उद्वाहक

right|thumb|300px|लंडन येथील भूमिगत स्थानकाच्या निम्न पातळीवरील उद्वाहक. तेथील लाल बाण हे प्रत्येक उद्वाहकाची स्थिती व प्रवासाची दिशा दर्शवितात.
मधील या उद्वाहकास आतील काय काम सुरू आहे हे बघण्यासाठी काचेच्या भिंती आहेत.]]
 

**उद्वाहक** (**इंग्रजी:** Lift किंवा Elevator ) हे ईमारतीच्या विविध मजल्यांवर सामान वा प्रवासी पोचविणारे, सरळ उभे चालणारे, एक प्रकारचे परिवहन आहे. त्यांना बल हे विद्युतचलित मोटर्स द्वारे मिळते ज्या एकतर खेच केबल व प्रती-वजनप्रणाली चालवितात किंवा दट्ट्या उचलण्यास तरल पदार्थ पंप करतात.  
इंग्रजी भाषेव्यतिरिक्त इतर भाषेत, ऍलिव्हेटर किंवा लिफ्ट या शब्दास उसने घेउन केलेले प्रतीशब्द आहेत.

अपंगांची चाकांची खुर्ची नेण्यासाठी तयार केलेल्या कायद्यानुसार, बहुमजली नवीन ईमारतींमध्ये उद्वाहक ही कायद्यानुसार केलेली विशेष तरतुद आहे, विशेषतः तेथे, जेथे चाकांची खुर्ची चालण्यासाठी उताराचा जिना तयार करता येउ शकत नाही.

## आरेखन
काही वाद घालतात की उद्वाहक हे साधारण दोर वा साखळी वापरून तयार केलेले उचलयंत्र आहे. उद्वाहक हा एक प्रकारचा, यंत्रांच्या सहाय्याने खेचता येणारा वा ढकलल्या जाणारा तराफाच होय. आधुनिक उद्वाहकात, पिंजरा वा कार,एका तराफ्यावर बसवलेला असून तो एका खास तयार केलेल्या सर्व बाजुंनी बंद पोकळीत चालतो.जुन्या जमान्यात उद्वाहक हे वाफ व पाण्याचे सहाय्याने चालत असत. खेच उद्वाहकात, पिंजरे हे लोखंडी दोरांच्या व फिरक्यांच्या सहाय्याने चालतात. पिंजऱ्यांचे वजन हे खास तयार केलेल्या प्रतीवजन-प्रणाली द्वारे संतुलित केल्या जाते. कधी-कधी अशी सोय केली असते की दोन उद्वाहक परस्परांविरोधी दिशेने चालतात जे एकमेकांचे प्रतीवजन असतात.
 
दोर आणि फिरक्यांमधील घर्षण खेच उत्पन्न करते व वजन उचलल्या जाते म्हणुन यास इंग्रजीत 'लिफ्ट' (वर-उचल) म्हणतात.

तरलशास्त्राच्या तत्त्वांवर चालणारे उद्वाहक हे जमिनीखाली वा जमिनीवर असणाऱ्या दट्ट्यांवर तरल पदार्थाचा दाब निर्माण करून पिंजरा वर वा खाली नेतात. यात असलेला दुसरा प्रकार म्हणजे दोर व तरलत्व-बल यांचे मिश्रण आहे.अत्याधुनिक व अलिकडचा प्रकारात,कायम पृथ्वी-चुंबक मोटर्स,यंत्र-खोली विरहीत रुळ,गीअरविरहीत यंत्र आणि मायक्रोप्रोसेसर नियंत्रक वापरल्या जातात.

नवीन उभारणीत वापरण्यात आलेले तंत्रज्ञान हे विविध बाबींवर अवलंबुन असते.तरलतत्त्वावर चालणारे उद्वाहक हे स्वस्त असतात परंतु एका विशिष्ट उंचीपेक्षा जास्त उंच दंडगोलक उभारणे हे अप्रायोगिक होते जेंव्हा,उद्वाहक नेण्यासाठीची उंची जास्त असते.सात मजली ईमारतींपेक्षा जास्त उंचीसाठी, खेच-उद्वाहक वापरण्यात यावेत.

उद्वाहक हे मोठ्या प्रमाणावर धंदा करण्यास व त्याच्या सुट्या भागांचे मोठ्या प्रमाणात उत्पादन करण्यास अनुकुल आहेत.परंतु,प्रत्येक ईमारतींची वेगवेगळी मागणी राहते जसे,वेगवेगळे मजले व त्याच्या उंची,पोकळीचा आकार व वापरण्याच्या पद्धती इत्यादी.
 
### उद्वाहकाचे दरवाजे 
उद्वाहकाचे दरवाजे उद्वाहकाच्या वापरकर्त्यास पोकळीत पडण्यापासुन वाचवितात.सर्वसामान्य बाह्यस्वरूप म्हणजे,दोन मधे मिळणारे व बाजुस सरकावण्याजोगे पट.पूर्ण एका बाजुस सरणारे दरवाजे हे वापरास जास्त जागा देतात.हे दरवाजे स्वतंत्र रुळांवर चालतात. कमी खर्चाच्या उभारणीत,यात एकच दरवाजा असु शकतो. सामान्य दरवाज्यांप्रमाणे डावी वा उजवीकडे उघडणारा दरवाजा.

### यंत्र-खोली विना  
**सर्वसामान्य**
सर्व उद्वाहकांस ते खेच पद्धतीचे असो वा तरलतत्त्विय, त्यास एक यंत्र-खोली असतेच.त्यात विद्युत मोटर वा तरल हाताळण्याचे पंप असतात, आणि एक नियंत्रक कपाट. ही खोली उद्वाहकाच्या पोकळीच्या वर असते तर तरलतत्त्विय उद्वाहका साठी,तळाचे खाली.यात एका अथवा अनेक उद्वाहकांसाठी यंत्रसामग्री बसविलेली असते. आधुनिक खेच-मोटर्स गिअरविना व कायम चुंबक मोटर्स असल्यास पर्यायाने फारच कमी जागा लागते. त्याने उद्वाहकांची कार्यतत्परताही वाढते. यांत्रिक पुनर्स्थापकांची जागा इलेक्ट्रॉनिक मायक्रोप्रोसेसर्सनी घेतली आहे.याने जागेची बचत होते.

 
नवीन उद्वाहकांचे आरेखन पारंपारिक उद्वाहकांपेक्षा, ज्यात खेच-दोर हे छतास असलेल्या फिरकीस गुंडाळून वापरण्यात येतात,वेगळे आहेत.यातील खेच दोरांची टोके ही आधारभूत बांधकामास जखडलेली असतात.दोरांची लांबी ही उर्जा बचत व बलगुणक अशी संयुक्त फिरकी वापरून उद्वाहकास व प्रती-वजन-प्रणालीस जोडलेली असते. यंत्र खोली विना असलेले उद्वाहक हे ,कमी व मध्यम उंचीच्या इमारतीत, जुन्या तरलतत्त्विय उद्वाहकांचा स्वागतार्ह पर्याय आहेत.

हे आधुनिक उद्वाहक 'कोन, द्वारा सन १९९६ मध्ये उत्पादिल्या गेलेत.

**हरीत दृष्टीकोनातुन फायदे**

* वापरण्यास जास्त जागा मिळते
* कमी उर्जेचा वापर
* तेलाचा वापर नाही
* सर्व भाग जमिनीवर असतात
याने पर्यावरणीय नुकसानीच्या कारणास दुर करण्यात आले. 
**इतर फायदे**
* ईतर उद्वाहकांपेक्षा कमी किंमत
* विनागिअरचे असल्यामुळे सवारी जास्त चांगली
* जास्त गती-तरलतत्त्विय उद्वाहकांपेक्षा

**वस्तुस्थिती**

* पुष्कळ कमी ध्वनी-प्रदुषण
* कमी व मध्यम उंचीच्या ईमारतींमध्ये वापर

## उद्वाहकाचे आधुनिकीकरण  
जास्तित जास्त उद्वाहक हे सुमारे १५ ते २५ वर्षांची सेवा देउ शकतील असे बनविलेले असतात, जर उत्पादकाने दिलेले सेवा निर्देश योग्य तऱ्हेने पाळले तर. उद्वाहकांच्या वाढत्या वयानुसार, जर काही भाग बदलविणे शक्य नसल्यास, मालकास संपूर्ण समुळ दुरुस्ती साठी सुचविल्या जाऊ शकते.

## इतिहास 
विट्रुव्हियस या रोमन स्थापत्यशास्त्राच्या कामात जगातील प्रथम संदर्भ आढळतो. त्याने नमुद केले आहे की आर्किमिडीस ने इ.स.पूर्व २३६ मध्ये प्रथम उद्वाहक बनविला.नंतरच्या काही साहित्यिक उल्लेखात, 'मानव वा पशुचलित बलाचे सहाय्याने व दोराच्या सहाय्याने  चालणाऱ्या छोट्या खोल्या' असे नमुद आहे. असे समजल्या जाते कि या प्रकारचे उद्वाहक हे इजिप्तच्या सिनाई मध्ये सर्वप्रथम उभारल्या गेले होते. सतराव्या शतकात फ्रांस मधील राजवाड्यात,उद्वाहक आढळले होते.

इ.स. १००० मध्ये 'गोपनिय पुस्तकात',एका अरब संशोधकाने, उद्वाहक- सदृष्य एक उचल-उपकरणाच्या वापराचे एक वर्णन केले आहे ,जे उपकरण,एक मोठा लाकडाचा ओंडक्याद्वारे किल्ला तोडण्यास वापरल्या जायचे.

सन १७९३ मध्ये, इव्हान कुलिबीनने सेंट पिटर्सबर्ग येथील विंटर पॅलेस मध्ये,पिळाद्वारे उद्वहनाची यंत्रणा असलेला,   एक उद्वाहक बनविला. १९१६ मध्ये,मास्कोचे उपनगर असलेल्या आर्खंगेलस्कोये खेड्यात,मुख्य ईमारतीत,एक उद्वाहक स्थापण्यात आला.सन १८२३ मध्ये, लंडन मध्ये *उतरणाऱ्या खोली*चे पदार्पण झाले.

१८व्या शतकाच्या मध्यावधीचे दरम्यान, वजनी सामान वाहतूकीचे अनेक पद्धतीचे कच्चे(अपूर्ण) उद्वाहक होते.त्यापैकी बहुतेक सर्व तरलतत्त्वावर चालत असत.पहिला तरलतत्त्वावर चालणाऱ्या उद्वाहकात, एका प्लंजरचा वापर करण्यात आला होता जो उद्वाहकाच्या खोलीस वर वा खाली नेत असे. प्लंजरवर वा एका उभ्या पोकळ नळीत असलेल्या लोखंडी दंडगोलावर, एका पंपद्वारे पाण्याचा दाब देण्यात येत असे. पाण्याचा दाब वाढविल्यास उद्वाहक खाली येत असे. या पद्धतीच्या उद्वाहकात, प्रती-संतुलन प्रणाली वापरल्या गेली होती, ज्यामुळे उद्वाहकास त्याचे स्वतःचे वजन व त्यातील सामानाचे वजन हे पूर्ण उचलण्याची गरज नव्हती. ते काम प्रती-संतुलन प्रणालीने हलके होत असे. प्लंजर हे उंच इमारतींसाठी व्यवहार्य नव्हते कारण प्लंजरला जमिनीखाली सामावण्यासाठी,त्यास इमारतीच्या उंचीएवढ्या खोल गढढ्याची आवश्यकता भासत असे. नंतर, अनेक फिरक्या व दोरांसमवेत गिअर्स वापरून उद्वाहकांचा विकास करण्यात आला.
 
हेन्री वॉटरमन यास, सन १८५० मध्ये,उद्वाहकासाठी 'उभ्या दोर नियंत्रकाचा' शोध लावण्याचे श्रेय जाते.
 
Henry Waterman of New York is credited with inventing the "standing rope control" for an elevator in 1850

सन १८५२ मध्ये, 'एलिशा ओटिस' ने सुरक्षित उद्वाहक प्रस्तुत केले, जे लोखंडी दोर तुटल्यास उद्वाहकाची खोली सरळ खाली पडण्यापासुन बचाव करीत असे. या प्रकारच्या 'ओटिस' ने तयार केलेल्या सुरक्षित उद्वाहकाचे आरेखन, आज वापरल्या जाणाऱ्या उद्वाहकासमानच आहे.अतिजलद गतीने उद्वाहक खाली आल्यास, त्यास एक नियंत्रक उपकरण, खाचेच्या फिरक्या उपयोगात आणुन, उद्वाहकास पथदर्शकाशी कुलुपबंद करते. त्याने  सन १८५४ मध्ये न्युयार्क मधील क्रिस्टल राजवाड्यात भरलेल्या प्रदर्शनात त्याचे प्रात्यक्षिक दाखविले..

ती पोकळी दंडगोलाकार होती कारण कुपरला वाटले कि हे सर्वात चांगले आरेखन होते. नंतर ओटिसने शाळेसाठी एक विशेष उद्वाहक निर्माण केले. आज ओटिस उद्वाहक कंपनी ही जगातील उंचीवर जाणारी परीवहन प्रणालीचे मोठ्या प्रमाणावर  निर्माण करणाऱ्या कंपन्यापैकी एक  आहे.

सर्वात प्रथम विद्युतचलित उद्वाहक सन १८८० मध्ये, वेर्नर व्हॉन सिमेन्स द्वारे बांधल्या गेला.

कोळसा इत्यादी कच्या मालाच्या टेकडीवरून ने-आणीसाठी एखाद्या उद्वाहकाची गरज भासु लागली. या कारखान्यांनी तसे तंत्रज्ञान विकसीत केले.त्यामुळे , प्रवासी व माल उद्वाहक निर्माण झालेत.
सन १८७४ साली, जे. ड्ब्ल्यु. मीकर याने एका पद्धतीचे पेटंट घेतले ज्याने उद्वाहकाचे दरवाजे सुरक्षितरित्या उघडत व बंद होत असत.
सन १८८२ मध्ये,जेंव्हा तरलतत्त्वीय उर्जा चांगल्या रितीने स्थापित झाली होती,लंडन हायड्रॉलीक पॉवर कंपनीची स्थापना झाली. या कंपनीने, थेम्स नदीच्या दोन्ही किनाऱ्यांवर एक-एक उच्च दाबाच्या वाहीनीची निर्मिती केली जी सुमारे १८४ मैल लांब होती.त्याद्वारे सुमारे ८,००० मशिन्सला, ज्यात उद्वाहक व क्रेन मुख्य होत्या, उर्जा पुरवठा करण्यात येत होता.

सन १९२९ मध्ये, क्लॉरेन्स कोनार्ड क्रिस्पेन याने, इंक्लिनेटर कंपनी ऑफ अमेरीका याचे सहाय्याने, पहिला घरघुती उद्वाहक निर्माण केला.त्याने सर्वप्रथम 'सरकत्या जिन्याचाही शोध लावला.http://inclinator.com/about-inclinator.asp

## उदवाहकाची सुरक्षा 
### हवाचलित किंवा निर्वात उद्वाहक
हवाचलित किंवा निर्वात उद्वाहक हे केबलविना कार्य करतात.ते त्यांच्या पर्यायी उद्वाहकांपेक्षा जलद रितीने उभारल्या जाऊ शकतात. त्यांचे बाह्यावरण हे पूर्वरचित पद्धतीचे असते.ते पर्यायाने, पारंपारिक उद्वाहक पोकळीपेक्षा पुष्कळ संकुचित जागेत मावतात. त्याचे खंड पारदर्शी असतात व प्रवाशांना ३६००(अंशात) सभोवतालचे दृष्य दाखवु शकतात.

### केबलच्या सहाय्याने चालणारे उद्वाहक
आकडेवारी बघून बोलल्यास, उद्वाहक हे अतिशय सुरक्षित आहेत. त्यांचे  सुरक्षा मानांकन हे ईतर वाहन प्रणालीपेक्षा उच्च दर्जाचे आहे. सन १९९८ मध्ये, असे अंदाजित केल्या गेले की, १ ट्क्क्याच्या ८०,००,००,००० व्या भागायेवढ्या (१/१२,००,०००) उद्वाहकाच्या सवाऱ्या यात दोष निर्माण झालेत.त्यापैकी अनेक फारच किरकोळ होते जसे, दार न उघडणे इत्यादी.प्रत्यक्षदर्शी कारणांसाठी, असे एकही प्रकरण नव्हते ज्यात उद्वाहक हे अनियंत्रितरित्या उंचीवरून खाली पडुन त्यात प्रवाश्यांचा अंत झाला.दरवर्षी,उद्वाहकांच्या प्रकरणात झालेल्या सुमारे २० ते ३० प्राणघातक अपघातात, जास्तीत जास्त प्रकार हे देखरेखीशी संबंधित होते, जसे-कारागिर हे पोकळीत अत्याधिक वाकल्यामुळे व फिरणाऱ्या वा हालणाऱ्या भागांत सापडल्यामुळेच, यातील अनेक हे 'सहज टाळता येण्याजोगे अपघात' या वर्गवारीत येतात.जसे- दार उघडुन, आंधळ्यागत(बघितल्याविना)(तेथे उद्वाहक आहेच असे समजुन) पाय टाकुन उद्वाहकाच्या पोकळीत पडणे,कपडे, स्कार्फ(ओढणी) अटकुन खेचल्या जाणे वगैरे. उद्वाहकाचा दोर तुटेल अशी शक्यता गृहित धरली तर,(जे अशक्यप्राय वाटते), आधुनिक जमान्यात उद्वाहकांना सुरक्षा उपकरणे बसविलेली असतात,जी उद्वाहकास विनाअडथळा पडण्यापासुन व चुराडा होण्यापासुन वाचवितात.

उद्वाहकास सहा वा आठ केबल जोडलेल्या असतात ज्या उद्वाहकाचे वजन अधिक २५ % अतिरिक्त भार एवढा एकएकट्या स्वतंत्रपणे सांभाळु शकतात.भरीस भर म्हणुन,यात असे एक उपकरण लावलेले असते, जे, उद्वाहक त्याच्या निर्धारीत गतीपेक्षा जास्त गतीने खाली येत आहे काय हे तपासते; असे असल्यास,ते उपकरण,ब्राँझ धातुपासुन बनविलेल्या गतीरोधकास,ज्या रुळांवर उद्वाहक चालतो त्या सरळ उभ्या असलेल्या रुळावर डकवितो व घासतो ज्याने उद्वाहक जलद गतीने थांबतो, ज्यामुळे जखम होईल अश्या रितीने झटक्यात नव्हे .

There are some problems with the system, though, and it is subject to gaming. Sometimes, one person enters the destination for a large group of people going to the same floor. The dispatching algorithm is usually unable to completely cater for the variation, and late comers may find the elevator they are assigned to is already full. Also, occasionally, one person may press the floor multiple times. This is common with up/down buttons when people believe this to be an effective way to hurry elevators. However, this will make the computer think multiple people are waiting and will allocate empty cars to serve this one person.

The same destination scheduling concept can also be applied to public transit such as in group rapid transit.

#### संदर्भ  
* Traffic Performance of Elevators with Destination Control 
* AI Planning for Destination Control in Elevators

## विशेष अनुचालन स्थिती/पद्धती 
#### गुन्हा-रोध बचाव 
गुन्हा-रोध बचाव प्रणाली प्रत्येक गाडीला पूर्वनियोजित थांब्यावर थांबण्यास व दरवाजे उघडण्यास भाग पाडते. यामुळे त्या थांब्यावर तैनात असलेला सुरक्षा रक्षक किंवा स्वागत अधिकारी प्रवाशांची दृश्य तपासणी करू शकतो. पुढील मागणी पूर्ण करण्यासाठी जात असताना गाडी या थांब्यावर थांबते.

#### उर्ध्व शिखर रिती
उर्ध्व शिखर रीतीदरम्यान, गटातील उद्वाहक गाड्या इमारतीत येणाऱ्या प्रवाशांना जलद सेवा देण्यासाठी प्रवेशद्वाराच्या (लॉबीच्या) स्तरावर परत बोलावल्या जातात. हे प्रामुख्याने सकाळी लोक कामासाठी येत असताना किंवा दुपारच्या भोजनावकाशानंतर घडते. पूर्वनिश्चित प्रवासी संख्येपर्यंत पोहोचल्यावर किंवा दरवाजे ठराविक कालावधीपर्यंत उघडे राहिल्यानंतर लिफ्ट एकामागून एक रवाना केल्या जातात. पुढे रवाना होणाऱ्या लिफ्टमध्ये सहसा हॉल दिवा प्रज्वलित केला जातो किंवा “ही लिफ्ट पुढे जाणार आहे” अशी सूचना दर्शविली जाते, ज्यामुळे प्रवाशांनी उपलब्ध लिफ्ट प्रणालीच्या क्षमतेचा जास्तीत जास्त उपयोग करावा.

उर्ध्व शिखराची सुरुवात वेळनियंत्रक घड्याळाद्वारे, दिलेल्या कालावधीत प्रवेशद्वारावरून पूर्ण क्षमतेने निघालेल्या ठराविक संख्येतील लिफ्टच्या निर्गमनाने, किंवा इमारतीच्या परिचराने हाताने चालविलेल्या स्विचद्वारे होऊ शकते.

#### अधः शिखर रिती Down peak
During Down Peak mode, elevator cars in a group are sent away from the lobby towards the highest floor served, after which they commence running down the floors in response to hall calls placed by passengers wishing to leave the building. This allows the elevator system to provide maximum passenger handling capacity for people leaving the building.

The commencement of Down Peak may be triggered by a time clock, by the arrival of a certain number of fully loaded cars at the lobby within a given time period, or by a switch manually operated by a building attendant.

#### सब्बाथ सेवा Sabbath service (SHO)
In areas with large populations of observant Jews or in facilities catering to Jews, one may find a "Sabbath elevator". In this mode, an elevator will stop automatically at every floor, allowing people to step on and off without having to press any buttons. This prevents violation of the Sabbath prohibition against operating electrical devices when Sabbath is in effect for those who observe this ritual.

However, Sabbath mode has the side effect of wasting considerable amounts of energy, needlessly running the elevator car sequentially up and down every floor of a building, repeatedly servicing floors where it is not needed. For a tall building with many floors, the car must move on a frequent enough basis so as to not cause undue delay for potential users that will not touch the controls as it opens the doors on every floor up the building.

#### स्वतंत्र सेवा Independent service (ISC)
Independent service is a special service mode found on most elevators. It is activated by a key switch either inside the elevator itself or on a centralized control panel in the lobby. When an elevator is placed on independent service, it will no longer respond to hall calls. (In a bank of elevators, traffic would be rerouted to the other elevators, while in a single elevator, the hall buttons will be disabled). The elevator will remain parked on a floor with its doors open until a floor is selected and the door close button is held until the elevator starts to travel. Independent service is useful when transporting large goods or moving groups of people between certain floors.

#### तपासणी सेवा Inspection service (INS)
Inspection service is designed to provide access to the hoistway and car top for inspection and maintenance purposes by qualified elevator mechanics. It is first activated by a key switch on the car operating panel usually labelled 'Inspection', 'Car Top', 'Access Enable' or 'HWENAB'. When this switch is activated the elevator will come to a stop if moving, car calls will be cancelled (and the buttons disabled), and hall calls will be assigned to other elevator cars in the group (or cancelled in a single elevator configuration). The elevator can now only be moved by the corresponding 'Access' key switches, usually located at the top-most (to access the top of the car) and bottom-most (to access the elevator pit) landings. The access key switches will bypass the door lock circuit for the floor it is located on and allow the car to move at reduced inspection speed with the hoistway door open. This speed can range from anywhere up to 60% of normal operating speed on most controllers, and is usually defined by local safety codes.

Elevators have a car top inspection station that allows the car to be operated by a mechanic in order to move it through the hoistway. Generally, there are three buttons - UP, RUN, and DOWN. Both the RUN and a direction button must be held to move the car in that direction, and the elevator will stop moving as soon as the buttons are released. The inspection panel also has standard power outlets for work lamps and powered tools.

#### अग्नीशमन रिती Fire service mode (EFS)
Depending on the location of the elevator, fire service code will vary state to state and country to country. Fire service is usually split up into two modes: Phase One and Phase Two.  These are separate modes that the elevator can go into.

Phase one mode is activated by a corresponding smoke sensor or heat sensor in the building. Once an alarm has been activated, the elevator will automatically go into phase one. The elevator will wait an amount of time, then proceed to go into nudging mode to tell everyone the elevator is leaving the floor. Once the elevator has left the floor, depending on where the alarm was set off, the elevator will go to the Fire Recall Floor.  However, if the alarm was activated on the fire recall floor the elevator will have an alternate floor to recall to. When the elevator is recalled, it proceeds to the recall floor and stops with its doors open. The elevator will no longer respond to calls or move in any direction. Located on the fire recall floor is a fire service key switch. The fire service key switch has the ability to turn fire service off, turn fire service on or to bypass fire service. The only way to return the elevator to normal service is to switch it to bypass after the alarms have reset.

Phase two mode can only be activated by a key switch located inside the elevator on the centralized control panel. This mode was created for firefighters so that they may rescue people from a burning building. The phase two key switch located on the COP has three positions: off, on, and hold. By turning phase two on, the firefighter enables the car to move. However, like independent service mode, the car will not respond to a car call unless the firefighter manually pushes and holds the door close button. Once the elevator gets to the desired floor it will not open its doors unless the firefighter holds the door open button. This is in case the floor is burning and the firefighter can feel the heat and knows not to open the door. The firefighter must hold door open until the door is completely opened. If for any reason the firefighter wishes to leave the elevator, they will use the hold position on the key switch to make sure the elevator remains at that floor. If the firefighter wishes to return to the recall floor, they simply turn the key off and close the doors.

#### वैद्यकिय आणीबाणी/'नीलसंकेत' सेवा Medical emergency/'Code Blue' service (EHS)
Commonly found in hospitals, Code Blue service allows an elevator to be summoned to any floor for use in an emergency situation. Each floor will have a 'Code Blue' recall key switch, and when activated, the elevator system will immediately select the elevator car that can respond the fastest, regardless of direction of travel and passenger load. Passengers inside the elevator will be notified with an alarm and indicator light to exit the elevator when the doors open.

Once the elevator arrives at the floor, it will park with its doors open and the car buttons will be disabled to prevent a passenger from taking control of the elevator. Medical personnel must then activate the Code Blue key switch inside the car, select their floor and close the doors with the door close button. The elevator will then travel non-stop to the selected floor, and will remain in Code Blue service until switched off in the car. Some hospital elevators will feature a 'hold' position on the Code Blue key switch (similar to fire service) which allows the elevator to remain at a floor locked out of service until Code Blue is deactivated.

#### आणीबाणी-उर्जा क्रियान्वयन Emergency power operation (EPR)
Many elevator installations now feature emergency power systems which allow elevator use in blackout situations and prevent people from becoming trapped in elevators.

##### खेच उद्वाहक 
When power is lost in a traction elevator system, all elevators will initially come to a halt. One by one, each car in the group will return to the lobby floor, open its doors and shut down. People in the remaining elevators may see an indicator light or hear a voice announcement informing them that the elevator will return to the lobby shortly. Once all cars have successfully returned, the system will then automatically select one or more cars to be used for normal operations and these cars will return to service. The car(s) selected to run under emergency power can be manually overridden by a key or strip switch in the lobby. In order to help prevent entrapment, when the system detects that it is running low on power, it will bring the running cars to the lobby or nearest floor, open the doors and shut down.

##### Hydraulic elevators
In hydraulic elevator systems, emergency power will lower the elevators to the lowest landing and open the doors to allow passengers to exit. The doors then close after an adjustable time period and the car remains unusable until reset, usually by cycling the elevator main power switch. Typically, due to the high current draw when starting the pump motor, hydraulic elevators aren't run using standard emergency power systems. Buildings like hospitals and nursing homes usually size their emergency generators to accommodate this draw. However, the increasing use of current limiting motor starters, commonly known as "Soft-Start" contactors, avoid much of this problem and the current draw of the pump motor is less of a limiting concern.

## उद्वाहकात असलेल्या सुविधा बाबी
Elevators may feature talking devices as an accessibility aid for the blind. In addition to floor arrival notifications, the computer announces the direction of travel, and notifies the passengers before the doors are to close.

In addition to the call buttons, elevators usually have floor indicators (often illuminated by LED) and direction lanterns.  The former are almost universal in cab interiors with more than two stops and may be found outside the elevators as well on one or more of the floors.  Floor indicators can consist of a dial with a rotating needle, but the most common types are those with successively illuminated floor indications or LCDs. Likewise, a change of floors or an arrival at a floor is indicated by a sound, depending on the elevator.

Direction lanterns are also found both inside and outside elevator cars, but they should always be visible from outside because their primary purpose is to help people decide whether or not to get on the elevator.  If somebody waiting for the elevator wants to go up, but a car comes first that indicates that it is going down, then the person may decide not to get on the elevator.  If the person waits, then one will still stop going up.  Direction indicators are sometimes etched with arrows or shaped like arrows and/or use the convention that one that lights up red means "down" and green means "up".  Since the color convention is often undermined or overrided by systems that do not invoke it, it is usually used only in conjunction with other differentiating factors.  An example of a place whose elevators use only the color convention to differentiate between directions is the Museum of Contemporary Art in Chicago, where a single circle can be made to light up green for "up" and red for "down."  Sometimes directions must be inferred by the position of the indicators relative to one another.

In addition to lanterns, most elevators have a chime to indicate if the elevator is going up or down either before or after the doors open, usually in conjunction with the lanterns lighting up.  Universally, one chime is for up, two is for down, and none indicates an elevator that is 'free'.

Observatory service elevators often convey other facts of interest, including elevator speed, stopwatch, and current position (altitude), as with the case for Taipei 101's service elevators.

## प्रमाणके Standards
The mechanical and electrical design of elevators is dictated according to various standards (aka elevator codes), which may be international, national, state, regional or city based. Whereas once many standards were prescriptive, specifying exact criteria which must be complied with, there has recently been a shift towards more performance-based standards where the onus falls on the designer to ensure that the elevator meets or exceeds the standard.

Some of the national elevator standards include:
*Australia – AS1735
*Canada – CAN/CSA B44
*Europe – EN 81 series (EN 81-1, EN 81-2, EN 81-28, EN 81-70, EN 12015, EN 12016, EN 13015, etc.)
*USA – ASME A17

Because an elevator is part of a building, it must also comply with standards relating to earthquake resilience, fire standards, electrical wiring rules and so forth.

The American National Elevator Standards Group (ANESG) sets an elevator weight standard to be 2200&nbsp;lbs.

Additional requirements relating to access by disabled persons, may be mandated by laws or regulations such as the Americans with Disabilities Act.

### US and Canadian elevator standard specifics
 Impulse fixtures) found in many modern residential and small commercial buildings.]]
In most US and Canadian jurisdictions, passenger elevators are required to conform to the American Society of Mechanical Engineers' Standard A17.1, Safety Code for Elevators and Escalators.  In Canada the document is the CAN/CSA B44 Safety Standard, which was harmonized with the US version in the 2000 edition.  In addition, passenger elevators may be required to conform to the requirements of A17.3 for existing elevators where referenced by the local jurisdiction. Passenger elevators are tested using the ASME A17.2 Standard. The frequency of these tests is mandated by the local jurisdiction, which may be a town, city, state or provincial standard.

Passenger elevators must also conform to many ancillary building codes including the Local or State building code, National Fire Protection Association standards for Electrical, Fire Sprinklers and Fire Alarms, Plumbing codes, and HVAC codes. Also, passenger elevators are required to conform to the Americans with Disabilities Act and other State and Federal civil rights legislation regarding accessibility.

Residential elevators are required to conform to ASME A17.1.  Platform and Wheelchair lifts are required to comply with ASME A18.1 in most US jurisdictions.

Most elevators have a location in which the permit for the building owner to operate the elevator is displayed.  While some jurisdictions require the permit to be displayed in the elevator cab, other jurisdictions allow for the operating permit to be kept on file elsewhere – such as the maintenance office – and to be made available for inspection on demand.  In such cases instead of the permit being displayed in the elevator cab, often a notice is posted in its place informing riders of where the actual permits are kept.

## आगळ्या उद्वाहक उभारण्या Unique elevator installations 
### जागतिक आकडेवारी World statistics
As of January 2008, Italy is the nation with the most elevators installed in the world, with 850,000 elevators installed that run more than one hundred million lifts every day, followed by United States with 700,000 elevators installed and People's Republic of China with 610,000 elevators installed since 1949. The world's largest market for elevators is Italy with more than 1,629 million euros of sales and 1,224 million euros of internal market.

### आयफेल टॉवर Eiffel Tower
The Eiffel Tower has Otis double-deck elevators built into the legs of the tower, serving the ground level to the first and second levels. Even though the shaft runs diagonally upwards with the contour of the tower, both the upper and lower cars remain horizontally level. The offset distance of the two cars changes throughout the journey.

There are four elevator cars of the traditional design that run from the second level to the third level. The cars are connected to their opposite pairs (opposite in the elevator landing/hall) and use each other as the counterweight. As one car ascends from level 2, the other descends from level 3. The operations of these elevators are synchronized by a light signal in the car.

### ताईपेई १०१ Taipei 101
Double deck elevators are used in the Taipei 101 office tower. Tenants of even-numbered floors first take an escalator (or an elevator from the parking garage) to the 2nd level, where they will enter the upper deck and arrive at their floors.  The lower deck is turned off during low-volume hours, and the upper deck can act as a single-level elevator stopping at all adjacent floors. For example, the 85th floor restaurants can be accessed from the 60th floor sky-lobby. Restaurant customers must clear their reservations at the reception counter on the 2nd floor. A bank of express elevators stop only on the sky lobby levels (36 and 60, upper deck car), where tenants can transfer to "local" elevators.

The high speed observation deck elevators accelerate to a world-record certified speed of 1010 meters per minute (60.6&nbsp;km/h) in 16 seconds, and then it slows down for arrival with subtle air pressure sensations. The door opens after 37 seconds from the 5th floor. Special features include aerodynamic car and counterweights, and cabin pressure control to help passengers adapt smoothly to pressure changes. The downwards journey is completed at a reduced speed of 600 meters per minute, with the doors opening at the 52nd second.

### गेटवे आर्च The Gateway Arch
The Gateway Arch in St. Louis, Missouri has a unique elevator system which carries passengers from the visitors' center underneath the Arch to the observation deck at the top of the structure.

Called a *tram* or *tramway*, people enter this unique tramway much as one would enter an ordinary elevator, through double doors. Passing through the doors the passengers in small groups enter a horizontal cylindrical compartment containing seats on each side and a flat floor. A number of these compartments are linked to form a train. These compartments each individually retain an appropriate level orientation by tilting while the entire train follows curved tracks up one leg of the arch.

There are two tramways within the Arch, one at the north end, and the other at the south end. The entry doors have windows, so people traveling within the Arch are able to see the interior structure of the Arch during the ride to and from the observation deck. At the beginning of the trip the cars hang from the drive cables, but as the angle of the shaft changes, they end up beside and then on top of the cables.

### न्यु सीटी हॉल हॅनोव्हर, जर्मनी New City Hall, Hanover, जर्मनी
The elevator in the New City Hall in Hanover, जर्मनी is a technical rarity, and unique in Europe, as the elevator starts straight up but then changes its angle by 15 degrees to follow the contour of the dome of the hall. The cabin therefore tilts 15 degrees during the ride. The elevator travels a height of 43 meters. The new city hall was built in 1913. The elevator was destroyed in 1943 and rebuilt in 1954.

### Luxor Inclinator Elevator
In Las Vegas, Nevada, at the Luxor Hotel, is the Inclinator. The shape of this casino is a pyramid. Therefore, the elevator travels up the side of the pyramid at a 39 degree angle. Although people refer to this "inclined elevator" as an inclinator, this is incorrect.

### Twilight Zone Tower of Terror
The Twilight Zone Tower of Terror is the common name for a series of elevator attractions at the Disney's Hollywood Studios park in Orlando, the Disney's California Adventure park in Anaheim, the Walt Disney Studios Park in Paris and the Tokyo DisneySea park in Tokyo.  The central element of this attraction is a simulated free-fall achieved through the use of a high-speed elevator system.  For safety reasons, passengers are seated and secured in their seats rather than standing.  Unlike most traction elevators, the elevator car and counterweight are joined using a cable system in a continuous loop running through both the top and the bottom of the drop shaft.  This allows the drive motor to pull down on the elevator car from underneath, resulting in downward acceleration greater than that of normal gravity.  The high-speed drive motor is used to rapidly lift the elevator as well.

The passenger cabs are mechanically separated from the lift mechanism, thus allowing the elevator shafts to be used continuously while passengers board and disembark from the cabs.  Multiple elevator shafts are used to further improve passenger throughput.  The doorways of the top few "floors" of the attraction are open to the outdoor environment, thus allowing passengers to look out from the top of the structure.

### "Top of the Rock" elevators
Guests ascending to the 67th, 69th, and 70th level observation decks (dubbed "Top of the Rock") atop the GE Building at Rockefeller Center in New York City ride a high-speed glass-top elevator. When entering the cab, it appears to be any normal elevator ride. However, once the cab begins moving, the interior lights turn off and a special blue light above the cab turns on. This lights the entire shaft, so riders can see the moving cab through its glass ceiling as it rises and lowers through the shaft. Music plays and various animations are also displayed on the ceiling. The entire ride takes about 60 seconds.

### ॲपल स्टोअर Apple Stores
An elevator located in the centre of the Apple Store in लंडन takes passengers between the ground and first floors. The elevator is operated by a hydraulic ram and made almost entirely of glass, consisting of a glass shaft, containing a car with glass walls and ceiling. The elevator, manufactured by Apex Lifts, is unique in a number of ways: firstly, the car-top controls are removable, so that whilst the lift is in normal service, there are no visible mechanics on top of the glass box that is the car; secondly, there are no lift position switches within the shaft, with the exception of the top final-limit switch. Instead of these conventional switches within the shaft, the lift employs a laser, which is aimed from under the pit floor to a target on the car, and in this way the exact height of the car can be obtained, enabling the car to stop with an accuracy of 1&nbsp;mm.

A similar elevator, installed by Otis, takes Apple customers in the New York City store from the 35-foot ground floor cube to the basement store. This elevator too is made entirely of glass. On May 29, 2006, just a week after its opening, it made the news when it trapped five passengers.

### डिस्नेलॅंड Disneyland, Anaheim, California
Part of the Haunted Mansion attraction at Disneyland in Anaheim, California, takes place on an elevator.  The "stretching room" on the ride is actually an elevator that travels downwards, giving access to a short underground tunnel which leads to the rest of the attraction.  The elevator has no ceiling and its shaft is decorated to look like walls of a mansion.  Because there is no roof, passengers are able to see the walls of the shaft by looking up, which gives the illusion of the room stretching.

### शहरी वहनासाठी उद्वाहक Elevators for urban transport
In some towns, where terrain is difficult enough to justify, elevators are used as part of the urban transport systems.

Examples:
* Skyway in Nagasaki, Japan
* Bad Schandau Elevator in Bad Schandau, जर्मनी
* Barcelona, Spain - Elevator and cableway line connecting the port terminal to Montjuic hill
* Bilbao - Casco Viejo Bilbao Metro station (fare-paying elevator connecting upper and lower neighbourhoods, as well as the station)
* Genoa, Italy - ten public elevators
* Hammetschwand Elevator in Bürgenstock, स्वित्झर्लंड
* Katarina Elevator in Stockholm, स्वीडन
* Lacerda Elevator in Salvador, Bahia, Brazil
* Marburg, जर्मनी - some parts of the historic city core built on higher ground (Uppertown, "Oberstadt" in German) are accessible from the lower street level by elevators. These elevators are unique in servicing also various buildings partially embedded in the steep-sloping terrain.
* Monaco, seven elevators
* Naples, Italy - three public elevators
* Lynchburg, Virginia - Outdoor Public elevator
* Oregon City Municipal Elevator in Oregon City, Oregon, United States
* Santa Justa Lift in Lisbon, Portugal
* Luxembourg
* Shanklin Cliff Lift in Shanklin, Isle of Wight
* Yalta, Ukraine
* Asansor, Izmir, Turkey
* Jersey City, New Jersey elevator at Bergen Hudson Light Rail station at 9th Street and Palisade Avenue.

## हे ही बघा हे सुद्धा पहा

*Escalator
*Grain elevator
*Elevator consultant
*Elevator inspector
*Elevator mechanic
*Elevator operator
*Elevator paradox
*Space elevator
*Elevator surfing
*Funicular
*Double-deck elevator
*Paternoster

## नोंदी
## संदर्भ 
*Manavalan, Theresa (30 October 2005). "Don't let them ride alone". *New Straits Times*, p. F2.

* Ford, M. (2009). Machine-Room-Less (MRL) Elevators. Retrieved on 27 Oct. 2009. from: http://www.buildings.com/ArticleDetails/tabid/3321/ArticleID/3076/Default.aspx 
* MonoSpace Mid-Rise Elevator. (2009). Retrieved on 28 Oct. 2009. from: http://www.kone.com/countries/en_US/Elevators/MonoSpace/Pages/default.aspx
* Tetlow, K. (2007, September). New Elevator Technology: The Machine Room-Less Elevator. Retrieved on 25 Oct. 2009. from: http://continuingeducation.construction.com/article.php?L=14&C=220 

## बाह्य दुवे External links
*The Elevator Radio Show  A weekly Podcast Dedicated To Elevator News!
*Elevator innovations 
*elevatorbob's Elevator Pictures  (scroll down past promotional material to folders)
*The Lifting Operations and Lifting Equipment Regulations 1998 (LOLER) Guidance
*Timeline of the elevator 
*A collection of elevator control panels
*Elevaattorit.org - Finnish website of elevators 
*ACE3  Opportunities for Elevator Energy Efficiency Improvements
*Nick Paumgarten, *The New Yorker*, 21 April 2008, Up And Then Down: The lives of elevators
*http://www.realvnc.com/cgi-bin/download.cgi?product=enterprise4/macvnc
*KONE Machine Room-less Elevators
*Comparisons of different types of Elevators 
*General and Historic Information on MRL Elevators 

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