FORM 2
THE PATENTS ACT, 1970 [39 OF 1970]
COMPLETE SPECIFICATION [SEE SECTION 10 & RULE 13]
1 TITLE
TAMPER-PROOF SEALING MECHANISM FOR VARIOUS ADJUSTMENT MEANS
2 APPLICANT
NAME MAHEVDRA & MAHEVDRA LTD. a company registered
under the Indian Companies Act, 1913 haying its Registered office at
ADDRESS 1, GATEWAY BUELDING, APOLLO BUNDER, MUMBAI
400001
2 4 MAY 2005
The following specification particularly describes the nature of the invention and the manner in which it is to be performed:-
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Field of invention:
The present invention relates to provision of tamper-proof sealing mechanism for protecting various adjustment means such as adjustment screws / nuts / bolts of fuel injection pump (FIP) or alike, to eliminate / avoid the possibility of resetting by disturbing original setting of these adjustment means other than recommended source. This will discourage / restrict users from fiddling with such adjustment means of FIP or alike, which further affects vehicle performance, inadequate warranty claims & various emission norms.
Background of invention:
Fuel Injection Pump (FIP) is heart of diesel engine, which supplies the required quantity of fuel as per speed & load conditions. Different fueling adjustments are carried out to achieve better vehicle performance & various emission norms through an external access, which are described as low dle, high Idle & full load adjustment means such as screws / nuts / bolts. These adjustments are determined by the manufacturer as suitable for the vehicle and the user of the vehicle or any unauthorized person should not disturb these settings as it may have an adverse effect on performance. After necessary fueling adjustment at manufacturer end by using standard FIP test bench, these adjustment means are sealed before handing over FIP to customer. At the same time there should be some means, which gives the indication of any changes in fuel setting carried out at user end, to avoid warranty claims on fueling adjustments at user end.
In current practices the locking (sealing) mechanism provided by certain manufactures is not able to completely fulfill desired requirements. Regular practice of providing tag wire & metal seal have not sufficiently discouraged operator(s) from adjusting these adjustment means to their particular desires.

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There have been periodic attempts to overcome the shortfall in the tag wire and metal system e.g. In US Patent 4,470,769 an attempt has been made to create a tamper-resistant seal for discouraging unauthorized access to an adjusting screw located in a fuel injection pump. According to this invention a separate cover and bracket are provided to cover the adjustment screw by using combination of studs, one-way fastners, push-on fastners and the like. Although the invention could discourage users and unauthorized personnel from tampering the adjustment screws in actuality the invention is of a mechanism, which is too complicated and hasa number of components which unnecessarily increases the seal size, packaging constrains, operating costs and time. Another attempt has been made by US Patent No 4,308,220 to provide for the enetosure^of the adjustment screw or the like within a closed chamber provided by a tubular surrounding wall and sealing plug. The mechanism under this invention can be opened by means of a special tool, which tool, in todays scenario, can be obtained with ease, giving rise to disputes or claims of defects as the means of opening by the special tool would not damage the seal and the opening may not be prima facie evident
In US Patent No 4,273,730 a tamper resistant device has been created for a carburetor idle adjustment screw. In this invention a cavity has to be created on the carburetor body above the adjustment screw and a blocking pin is placed between the adjustment screw and a plug, blocking the access to the adjustment screw from the outer end of the carburetor. The mechanism does not suit any other device other than a carburetor and does not prevent manipulation of various FIP adjustment screws at the user end. Additionally in case of any damages during authorised / unauthorized use, to the area where the locking members are provided will cause complete replacement of whole carburetor body.
All the above Patents have limitations in applications.

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Therefore, it is necessary for a manufacturer to provide simpler, compact in design, cost effective Tamper-proof locking (sealing) mechanism for various adjustment means of FIP or alike either commonly or separately, which will ensure fuel or alike setting to be done by authorized source on standard FIP test bench only. The adjustment of fuel setting is carried out at the outset to achieve better vehicle performance & various emission norms forever and identification of any disturbance in fuel adjustment at user can be easily identified to negative wrongful warranty claims.
Summary of the Invention:
Therefore it is an objective of this invention to provide a simpler, compact, cost effective tamper-proof locking (sealing) mechanism for various adjustment means such as adjustment screws / nuts / bolts of fuel injection pump (FIP) or alike , which will ensure fuel or alike setting only on standard FIP test bench as per specification.
Another object of the present invention is to discourage / restrict users from fiddling with FIP fuel setting without referring to authorized source, thereby maintaining standard & better vehicle performance with various emission norms forever.
Another object of the present invention to avoid inadequate / faulty warranty claims created because of disturbing original FIP fuel settings by unauthorized source.
Other objects and features of the present invention will be apparent to those skilled in the art, based on the following description taken in combination with the accompanying- drawings & can be used in other sealing areas depending up on the requirements & benefits.
Brief description of the Drawing:
Figurel shows the fuel injection pump (without engine) along with various fuel adjustment screws.
Figure 2 shows at least one type of tamper-proof sealing mechanism developed for sealing FIP or alike adjustment screws.

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Detailed description of the preferred Embodiments
To eliminate problems created by tampering of these adjustment means [pertaining to fueling adjustments] of FIP, it is desired to have a tamper-proof seal mechanism which will avoid easy access to these adjustment means , thereby avoiding fiddling with these adjustment means at customer end without referring authorized FIP setting source.
The invention is explained in accordance with the drawings shown in figures 1 & 2, in which adjustment means (hereafter referred as screws) are Low Idle (1), High Idle (2) and Full Load (3) are at there their respective locations on FIP (8). Each of these screws (1, 2 & 3), are adjusted as per the specification for better vehicle performance & various emission norms requirement, at manufacturer end and locked at their final position. Depending upon the adjustment screws' locking arrangement, screw locking nut (4) may be provided on each adjustment screw (1.2&3).
In order to adjust these screws (1, 2 & 3), screw locking nut (4) has to be loosened. Therefore, by covering this locking nut (4) by tamper-proof sealing mechanism (9), access can be denied from unauthorized users. According to the requirement for a tamper-proof seal, at least one type of seal mechanism is shown in figure 2, in which sleeve (5) having cylindrical bores on either side of it's middle wall (14) is mounted in such a way to cover fuel adjustment screws (1, 2 & 3) with or without screw locking nut (4). Sleeve (5) is locked against FIP body (12) with sleeve locking nut (6) entered from opposite side cylinder bore of fuel adjustment screws. Thereby sleeve (5) is locked against pump body surface / plan (12) covering adjustment screws & / or screw locking nut. Spring washers (13) are provided on either side of the middle wall (14) of the sleeve (5), for proper nut tightening. Part of FIP body (12) covers one side of the sleeve (5) and other side of the sleeve (5) is to be closed by using plug (7) having permanent sealing with sleeve (5). Counter bore (10) or alike thing is provided on sleeve (5) to ensure permanent sealing of the plug (7).

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To adjust adjustment screws (1, 2 & 3) of FIP access to the screw locking nut (4) is required. As a general practice, user may try to open this tamper-proof sealing mechanism (9) by hammering the sleeve (5) in the direction (11) as shown in figure 2. Since the sleeve (5) is fixed with sleeve lock nut (6), it will nof allow removal of sleeve
(5).
The only way to get access to the screw locking nut (4) is by removing sleeve (5). This is possible when plug (7) is tempered by means of drilling or alike operations and subsequently unlocking sleeve lock nut (6). In this process, plug (7) will gets permanently damaged and user can not replace with similar type of plug (7) and the tamper-proof sealing mechanism (9) can be seen to be tampered.
Hence tamper-proof sealing mechanism (9), which is simpler, compact in design, effective in cost & serviceability helps in avoiding users from fiddling with the various adjustment means such as screws / nuts / bolts of FIP or alike without referring to authorized source. Thereby maintaining vehicle performance & emission norms by setting the fuelling or alike as per specifications by authorized source only. Also this will reduce the faulty claims pertaining to disturbing original FIP settings at the user end.
As various changes could be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description & shown in the accompanying drawings shall be interpreted as illustrative & not in a limiting sense.

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We claim:
1. A tamper-proof sealing mechanism (9) for protecting various adjustment /
setting means comprising:
- a sleeve (5) having cylindrical bores on either side of it's middle wall (14) for covering said adjustment means (1, 2 & 3) from one side and sleeve locking nut (6) or any other locking means from another side,
- a spring washer (13) or such other washers provided on both the side of said middle wall (14) of said sleeve (5) for proper nut tightening,
- a sleeve locking nut (6) provided next to said spring washer (13), from opposite side of said adjustment means,
- a plug (7) is positioned on one side ojf said sleeve (5) at counter bore (10) to form permanent sealing in betweienjplug (7) & sleeve (5).
2. A tamper-proof sealing mechanism as set forth in claim 1, in which easy
access to said sleeve locking nut is restricted or hindered by providing
permanent sealing of said plug at said counter bore and access to said
adjustment means is denied by locking the said sleeve with said sleeve
locking nut against the surface / plan (12) on which said adjustment / setting
means is provided.

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3. A tamper-proof sealing mechanism as set forth in claim 1 could be used either commonly or separately for protecting various adjustment means such as setting screws / nuts / bolts of fuel injection pump (8) or alike mechanisms requires authorised / recommended source for readjustment / resetting.
Dated this 25™ day of OCTOBER 2004
TO
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, MUMBAI