2,4 & 5 the top (29) and bottom jaw (28) fitted with "Pneumatic foot mounting clamping modules (19)and (24).
The "Pneumatic foot mounting clamping module" is securely fitted on the vertical plate (20). Usually the conventional clamping module is fitted with flat metal faces. But in this invention we have changed the metal faces (16) to V type instead of flat one. At front side of the clamping module (19), the Jaw face (17) is fitted with the bottom plate (18). This Jaw face (17) is V grooved to accomodate the"v" shape metal face (16) of the clamping module(19).
The distance between the Jaw faces depends upon the capacity of the machine.in between facesof the top Jaw (29), a groove is provided in the bottom plate(18) in such a way not to disturb thespecimen(21) while Pre-tensioning, clamping and testing. The bottom Jaw (28) is also arranged in similar way like top Jaw (29) but mounted on the load cell (23). The V groove is also provided on the Bottom Jaw (28) for similar purpose as in top Jaw (29) ref fig 4.

Testing Procedure:-
The suitable Pre-tension weight (10) is placed on the hook(7) according to the test specimen(21).When the instrument is switched "ON" the bottom Jaw (28) will clamp the test specimen(21). Immediately after clamping, the pneumatic cylinder (2) of Pre-tension mechanism will operate and hold the specimen sample(21).
After that the pneumatic cylinder (2) will release the Pre-tension body (1) to act Pre-tension on test specimen(21).This Pre-tension applied on test specimen(21) is proportional to distance of the hook(7) and specimen(21) from centre of the Balancing hollow shaft (4).
After applying the selective Pre-tension the top" Pneumatic foot mounting clamping module(19) will be energized by compressed air, to hold the specimen (21) firmly in between the V groove and centre of clamping module. Immediately after clamping the pneumatic cylinder (3) will operate to bring down the front portion of Pre-tension body (1) towards top Jaw (29) i.e. the release of the Pre-tension,
Due to this movement the specimen(21) is relaxed in between top Jaw(29) to Pre-tension pad (12). Now the Pre-tension is applied to specimen(21) only in between top (29) and bottom Jaws (28).Then the top jaw(29) will move upward by screw rod (13) mechanism which slides on the guide rod (14).
Due to this upward movement, load will be applied on the test specimen (21) and it is measured by the load cell(23). Immediately after breakage of the test specimen(21), the load celf(23) will measure the maximum breaking load.
After completion of breaking the test specimen (21), screw rod (13) will rotate in opposite direction to bring down initial selected test distance of top Jaw(29). After reaching its original position the Pneumatic cylinder (2) & (3) of Pre-tension mechanism , top(29) and bottom(28) Jaws will operate to release the test specimen(21) simultaneously. Now Machine is ready for conducting next test as similar to previous one.

I Claim:
1. "Special Pre-tensioning Mechanism with clamping module for Jaws of Tensile Testing Instruments/
Machines"comprising of;
a pneumatic cylinder (2} fitted inside a pre-tension body(1);
a pre-tension pad (12) connected with piston rod(11) of the pneumatic cylinder(2);
the two hollow balancing shafts (4),(5) covered by a ring (9) are mounted on bearings (6);
a spiral hose (22) fitted on one side of hollow balancing shaft (4);
a pre-tension weight (10) mounted on other side of the pre-tension body(1);
the pneumatic cylinder (3) mounted under the backside of pre-tension body(1).
2. "Special Pre-tensioning Mechanism with clamping module for Jaws of Tensile Testing Instruments/
Machines"consisting of;
a pneumatic foot mounted clamping modules (19), (24) fitted on a vertical plate (20) and arranged in perpendicular for test specimen(21);
a triangular metal face(16) of clamping module (19), (24) is provided;
a V groove face provided for jaw face (17) ,(26);
a proper alignment is provided such that centre of the pre-tension body (1) and centre of the clamping module (19),(24) are in same line.similar arrangement made in bottom jaw(28),but bottom plate fitted on a load cell (23).


825-mas-2001 abstract.pdf

825-mas-2001 claims duplicate.pdf

825-mas-2001 claims.pdf

825-mas-2001 correspondence others.pdf

825-mas-2001 correspondence po.pdf

825-mas-2001 description (complete) duplicate.pdf

825-mas-2001 description (complete).pdf

825-mas-2001 drawings duplicate.pdf

825-mas-2001 drawings.pdf

825-mas-2001 form-1.pdf

825-mas-2001 form-13.pdf

825-mas-2001 form-19.pdf

Patent Number 209083
Indian Patent Application Number 825/MAS/2001
PG Journal Number 38/2007
Publication Date 21-Sep-2007
Grant Date 20-Aug-2007
Date of Filing 08-Oct-2001
# Inventor's Name Inventor's Address
PCT International Classification Number G 01 N 3/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA