DESC:LATCH ASSEMBLY FOR HOOD OF VEHICLE
Field of the invention:
The present invention generally relates to a latch of a vehicle and more particularly, to a latch assembly for a hood of the vehicle
Background of the invention:
A hood latch system is a vital component of a vehicle. Conventional hood latches are used in automobiles and trucks to maintain the hood in a closed position as well as to protect and cover an engine compartment. The hood latch system is designed to prevent the movement of the hood due to road vibrations to avoid slamming of the hood into the windshield and to prevent blocking of the driver’s view. However, the conventional hood latch system does not include a slam blocker to avoid the over slam of the hood during a high velocity drop. Further, the hood latch system of the prior art does not protect head lamps or engine compartment parts from the damage during over slam.
Accordingly, there exists a need to provide a latch assembly for a hood of a vehicle that overcomes the abovementioned drawbacks of the prior art.
Objects of the invention:
An object of the present invention is to prevent the over slam of a hood during a high velocity drop.
Another object of the present invention is to protect head lamps from damage during over slam of the hood.
Summary of the invention
The present invention discloses latch assembly for latching a striker of a vehicle hood and for preventing over slam of the hood during a high velocity drop. The latch assembly comprises a base plate having a fishmouth profile for receiving the striker. The fishmouth profile defines depth of the striker travel. A safety hook / secondary lever is pivotally mounted on one side of the base plate. with a lever pin and it is loaded on a safety hook spring. The safety hook is having a proboscis profile for receiving the striker threon and a extended profile with a slot configured thereon. The safety hook rotates on receiving the striker hit on the proboscis profile to allow the striker to enter into the fishmouth profile and it is biased to regain the original position thereafter. A catch and pawl arrangement is pivotally mounted to the other side of the base plate for releaseably latching the striker escaped from the safety hook, in a latching profile of the catch. The pawl loaded on a pawl spring holds the catch in latched position. A pop-up lever pivotally mounted to the catch loaded with a pop spring is profiled in such a way that it blocks the pawl walkout during striker latch condition and also blocks the striker movement to avoid rattling. In high velocity drop condition, the over slam of the hood is received by a slam blocker. The slam blocker is pivotally mounted to the safety hook with the lever pin and loaded with a slam blocker spring. A bush guided to move through the slot on the safety hook is fitted at one end of the first profile. While the slam blocker moves parallel with the safety hook, the bush travels through the slot. During over-slam of the hood, the bump profile first receives the striker hit and the slam blocker rotates thereby blocking the over travel of the striker with the first profile. The latch system of the present invention thus blocks the over slam of hood and protects head lamps and engine compartment parts from the damage during the over slam.
Brief description of the drawings:
The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1 shows an exploded view of a latch assembly for a hood of a vehicle, in accordance with the present invention;
Figure 2 shows front view of the latch assembly, in accordance with the present invention;
Figure 3 shows back view of the latch assembly, in accordance with the present invention;
Figure 4 shows detailed view of latch assembly showing a striker in latched position, in accordance with the present invention;
Figures 5A, 5B and 5C show sequential function of a slam blocker of the latch assembly, in accordance with the present invention.
Detailed description of the embodiments:
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiments.
Accordingly, the present invention provides a latch assembly for a hood of a vehicle. The latch assembly prevents the over slam of the hood during a high velocity drop. Further, the latch assembly protects head lamps or engine compartment parts from damage during over slam of the hood. Apart from the catch and pawl latch in the existing latches, the latch assembly of present invention comprises of a pop-up lever for avoiding rattling noise of a hood striker in latched condition and a slam blocker for blocking over travel of the striker.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description and in the table below.
Table:
Ref No: Component Ref No: Component
4 Base plate 40 Alarm switch connector
8 Pawl 44 Slam blocker
12 Catch/ Ratchet 44A First profile of slam blocker
12A Latching profile of catch 44B Bump profile of slam blocker
16 Pop-up lever 48 Slam blocker spring
20 First washer 52 Bush
24 Secondary lever 56 Damper
24A Proboscis profile of the safety hook 60 Second washer
24B Extended profile of the safety hook 64 Catch pin
24C Slot in the secondary lever 68 Pawl pin
28 Pop spring 72 Lever pin
32 Pawl spring 76 Plastic mould
36 Safety hook spring 80 Latching point
Referring to figures 1-5, a latch assembly (100) for a hood of vehicle in accordance with the present invention is shown. The latch assembly (100) mainly comprises a base plate (4), a catch/ratchet and a pawl latching arrangement, a safety hook (24), a pop up lever (16) and a slam blocker (44).
The base plate (4) includes a fishmouth profile for receiving a striker (150). The fishmouth profile including an open top end and a closed slot bottom end defines the depth of striker travel.
The safety hook (24) alternately named as the secondary lever (24) is pivotally mounted on one side of the base plate (4) with a lever pin (72) and a second washer (60). The safety hook (24) is loaded with a safety hook spring (36). The safety hook (24) is having a proboscis profile (24A) first receiving the striker when the hood is closed, and an extended profile (24B)) configured with a slot (24C) thereon. On receiving the striker hit on the proboscis profile (24A), the safety hook (24) rotates in anticlockwise direction to allow the striker (150) to enter into the fishmouth profile. The safety hook (24) is biased to regain the original position thereafter due to the safety hook spring (36).
A catch (12) and a pawl (8) are pivotally mounted to other side of the base plate (4) respectively with a catch pin (64) and a pawl pin (68) and loaded respectively with a pop spring (28) and a pawl spring (32). The pop spring (28) is mounted in a damper (56). The catch (12) is having a latching profile (12A) for latching the striker(150) escaped from the safety hook (24) while the pawl (8) releaseably holds the catch (12) in latched condition. A latching point of the striker (150) is the point in the fishmouth profile where the hood is in completely closed condition. The locking profile (12A) of the catch (12) is designed based on the latching point of the striker (150) in the fishmouth profile. When the striker (150) comes to the latching point, the catch (12) and the pawl (8) get locked.
The pop-up lever (16) is pivotally mounted to the catch (12) with the catch pin (64) and loaded with the pop spring (28) to achieve the pop up height. The pop-up lever (16) is having a profile overlapping with the latching profile (12A) such that when the striker (150) is latched, the pop-up lever (16) blocks the movement of the striker (150) and hence avoids the rattling sound. The pop-up lever (16) engages with the pawl (8) and blocks the pawl walk during latched condition thereby retaining the striker (150) in the fishmouth profile.
The slam blocker (44) is designed for blocking the over travel of the striker (150) beyond the latching point. The slam blocker (44) is pivotally mounted to the safety hook (24) with the lever pin (72) and loaded with a slam blocker spring (48). The slam blocker (44) is having a first profile (44A) and a bump profile (44B). A bush (52) fixed to one end of the bump profile (44B) through a plastic mould (76) and is guided to move through the slot (24C) on the safety hook (24). The slam blocker(44) moves parallel with the secondary lever (24). During over-slam of the hood, the bump profile (44B) first receives the striker hit hereby moving the bush (52) through the slot (24C) and rotating the slam blocker (44) in anticlockwise direction. When the slam blocker (24) rotates, the striker (150) is blocked with the first profile (44A) thereby restricting the further movement/ over travel of the striker (150) up to the closed slot bottom end of the fish mouth.
A switch (40) is mounted to the base plate (4) using M3 screw for indicating the open and closed condition of the hood using light on/off in instrumental panel or beep sound based on the customer vehicle integration. Generally the catch position is used for detecting the latch state. This can either be done by using switches that trip off directly with the catch (12).
When the hood is dropped from the certain height, the striker (150) enters into the fish mouth of the base plate (4) and it is received by the catch (12). The catch (12) rotates in clockwise direction and the latching profile (12A) tangentially moves away from the switch (40) thereby attaining unpressed condition indicating the hood is in closed condition. When the hood is in open condition, the switch (40) is pressed by the latching profile (12A) of the catch (12)
In an operation, the striker (150) first hits the proboscis profile causing the secondary lever (24) to rotate in anticlockwise direction and allows the striker (150) to enter into the fishmouth profile. Once the striker (150) escapes from the secondary lever (24) and reaches the catch/ratchet (8), the secondary lever (24) comes to an original position due to spring action of the safety hook spring (36) and the catch/ratchet (12) rotates in the anticlockwise direction with combination of the pawl (8), the pop up spring (28) and the pawl spring (32). Once the catch/ratchet (12) rotates in the anticlockwise direction, the pawl (8) always tends to rotates in the clockwise direction due to spring action of the pawl spring (32).The catch/ratchet (12) is connected with the pop up lever (16) loaded with the pop spring (28), to avoid the rattling noise and pawl walkout. When the striker (150) gets latched in the latching profile (12A), the catch/ratchet (12) locking profile gets locked in the pawl (8) locking profile.
The bush (52) connected on one end of the bump profile (44B) moves with the guidance of the secondary lever (24) causing the slam blocker(44) to rotate in parallel with the secondary lever (24). Further, when the striker (150) having high velocity hits the bump profile (44B) of the slam blocker (44), then the slam blocker (44) rotates in the anticlockwise direction and the first profile (44A) blocks the over travel of the hood. On blocking the over travel, the slam blocker (44) reaches to the original position due to the slam blocker spring (48) provided for rotational movement.
Advantages of the invention:
1. The latch assembly (100) prevents the over slam of the hood during a high velocity drop.
2. The latch assembly (100) protects head lamps or engine compartment parts from damage during over slam of the hood.
3. Slam blocker lever is designed for inertia balance to achieve blocking effect with various velocity hits from striker (150).
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the claims of the present invention.

,CLAIMS:CLAIMS
We claim:
1. A latch assembly (100) for latching a striker (150) of a vehicle hood and for preventing over slam of the hood during a high velocity drop, the latch assembly (100) comprising:
a base plate (4) having a fishmouth profile for receiving a striker (150) of the hood, the fishmouth profile having a an open top end and a closed slot bottom end defining depth of the striker travel;
a safety hook (24) pivotally mounted on one side of the base plate (4) with a lever pin (72) and loaded with a safety hook spring (36), the safety hook (24) having a proboscis profile (24A) and an extended profile (24B)) configured with a slot (24C) thereon, the safety hook (24) rotating on receiving the striker hit on the proboscis profile (24A) to allow the striker to enter into the fishmouth profile and biased to regain the original position thereafter;
a catch (12) and a pawl (8) pivotally mounted to other side of the base plate (4) respectively with a catch pin (64) and a pawl pin (68), the catch (12) having a latching profile (12A), the catch (12) and the pawl (8) releaseably latching the striker (150) in the latching profile (12A) and at a latching point (80) in the fishmouth profile;
a pop-up lever (16) pivotally mounted to the catch (12) with the catch pin (64) and loaded with a pop spring (28), the pop-up lever (16) having a profile overlapping with the latching profile (12A) for blocking movement of the striker (150) latched in the latching profile (12A), and for blocking the pawl walkout during striker latched condition; and
a slam blocker (44) pivotally mounted to the safety hook (24) with the lever pin (72) and loaded with a spring (48), the slam blocker (44) having a first profile (44A) and a bump profile (44B), the first profile (44A) having a bush (52) fixed to one end thereof guided to move through the slot (24C), thereby causing the slam blocker (44) to rotate in parallel with the safety hook (24), wherein on receiving the striker hit on the bump profile (44B) during over-slam of the hood, the slam blocker (44) rotates and the first profile (44A) blocks travel of the striker (150) between the latching point (80) and the closed slot bottom end of the fishmouth profile.
2. The latch assembly (100) as claimed in claim 1, wherein the bush (52) is fixed to one end of the bump profile (44B) through a plastic mould (76).
3. The latch assembly (100) as claimed in claim 1, wherein the catch (12) and the pawl (8) are loaded respectively with a pop spring (28) and the pawl spring (32).
Dated this on 27th day of July, 2019

Ashwini Kelkar
(Agent for the applicant)
(IN/PA-2461)