Abstract:
A self-closing buffer and automatic rebound mechanism for a slide rail includes a buffer body, a buffer slide block, a buffer hook block, a buffer element, at least one pull-back spring, at least one push-out spring, a pressing toggle plate and a pressing block. The slide rail consists of an outer rail, a middle rail and an inner rail, and the inner and middle rails can be sequentially pulled and extended outward or pushed inwardly, overlapped and shortened. The slide rail is installed between a drawer and a cabinet for use. When the drawer is pushed inwardly to a certain degree, the drawer is pulled back automatically to a locked position, and the pushing force is damped to lower noises. After the drawer is pushed again, the drawer is rebounded automatically to a certain distance to facilitate operations that follow, so as to improve the convenience of use significantly.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of a slide rail for cabinets, and more particularly to a self-closing buffer and automatic rebound mechanism for slide rails with the functions of buffering and lowering noises when closing the a cabinet and automatic ejection by pressing. 
     2. Description of the Related Art 
     In recent years, various slide rails structure such as those with a drawer interlock function, an automatic return function and a closing buffer function or even combined with the automatic return function and the buffer function are used extensively in industrial applications and even for cabinets at home, and these slide rails improve the smoothness and safety of pulling out a drawer. 
     An improved automatic closing device of a slide rail as disclosed in R.O.C. Pat. No. M385280, and I319465 serves as a buffer self-closing device for a slide rail and comprises a self-closing fastener, at least one elastic element and a buffer element, wherein the elastic element provides a pull-back force required by the slide rail assembly, and the self-closing fastener automatically closes the slide rail assembly to prevent the slide rail assembly from sliding to open accidentally at a non-operating status. In addition, the buffer element has a damping function to reduce the impact force when the slide rail assembly is withdrawn and prevent users from being clamped or injured by the fast-moving slide rail components. 
     In addition, an auxiliary positioning apparatus for slide rail assembly as disclosed in R.O.C. Pat. No. I404868 comprises a positioning element pivotally coupled to a first rail, and the positioning element comprises: a latch; a guide seat coupled to the second rail, and including a first channel, a first groove and a first wall, wherein the first wall has a first guide surface disposed opposite to the first channel; a second channel; a second groove and a second wall, and the second wall has a second guide surface disposed opposite to the second channel; a separator, having a guide end opposite to the first groove; a latching member having a latching surface, and a portion of the latching surface being disposed opposite to the second groove; a third channel, a third groove and a third wall, and the third wall has a third guide surface disposed opposite to the other portion of the latching surface; and a fourth wall has a fourth guide surface; a link element, corresponding to the positioning element. If the second rail is situated at a position opposite to the first rail at a received position, the latch will be situated in the first channel, so that when the rail is pushed inwardly by a force, the latch is moved into the first groove, and when the force is released and one of the rails is ejected, the latch is guided by the separator to pass through the second channel. When the rail is pushed inwardly and received, the latch and the latching member are engaged with each other. When a pushing force is applied to the rail again, the latch and the latching member are disconnected, and the latch is released through the third groove and the third channel, so as to define a three-stage press locking/unlocking function. 
     A drawer automatic opening and closing buffer device as disclosed in R.O.C. Pat. No. M370971 is installed between a drawer and a cabinet, and the drawer automatic opening and closing buffer device comprises: a fixing base, fixed at a predetermined position of an inner wall of the cabinet, and having a buffer cylinder installed onto a side of the fixing base, and a positioning portion disposed on the other side of the fixing base, and the fixing base further including two guide slots; a slide seat, with a side coupled to a shaft of the buffer cylinder by sheathing guide portions on both sides on two guide slots of the fixing base respectively, and having a swing element pivotally installed to a side of the slide seat and a slide hook pivotally installed to the other side of the slide seat, and the slide seat further including two guide slots disposed opposite to each other, and each guide slot having a stop portion; a self-opening control element, having a hook block and a latch portion capable of latching and positioning the swing element, and one or more guide columns disposed on both sides of the self-opening control element, such that the self-opening control element can be slid into the two guide slots of the slide seat through the guide columns, and the self-opening control element is coupled to a side of an elastic element, and the other side of the elastic element is coupled to the other side of the slide seat; one or more slide seat resetting elastic elements, with an end coupled to the slide seat and the other end coupled to a predetermined position of a connecting portion of the fixing base or an inner wall of the cabinet; a slide hook, pivotally installed to a side of the slide seat and having a hook portion, a latch portion and an abutting portion, wherein the latch portion can be latched to the positioning portion of the fixing base; a starting frame, mounted to a predetermined position of an outer wall of the drawer and having a link element disposed on a side of the staring frame, a link portion disposed on a side of the link element for linking the hook block of the self-opening control element, and an abutting portion disposed at the link element for abutting the hook block of the slide hook, wherein the other side of the starting frame has a starting portion for abutting the abutting portion of the slide hook. Therefore, the side-locked ball-bearing slide rail originally having the basic functions of pulling or pushing the drawer out of or into the cabinet can also have the automatic opening effect and the self-closing buffer effect for drawers, and also can reduce shocks and noises. 
     However, the aforementioned self-closing buffer and automatic opening functions cannot be integrated effectively, thus causing inconvenience to use. Even if these functions are integrated, users are unable to troubleshoot the problem on their own when there is a wrong operation that results in unsmooth operations or even damages of the slide rail mechanism. Obviously, the prior art requires further improvements. 
     SUMMARY OF THE INVENTION 
     It is a primary objective of the present invention to provide a self-closing buffer and automatic rebound mechanism for slide rails, such that when a drawer is pushed into a cabinet to a certain degree, the drawer is pulled back, closed, and locked at a position automatically, and the pushing force is buffered to reduce noises. After the drawer is pushed again, the drawer is bounced to a certain distance automatically to facilitate operations that follow, so as to improve the convenience of use significantly. 
     To achieve the aforementioned objectives, the present invention provides a self-closing buffer and automatic rebound mechanism for slide rail, such that when the drawer is pushed to a certain degree, the drawer is pulled back and locked at a locked position automatically, and the pushing force is buffered to reduce noises, and after the drawer is pushed again, the drawer is rebounded to a certain distance to facilitate operations that follow, so as to improve the convenience of use significantly. 
     To achieve the aforementioned objective, the present invention provides a self-closing buffer and automatic rebound mechanism for a slide rail, wherein the slide rail is comprised of an outer rail, a middle rail and an inner rail, such that the inner rail and the middle rail can be pulled sequentially outward and extended, or pushed inwardly, overlapped, and shortened, and the inner rail has a first trigger element, and the self-closing buffer and automatic rebound mechanism comprises: 
     a buffer body, disposed at an inner end of the outer rail, and having a containing groove and a pair of first engaging portions formed at the center of the buffer body, and the pair of first engaging portions being disposed parallelly on both sides of the containing groove, and an end of the buffer body being extended in a direction along the containing groove and having a long-strip block, and the long-strip block having a limit slide slot, and a first positioning portion and a second positioning portion being formed at both end portions of the limit slide slot respectively; 
     a buffer slide block, covered onto the exterior of the long-strip block, and capable of moving reciprocally in an extending direction of the long-strip block, and having a pivot hole formed on a lateral side of the buffer slide block and corresponding to the limit slide slot; 
     a buffer hook block, pivotally installed to the pivot hole, and having a limit block disposed on the bottom side of the buffer hook block and movably installed in the limit slide slot, such that when the buffer slide block is moved outwardly, the limit block can be latched to the first positioning portion, and when the buffer slide block is moved inwardly, the limit block can be latched to the second positioning portion, and the buffer hook block has a V-shaped grooved disposed on the top side of the buffer hook block to form two first openings, so that the first trigger element can be moved together with the inner rail, and movable into/out of the second opening, so that the first trigger element can be moved together with the inner rail and movable into/out of the first openings; 
     a buffer element, installed in the containing groove, and having an actuation rod disposed at an end of the buffer element, and an end of the actuation rod being coupled to the buffer slide block, for buffering the force produced when the buffer slide block is pulled back; 
     a pressing slide block, disposed with an interval apart from a side of the buffer slide block, and situated on a side of the buffer element, for abutting an end portion of the inner rail; 
     at least one pull-back spring, coupled between the buffer body and the buffer slide block, for pulling back the buffer slide block; 
     at least one push-out spring, coupled between the buffer slide block and the pressing slide block, for pushing out the buffer slide block; 
     a pressing toggle plate, being an L-shaped plate structure corresponding to the buffer hook block, and pivotally installed to the outer rail, and having a bump formed at an end on a side facing the inner rail, such that when the inner rail is driven to move outwardly or inwardly, the pressing toggle plate is linked to swing at different angles; and 
     a pressing block, installed at an outer end of the inner rail, and having a first slide slot, a second slide slot and a third slide slot formed on the pressing block and corresponding to the bump of the pressing toggle plate, and the first slide slot, the second slide slot and the third slide slot being communicated with one another, and a divergent block being disposed between the first slide slot and the second slide slot, and a positioning block being disposed between the second slide slot and the third slide slot, and the divergent block has two second openings formed on a side of the pressing block and corresponding to the pressing toggle plate, such that when the pressing toggle plate is swung at different angles, the bump enters from one of the second openings to change a moving path to produce an rebounding or locking action. 
     In a preferred embodiment, a hook is bent from an end portion of the inner rail, and provided for driving the buffer hook block to resume its original position when the inner rail and the middle rail are pulled outwardly, so as to standardize the action. To further overcome wrong actions performed during an operation, users can troubleshooting the problems on their own, wherein the hook has a bevel portion corresponding to a side of the buffer hook block, such that when a wrong action is performed at the buffer hook block, the hook passes across the buffer hook block to resume its original position. In addition, the middle rail has a second trigger element corresponding to the pressing toggle plate, such that after the inner rail is pulled out completely, the pressing toggle plate can be pushed to resume its original position. 
     In a preferred embodiment, a third positioning portion is disposed on a side of the positioning block for temporarily latching the bump to define a locking status. In addition, a first moving path is formed at the first slide slot and along a side of the divergent block, and a second moving path is formed at the first slide slot and along the other side of the divergent block to the second slide slot, and a third moving path is formed at the second slide slot and along a side of the positioning block having the third positioning portion to the third slide slot, and a fourth moving path is formed at the third slide slot and along the other side of the positioning block. Therefore, there is a four-stage movement of the slide rail when the slide rail is pulled, and the first moving path is corresponsive to one of the second openings, and the second moving path and the fourth moving path are corresponsive to the other second opening. The four-stage movement design not just achieves the function of pressing the automatic opening only, but also resumes the pressing toggle plate to its original position during a wrong operation by pressing through this design. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of a preferred embodiment of the present invention viewing from a first angle; 
         FIG. 2  is an exploded view of a preferred embodiment of the present invention viewing from a second angle; 
         FIG. 3  is a schematic structural view of a pressing block of a preferred embodiment of the present invention; 
         FIGS. 4 to 20  are schematic views of consecutive movements in accordance with a preferred embodiment of the present invention respectively. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The technical content of the present invention will become apparent with the detailed description of preferred embodiments and the illustration of related drawings as follows. 
     With reference to  FIGS. 1 to 3  for the exploded views of a self-closing buffer and automatic rebound mechanism  2  of a slide rail  1  in accordance with a preferred embodiment of the present invention viewing from two different angles and a schematic structural view of a pressing block of a preferred embodiment of the present invention respectively, the slide rail  1  is comprised of an outer rail  11 , a middle rail  12  and an inner rail  13 , such that the inner rail  11  and the middle rail  12  can be pulled sequentially outward and extended for a longer length, or pushed inwardly and overlapped with each other for a shorter length, and the inner rail  13  includes a first trigger element  132 . The self-closing buffer and automatic rebound mechanism  2  comprises a buffer body  21 , a buffer slide block  22 , a buffer hook block  23 , a buffer element  24 , a pressing slide block  25 , a pair of pull-back springs  26 , a push-out spring  27 , a pressing toggle plate  28  and a pressing block  298 . 
     The buffer body  21  is manufactured by plastic injection molding, and the buffer body  21  is corresponsive to the shape of the outer rail  11  and embedded into an inner side at an inner end of the outer rail  11 , and a containing groove  211  and a pair of first engaging portions  212  are formed at the center of the buffer body  21 , and the pair of first engaging portions  212  are disposed parallel to both sides of the containing groove  211  respectively, and an end of the buffer body  21  has a long-strip block  213  extended in an extending direction of the containing groove  211 , and the long-strip block  213  has a limit slide slot  214 , and a first positioning portion  2141  and a second positioning portion  2142  formed at both end portions of the limit slide slot  214  respectively, and the first positioning portion  2141  is an outer end position disposed at the long-strip block  213 , and the second positioning portion  2142  is disposed at an intersection proximate to the buffer body  21 . 
     The buffer slide block  22  is also manufactured by plastic injection molding, and the buffer slide block  22  is covered onto the exterior of the long-strip block  213  and moved reciprocally along the extending direction of the long-strip block  213 , and a pivot hole  221  is formed at an edge of the buffer slide block  11  and corresponding to the limit slide slot  214 . 
     The buffer hook block  23  is also manufactured by plastic injection molding, and an end of the buffer hook block  23  is pivotally installed to the pivot hole  221 , and a limit block  231  is disposed at the bottom side of the buffer hook block  23  and movably installed into the limit slide slot  214 . When the buffer slide block  22  synchronously drives the buffer hook block  23  to move outward, the limit block  231  can be latched to the first positioning portion  2141 , and when the buffer slide block  22  synchronously drives the buffer hook block  23  to move inward, the limit block  231  can be latched to the second positioning portion  2142 . In addition, a V-shaped groove  232  is formed at the top side of the buffer hook block  23  and has two first openings  2321 , such that the first trigger element  132  can be moved together with the inner rail  13  and movable into/out of the first openings  2321  to link the buffer hook block  23  to move reciprocally. 
     The buffer element  24  can be a hydraulic rod or a pneumatic rod fixed into the containing groove  211 , and an actuation rod  241  is disposed at an end of the buffer element  24 , and an end of the actuation rod  241  is coupled to the buffer slide block  22 , for buffering the force produced when the buffer slide block  22  is pulled back. 
     The pressing slide block  25  is also manufactured by plastic injection molding and disposed at a position with an interval from a side of the buffer slide block  22  and situated at a side of the buffer element  24  for abutting an inner end portion of the inner rail  13 . 
     The pair of pull-back springs  26  is coupled between the first engaging portions  212  and the buffer slide block  22  of the buffer body  21 , and the resilience force of the pair of pull-back springs  26  can pull back the buffer slide block  22  inwardly. 
     The push-out spring  27  is coupled between the buffer slide block  22  and the pressing slide block  25 , and the resilience force of the push-out spring  27  can push the buffer slide block  22  outwardly. 
     The pressing toggle plate  28  is manufactured by plastic injection molding, and corresponding to the buffer hook block  23  and pivotally installed to the outer rail  11 , and the pressing toggle plate  28  is an L-shaped plate structure having a bump  281  formed at an end and disposed on a side facing the inner rail for linking the pressing toggle plate  28  to swing a different angles when the inner rail  13  is driven to move outwardly or inwardly. 
     The pressing block  29  is manufactured by plastic injection molding and fixed to an outer end of the inner rail  13 , and the pressing block  29  has a first slide slot  291 , a second slide slot  292  and a third slide slot  293  corresponding to the bump  281  of the pressing toggle plate  28 , and the first slide slot  291 , the second slide slot  292  and the third slide slot  293  are communicated with one another, and a divergent block  294  is disposed between the first slide slot  291  and the second slide slot  292 , and a positioning block  295  is disposed between the second slide slot  292  and the third slide slot  296 , and the divergent block  294  has two second openings  296  formed on a side of the pressing block  29  and corresponding to the pressing toggle plate  28 . When the pressing toggle plate  28  is swung to a different angle, the bump  281  enters from one of the second openings  296  to change the moving path to perform a rebounding or locking action. In addition, a third positioning portion  2951  is disposed on a side of the positioning block  295  for temporarily latching the bump  281 , and a first moving path M 1  is formed at the first slide slot  291  and along a side of the divergent block  294 , and a second moving path M 2  is formed at the first slide slot  291  and from the other side of the divergent block  294  to the second slide slot  292 , and a third moving path M 3  is formed at the second slide slot  292  and from a side of the positioning block  295  to the third slide slot  293 , and a fourth moving path M 4  is formed at the third slide slot  293  and along the other side of the positioning block  295 . In addition, the first moving path M 1  is corresponsive to one of the second openings  296 , and the second moving path M 2  and the fourth moving path M 4  are corresponsive to the other second opening  296 . 
     In addition, a hook  131  is bent from an end of the inner rail  13  and provided for driving the buffer hook block  23  to resume its original position when the inner rail  13  and the middle rail  12  are pulled inwardly, and a bevel portion  1311  is formed on a side of the hook  131  and corresponding to the buffer hook block  23  and provided for passing across the buffer hook block  23  to resume the original position. In addition, the middle rail has a second trigger element corresponding to the pressing toggle plate, such that after the inner rail is pulled out completely, the pressing toggle plate can be pushed to resume its original position. 
     With reference to  FIGS. 4 to 20  for the schematic views of consecutive movements in accordance with a preferred embodiment of the present invention respectively as well as  FIGS. 1 to 3 , when the inner rail  13  is pushed into the outer rail  11 , the buffer hook block  23  is latched at a position of the first positioning portion  2141 , so that the hook  131  can be dodged away from the buffer hook block  23  and passed through from the bottom, and then after the first trigger element  132  is entered into the first opening  2321  from the bottom of the buffer hook block  23  and the first trigger element  132  is latched into the V-shaped groove  231 , the buffer hook block  23  is turned in an opposite direction to separate from the first positioning portion  2141  and return into the limit slide slot  214 . After being acted by the action force of the two pull-back springs  26 , the buffer slide block  22  is pulled to slide towards the innermost side of the slide rail  1  until it reaches the position of the second positioning portion  2142  and is latched. Therefore, the inner rail  13  is situated at a locked status. When it is necessary to have an automatic pressing rebound, the inner rail  13  drives the middle rail  12  to be pushed inwardly, so that the buffer slide block  22  is squeezed and pushed inwardly. In the meantime, the bump  281  of the pressing toggle plate  28  is moved along the first moving path M 1 , and the buffer hook block  23  is turned in an opposite direction, such that the first trigger element  132  can be separated from the V-shaped groove  231 , and the inner rail  13  is situated at a released status, and then the resilience force of the push-out spring  27  drives the pressing slide block  25  to eject from the inner rail  13 . Now, the hook  131  of the inner rail  13  is blocked by the buffer hook block  23 , so that the buffer hook block  23  is turned in a forward direction and separated from the second positioning portion  2142 . Until the buffer hook block  23  is moved to a position of the first positioning portion  2141 , the buffer hook block  23  is rotated in the forward direction again to define a latched status, and the hook  131  can be released from the blocking of the buffer hook block  23 . In the meantime, the bump  281  of the pressing toggle plate  28  is moved along the second moving path M 2 , and thus the bump  281  can be separated from the pressing block  29 . If the inner rail  13  has not been pulled out completely and closed again, then the bump  281  will move along the third moving path M 3  to latch to the third positioning portion  2951 . After being pressed again, the bump  281  will be separated from the third positioning portion  2951  and entered into the fourth moving path M 4 , so that the pressing toggle plate  28  can be separated from the pressing block  29  to return to the press rebounding status. In summation of the description above, the present invention emphasizes on the convenient operation and foolproof operation. Even if there is a wrong movement, the invention allows the users to troubleshoot the problem on their own conveniently.