IMPACTACTUATED SYSTEM

Technical Field

The invention relates to an impact actuated system applicable to door, gate and the like structures and more particularly, to actuating system with emergency release mechanism that permits manual release of said structures from locked position in an emergency.

Background Art

Gates or similar structures are installed at public places such as ticketing tellers and payment counters for crowd control. However, some of said structures need to be close temporarily at times for certain reasons such as when there is a shortage of manpower in manning the counters or when business has slowed down during off peak hours. In such situation, the counter gates are normally shut down and indicated by no-entry signage to prohibit any passage thereof by patrons.

It has long been a problem in that when payment counter counters in supermarkets are temporarily shut down, there are always absent minded patrons who continue to want to use the counters, resulting in trolleys loaded with groceries and goods being crashed into gates used for closing said counters. The impact created by the crashing trolleys or other untoward external forces can be substantial, causing extensive damage to the locked gate structures, counter fixtures and even injuries to persons around the vicinity.

The above problem and associated damages caused by the unwanted impact can be avoided if such gates or similar structures have been provided with impact actuated mechanism. When impact actuated mechanism is incorporated into a locking system, it works in a manner that when a sudden external force beyond certain magnitude is acted

upon said locking system, the impact actuated mechanism will function by actuating the locked gates or similar structures to release to an open position.

There are a couple of prior arts concerning actuating system for gates and like structures but are generally expensive to build or involve complicated installation procedures. One of the prior art as cited in US-A

6,754,990 discloses an actuator for gates that works with an electrical motor in cooperation with a torque limiting device to prevent excess stresses on the device by excessive external forces. Said invention involves installation of electrical systems that may be expensive and considered as undesirable by some operators.

Another prior art as that disclosed in patent document US-A 4,115,954 mentions an actuated system that is operable from a remote position by means of energy transmitting members such as hydraulic means and electrical means. Such prior art requires elaborate installation works as hydraulic lines need to be buried underground and the same is also applicable for electrical conductors.

The primary object of the present invention to provide an impact actuated system for sensing a sudden external impact forces imposed on gates or similar structures and reacting to said forces in a manner to release the gate structures from a locked to an open position. In such operation, said gate structures and support structures thereof will be saved from being damaged.

However, it is desirable to have gate structures that can be actuated to open position upon impact by any minimal force, which will then defeat the purpose of the locking mechanism provided therein. It is therefore another object of the present invention to introduce an impact actuated

system with build-in mechanism for sensing a certain minimum force that is sufficient to effect releasing of the locking mechanism of the gate structures concerned. The magnitude of such minimum impact force is pre-determined in the system so that the impact actuated system would only react to impact forces that are of higher order and are likely to cause damages.

The present invention also has the object that the impact actuated system should be inexpensive to build with minimal mechanical components and does not involve any electrical installation. The proposed impact actuated system is therefore simple to operate and easy to maintain.

The present invention has a further object in that the proposed impact actuated system includes a provision for manually operating the lock release mechanism associated with the gate structure concerned. Even without an external impact force, the end users can over ride the system by manually operate the gate structure from a locked into an open position, especially in an emergency.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example through certain embodiments of the present invention.

Summary of Invention

According to the present invention, the impact actuated system for gate and the like structures provided with rotating gate wing, said actuated system comprises a link shaft connected substantially parallel to a back plate and constructed to rotate about its axis. Said impact actuated system further comprises a holder shaft and a drive pin being separately coupled to said link shaft and extending laterally therefrom.

Said impact actuated system further comprises a pair of retainer plates disposed co-axially along the length of said link shaft, a compression spring and a cam means with center bore for receiving said link shaft. Said compression spring and said cam means are arranged in an end to end position along the axis of said link shaft within said retainer plates.

The cam means of the impact actuated system engages with the drive pin under the restraining force of said compression spring. When excessive external force is imposed on the holder shaft, said drive pin cooperates with the cam means to overcome the restraining force of the compression spring for actuating the system to rotate the gate wing from a locked to an open position.

Specific Example

The invention will now be described by way of example and with reference to the accompanying drawings in which:

Fig. 1 shows a schematic side view representation of the present invention in an application involving a gate wing in a locked position.

Fig. 2 shows the sectional front view of the preferred embodiment according to the present invention in a locked position.

Fig. 3 shows the sectional front view of the preferred embodiment according to the present invention during a manual operation.

Fig. 4 shows the cross-sectional side view of the preferred embodiment in the locked position.

Fig. 5 shows the cross-sectional side view of the preferred embodiment in the semi open position.

Fig. 6 shows an exploded pictorial view of components associated with the preferred embodiment according to the present invention.

Fig. 7 is a partial view of Fig. 6 showing components associated with the preferred embodiment i.e. Fig. 7(a), Fig. 7(b), Fig. 7(c) and Fig. 7(d) showing the perspective, top, side and bottom view of the first cam member respectively.

Fig. 8 is another partial view of Fig. 6 showing components associated with the preferred embodiment i.e. Fig. 8(a), Fig. 8(b), Fig. 8(c) and Fig. 8(d) showing the perspective top and bottom, top, side and bottom view of the second cam member respectively.

Fig. 9 is another partial view of Fig. 6 showing components associated with the preferred embodiment i.e. Fig. 9(a), Fig. 9(b), Fig. 9(c) and Fig. 9(d) showing the perspective, top, side and bottom view of the spacer unit respectively.

Fig. 1 shows a schematic side view representation of the preferred embodiment for an impact actuated system 10 in an installed position involving a gate wing 56, the latter being in a locked position. The preferred embodiment is secured to a rigid support structure 54. The preferred embodiment comprises a link shaft 12 in an upright direction, said link shaft being coupled to a holder shaft 16 to which the gate wing

56 is connected to deny entry into the passageway of a payment counter.

As shown in Fig. 2 and Fig. 4, the impact actuated system comprises a link shaft 12 connected substantially -parallel to a vertical back plate 18, said back plate being provided with fixtures 20 for installation onto the rigid support structure 54. A pair of anchor plates 14, 50 is fixedly connected to the back plate and extended perpendicularly therefrom at

two spaced locations on the same side. Said anchor plates include an opening each there through the link shaft being received in a vertical position.

Said link shaft 12 having uniform diameter and an axis, is free to rotate about its axis within the opening of each of the anchor plate 14, 50. Said holder shaft 16 includes two arms, each arm being affixed rigidly each to one end of said link shaft extending substantially at right angles therefrom. Both arms of said holder shaft 16 and said link shaft 12 are aligned in a manner forming a single plane with each other. The arms of said holder shaft are adapted to receive and connect to an external gate wing 56 that is used to close the passageway of the counter.

Said impact actuated system further comprises a drive pin 22 coupled to said link shaft 12 midway along its vertical axis as shown in Fig. 2 and Fig. 6. Said drive pin has the shape of a solid rod-like structure made of hardened material with length measuring more than the diameter of said link shaft. Said drive pin 22 is provided across the body of said link shaft 12 approximately mid-way through its length. As said drive pin has a length greater than the diameter of the said link shaft, both its terminals project laterally out of at opposite sides of said link shaft to form ear protrusions 24, 26.

By construction, the ear protrusions 24, 26 of said drive pin 22 are aligned with the holder shaft 16 at both ends of the link shaft 12 to form a single plane as shown in Fig. 2 and Fig. 4. It must be appreciated that the drive pin is provided into the link shaft body and secured rigidly therein by conventional methods.

As shown in Fig. 2, a cam means made up of two separate cam members 28, 36 is disposed along the link shaft body between the anchor plates

14, 50. As further indicated in Fig. 6, said cam members are solid ring- shaped structures having essentially similar radial measurement i.e. first cam member 28 and second cam member 34 arranged in an end to end position.

Both the first cam member and second cam member include a common center bore adapted to slide along the body of said link shaft 12. Said first cam member 28 includes a bottom flat surface 32 facing the anchor plate 50 and an upper surface defined by four radial groove elements 30a, 30b, 30c, 3Od extending from the common center bore until the edges of the cam body. Said groove elements are spaced at 90 degrees apart.

Said groove elements 3Oa ₁ 30b, 30c, 3Od have uniform cross-sectional profile of the letter "V" with straight inclined walls and a flat bottom. As the four radial groove elements are spaced at 90 degrees apart, they form two sets of groove elements arranged in a "cross" pattern and interrupted at the center by the common center bore where the link shaft 12 passes through, as shown in Fig. 7. Therefore, there are two sets of radial groove elements disposed in end to end arrangement.

Four screw-treaded apertures 34a, 34b, 34c, 34d are provided, each at the vicinity between any two of the radial groove elements 30a, 30b, 30c,

3Od of the first cam member 28, that are spaced 90 degrees apart.

Conventional mounting screws are provided through said apertures for mounting said first cam member 28 onto the anchor plate 50, with the bottom flat surface 32 of the first cam member in contact with said anchor plate.

As shown in Fig. 4, the first cam member is installed in position that either set of its groove elements 30a, 30c or 30b, 3Od has an orientation

laterally at right to the back plate 50 of the actuated system. Since they are arranged in a "cross" pattern, the reminder set of groove elements shall have orientation parallel to the face of said back plate 50.

As shown in Fig. 8, the second cam member 36 includes at its down side a downwardly projecting "ridged" contour defined by four radial noses

38a, 38b, 38c, 38d extending from the common center bore until the edges of the cam body. Said noses are spaced at 90 degrees apart from one another and have uniform cross-sectional profile of the "V" letter with straight sloping walls and a flat base. Said noses 38a, 38b, 38c, 38d are adapted to cooperate with the groove elements 30a, 30b, 3Oc ₁ 3Od of the first cam member 28. The "V"-shaped projections of said noses are adapted to fittingly engage with the "V"-shaped depressions of the groove elements as shown in Fig. 4.

On the up side of saidjsecond cam member 36, there are four slots or recesses 40a, 40b, 40c, 40d being constructed partially into the cam body, one end of said recesses being open into the center bore area of the second cam member 36. Said recesses are spaced at 90 degrees apart and arranged in a radial pattern. As shown in Fig. 8, individual recesses are aligned back to back with each of the four radial noses 38a, 38b, 38c, 38d on the reverse side of the second cam member 36. This can be done easily as recesses and noses on each side of the second cam member are spaced evenly at 90 degrees apart.

Said recesses 40a, 40b, 40c, 40d of the second cam members 36 have uniform cross-sectional profile that includes vertical walls with flat base. Each of said recesses is designed with a dimension capable to receive and engage with each of the ear protrusions 24, 26 of the drive pin 22 that projects laterally from the link shaft 12. As said four radial recesses are spaced at 90 degrees apart, they form two sets of recesses arranged

in a "cross" pattern and interrupted at the center by the common center bore where there ^' link shaft 12 passes through. In this manner, said ear protrusions of the drive pin are adapted to fit into either set of the recesses and therefore couple said second cam member 36 with the link shaft 12.

According to Fig. 6, a spacer unit 42 is disposed next to the side of the second cam member 36 bearing the recesses 40a, 40b, 40c, 4Od. Said spacer unit is a cap-like structure with its open end facing said second cam member. As illustrated in Fig. 9, said spacer unit includes an annular wall and a roof element 44 with a center bore to accommodate the link shaft 12. With compatible circular dimension, said annular wall is adapted to support the spacer unit 42 on the rim of the second cam member 36. Said roof element 44 of the spacer unit defines an empty space thereunder. It will be appreciated that the annular wall of the spacer unit possesses sufficient height such that when the spacer unit sits on the second cam member, the ear protrusions 24, 26 of the drive pin 22 have enough space to rotate freely therein.

As shown in Fig. 6, a helical compression spring 46 is disposed next to the spacer unit 42 along the link shaft 12. The choice regarding the strength of the compression spring is a subject of consideration for actuating the impact actuated system as will be described hereinafter.

Adjacent to the compression spring 46, a pressure plate 48 having a center bore to receive the link shaft body 12 is provided. Said pressure plate includes a pair of screw-treaded apertures such that it can be connected to the anchor plate 50 by conventional bolts and nuts arrangement as shown in Fig. 2 and Fig. 3. Said pressure plate 48 is adapted to work in cooperation with said anchor plate 50 as a pair of retainer plates in keeping the various components of the impact actuated

system in place as a working unit.

In an installed position as the retainer plates 48, 50 are connected, the compression spring 46 is compressed under tension as a result of tightening the bolts and nuts arrangement. Therefore, said compression spring results in a restraining force that will bias on the various components keeping them in engagement as an assembled unit within a housing 62 as indicated in Fig. 6. To ensure that the restraining force is to be distributed more evenly, a couple of washers 52 are installed on both sides of the compression spring 46 that come into contact with neighboring components.

As mentioned earlier, the position of the first cam member 28 has been pre-arranged when mounted onto the anchor plate 50 in that an arbitrary first set of its radial groove elements is oriented laterally at right angle to the back plate 18 of the impact actuated system. The reminder set of its radial groove elements is oriented laterally parallel to the back plate.

The above-mentioned first set of radial groove elements of the first cam member 28 then engages with an arbitrary first set of radial noses of the second cam member 36 located immediately above. Back to back to the first set of radial noses and on the reverse side of said second cam member 36, one set of the radial recesses is disposed laterally at right angle to the back plate 18.

To result in a locked position of the impact actuated system, the drive pin 22 is manually performed via the link shaft 12 such that the ear protrusions 24, 26 thereof engage with the above-mentioned set of the recesses that is laterally at right angle with the back plate 18. As the drive pin 22 and the holder shaft 16 are pre-arranged to be in a same plane, said holder shaft projects laterally at right angle with and away

from the back plate 18. In this locked position, the gate wing 56 is disposed across the passageway of the counter concerned as shown in Fig. 1.

The ear protrusions 22, 24 of the drive pin 22 will remain engaged with said particular set of recesses of the second cam member 36 due to the restraining force being biased by the compression spring 46. However, the impact actuated system according to the present invention may subject to various external impact stresses from time to time, such external forces usually being imposed on the holder shaft 16 by some external agents e.g. a travelling trolley wrongfully entered the locked counter. Any impact force on the actuated system is set to transmit through the rotary link shaft 12 to the drive pin 22 that in turn acts on the second cam member 36 that is engaging with it.

Accordingly, the ear protrusions 24, 26 of said drive pin 22 exert pressure on the side wall of the recesses of the second cam member 36 with which they are engaged. Therefore, a rotational torque is being resulted, which causes said second cam member to move in a forward circular movement about the link shaft 12. The rotational torque is acting to push the set of noses immediately on the reverse side of the second cam member 36 to move on in the same forward direction relative to the stationary first cam member 28. Under such circumstances, the straight sloping walls of the noses of the second cam member 36 have the tendency to slide along the straight inclined surfaces of the groove elements in the first cam member 28 that they are engaging with.

It will be appreciated that whenever the second cam member 36 is making slight rotational forward movement caused by external stresses, it immediately encounters the combination of the restraining force by the compression spring 46 and the frictional forces that exist between the

various components in the impact actuated system. The restraining force of said compression spring works against any further axial movement by the second cam member 36 as a whole, prohibiting the noses of said second cam member from sliding up the inclined surfaces found in the groove elements of the first cam member 28.

When the external impact force acting on the holder shaft 16 has reached a certain predetermined level, the rotational torque thus generated through the drive pin 22 becomes sufficient to overcome the combination of the restraining force of the compression spring of the actuated system and the frictional forces therein. Under such condition, the impact actuated system becomes actuated whereby the set of noses of the second cam member 36 that has been in engagement with the first set of groove elements of the first cam member 28 manage to slide along the inclined side wall of the groove elements.

As the rotational torque generated through the drive pin 22 persists, said set of noses of the second cam member 34 slide further up the straight inclined surfaces of the first cam member 28 until they move out of the contour of the grooved vicinity. Said set of noses then dislodge themselves out of the groove elements of the stationary first cam member as shown in Fig. 3. The rotational torque forces continue to push the second cam member 36 forward in a circular manner by sliding along the flat plateau surfaces of the first cam member 28. When the same set of noses of said second cam member 36 meets the next set of groove elements of the stationary first cam member 28, said noses and groove elements will engage therein.

As the next set of groove elements of the first cam member 28 is spaced 90 degree apart from the previous set of groove elements, the second cam member 36 has actually made a 90 degrees forward angular

displacement. Such right angle angular forward displacement by the second cam member would mean a similar forward angular displacement achieved by the drive pin 22 because its ear protrusions remain seated in the same set of recesses located on the reverse side of the second cam member 34 at all time.

Similarly, the same forward angular movement by the drive pin 22 results in a similar forward angular displacement by the holder shaft 16 that has been coupled to it via the link shaft 12. In this manner, said holder shaft actually facilitates the rotation of the gate wing 56 by 90 degrees in a forward manner causing it to move from the original locked position to the open position.

It must be appreciated that by appropriately constructing the impact actuated system of the present invention, such as by varying the sizes of the components and controlling the frictional forces between said components, the actuating system can be made sensitive to different levels of external impact forces. The choice of different sizes of compression spring including the adjustment of the compression strength thereof by the bolts and nuts arrangement provided would likewise enable the actuating system responsive to different external impact forces.

At times, end users of the impact actuated system may wish to return the displaced gate wing 56 back to the locked position after an actuating operation. As illustrated earlier, in an actuating operation the drive pin 22 has actually made a 90 degrees forward angular movement. Therefore, such forward movement has to be compensated by an equivalent backward movement by the drive pin 22 in order that the holder shaft 16 returns to its original locked position.

To achieve the above backward movement of the drive pin 22, the ear

protrusions 22, 24 have first to be disengaged from the set of recesses of the second cam member 36 that has been associated with them before the impact incidence. Said ear protrusions are turned backward by 90 degrees angular movement. In such operation, said link shaft 12 is manually lifted in an axially upward manner until its ear protrusions 22, 24 have moved out of the then recesses of the second cam member 36 into the space above as defined by the spacer unit 42. Within the space defined by said spacer unit, said ear protrusions 22, 24 of the drive pin are then rotated backward by a 90 degrees angular displacement via rotary movement of said link shaft.

During the above operation, said ear protrusions 22, 24 of the drive pin 22 are adapted to slide along the upper surface of the second cam member 36 before engaging with another set of recesses that is spaced 90 degrees apart from the fist set. As the drive pin 12 and the holder shaft 16 are aligned in a same plane, said holder shaft returns the wing gate 56 to its original locked position as in Fig. 1.

Therefore, it will be appreciated that the impact actuated system has the provisions for manual operation that enable the gates or like structures to be opened or closed manually by operators according to demand. While only one embodiment of the present invention has been shown and described, it will be clear that various modifications and changes could be made without departing from the spirit and scope of the invention.