PUSH LATCH Mechanisms (DIY!)

hello my internet friends long time no chat huh I hope you're all doing exceedingly okayish at the very least not a lot of videos going on not for a lack of trying but it's summertime the kids this year not running around as wild and free as last season because situation however they did shove off to their grandparents for the weekend wife and I finally have some alone time can't tell you how long it's been and have we ever been taken advantage of that like we just spent all morning playing the best game of so that's where she hit it e mt this thing amazing or what I mean just look at that sitting there like no big deal I keep pushing it same exact way every single time and I keep getting a different result sometimes it sticks sometimes it doesn't it reminds me of that old quote I've long come to hate you know the one about doing the same thing over and over and expecting different results but this thing somehow changes every time I push it and I've been doing this for about five continuous hours now so I ask you who's the insane one here me or this obvious work of the devil if there's one thing that history has taught us if you don't understand something your best recourse is to destroy it you know what it'd be fun to talk about you'll never guess what'll be fun to talk about go on guess I'll give you three good lashing mechanisms all sorts of latching mechanisms specifically to and as if going on and on and waving my hands in the air weren't enough we'll build our own a bit simplified sure but hopefully it goes a long way to helping you make heads or tails of them more complicated ones and you know maybe add a little know-how to your cerebral toolbox maybe one day you'll want to add one to one of your projects you already know latching mechanisms from such popular films as the amazing retractable pens just like the other latches push once to get your point across push again to just never mind forget I even brought it up I think it's safe to say everybody loves these things I know that because the manufacturers got a lot of trouble to keep the mechanism visible it's just like everything else there are a few variants of this latch because patents probably this one has a cylindrical cam inside that just gets bumped around and round every time someone or some thing pushes the button this part that I'm making has absolutely nothing to do with this video but what kind of relationship would you and I have we started keeping secrets I'm not going to get into these if you're interested and I don't know how you couldn't be engineerguy did a really cool video on the cylindrical cam latch nice 3d graphics and a great walkthrough even if in my opinion the drunk dancing cone variant is way cooler what is that thing even doing in there I tried my best to deburr this it's tricky getting these tight spaces with my angle grinder I think that's working pretty alright I'm trying to get you in here as close as possible you may have to adjust the depth of field on your TV it's me old Tony from the future you can tell because I'm wearing a different shirt I realized too late I never demonstrated how these latches were used took it for granted I suppose and you know what they say about taking things for granted you make a G out of are and travel back in time to before the vivisection to right that wrong though since I'm doing this now there will be no reason for future me well past future me to go back in time to fix I've got two latches here both do the same exact thing but in their own special way again these are meant for things like kitchen cabinets or drawers maybe the latch bit is fixed maybe inside the cabinet and this little hook thing would be on the door so perhaps when you swung the door closed push the latch it would catch and the door won't open unless you push the door again this little angry be you looking thing does the same except this interfaces with like a ball catch close the cabinet door or the drawer or what have you the ball is captured it won't separate push it again and it releases okay find the angry beetle is pretty neat but this thing takes advantage of some of the weirder geometries you can get out of injection molded plastic this one is more clockwork II and I think easier to administrate how the concept works so that's why I'm taking this one apart and not that one anyway let's get back to whatever it was always this thing has two moving pieces the one we see from the outside what I'm calling the latch the bit you move it's kind of this pie shaped 90 degree wedge thing with a pin in the top both parts are spring-loaded the latch has its spring tucked under here around the pin that it's rotating on you can see just the leg of it there and then there's this sort of Paul thing what I'm calling the Paul for now it too is spring-loaded maybe you can make the spring out back here this spring keeps this biased forward towards the latch the latch part also has this little foot on it that little tab sticking up that's really important that's really the only part that interfaces with the Paul so the key to these push push mechanisms the part that you push the actuator in this case the latch I guess takes one path on the forward stroke so it takes one path when you push it and then a second path when you push it again a different path on the return stroke since most people can't magically change the shape of the actuator something needs to happen in the clockwork something inside changes on the actuators return trip now what I just said might make more sense in the simpler version of this that we'll build but maybe you'll see it happen here if you're looking for it on the push stroke that little tab we saw on the actuator there it is I can't see what you're seeing I'm behind this cutout section that little foot rides on the outside of the PAS until it falls into this hook recess that's the first click when I let this go the springs push everything together which is the second click so the latch is now stuck there I can't pull this latch back open it's now putting this whole paw in compression up against its pin the only way to open this is to destroy the entire mechanism but now watch what happens when I push it again watch how the paul releases the latch I push it in it gets past that little step falls deeper into the hook and you see that a little diving board type tab on the paw when I let this go the Paul will lift and the actuator slips underneath it let's do that again push the paw of the way it snaps into that hook shape and it's latched push it again that's the third click and I now have access to that little ramp feature which picks up the paw like it isn't even there effectively that creates two different paths for the actuator to take one on the forward path and a different one on the return pretty cool huh since we're now latched design experts in the world is our push push Easter let's build our own perhaps simpler versions based entirely on the one I already built well need to start with two parts that move relative to each other some things we can latch together let's do two circles no no no no two squares that'll save me some time we need one to track with the other so maybe two posts the blocks can ride on perfect and to keep these separated let's throw in a couple of Springs this will give us some mechanism whatever mechanism to build the push push latch into let's get started with the blocks [Applause] and here we go there are the two blocks the moving block and the fixed block I've locked tight it in just some precision rounds hopefully those just slip together and there we have it our relative motion next I just want to build a couple of Springs that keep these two blocks apart what's really weird though are these two counter bores this slot and that threaded hole which I haven't done yet so I have no idea how they got there but those two counterbored holes are just to give my spring some body length when it's fully compressed I want this thing to look closed or closed ish when we push it shut and compression springs that have zero body length haven't been invented yet so I can't show you those again just some place for the springs to go set over to the leaf this is the spring you just saw me make and unfortunately it failed miserably I had a hunch that would happen I don't have the wire size I needed and just cross my fingers and use the bigger one I've made two others using lighter gauged wire and these work better I wanted stronger Springs just because it would make this whole thing click here but these will have to do you see how this first one with the bigger wire is about a half-inch shorter well it started out the same length this is the length of spring I need but on the first squeeze it took a set taking a set means you exceeded the wire strength and it permanently deformed this spring took a set and technically failed to views just right on the posts perfect now let's move on to the geometry that creates the push push latch this thing that looks like a poorly engraved letter P for you tax anima sout there is a cam path or maybe cam follower path I'm not sure I look like I work for H&R Block or so in this context I guess in a latch it's sometimes called a car toy path heart-shaped path maybe a Raceway call it whatever you want but this particular specimen looks terrible unfortunately it had a bad run-in with a CNC router okay here's what's what this camp atth worked just fine that was my justification for keeping it but in editing under high magnification it was just eating me up alive inside so I made another one this one ain't winning any prizes either but looks a little cleaner than the last one otherwise they're exactly the same I realize I'm just springing this on you you're likely wondering how on earth we got here allow me to just walk you through how this works is it okay if we hold hands while you do this stay with me now we just need one more piece which is just a simple wire or is it this wire acts like the paw we saw in the commercial latch let me put this thing in a vise I just want to keep it steady while we write so hopefully this is less squirrely so the wire we said is like the paw in the commercial latch and the first thing it does is keeps the two parts from separating the track ends there so the block can't fly off the guides this first straight section of track is really like the extents of motion of the whole mechanism I mean in this case the spring bottoms out before that wire actually reaches the top but you could use that to set I guess the limit of motion now although that's pretty freakin exciting as is it's not really doing much again other than keeping my parts from flying apart in order for the rest of this track to do its magic we just need a bit of spring force in that wire to push it over to the right in this case towards me into the track we want the tip of that wire to follow this track I'm just going to loosen the spring I don't know place it about here now it's got a bit of a spring force if I drop it in the track not only is it holding the parts together but the tip of that wire is pushing towards me sprung loaded towards me watch what happens now the wire shifted fell into sort of that center portion of the heart and the mechanism can't open if I push it again watch how it tracks this curved portion of the heart the curved portion of the track bends my wire spring back I'll just shut up now and let you watch that notice that the last leg of this track is 3d for lack of a better description the groove isn't cut all in the same plane there's a small step there so when I push it on the actuation stroke the wire can't get up there it's forced to follow the straight section of the track when I come around it can drop off and fall back down it happened kind of fast maybe I can it still happened fast maybe you get the idea now if that ain't cooler than me and you put together I don't know what is at first blush and stop blushing it's making me uncomfortable you might not recognize these as the same mechanism and maybe they're not I mean what do I know but hopefully it's clear the stages are the same and how this more two-dimensional version it's just kind of a flattened out version of this or rather this more complicated looking one is just a folded version of one of these and here it's just rolled up into a circle the flat one of course takes up more space and is used a lot where manufacturers can get that track geometry almost for free instead of having to add additional parts like in this cabinet latch this flat one is used a lot in plastic stuff for example where they're molding the part anyway like a pop out tray or a cup holder or something they could just mold that track into a part they're gonna be making anyway if you have one of those sunglass drop down trays in your car something like this depending on what type you have you can maybe see the heart-shaped track on the side your car is likely full of these things but the glasses tray is probably the easiest place to see this mechanism in the wild and fun fact these things are usually damped - if you look in this picture the other side has molded in gear teeth that more than likely interfaces with a small rotary damper and don't even get me started on rotary dampers the damper slows the motion down giving the tray or whatever a more premium feel versus it just snapping open like a mousetrap though frankly for all I know that could be a damper and push push all in one what a time to be Allah speaking of cars let's take a moment to thank today's sponsor the broken ashtray in my wife's car maybe not an ashtray anymore what do you call these things now change try to sing broke a year or two ago my wife's been asking me to sort it out ever since I'm sure there's a heart-shaped track in there somewhere maybe the spring broke the pin fell out of the track who knows what knowing her there's probably an empty can of sprite in a shoe stuck back there and now that we know how these things work we can fix them unfortunately in this particular situation it had take me 8 hours just to get through the center console and the dashboard to even get a look at the spring and track inside so it's staying broken its head back into the garage it's like 400 degrees in this car no I could probably go on about this stuff forever but I'm afraid I might have already said too much I hope you like that thanks for watching

Channel: This Old Tony

Views: 859,813

Rating: 4.9477401 out of 5

Keywords: pushpush, push click, push to latch, push to release, cartoid path, heart shaped path, latching mechanism

Id: 3_wPH904a_8

Length: 18min 38sec (1118 seconds)

Published: Sun Jul 12 2020

Reddit Comments

[u/Doggfite]

Too long between videos!
I had to watch Minila The like 20 times while I waited.