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You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is related to electrical lock mechanisms and, in particular, to an electrically actuated lock mechanism for the rear deck lid of an automotive vehicle having electrical failure protection. 
     2. Description of the Prior Art 
     Lock mechanisms for the rear deck lid of automotive vehicles are well known in the art. In general, most of the rear deck lid locking mechanisms are purely mechanical and incorporate a latch member entrapping a mating member, such as a lock bar. The locking mechanism may be attached to the rear deck lid and the mating lock bar attached to a structural element of the vehicle below the lower extremity of the rear deck lid opening, or the locking mechanism may be attached to a structural member of the vehicle and the lock bar attached to the rear deck lid. Normally, the mechanical locking mechanisms are locked by forcefully closing the rear deck lid causing the lock bar to engage the latch member and displace it to a locked position. The latch member is mechanically released from the locked position by the rotary motion of a key actuated lock. 
     In recent years, rear deck lid lock mechanisms have been developed which permit the lock mechanism to be electrically unlatched from inside the vehicle&#39;s passenger compartment, as well as manually unlatched by means of the key lock. Typical electrically released rear deck lid lock mechanisms have been disclosed by Quantz in U.S. Pat. Nos. 3,917,330, 4,652,027 and 4,667,990, and by Allen in U.S. Pat. No. 3,504,511. Additionally, power locking mechanisms have been incorporated into the rear deck locking mechanisms to displace the latch member to its locked position such as taught by Peters, in U.S. Pat. Nos. 3,580,623 and 3,596,484, in which a hydraulic mechanism displaces the latch member to the locked position when the rear deck lid is closed. Alternatively, Bellot et al, U.S. Pat. No. 4,395,064, discloses a rear deck lid having an electric motor connected to a lock member and a latch member by a pair of lost motion links. De Claire et al, in U.S. Pat. No. 3,332,713, disclose an electrically driven latch closure having motor driven rack engaging a toothed sector of the latch member to rotate the latch member between its open and latched position. Oishei, U.S. Pat. No. 3,113,447, and Lentz et al, U.S. Pat. No. 3,016,968, disclose a pneumatically operated latch closure mechanism. Garvey et al, in U.S. Pat. No. 2,896,990, disclose a rear deck lid closure mechanism having an electrically driven jack screw for lowering the rear deck lid to its closed position after the latch mechanism has engaged the lock bar. The problem with most of these deck lid power mechanisms, and in particular the electrically actuated rear deck lid locking mechanism taught by Quantz in U.S. Pat. No. 4,667,990, is that the deck lid cannot be locked when the electrical actuator fails in a release position. 
     The invention is an improved rear deck lid lock mechanism of the type disclosed by Quantz in U.S. Pat. No. 4,667,990 which may be unlocked with a conventional key lock or by an electrical actuator remotely actuated from inside the vehicle&#39;s passenger compartment. The lock mechanism disclosed by Quantz may be latched by forceably closing the rear deck lid, causing the latch member to move to its locked position, or by lowering the deck lid with a force only sufficient to displace the latch member towards its locked position. The displacement of the latch member will activate an electrical actuator and thereafter the latch member will be electrically driven to its locked position. The improved rear deck lid lock mechanism also includes a bypass mechanism which allows the rear deck lid to be locked under all types of failure of the electrical actuator. 
     SUMMARY OF THE INVENTION 
     The invention is an electrically actuated rear deck lid lock mechanism having a support frame, a lock member pivotally attached to the support frame, and a latch member pivotably connected to the support frame which is displaceable between an open and locked position. The lock member has a lock dog and the latch member has a dog catch which engages the lock dog to lock the latch member in the locked position. The latch member further has a catch slot which receives a lock bar in its open position and entraps the lock bar in the locked position. First resilient means produce a force which biases the latch member towards the open position and a second resilient means produces a force which biases the lock member to engage the lock member&#39;s lock dog with the latch member&#39;s dog catch. 
     A release member is slidably attached to the lock member and is laterally displaceable by a bypass cam when the deck lid is manually closed. An electrical actuator is provided for pivotably displacing the latch member against the force of the first spring to a locked position engaging the dog catch with the lock dog and for pivotably displacing the lock member to disengage the lock dog from the dog catch. The electrical actuator has an electric motor which rotates a cam gear. The cam gear has a predetermined cam surface which actuates an electrical switch controlling the operation of the electric motor. The cam gear also has at least one stud which engages the latch member with the rotation of the cam gear to pivot it to the locked position during a first rotational interval and engages the release member during a second rotational interval to pivot the lock member, disengaging the dog catch from the lock dog. The disengagement of the dog catch from the lock dog releases the latch member from the lock member. The electrical switch is responsive to the displacement of the latch member from its open position towards its closed position to provide electrical power to the electric motor and responsive to the contour of the cam surface to terminate the electrical power to the electric motor. 
     One object of the invention is to provide a lock mechanism which may be mechanically or electrically locked or unlocked. 
     Another object of the invention is to provide a lock mechanism in which the electrical locking mechanism does not interfere with the mechanical locking of the lock mechanism. 
     A further object of the invention is to provide a lock mechanism in which the electrical locking mechanism is free of all the mechanical forces applied to the latch member when the latch member is in its locked position. 
     Still another object of the invention is to provide the capability to manually lock and unlock the lock mechanism in the event of any electrical failure. 
     These and other objects of the invention will become more apparent from reading the specification in conjunction with the drawings appended hereto. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of the rear deck lid lock mechanism in the locked position; 
     FIG. 2 is a plan view of the rear deck lock mechanism in the locked state in which the electrical lock actuator is removed; 
     FIG. 3 is a plan view of the rear deck lock mechanism in the unlocked state in which the electrical lock actuator is removed; 
     FIG. 4 is a perspective view of the release plate; 
     FIG. 5 is a cross-sectional side view of the electrical lock actuator taken through line 5--5 of FIG. 1; 
     FIG. 6 is a plan view of the cam gear; 
     FIG. 7 is a cross-sectional side view of the cam gear taken along line 7--7 of FIG. 6; 
     FIG. 8 is a circuit diagram of the electrical lock actuator; 
     FIG. 9 is a partial cross-sectional view showing the details of the post lock; 
     FIGS. 10 through 12 are partial cross-sectional views showing the state of the switch mechanism 40 during sequential stages of operation; 
     FIG. 13 is a partial cross-sectional view showing the bypass cam engaged with the latch member; 
     FIG. 14 is a plan view of the locking member with the latch member disengaged from the bypass cam; 
     FIG. 15 is a partial side view showing the position of the bypass cam upon rotation of the key actuated cam; 
     FIG. 16 is a plan view of the locking mechanism with the cam gear&#39;s stud stuck in a position holding the lock member disengaged from the latch member; and 
     FIG. 17 is a plan view of the locking mechanism showing the displacement of the release plate by the bypass cam to release the locking member from the stuck stud. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The improved electrically actuated rear deck lock mechanism, generally identified by reference numeral 10, is shown in FIG. 1. The electrically actuated rear deck lock mechanism is structurally very similar to the electrically actuated rear deck lock mechanism disclosed in my prior U.S. Pat. No. 4,667,990 issued Mar. 24, 1987. Referring to FIG. 1, the lock mechanism 10 has a support bracket 12 and includes a latch member 14 and a bypass cam 16. The latch member 14 and bypass cam 16 are pivotally connected to the support bracket 12 by means of a first pivot pin 18. The latch member 14 has a laterally offset catch slot 20 which captivates vehicle lock bar 22 and a raised dog 24 which engages an edge of the bypass cam 16. 
     A lock member 26 is pivotally connected to the support bracket 12 by a second pivot pin 28, as shown in FIG. 2, and locks the latch member 14 in its locked position as shall be described hereinafter. The end of the lock member 26 opposite the second pivot pin 28 engages the surface of a key actuated cam 30 which is rotatably attached to the support bracket 12, as more clearly shown in FIG. 2. The cam 30 has a slot 32 for receiving the extension bar of a manually operated lock mechanism (not shown), such as is normally provided for manually unlocking the rear deck lid lock mechanism. The key actuated cam 30 also has a ramp surface 34 which lifts the bypass cam 16 disengaging it from the latch member&#39;s raised dog 24, as shall be explained hereinafter. An electrical lock actuator 36, which has an electric motor 38 and a cam actuated single pole double throw switch mechanism 40 is provided. The electrical lock actuator 36 displaces the latch member 14 to its locked position when the rear deck lid is closed and will unlock the latch member in response to an electrical unlock signal. 
     In FIGS. 2 and 3, the electrical lock actuator 36 is removed to more clearly show the details of the latch member 14, bypass cam 16, and lock member 26. Referring to FIGS. 2 and 3, the lock member 26 has a dog 42 provided at an intermediate location along its lateral length which is engaged by a dog catch 44 provided at the extremity of the latch member 14. A first coil spring 46, circumscribing the first pivot pin 18, biases the bypass cam 16 to rotate it in a counterclockwise direction about the first pivot pin 18. A second coil spring 48 biases the lock member 26 against the key actuated cam 30. In the locked position of the lock mechanism, the dog 42 engages the dog catch 44 as shown in FIG. 2. The bypass cam 16 has a tab 50 which engages the mating edge of the latch member 14 so that the latch member 14 rotates with the bypass cam 16 in the counterclockwise direction. A third spring 52 independently biases the latch member 14 to rotate in a counterclockwise direction towards the unlocked position. 
     Unlatching of the dog catch 44 from the dog 42 may be accomplished mechanically by the manual rotation of the key actuated cam 30 by a key inserted in the rear deck lid lock, or electrically, as shall be explained hereinafter. 
     A release member or plate 54 is slidably connected to the lock member 26 by means of a spring post 56 and a tab slot 58. The spring post 56 is attached to the lock member 26 through a guide slot 60 provided through the release plate 54 as more clearly shown in FIG. 4. The spring post 56 has a head which holds the release member 54 against the lock member 26. The tab slot 58 straddles a guide tab 62 projecting outward from the face of the lock member 26. The tab slot 58 and guide slot 60 permit the release member 54 to be longitudinally displaced along the surface of the lock member 26. A fourth coil spring 64 is connected between a spring tab 66 provided at the end of the release member 54 and the spring post 56. The fourth coil spring 64 biases the release member 54 towards the right, as shown in FIGS. 2 and 3, so that the guide tab 62 is at the left end of the tab slot 58. 
     The details of the electrical lock actuator 36 are shown in FIG. 5. Referring now to FIG. 5, the electrical lock actuator 36 has a housing 68 which is attached to the support bracket 12 by a plurality of screws (not shown). Attached to the housing 68 is the fractional horsepower electrical motor 38 which drives a cam gear 70 through a gear train 72. 
     A pair of diametrically opposed studs 74 and 76 protrude from the surface of the cam gear 70 which faces the support bracket 12 and are operative during a first rotational interval of the cam gear to engage the edge of the bypass cam 16 and return the latch member 14 to its latched position, as shown in FIG. 2, and during a second rotational interval to engage the end of the release member 54 to pivot the lock member and release the latch member&#39;s dog catch 44 from the dog 42. The two diametrically opposed studs 74 and 76 are provided so that the cam gear needs to rotate only through a half of a revolution for each complete operational cycle. 
     As shown in FIGS. 6 and 7, the cam gear 70 has a pair of diametrically opposed arcuate cam grooves 78 and 80 provided in its surface opposite the support bracket 12 immediately preceding each of the studs 74 and 76 in the direction of rotation indicated by arrow 82. As shown in greater detail in FIG. 7, both of the cam grooves 78 and 80 are bi-level such that leading sections 84 of the cam grooves are deeper than trailing sections 86. The bi-level cam grooves 78 and 80 cooperate with the switch mechanism 40 embodied in the housing 68 to lock and release the latch member 14. 
     In FIG. 5, the electrical lock actuator is shown with the lock mechanism in its locked state with the stud 74 in the position &#34;A&#34; as illustrated in FIG. 3. In this position, a cam follower 88 is in the leading section 84 of the cam groove 78 or 80, and a center spring contact 90 is in electrical contact with a lower spring contact 92. The center spring contact 90 is connected to a coil 96 of a relay switch 98 as shown in FIG. 8. The relay switch 98 has a normally open contact 100 connected to the motor 38, and a normally closed contact 102 connected in parallel with the motor 38. The lower spring contact 92 is connected to a source of electrical power 94 through an unlock switch 105. The center spring contact 90 produces a force on the cam follower 88 causing it to follow the contour of the bi-level cam grooves 78 and 80. A post 104, which is slidably received in an aperture in the housing 68, is attached at one end to an upper spring contact 106. In the locked state, the post 104 is held in an elevated position by a post lock such as a post bar 108 biased by a spring 110 as illustrated in FIG. 9. The post bar 108 holds the post 104 in the highest elevated position when the lock mechanism is in its locked state. In the elevated position of the post 104, the upper spring contact 106 is disengaged from the center spring contact 90. The post bar 108 is displaced from under the post 104 by the bypass cam 16 when the lock mechanism is unlatched, permitting the post 104 to descend to an intermediate level. At the intermediate level the post 104 prevents the post bar 108 from assuming a position under the post 104 until the post 104 is again raised to its elevated position by the cam follower 88 acting on the upper spring contact 106. The upper spring contact 106 produces a force on the post 104, urging it downward to its lowest permitted level. 
     Referring now to FIG. 8, when the unlock switch is depressed, the relay switch 98 is energized through the electrical contact between the spring contacts 90 and 92 which causes the normally open contact 100 to close and the normally closed contact 102 to open. The closing of the normally open contact 100 energizes the electric motor 38 to rotate the cam gear to displace the stud 74 from position &#34;A&#34; to position &#34;B&#34;, as shown in FIG. 3. During this rotational interval the stud 74 engages the end of the release member 54 pivoting the lock member 26 away from the latch member 14. The pivoting of the lock member 26 disengages the dog 42 from the dog catch 44, and releases the latch member 14. The latch member 14 and bypass cam 16, biased by the first and third coil springs 46 and 52, respectively will then rotate to the open position as shown in FIG. 3. 
     When the stud 74 reaches position &#34;B&#34;, the cam follower 88 rises up in the leading section 84 of the arcuate bi-level groove 78 or 80, which displaces the center contact spring 90 upward a distance sufficient to break the electrical contact between the center spring contact 90 and the lower spring contact 92 but not high enough to make electrical contact between the center spring contact 90 and the upper spring contact 106, as shown in FIG. 10. In this state, the solenoid switch is deenergized, opening the normally open contact 100 and closing the normally closed contact 102. The opening of the normally open contact 100 terminates electrical power to the motor 38, causing the rotation of the cam gear 70 to stop with the stud 74 in position &#34;B&#34; and the stud 76 in position &#34;C&#34;. The closing of the normally closed contact 102 shorts out the motor 38. This dynamically brakes the motor to keep the cam gear 70 from coasting beyond the desired position. 
     The lock mechanism will remain in this state until an attempt is made to close the rear deck lid. When the rear deck lid is closed sufficiently to displace the latch member 14 and the bypass cam 16 from under the post 104, the post 104 will descend under the bias of the upper spring contact 106, and the upper spring contact 106 will descend and make electrical contact with the center spring contact 90, as shown in FIG. 11. Electrical contact of the upper spring contact 106 with the center spring contact 90 will energize the relay switch 98 to again provide electrical power to the motor 38 and rotate the stud 76 from position &#34;C&#34; to position &#34;A&#34;, as shown in FIG. 3. During this rotation interval the stud 76 will engage the edge of the bypass cam 16 and rotate it in a clockwise direction. The bypass cam 16 will engage the latch member&#39;s raised dog 24 and rotate the latch member 14 along with the bypass cam 16 towards the latched position. At the position &#34;D&#34; the stud 76 will have rotated the bypass cam 16 and latch member 14 a distance sufficient to permit the dog 42 to engage the dog catch 44, locking the latch member 14 in the latched position. As the cam gear 70 is being rotated, the cam follower 88 will rise out of the cam groove 78 or 80, raising both spring contacts 92 and 106 to their maximum heights, as shown in FIG. 12. The upper spring contact 106 will elevate the post 104 to a height sufficient to permit the post bar 108 to be displaced under the post 104 by the spring 110, thereby holding the post 104 in its elevated position. When the stud 76 reaches position &#34;A&#34;, the cam follower 88 will fall in the leading section 84 of the next cam groove, returning the switch mechanism 40 to the state shown in FIG. 10, which is the latched state of the lock mechanism. 
     If the latch member 14 is released manually rotating the key actuated cam 30 by means of the key lock, the bypass cam 16 will displace the post bar 108 such that when the rear deck lid is closed sufficiently to displace the bypass cam 16 from under the post 104, the post 104 will descend permitting the upper spring contact 106 to make electrical contact with the center contact spring 90 and energizing the relay switch 98 to energize the motor 38 to lock the latch member 14, as previously described. If the rear deck lid is forceably closed down hard enough to lock the latch member 14 in the dog 42, the post 104 will descend, energizing the motor, which will continue to run until one of the studs 74 or 76 assumes position &#34;A&#34;, as shown in FIG. 3. 
     If the latch member 14 is released from the dog 42 but the rear deck lid does not open due to an accumulated weight, such as heavy snow, the motor will drive the cam gear 70 until one of the studs 74 or 76 reaches position &#34;A&#34; and then will stop. The bypass cam 16 will not have moved far enough to displace the post bar 108; therefore, the upper spring contact 106 remains separated from the center spring contact 90 by the cam follower. To actuate the lock mechanism, the rear deck lid must be lifted a distance sufficient to cause the bypass cam 16 to displace the post bar 108. This prevents continuous recycling of the lock mechanism when the rear deck lid does not open after the latch member 14 is released. 
     The function of the bypass cam 16 will be explained with reference to FIGS. 3, 13, 14 and 15. The bypass cam 16 is connected to the latch member 14 by means of the raised dog 24 and the tab 50, so that the two will pivot together about the first pivot pin 18 as shown in FIGS. 3 and 13. The first coil spring 46 produces a force biasing the bypass cam 16 towards the latch member 14 so that the raised dog 24 engages the edge of the bypass cam 16, as shown in FIG. 13. 
     As illustrated in FIG. 3, if there is an electrical failure or a failure of the electrical lock actuator 36 which results in the cam gear 70 stopping with one of the studs 74 or 76 in the position designated &#34;D&#34;, or any other nearby position, the stud will prohibit the bypass cam 16 from rotating to the unlatched position shown. Under this condition, the latch member 14 may still be released to the unlatched position by rotating the key actuated cam 30 to the position shown in FIG. 14. In this position, the ramp surface 34 provided on the key actuated cam 30 will slide under the bypass cam 16 and lift the bypass cam above the upper surface of the raised dog 24, as shown in FIG. 15. The rotation of the key actuated cam 30 will also pivot the lock member 26, releasing the latch member 14 from the dog 42. With the bypass cam 16 in the raised position, the latch member 14 is free to rotate to the unlatched position, independently of the bypass cam 16, as shown in FIG. 14. As previously indicated, the latch member 14 is independently biased by the third spring 52 to rotate the latch member 14 to the unlatched position. Therefore, when the rotation of the bypass cam 16 to the unlatched position is prohibited by one of the studs 74 or 76, the electrically actuated lock mechanism may still be manually unlocked using the conventional key lock. 
     The function of the release member 54 will now be explained with reference to FIGS. 16 and 17. In the event the electric motor 38 fails with one of the studs 74 or 76 in the position designated &#34;E&#34;, as shown in FIG. 16, the stud, for example stud 76, is in engagement with the release member 54 and prevents the lock member 26 from pivoting back to the locked position as shown in FIG. 3. In this state, the dog catch 44 cannot engage the dog 42 and the deck lid cannot be locked. However, there is sufficient resiliency in the weather seals of the deck lid to permit the deck lid to be slightly depressed. Depression of the deck lid against the resiliency of the weather seals will cause the lock bar 22 to rotate the latch member 14 and the bypass cam 16 in a clockwise direction as indicated by arrow 114 in FIG. 17. This will cause the end of the bypass cam 16 to displace the release member 54 to the left a distance sufficient to disengage it from the stud 76, as shown. 
     When the release member 54 is disengaged from the stud, the lock member 26 and release plate may now be rotated by the second coil spring 48 to the position shown in FIG. 3. In this position, the dog catch 44 can engage the dog 42, locking the deck lid in the closed position. Thereafter the deck lid may be locked or unlocked with a key until the motor or cause of failure is repaired. 
     One advantage of the rear deck lid lock mechanism is that the locking of the rear deck lid in its closed position is assured, independent of the closing force. Another advantage of the rear deck lid lock mechanism is that the deck lid does not have to be slammed down to set the latch member in its locked position. Still another advantage of the rear deck lid lock mechanism is that the deck lid may be locked mechanically or electrically. A further advantage is that once the latch member is in the locked position, the electrical locking mechanism is disengaged from the latch member and all subsequent forces applied to the deck lid are sustained by the mechanical elements of the lock and not by any of the components in the electrical locking mechanism. Still another advantage of the lock mechanism is that it may be manually unlatched using the conventional key lock in the event of an electrical failure. A still further advantage is that the deck lid may still be locked in the closed position even if the electric motor fails in a position in which a stud on the cam gear is holding the lock member disengaged from the latch member. 
     It is intended that the invention not be limited to the specific embodiment illustrated in the drawings and discussed in the detailed description above. It is recognized that a person skilled in the art will be able to conceive different structural arrangements for performing equivalent function without departing from the spirit of the invention as described above and set forth in the appended claims.

Summary:
An electrically actuated rear deck lock mechanism which may be locked or unlocked in a conventional manner. The lock mechanism latches the deck lid with a latch member engaging a lock bar after closure of the deck lid. An electric actuator moves the latch to a locked position. Once in the locked position, the electrical actuator mechanism is free of the mechanical forces applied to the latch member such that any forces experienced during normal operation of the vehicle are absorbed through the mechanical interaction of the latch with the lock bar without undue effect on the electrical actuator. The latch member can also be manually moved to a locked position without interfering with the electrical locking position of the mechanism. A bypass cam and a release member are provided which permit the rear deck locking mechanism to be manually locked and unlocked in the event of a power failure or a failure of the electric actuator.